Page 1 of 45
By
Dr V Laxmanan
Carnage on the
US Highways
Does Speed Kill
Forgotten Facts of
US Highway
Deaths in
1950s and 1960s
Page 2 of 45
Table of Contents
Page No Summary 3 Introduction 4 A brief review of historical fatalities data 6 Brief history of traffic safety legislation 13 The reason for the historical decrease in highway fatalities 15 Impact of NMSL on fatalities post-1973 18 Further considerations Pros and Cons 20 Conclusions 33 Table 1 Historical highway fatalities data 35 Appendix 1 42 Comments and Feedback 43
Page 3 of 45
Summary
A brief review of the historical trends in US traffic fatalities since 1929 is
presented here within the context of the recent attempts to increase the
posted speed limits on US highways most notably in Texas The public
outrage due to the ―epidemic of US highway deaths in the 1950s and the
1960s prompted Congress to hold its highly publicized hearings in 1966 and
the enactment of safey legislation signed by President Johnson later that
year However it appears that the National Maximum Speed Limit (NSML) of
55 mph enacted as an energy saving measure in 1973 following the Arab oil
embargo had a greater and immediate impact on the reduction in highway
traffic fatalities than the traffic safety legislations which no dobut had a
delayed and longer term effect (via the introdcution of vehicle safety features
like seat belts and airbags)
Some pros and cons in the debate on increasing speed limits and the impact
on fatalities and crashworthiness of vehicles have been discussed briefly A
more detailed discussion of the specific effect of speed limits (on fatalities)
may be found in a companion document where it is shown that the universal
mathematical law y = hx + c relating the number of fatal crashes (x) and the
number of fatalities (y) can be used to assess the effect of increasing or
decreasing the speed limits
A Fresh look at the Iowa Kansas Montana and Txas motor vehicle fatalities
data Effect of Speed Limits on Fatalities Texas Proofing of Vehicles
httpwwwscribdcomdoc59153773Effect-of-Speed-Limits-on-Fatalities-
Texas-Proofing-of-Vehciles
Page 4 of 45
1 Introduction
In traffic safety research we encounter two important dates or years 1966
and 1973 The main purpose here is to call attention to the historical facts
regarding the ―epidemic levels of highway traffic fatalities that engaged our
national attention in the fateful year of 1966
Does Speed Kill This is no doubt a politically charged topic with different
interest groups drawing their own conclusions and pulling in different
directions even when confronted with exactly the same facts Nonetheless
here is a humble attempt by a lone citizen to sound a cautionary note amid
the renewed attempts in many states across the US to increase the speed
limits on our highways
Page 5 of 45
The 1927 Durant Motor Star produced by William Durant the founder and the first
CEO of General Motors This car can be rented to tour San Diego for $50 to $70 per
hour plus $150 to $200 for the first half-hour httpeditorialautosmsncommost-
unusual-tourist-vehicles4
Also for the first time the Center for Disease Control (CDC) has recently
released the state-by-state societal costs of motor vehicle crashes Highway
fatalities cost $41 billion annually The CDC announcement coincides with the
kickoff of the United Nations Decade of Action an international effort aimed
at saving 5 million lives though 2020 by working cooperatively towards
greater road safety
httpwwwthecarconnectioncomnews1059966_cdc-highway-fatalities-cost-
41-billion-annually
Indeed it would be tragic if highway-accident-related fatalities were to start
increasing once again and reach the historically high level that was last seen
in 1972 the year before the Arab oil embargo of 1973 Statistical projections
of traffic fatalities show that in 2010 an estimated 32788 people died in motor
vehicle traffic crashes This is a 3 reduction over 2009 levels If these
Page 6 of 45
projections are realized highway traffic fatalities will be lowest on record
(since 1949)
The graphical representation of the traffic fatality data compiled annually by
the National Highway Traffic Safety Administration (NHTSA) as seen in
Figures 1 to 4 here tells its own story Indeed here a picture is certainly
worth a thousand words Let these graphs do the talking The detailed
captions attached with each figure permit an unbiased assessment of the
traffic fatality data and will hopefully lead to a repeal of the misguided
attempts to increase speed limits This also represents a simple and new
approach to analyzing the fatality data without excessive reliance on the
calculation of simple ratios such as the widely used fatality rate
As will become obvious the national speed limit of 55 mph instituted in
the historical year of 1973 yielded the twin benefits of improved fuel
economies and reduced traffic fatalities
The 1955 Cadilla available for tours of Memphis TN
httpeditorialautosmsncommost-unusual-tourist-vehicles2
Page 7 of 45
httpwwwugptiorgpubspdfDP188pdf
httpwwwlakecountypublichealthorgindexphpbuckle-up-montana
2 A brief review of historical traffic
fatality data compiled by NHTSA
The NHTSA uses the fatality rate as its single most important measure of
traffic safety The fatality rate is the ratio yx where x is the total vehicle miles
traveled (usually expressed in billions) by all US drivers and y is the absolute
number of highway fatalities To arrive at a simple tractable number the rate
is determined per 100 million vehicle miles traveled (acronym VMT)
Although this fatality rate yx has now reached a historical low in 2010
exclusive focus on this ratio while overlooking the underlying x-y trend might
be misleading as will become evident from the graphical representation of
the historical data being attempted here
Driver Behavior
Driver Drinking
Too Fast
Not Wearing
Seat Belts
Montanarsquos Likeliest
Fatal Crash Scenario
A Pick up
A Rural road
And Seat belts not
used
Page 8 of 45
Figure 1 Graph of the absolute number of US highway fatalities since 1957 The raw
data used to prepare this graph may be found in Table 1(relegated to the end of this
document) The absolute number of highway fatalities were quite low in the 1950s
and reached a peak in the late 1960s to early 1970s and have since decreased to
levels seen in the 1950s although the vehicle miles driven (in millions) has been
increasing from 646915 in 1957 to 2560373 in the year 2000 see also Figure 2
The fatality data from other government sources have also been studied by the author
and lead to the same conclusion of a peak in highway deaths around the late 1960s to
early 1970s
Page 9 of 45
Figure 2a Graphical representation of the absolute number of US highway fatalities
versus annual vehicle miles driven (in trillions) The number of miles driven by US
drivers has increased each year since 1957 as seen in Table 1 The absolute number
of highway fatalities has increased as well reaching a peak in the late 1960s to early
1970s The same peak is also seen here in the graph of the absolute number of
highway fatalities versus vehicle miles driven Improvements in vehicle safety devices
(notably seat belts and airbags) coupled with the institution of the national highway
speed limits (starting mid 1970s) and also improved highways are the primary
reasons for the decrease in fatalities These historical trends suggest that renewed
attempts to increase the speed limits on our highways would be counterproductive
and may eventually lead once again to an increase in fatalities with tragic
Page 10 of 45
consequences
Figure 2b Graphical representation of the US highway fatality data for the period
1921-1982 The first year for which a fatality rate yx could be computed is 1921 The
number of fatalities was 13253 and VMT was 5503 billion yielding a fatality rate of
2408 per 100 million VMT The fatality rate for any year is the slope of the ray ie
the straight line joining the (x y) data point back to the origin (00) of this graph see
dashed line for 1921 superimposed on to the graph The fatality rates (slopes of such
rays) had been declining quite consistently although the absolute number of fatalities
increased as seen here ultimately leading to the Congressional hearing in 1966 Is
VMT the single most important reason for the increasing fatalities
Page 11 of 45
Figure 3 Graphical representation of the traffic fatality data for the 15 year period
1994-2009 A sudden precipitous drop in the absolute number of fatalities (at least on
the magnified scale used here) and hence the fatality rate has been observed over
the three-year period 2007-2009 However it should be noted that the x-y scatter
graph here shows a general upward trend with fatalities actually increasing with
increasing VMT (as in the earlier era 1950s and 1960s) during the 12-year period
spanning 1994-2006 although the rate yx shows a misleading downward trend Why
is the rate yx going down
The reason is very simple and it may be just a mathematical artifact The equation of
the best-fit straight line through the most recent data points is of the form y = hx + c
= 2865 x + 34420 where h is the slope of the line and c the intercept (Note that x
here is VMT in billions The numerical value determined using this equation must be
divided by 10 to get the rate per 100 M VMT) Hence the fatality rate given by the
ratio yx = h + (cx) = 2865 + 34420x can actually decrease with increasing
values of x because of the nonzero intercept c Unlike the ray through the origin the
best-fit line does not pass through the origin (00) If we consider only the most
Page 12 of 45
recent data the intercept c is positive and fatality rates yx decrease with increasing
VMT and increasing fatalities In the earlier era both the slope h and intercept c had
very different values due to several factors being discussed here (speed limits
technology highway design etc)
Table 2 Traffic fatality data for the recent 15-year period
1994-2009 (Source NHTSA)
Year
Highway
fatalities y
Vehicle miles
traveled
VMT
(billions) x
Fatality rate
yx per 100
million VMT
Fatal crashes
1994 40716 2358 173 36254 1995 41817 2423 173 37241 1996 42065 2486 169 37494 1997 42013 2562 164 37324 1998 41501 2632 158 37107 1999 41717 2691 155 37140 2000 41945 2747 153 37526 2001 42196 2797 151 37862 2002 43005 2856 151 38491 2003 42884 2890 148 38477 2004 42836 2965 144 38444 2005 43510 2989 146 39252 2006 42708 3014 1 42 38648 2007 41259 3032 136 37435 2008 37423 2974 126 34172 2009 33808 2979 113 30797
Page 13 of 45
Figure 4 The most significant metric used by NHTSA is the fatality rate per 100
million vehicles miles traveled (VMT) This is now at a historical low of 113 for
2009 having declined year after year from 173 in 1994 The NHTSA however also
compiles other types of data on crashes There are three types of crashes fatal
injury but no death and property damage only A careful review of this crash data
for the period 1994-2009 reveals the obvious the lower the number of (fatal)
crashes x the lower the number of highway-accident-related fatalities y It is also
obvious that the number of fatalities per crash is greater than one ie more than one
person is being killed when one of more vehicles experience a crash
Clearly this is the single most important piece of information that one needs to
reduce the number of fatalities on our highways Vehicle design and engineering as
well as all other policy matters (legal political social environmental financial)
must be guided by this simple graph The best-fit line through the data derived using
simple linear regression has the equation y = hx + c = 114x ndash 10266 and is
Page 14 of 45
superimposed on to the data The design engineering goal and societal goal should
be to reduce the slope h of this statistically significant best-fit line to its ideal value of
h = 1 A fatal crash by definition is one where at least one person dies either an
occupant or a non-motorist in the path of the vehicle Hence the ideal slope h = 1
Photograph of an accident scene from the period 1955-1965
httpwwwcorinthsocialhistoryprojectorghtmlhighwaytollshtml
3 A Brief History of Traffic Safety Legislation
The following is extracted from the Wikipedia article on National Highway
Traffic Safety Administration (NHTSA)
httpenwikipediaorgwikiNational_Highway_Traffic_Safety_Administration
In 1965 and 1966 public pressure grew in the US to increase the safety of
cars The number of deaths on US highways were increasing year after year
Page 15 of 45
see Figure 1 and in 1966 Congress held a series of highly publicized
hearings on highway safety This led to the legislation for mandatory
installation of seat belts which also created the US Department of
Transportation (on Oct 15 1966)
httpwwwemsgovpdf2011EMSWeek2011_Stricklandpdf
The following is extracted from a Washington Post article on
NHTSA dated April 2 2002
httpwwwwashingtonpostcomwp-srvbusinessincludesnhtsa_primerhtm
In 1966 after decades of rising traffic fatalities (also vividly illustrated in
Figures 1 and 2 here) the publication of Ralph Naders Unsafe at Any
Speed and increasing public outcry for safer automobiles Congress held a
series of highly publicized hearings on creating a regulatory agency for traffic
safety Among the witnesses was William Haddon an epidemiologist who
introduced the idea that traffic accidents could be analyzed scientifically and
injuries reduced by changing auto design such as installing collapsible
steering columns safety glass head rests and seat belts
Congress passed the Highway Safety Act of 1966 creating the National
Highway Safety Bureau with Haddon as its first administrator The bureau
became NHTSA in 1970 under the newly established Department of
Transportation An early Nader convert Joan Claybrook headed NHTSA
under President Carter and now runs Naders organization Public Citizen
National Traffic and Motor Vehicle Safety Act
httpwwwanswerscomtopicnational-traffic-and-motor-vehicle-safety-act
Signed into law by President Lyndon Johnson on September 9 1966 this act
created the first mandatory federal safety standards for motor vehicles The
act was motivated by a variety of factors First and foremost the public was
growing increasingly concerned over the rising number of traffic fatalities on
the nations roads Such fatalities had increased by nearly 30 percent
between 1960 and 1965 and experts forecasted 100000 such deaths
Page 16 of 45
annually by 1975 unless something was done to improve traffic safety
Adding fuel to the fire Ralph Naders Unsafe at Any Speed published in
November 1965 criticized the automobile industry for neglecting safety in
favor of power and styling when designing new vehicles
4 The reason for the historical
decrease in highway fatalities
A recent news item see link given below regarding renewed attempts to
increase the speed limit by many states prompted this write up by the
present author who has studied traffic fatality data extensively and analyzed
them very carefully over the last several years
httpmoneymsncomauto-insurancewhy-speed-limits-are-
risingaspxGT1=33033
Residents of Metro Detroit area who frequently cross into Ohio from
Michigan notice that the speed limit has now increased in Ohio The speed
limit on Michigan highways was increased to 70 mph in the late 1990s but
Ohio retained its lower speed limit for many years leading Michigan drivers to
experience a ―speed trap of sorts The speed limit is also increasing in many
other states notably Texas where it is proposed to increase it to 85 mph at
least in West Texas
Historically speaking from a traffic fatality standpoint we must consider two
important dates 1966 and 1973 Only 1973 the year of the Arab oil embargo
following the Arab-Israeli war (that led to what President Obama has recently
called the pre-1967 border for Middle East peace) is mentioned in the above
article It fails to mention the significance of the year 1966
Prior to 1966 there was actually NO speed limit in many Western states and
deaths due to highway accidents were increasing year after year The
Page 17 of 45
number of highway fatalities went up from 38702 in 1957 to 51524 in 1965
a 33 increase over the 1957 level and an additional 12822 deaths in 1965
compared to 1957 It was this carnage on the US highways that forced
Congress to hold its hearings on highway traffic fatalities in 1966
Nonetheless a careful examination of the fatality data in Table 1 shows that
notwithstanding the highly publicized Congressional hearings of 1966 and
new safety legislation that was enacted the absolute number of fatalities
continued to increase after 1966 and only started decreasing after 1973
Vehicle designs especially the introduction of safety features (even the
simplest like safety belts) did not change significantly between 1966 and
1973 Nonetheless post-1973 we begin to see a dramatic turnaround
Why
After the 1973 Arab oil embargo a nationwide maximum speed limit (NMSL)
of 55 mph was imposed and accepted in the USA (effective Jan 1 1974)
during the Nixon administration primarily as an effort to conserve fuel and
reduce the US vulnerability to oil imports The unintended and indeed
fortunate consequence of this reduced speed limit was the immediate
reduction in the fatalities revealed in Figures 2 and 3 This is the real reason
for the peaks in highway fatalities observed in these two graphs
The Congressional hearings of 1966 did eventually have an impact but it was
a delayed one The impact of the 1973 nationwide speed limit of 55 mph was
however immediate as we see from the magnified plot of the same data in
Figure 5 and a closer examination of the raw fatality data in Table 1
The number of highway-accident-related fatalities decreased immediately
from a high of 55704 in 1972 to just 46078 in 1974 a 173 drop see
arrows There were 9626 fewer deaths annually even with a slight increase
in the vehicle miles driven (see Table 1) Indeed the number of highway
death reached its absolute peak value in 1972 never to be seen again
Fatalities have been decreasing every since with slight fluctuations about
each new low value
Page 18 of 45
Figure 5 Expanded view of the fatality data showing the immediate impact of the
national speed limit of 55 mph following the Arab oil embargo of 1973 Note that
fatalities continued to rise between 1966 and 1973 in spite of the highly publicized
Congressional hearings in 1966 and the traffic safety legislation enacted soon after
Each new low is probably associated with vehicle safety innovations and the
improvements in vehicle design and engineering The combined beneficial
effect of improved vehicle designs primarily the introduction of seat belts
and the laws enforcing usage of seat belts aided by the reduced speed
limits contributed to the continued decline in the absolute number of fatalities
that started since 1973 and has continued to this day The subsequent
introduction of other safety features notably air bags has contributed to a
further reduction in highway fatalities
Page 19 of 45
State police Trooper First Class Jeffrey Flowers looking at a car in which a Boswell
Pennsylvania woman was injured Tuesday (May 31 2011) The accident occurred at
an intersection when a truck (seen behind the wrecked car) entered this accident
prone intersection (part of a highway safety corridor where signs are posted to
reduce unsafe driver behavior) There have been four accidents at this intersection
since 2006 none fatal httpwwwdailyamericancomnewssomersetda-ot-woman-
injured-in-route-30-wreck-2011053104165420story
5 Numerical calculations of decline in
fatalities and the impact of NMSL post-1973
Letlsquos consider the decline in fatalities between 1972 the last year before the
adoption of the NMSL and 1974 the first year following its adoption after the
Arab oil embargo There was an immediate decrease in the number of
fatalities by 9393 ie y = -9393 with a slight increase in the VMT ie x
= 20758 millions The NHTSA data used here may be found in the table at
the end of this document The numerical value of the rate of change per
billion VMT (ie neglecting the sign) was therefore
yx = 4525 fatalitiesbillion VMT (1972-1974)
Page 20 of 45
It is instructive to compare this rate of change in fatalities with similar short
periods of a decline in fatalities in the pre-1973 era when speed limits were
much higher The absolute number of fatalities declined over a relatively
short period with both an increase and a decrease in VMT The results are
given below and are self-explanatory
yx = 454 fatalitiesbillion VMT (1953-54) decline with increase in VMT
yx = 655 fatalitiesbillion VMT (1942-43) decline with decrease in VMT
yx = 1739 fatalitiesbillion VMT (1941-42) decline with decrease in VMT
yx = 4528 fatalitiesbillion VMT (1937-39) decline with increase in VMT
yx = 2548 fatalitiesbillion VMT (1931-32) decline with decrease in VMT
The rate of decline observed between 1953 and 1954 with an increase in
VMT was just one-tenth of that observed following the adoption of the 55
mph speed limit The war years (1941-43 WWII) and the Great Depression
era (1931-32) were accompanied by big declines in fatalities with decreasing
VMT but the rate of change was still significantly lower than observed after
the adoption of the NMSL
The only apparently inexplicable decline is that between 1937 and 1939
where a nearly identical high rate of decline was observed Notice also the
big drop in the traditional fatality rate between 1937 and 1938 This large drop
appears to coincide with the creation of the National Safety Council (NSC) by
William H Cameron in June 1937 (see link below) with its far-flung campaign
of education legislation research highway engineering and traffic training
undertaken by the NSC and some two dozen other groups with the backing of the
automotive industry through its Automotive Safety Foundation Other factors
unknown to the present author probably also played a role
httpwwwtimecomtimemagazinearticle0917188379700htmlixzz1O2G
7rnUg
Page 21 of 45
These simple computations here however reveal the significant effect of
reduced speed limits on highway fatalities much more so than other factors
6 Further Considerations Pros and Cons
The singular effect of increased speeds (or speeding) on highway fatalities
has been studied and demonstrated by a number of industry sources such
as the Insurance Institute for Highway Safety (IIHS) Consumers Union and
also by government researchers
httpwwwsmartmotoristcomtraffic-and-safety-guidelineexcessive-speed-is-
a-factor-in-one-third-of-all-fatal-crasheshtml
httpwwwconsumersunionorgotherspeedlimitsspeed031500a2htm
Speed ndash defined as exceeding the posted speed limit or driving too fast for
given conditions ndash is a factor in nearly one-third of all fatal crashes Besides
fatality in 1998 nearly 40000 people were critically injured in speed-related
crashes and nearly 72000 were moderately injured
The salutary and immediate beneficial effect of the nationwide 55 mph speed
limit has been noted by other researchers (see Susan Ferguson link below)
httpwwwnhtsagovpeopleinjuryenforcespeed_forum_presentationsfergu
sonpdf
After a partial repeal of this law in 1987 which granted states the authority to
increase speed limit (especially in rural interstates) a 1989 study showed a
15 increase in fatalities in rural interstates and a 5 increase in non-rural
interstates Unfortunately such studies often tend to be discounted by
advocates of increasing the speed limits as being produced by biased
industry sources
Similar conclusions were also presented by NHTSA in February 1998 in its
report to the Congress entitled ―Report to Congress The Effect of Increased
Speed Limits in the Post-NMSL Era see link given below Among its key
Page 22 of 45
findings is the following quoted in its entirety NMSL refers to the National
Maximum Speed Limit legislated after the Arab oil embargo of 1973
httpwww-nrdnhtsadotgovPubs808-637PDF
hellip Nevertheless it is important to note that data currently available from the
National Highway Traffic Safety Administrationrsquos (NHTSA) Fatality Analysis
Reporting System (FARS) shows that states that increased speed limits in 1996
experienced approximately 350 more Interstate fatalities than would have been
expected based on historical trends -- about 9 percent above expectations
Concurrently the Interstate fatalities experienced in states that did not increase speed
limits in 1996 was consistent with pre-1996 trends The estimated increase in
Interstate fatalities found in this study while smaller in magnitude compared to the
estimated change in fatalities found in 1987 following the increase of speed limits on
rural Interstates does follow the historical pattern of increases in fatalities being
associated with increases in posted speed limits
The annual crash reports compiled by NHTSA see Table 3 indicate that the
number of fatal crashes (and hence fatalities using the regression equation
developed in Figure 4) increase as the posted speed limits increase
Page 23 of 45
Table 3 Posted speed limits and number of crashes
Speed Limit Crashes (2008) Crashes (2009)
30 mph or less 3705 3277 35 or 40 mph 6115 5516 45 or 50 mph 6461 6074
55 mph 9794 8847 60 mph or higher 6908 6124
Total 34017 30797
Source httpwww-nrdnhtsadotgovPubs811402EEpdf
61 Studies cited in favor of lower speed limits
A detailed analysis of speeding related fatalities (see link below) by NHTSA
shows that a third of all crashes involve speeding ie at least one driver was
speeding
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Furthermore the above report which covers the period 1983-2002
indicates that immediately after the NMSL was completely abolished in
December 1995 the number of speeding related fatalities at speeds
above 65 mph increased from just 15 in 1995 to a 677 in 1996 (see Table
62 on page 43 of above report) It continued to increase in the years
since climbing to 930 in 2000
More detailed studies similar to that noted above by researchers at the
University of Illinois Chicago led by Lee S Friedman again lead to the
conclusion that higher speed limits lead to an increase in the number of
fatalities (see American Journal of Public Health online July 16 2009)
httphealthusnewscomhealth-newsmanaging-your-
healthcarearticles20090716deaths-injuries-increase-with-higher-speed-
limits
Page 24 of 45
httpwwwmedpagetodaycomPublicHealthPolicyPublicHealth15122
httpwwwamericaneercomspeed-limits
httpwwwactuarialoutpostcomactuarial_discussion_forumarchiveindexph
pt-171870html
For the study period 1995-2005 these researchers found that 12545 deaths
and 36582 injuries could be attributed to the increased speed limits The
benefits of reduced speed limits are stated quite eloquently by Dr Friedman
and are reproduced below (from above news article see link)
Reduced speed limits would save lives Friedman said They would also reduce
gas consumption cut emissions of air pollutants save valuable years of productivity
(lost due to injuries)and reduce the societal cost of motor vehicle crashes (due to
both fatal crashes and due to nonfatal and severe life-changing injuries) he added
Friedman and coworkers have also shown that increasing the speed limit led
to an immediate increase in the number of fatalities on Israeli roadways (see
link below)
httpinjurypreventionbmjcomcontent133156
The effect of speeding is very significant especially in rural areas resulting
in significantly higher fatalities Fatality rates are frequently double or triple
that in urban areas (see link below)
httpsafetyfhwadotgovspeedmgtdata_factsdocsspeeding_ruralpdf
As of Jan 1 2005 five Midwestern states had increased the speed limits to
above 65 mph (Illinois Iowa Kansas Minnesota Missouri Nebraska and
South Dakota) whereas three (Illinois Iowa and Wisconsin) had not All the
five states with increased speed limits showed a 7 to 13 increase in
fatalities The NHTSA study considered an eight year period before and after
the change in Dec 1995 (see Table 1 in link below) The collective experience
of the states that did NOT increase the speed limit was a 7 decline in
fatalities (see Table 2 of link below)
httpwwwiowadotgovmvdodsstats2006speedstudypdf
Page 25 of 45
Moreover Table 5 in the above study shows the effect of imposing the NMSL
of 55 mph in Iowa and its repeal in 1995 Considering a four-year average
before 1974 when the speed limit was 75 mph there were 35 fatal crashes
with 43 fatalities In the first four years after the 55 mph there were only 23
fatal crashes and 28 fatalities In the last four years before the repeal of 55
mph in 1995 there was a further decline to 14 fatal crashes with 17 fatalities
The Iowa fatality data will be discussed in more detail separately (in a later report)
since it provides the opportunity to assess the effect of a change in the speed limit
on the relationship between number of fatalities and fatal crashes (as seen in
Figure 4 for the US as a whole)
North of the US border Canadians seem to be citing the ―shocking increase
in highway fatalities in the US states where the speed limits were raised to
curb their own speed limits
httparchivesafety-councilorginfotrafficspeed-02html
httparchivesafety-councilorginfotrafficspeedhtml
Speed kills but speed also sells notes the second of the above news items
Manufacturers are producing more high performance cars (with higher horse
power to weight ratio) and ads feature enticing cars that race and swerve in
miraculous ways on empty roads These subliminal messages encourage
drivers especially young drivers to break the speed limit leading to the
absolute increase in highway fatalities (although the rate itself is going
down) The article emphasizes the need to enforce the speed limit on
Canadian highways and in cities where street racing is becoming a problem
62 Studies cited by opponents of lower speed limits
In fairness to quote the opponents on the other side of this debate Montana
reverted back to Reasonable and Prudent speed limits when the National
Maximum Speed Limit was repealed in 1995 and appears to have
experienced no significant increase in fatalities
Page 26 of 45
httpwwwhwysafetycomhwy_montanahtm
httpwwwmotoristsorgpressmontana-no-speed-limit-safety-paradox
httpwwwsouthbayriderscomforumsshowthreadphpt=81453amppage=1
Likewise studies in the state of Maryland showed no significant increase in
highway fatalities when the speed limit was increased from 55 mph to 75
mph The reason might simply be that drivers were already speeding much
more so when the speed limit was 55 mph than after the increase to 75 mph
In other words the fatalities data already reflects the effect of higher speeds
(not speed limits) on the number of fatalities
In Utah the experimental increase in the speed limit to 80 mph was
considered to be a success in terms of safety
httpautosaolcomarticleutah-speed-limit-tests
The UDOT Director noted that there was no increase in the number of
accidents on Interstate 15 But what happens in the event of an accident
when the speed limits are higher and drivers are driving at higher speeds and
two objects collide at this higher speed However no increase in the number
of accidents is not the same as no increase in fatalities due to the higher
speeds When accidents do occur do fatalities increase
Likewise in California when the speed limit went up from 55 mph to 65
mph in 1995 (after repeal of NMSL) fewer deaths were reported in 1998
compared to the peak year of 1979 or even 1987 Again the explanation
seems to be that motorists were already speeding when the limit was 55 mph
and that increasing the speed limit did not change driver behavior in any
significant way
httparticlessfgatecom1998-11-02news17735730_1_speed-limits-mph-
limit-death-rate
The National Motorists Association (NMA) a group which advocates higher
speed limits emphasizes the importance of considering fatality rates as
opposed to the raw fatalities The argument used is that fatality rates based
on the fatality per 100 million VMT is the legitimate way to look at the data
Page 27 of 45
This is a never ending debate Historically speaking fatality rates have been
going down ever since the compilation of traffic accidents data began Table
A1 in the appendix of a recent report by NHTSA (see link below) has highway
fatality rate data going back 1921
httpwww-nrdnhtsadotgovPubs811346pdf see appendix page 31
httpwwwmotoristsorgspeed-limitstruth
httpwwwmotoristsorgothercrash-data
httpwwwraisethespeedlimitorgmythshtml
httpwwwcatoorgpubspaspa346pdf
According to Stephen Moore of the Cato Institute (see last of the links above)
―All measures of highway safety show improvement not more deaths and
injuries since 1995 Despite the fact that 33 states raised their speed limits
immediately after the repeal of the mandatory federal speed limit the NHTSA
reported last October that the traffic death rate dropped to a record low level
in 1997lsquo Moreover the average fatality rate even fell in the states that raised
their speed limits
63 The Fatality rate Is it a reliable metric
In 1921 with fewer fatalities and fewer miles driven and the first year for
which the fatality rate could be computed the rate was 2408 It was down to
1479 in 1931 but the number of deaths had climbed to 31963 more than
double the 1921 absolute fatality number of 13253 It had dropped to 550 in
1966 the year of the highly publicized Congressional hearings but the
number of fatalities had climbed to 50984 in that fateful The Highway Safety
Act of 1966 ranks as one of the major acts of Congress and President
Johnson signed it saying that ―we have been tolerating a raging epidemic of
highway deathshellip see extract pasted below
httpwwwenotescommajor-acts-congresshighway-safety-act
Page 28 of 45
The act was motivated primarily by growing public concern over the rising number
of traffic fatalities in the United States Between 1960 and 1965 the annual number
of traffic fatalities increased by nearly thirty percent As President Lyndon B
Johnson stated at the signing of the act on September 9 1966 we have tolerated
a raging epidemic of highway death which has killed more of our youth than all
other diseases combined Through the Highway Safety Act we are going to find out
more about highway diseasemdashand we aim to cure it
Nonetheless highways fatalities continued to increase until the Arab oil
embargo of 1973 led to the NMSL of 55 mph all across the USA Do we just
ignore this undeniable historical record and focus only on the declining fatality
rate as the NMA and other proponents of higher speed limits seem to argue
(see links above)
The misleading nature of using fatality rates (per 100 M VMT) alone is also
obvious if one considers fatality data for individual states Take for example
the state of Montana which seems to have experienced no increase in
fatalities after repeal of NMSL
httpwww-nrdnhtsadotgovdepartmentsnrd-
30ncsaSTSI30_MT200930_MT_2009htm
For the period 2005-2009 the absolute number of fatalities for Montana
varied between a high of 277 in 2007 to a low of 229 in 2009 The fatality
rates per 100 M VMT on the other hand varied from a high of 245 for 2007
to a low of 201 for 2009 The corresponding US fatality rates varied from
136 to 114 Is the higher number for the fatality rate for Montana compared
to USA good or bad Likewise fatality rate per 100000 of population was
much higher for Montana than the US as a whole
This again highlights the pitfalls of using simple ratios to assess fatality statistics
without a full analysis of the underlying trends We will discuss this point
separately
As shown already the continuous decline in the fatality rate is a mathematical
artifact and essentially overlooks the unmistakable positive correlation
between the variables x and y of the type y = hx + c which becomes obvious
Page 29 of 45
only when we prepare the x-y scatter graph The ratio yx = h + (cx) can
decrease with increasing x (VMT) and increasing y (fatalities) since the
intercept c has a positive value when we consider only data spanning a short
period (such as 1994-2009 of more relevance to the current situation)
The debate between fatality rates and absolute number of fatalities is an
unending one A few years ago the Wall Street Journal carried an article
which was entitled (or something close) ―Unemployments rate in Ohio are
going down but why is the number of unemployed increasing The reason is
the same The graph of the number of unemployed (y) versus the number in
the labor market (x) is linear with a positive slope h and a positive intercept c
So the unemployment rate computed using the ratio yx keeps going down
year after year although the number unemployed keeps increasing Is it a
good thing that the unemployment rate is going down when more people
seem to be unable to find gainful unemployment
Or consider the situation with cancer death rates This too has been going
down in recent years but the actual number of cancer-related deaths has not
declined in any significant way Is it good that cancer death rates are going
down In all these situations the researchers or the socio-econo-politico
analysts involved in analyzing the trends in the data have failed to consider
the underlying x-y relation describing each problem
Hence it appears that the debate on the effect of increased speed limits
should not be focused on only the fatality rates (which have been decreasing
and proponents of higher speed limits cite this in their arguments) or even the
absolute number of fatalities (which has been the focus here) but on the
relationship between speed and the number of fatal crashes and the number
of fatalities within each speed segment (see Table 3 and also Figure 4)
Unfortunately details of number of fatalities and the number of fatal crashes
at each speed limit are not available even from NHTSA for detailed study
When a crash does occur (it is immaterial how many miles were driven) the
speed of the driver and vehicle design and engineering including safety
devices in place (seat belts airbags other impact absorbing technologies)
Page 30 of 45
determine if the occupants(s) will be killed One cannot argue that speed
does NOT kill That would be an absolute denial of the laws of physics
Studies show that setting the speed limit at the 85th percentile in any given
zone (this is the speed at or below which 85 of drivers are observed to
travel in traffic engineering studies) is the safest speed limit The majority of
drivers try to obey the posted speed limit while a few choose to drive at a
speed they consider is safe and prudent These are also perhaps the most
vociferous advocates of higher speed limits It is this tension caused due to
differences in speeds that leads to tailgating improper passing reckless
driving weaving from lane to lane and ultimately crashes and deaths in some
unfortunate cases
httpblogmotoristsorgspeed-limits-slower-safer
MARK TAYLOR
ANOTHER LOST A man was killed when his 4WD drive hit a tree east of Morrinsville (in New
Zealand) on Monday May 30 2011 The driver lost control of the vehicle on a bend probably tried
to correct his mistake and put the car into a ―yaw causing it to leave the road and smash sideways
into a tree Alerts to slow down had been posted since this was a high accident area but the driver
probably did not pay attention
64 Other factors
Many other factors besides speed no doubt affect highway fatalities The
vehicles of the 21st century are very different from the vehicles of the mid 20th
Page 31 of 45
century Technological innovations such as improvements in vehicle design
and engineering have greatly increased crash worthiness of vehicles even at
high speeds Environmental factors such as the weather also contribute to
accidents but not necessarily to increased fatalities Drivers actually tend to
slow down instinctively during adverse weather conditions (rain snow storms
etc) and although such weather may contribute to increased accidents the
lower speeds actually reduce fatalities
Yes technology has changed fundamentally from 1966 Drivers today are
more distracted by their cellmobile phone conversations (and also built-in
phones in luxury models) and text messaging than the drivers of the pre-1966
era High end cars now have many multimedia and internet features Again a
careful observation (even personal experience by the author) suggests that
such distracted drivers actually tend to (instinctively) drive more slowly and
hold up the traffic Perhaps such behavior leads to an increase in the number
of accidents but it does not necessarily lead to an increase in the number of
accident-related fatalities
Much talked about technological innovations such as automatic collision
avoidance systems and sensors (on the sides of vehicles) can indeed detect
vehicles in the front and neighboring lanes Furthermore vehicle-to-vehicle
communication systems vehicle-to-infrastructure communication systems
can no doubt avoid collisions and accidents Again such collision avoidance
systems work and are effective entirely because they automatically reduce
vehicle speeds - even if one of the offending vehicles is being at a super
high speed Also it must be remembered that such futuristic systems have
not yet been implemented widely nor can they be implemented widely since
the large majority of vehicles on the road are NOT luxury models Advanced
safety features come with a price and not all drivers can afford to pay that
price and ―buy that ―additional safety
Ultimately it is the laws of physics that govern what will happen when two or
more vehicles collide or even when a single vehicle collides with a stationary
infrastructural object (a bridge a wall a building or some impediment on the
road) The lower the number of crashes the lower the number of fatalities as
revealed by the 1994-2009 data graphed in Figure 5 The higher the speed of
Page 32 of 45
the object or objects that are involved in a collision the higher the kinetic
energy K that must be absorbed andor dissipated Increasing the posted
speed limit only increases the energy that must be absorbed when a crash
does occur This ultimately is the most important criterion determining the
number of fatalities
The kinetic energy increases as the square of the speed being given by the
well-known formula K = frac12 mv2 where m is the mass of the vehicle (in
laypersonlsquos language m increases directly with vehicle weight) and v is the
speed For the same vehicle mass an increase in the speed from 55 mph to
85 mph increases the kinetic energy K by a factor of 239 or roughly a 250
increase in the kinetic energy that must be absorbed in a collision
Ideally speaking the kinetic energy of the colliding object(s) is absorbed by
the vehicle infrastructure (a sturdy space frame the engine other vehicle
components etc) andor the surroundings However in the unfortunate
cases where this kinetic energy must be absorbed by the vehicle occupant(s)
the result is severe life-altering injuries andor death An unequivocal
relationship between an increase in vehicle speeds and fatal accidents can
be demonstrated by a careful examination of available traffic fatality data
This is a more involved discussion and is not the purpose of this short
communication These topics are no doubt very politically charged with many
social legal and financial implications with each interest group favoring a
different conclusion Nonetheless we cannot escape the laws of physics as
they govern the fundamental need to absorb higher and higher values of the
kinetic energy K with increasing vehicle speeds This same point is also
emphasized by Dr Friedman of the University of Illinois Chicago (see earlier
discussion)
Speed kills because of these energy transfer considerations and there can be
no doubt about it
Innovative 21st century solutions to speed management on the highways
such as strict enforcement of speed limits minimizing speed dispersion
(difference between speeds at which different drivers travel) while using
cameras to track the 15 of drivers who willfully violate the speed limit and
Page 33 of 45
create hazardous driving conditions is certainly recommended (Recall that
the optimum recommended speed limit is at or below which 85 of all drivers
travel ndash a policy also supported by NMA) Even on this score however the
results are confounding if we consider the Australian experience
httpwwwthenewspapercomnews282840asp
Up until 2007 there was no speed limit in the Northern Territory of
Australia Imposing a speed limit 130 kmph (80 mph) on some areas and
110 kmph (68 mph) in some others actually increased the number of deaths
The death toll in 2006 when there was no speed limit in this region was 44
and went up to 75 in 2009 see data table in link below
httpwwwthenewspapercomrlcdocs2009au-ntroadtollpdf
Furthermore it appears that installation of cameras to enforce speed limits
has proved to be a hazardous distraction to drivers and deaths actually
began to skyrocket between 2005 and 2007 in all Australian roadways
The main purpose here is to sound a cautionary note amid renewed attempts
in many states across the US to increase the speed limits on our highways by
calling attention to the historical facts regarding the ―epidemic levels of
highway traffic fatalities that engaged our national attention in the fateful year
of 1966 The graphical representation of the traffic fatality data in Figures 1
to 5 tells its own story
Indeed it would be tragic if highway-accident-related fatalities were to start
increasing once again and reach the historically high level that was last seen
in 1972 the year before the Arab oil embargo of 1973
Page 34 of 45
Conclusions
1 The graphical representation of the highway fatality data and the brief
summary of the historical facts of traffic safety legislation suggest that
recent attempts to increase the speed limits by various states (notably
Texas) may be misguided The distinct peak in the highway fatalities
observed in these graphs is highly alarming This appears to be related to
the enactment of the National Maximum Speed Limit (NSML) in 1974
following the 1973 Arab oil embargo Although NSML was motivated by a
desire to reduce gasoline consumption an unintended benefit might have
been a dramatic reduction in fatalities The fundamental reasons for the
peak in the fatalities-VMT curve must be examined carefully without
political posturing
2 The widely used fatality rate fatalities per 100 M vehicle miles traveled
has been declining since 1921 the first year for which a fatality rate could
be computed and has now reached a historical low The absolute number
of fatalities on the other hand was increasing in the 1950s and 1960s at
an alarming rate and the public outcry that ensued led to the highly
publicized Congressional hearing of 1966 and the subsequent traffic safety
legislations The fatality rate has been decreasing even in the most recent
15-year period (1994-2009) again with increasing fatalities although less
dramatically Thus it appears that fatality rate calculation based on vehicle
miles traveled (VMT) might not be a reliable indicator of the underlying
dynamics in the fatality trends
3 More detailed compilation of number of fatalities and the number of fatal
crashes within each speed limit segment is required to better understand
the effect of increasing speed limits on highway fatalities (and also fatality
rates) Such data is already available and is being compiled at the local
city and county levels in all jurisdictions and only needs to be reorganized
to highlight the effect of (posted) speed limits on the number of crashes
and fatalities This will require some minor rewriting and revisions to the
chapters named ―Crashes and ―States in the annual NHTSA reports
Page 35 of 45
Analysis of the fatalities-crashes data for several years with various
speed limits will be more revealing and meaningful than the current
fatality rates analysis and will be discussed separately in a follow up
report
4 One should not be lulled by the fact that vehicles of the 21st century are
now equipped with advanced safety features not available in the 1950s
and the 1960s In spite of these safety features the laws of physics dictate
that the higher the speed the higher kinetic energy of the colliding objects
and hence the greater the risk indeed near certainty of fatalities in a
higher speed collision compared to a lower speed one
5 The higher the speed at which the vehicle that is involved in a crash is
traveling the higher the kinetic energy that must be absorbed andor
dissipated without affecting the occupant(s) to avoid serious injuries andor
death This was true in the 1950s and the 1960s and will continue to be
true in the 21st century as well
Speed Kills for this just reason
6 It appears that higher fuel economies and reduced
highway fatalities were the twin societal benefits of 55
mph adopted after 1973 If so the current attempts to
increase the speed limits appear to be in conflict with
other important societal objectives
Page 36 of 45
Table 1 Annual US Street amp Highway
Fatalities from 1957
Year
Fatalities
Vehicle Miles
(millions)
Rate100M Vehicle Miles
1957 38702 646915 598
1958 36981 664915 556
1959 37910 700478 541
1960 38137 718845 531
1961 38091 737535 516
1962 40804 766852 532
1963 43564 805423 541
1964 47700 846500 563
1965 49163 887640 554
1966 51524 927915 555
1967 51559 965132 534
1968 53831 1019726 528
1969 55032 1066108 516
1970 53672 1114098 482
1971 53761 1183524 454
1972 55704 1264614 440
1973 55113 1316207 419
1974 46078 1282790 359
1975 45500 1330074 342
1976 45523 1402380 325
1977 47878 1467027 326
1978 50331 1544704 326
1979 51103 1529133 334
1980 51091 1527295 335
1981 49301 1552803 317
1982 43945 1595010 276
1983 42589 1652788 258
1984 44257 1720269 257
1985 43795 1774179 247
Page 37 of 45
1986 46056 1835000 251
1987 46385 1921000 241
1988 47093 2026000 232
1989 45555 2107040 216
1990 44529 2147501 207
1991 41162 2172214 189
1992 39235 2239828 175
1993 40115 2296585 175
1994 40676 2359984 172
1995 41798 2422696 173
1996 41907 2485848 169
1997 41967 2560373 164
Data from Federal Highway Administration
Source httpwwwpublicpurposecomhwy-fatal57+htm
Telephone +16186328507 - Facsimile +16186328538
WENDELL COX CONSULTANCY P O Box 841 - Belleville IL 62269 USA
Page 38 of 45
Fatality data for 1921-1982 compiled by NHTSA
Year
VMT
(Millions)
VMT
(Billions)
Fatalities
Fatality rate
per 100 M VMT
1921 55027 5503 13253 241 1922 67697 6770 14859 219 1923 84995 8500 17870 210 1924 104838 10484 18400 176 1925 122346 12235 20771 170 1926 140735 14074 22194 158 1927 158453 15845 24470 154 1928 172856 17286 26557 154 1929 197720 19772 29592 150 1930 206320 20632 31204 151 1931 216151 21615 31963 148 1932 200517 20052 27979 140 1933 200642 20064 29746 148 1934 215563 21556 34240 159 1935 228568 22857 34494 151 1936 252128 25213 36126 143 1937 270110 27011 37819 140 1938 271177 27118 31083 115 1939 285402 28540 30895 108 1940 302188 30219 32914 109 1941 333612 33361 38142 114 1942 268224 26822 27007 101 1943 208192 20819 22727 109 1944 212713 21271 23165 109 1945 250173 25017 26785 107 1946 340880 34088 31874 94 1947 370894 37089 31193 84 1948 397957 39796 30775 77 1949 424461 42446 30246 71 1950 458246 45825 33186 72 1951 491093 49109 35309 72
1952 513581 51358 36088 70
Page 39 of 45
1953 544433 54443 36190 66 1954 561963 56196 33890 60 1955 605646 60565 36688 61 1956 627843 62784 37965 60 1957 647004 64700 36932 57 1958 664653 66465 35331 53 1959 700480 70048 36223 52 1960 718762 71876 36399 51 1961 737421 73742 36285 49 1962 766734 76673 38980 51 1963 805249 80525 41723 52 1964 846298 84630 45645 54 1965 887812 88781 47089 53 1966 925899 92590 50894 55 1967 964005 96401 50724 53 1968 1015869 101587 52725 52 1969 1061791 106179 53543 50 1970 1109724 110972 52627 47 1971 1178811 117881 52542 45 1972 1259786 125979 54589 43 1973 1313110 131311 54052 41 1974 1280544 128054 45196 35 1975 1327664 132766 44525 34 1976 1402380 140238 45523 32 1977 1467027 146703 47878 33 1978 1544704 154470 50331 33 1979 1529133 152913 51093 33 1980 1527295 152730 51091 33 1981 1555308 155531 49301 32 1982 1595010 159501 43945 28
Source Analysis of Significant Decline in Motor Vehicle Traffic Fatalities in
2008 httpwww-nrdnhtsadotgovPubs811346pdf see Table A1 page 31
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Page 40 of 45
Acknowledgements
The author is grateful for thoughtful comments provided by friends and colleagues
with whom this document was shared via email prior to it being uploaded as a
publicly available document for wider dissemination and study The comments
offered by Prof Subra Ganesan of Oakland University Electrical and Computer
Engineering Department are reproduced with permission in their entirety
About the author
The author obtained his Masterrsquos (S M) and Doctoral (Sc D) degrees in Materials Engineering
from the Massachusetts Institute of Technology Cambridge USA He then spent his entire
professional career at leading US research institutions (MIT NASA Case Western Reserve
University and General Motors R amp D Center in Warren MI) He holds four patents in advanced
materials processing has co-authored two books and has published several scientific papers in
leading peer-reviewed international journals His expertise includes developing simple
mathematical models to explain the behavior of complex systems He can be reached by email at
vlaxmananhotmailcom
Page 41 of 45
Please Buckle Up
httpwwwlakecountypublichealthorgindexphpbuckle-up-montana
Public Awareness
Respect the Cage Exhibit
The Department of Transportation hopes that showing the reality of the crash will reduce traffic
fatalities A crushed car crash dummies and a sobering message ndash all part of the ―Respect The
Cage exhibit that is traveling across Montana The exhibit sponsored by the Montana Department
of Transportation stopped in Ronan on November 6th and is aimed at raising awareness about the
importance of wearing seat belts
The car in the exhibit was in an actual wreck many years ago
the passenger in the vehicle died because he was not wearing a
seat belt the driver who was wearing his seat belt survived
Montanarsquos likeliest crash fatality scenario
A Pickup
A Rural road
And Seat belts that
arenrsquot used
Page 42 of 45
Occupants of pickups are less likely to wear seat belts and pickups are more likely to
roll over than passenger cars
Seat belts reduce the risk of death by 60 percent in pickups and SUVs
In Montana from 2006-2008 81 of those killed in a crash while riding in a pickup were not wearing seat belts
In Montana pickups make up 401 of the vehicle population
For more information on Respect the Cage click here
Page 43 of 45
Appendix 1
Lack of seat belts leading cause of Louisiana highway deaths
1251 AM May 28 2011 |
Written by Adam Duvernay
Crashes involving unbuckled motorists were the leading cause of highway fatalities
in Louisiana last year and cost $9888 million according to recent reports The
Louisiana Highway Safety Commission reported 59 percent of vehicle occupants
killed in Louisiana crashes last year mdash about one in four mdash werent wearing seat
belts
httpwwwshreveporttimescomarticle20110528NEWS01105280354Lack-seat-
belts-leading-cause-La-highway-deathsodyssey=tab|topnews|text|FRONTPAGE
Crash bull Stats Published by NHTSAlsquos National Center for Statistics and Analysis 1200 New Jersey Avenue SE Washington DC 20590
DOT HS 811 451
Early Estimate of Motor Vehicle Traffic Fatalities in 2010
httpwww-nrdnhtsadotgovPubs811451pdf
Summary
A statistical projection of traffic fatalities in 2010 shows that an estimated 32788
people died in motor vehicle traffic crashes This represents a decline of about 3
percent as compared to the 33808 fatalities in 2009 as shown in Table 1 If these
projections are realized fatalities will be lowest on record (since 1949)
Traffic Safety Facts Overview 2009 Data
httpwww-nrdnhtsadotgovPubs811392pdf
In 2009 33808 people were killed in the estimated 5505000 police-reported
motor vehicle traffic crashes 2217000 people were injured and 3957000
crashes involved property damage only Compared to 2008 this is a 10-
percent decrease in the number of fatalities and a 5-percent decrease in the
Page 44 of 45
number of police-reported motor vehicle traffic crashes people injured and
crashes involving property damage
An average of 93 people died each day in motor vehicle crashes in 2009 mdash
an average of one every 16 minutes
Traffic Safety Facts Overview 2008 Data
httpwww-nrdnhtsadotgovPubs811162pdf
In 2008 37261 people were killed in the estimated 5811000 police-reported
motor vehicle traffic crashes 2346000 people were injured and 4146000
crashes involved property damage only
Some comments and Feedback
The following comments were received from Prof Ganesan after his review of the
first draft of this document It was subsequently revised thanks to this input to
address some of the very important issues raised here
Dear Laxman
The write up is not enough
You are emphasizing that the speed limit reduces the fatal accidents (comparing 1966
to 2000 accident numbers)
Can you also add a few sentences why the number is decreasing from 1980 to 2000
values (May be due to better design of vehicles)
Can you say anything about the fuel consumption with the speed for any typical
vehicle in 2011 or 2010 (do not consider the fatalities issue)
Probably a speed between 55 and 60 mph gives a better mileage If so this is a
compelling reason to keep the speed limit low But cars probably can be tuned to
give better mileage at any high speed also
Page 45 of 45
Weather is also a major factor in fatal accidents Speed limit may be kept low during
winter and kept higher in summer Give your comments on this too
Driver distractions can cause more accidents Now cars have many multimedia and
internet features Automatic collision avoidance systems and sensors on the sides can
detect vehicles in the front and neighboring lanes and it can automatically decrease
speed even if the driver speeds at super high speeds
Give some comments on this too There is also Vehicle to Vehicle communications
vehicle to infrastructure communications and they can avoid collisions and accidents
Technology has changed from 1966 I cannot agree with you on the speed limit
without any discussion on the above and other factors
Have a great day
Subra Ganesan
Professor Subramaniam Ganesan
Director Real Time amp DSP Lab
Electrical and Computer Engineering Department
2200 Squirrel Road Dodge Hall Room 105
Oakland University Rochester MI 48309 USA
Phone 248 370 2206 Fax 248 370 4633
wwwsecsoaklandedu~ganesan
IEEE Distinguished Visiting Speaker (2005-2009) Coordinator
IEEE SEM CS chapter Chair Region 4 and CS Society Board member
SAE ASEE ACM member
Page 2 of 45
Table of Contents
Page No Summary 3 Introduction 4 A brief review of historical fatalities data 6 Brief history of traffic safety legislation 13 The reason for the historical decrease in highway fatalities 15 Impact of NMSL on fatalities post-1973 18 Further considerations Pros and Cons 20 Conclusions 33 Table 1 Historical highway fatalities data 35 Appendix 1 42 Comments and Feedback 43
Page 3 of 45
Summary
A brief review of the historical trends in US traffic fatalities since 1929 is
presented here within the context of the recent attempts to increase the
posted speed limits on US highways most notably in Texas The public
outrage due to the ―epidemic of US highway deaths in the 1950s and the
1960s prompted Congress to hold its highly publicized hearings in 1966 and
the enactment of safey legislation signed by President Johnson later that
year However it appears that the National Maximum Speed Limit (NSML) of
55 mph enacted as an energy saving measure in 1973 following the Arab oil
embargo had a greater and immediate impact on the reduction in highway
traffic fatalities than the traffic safety legislations which no dobut had a
delayed and longer term effect (via the introdcution of vehicle safety features
like seat belts and airbags)
Some pros and cons in the debate on increasing speed limits and the impact
on fatalities and crashworthiness of vehicles have been discussed briefly A
more detailed discussion of the specific effect of speed limits (on fatalities)
may be found in a companion document where it is shown that the universal
mathematical law y = hx + c relating the number of fatal crashes (x) and the
number of fatalities (y) can be used to assess the effect of increasing or
decreasing the speed limits
A Fresh look at the Iowa Kansas Montana and Txas motor vehicle fatalities
data Effect of Speed Limits on Fatalities Texas Proofing of Vehicles
httpwwwscribdcomdoc59153773Effect-of-Speed-Limits-on-Fatalities-
Texas-Proofing-of-Vehciles
Page 4 of 45
1 Introduction
In traffic safety research we encounter two important dates or years 1966
and 1973 The main purpose here is to call attention to the historical facts
regarding the ―epidemic levels of highway traffic fatalities that engaged our
national attention in the fateful year of 1966
Does Speed Kill This is no doubt a politically charged topic with different
interest groups drawing their own conclusions and pulling in different
directions even when confronted with exactly the same facts Nonetheless
here is a humble attempt by a lone citizen to sound a cautionary note amid
the renewed attempts in many states across the US to increase the speed
limits on our highways
Page 5 of 45
The 1927 Durant Motor Star produced by William Durant the founder and the first
CEO of General Motors This car can be rented to tour San Diego for $50 to $70 per
hour plus $150 to $200 for the first half-hour httpeditorialautosmsncommost-
unusual-tourist-vehicles4
Also for the first time the Center for Disease Control (CDC) has recently
released the state-by-state societal costs of motor vehicle crashes Highway
fatalities cost $41 billion annually The CDC announcement coincides with the
kickoff of the United Nations Decade of Action an international effort aimed
at saving 5 million lives though 2020 by working cooperatively towards
greater road safety
httpwwwthecarconnectioncomnews1059966_cdc-highway-fatalities-cost-
41-billion-annually
Indeed it would be tragic if highway-accident-related fatalities were to start
increasing once again and reach the historically high level that was last seen
in 1972 the year before the Arab oil embargo of 1973 Statistical projections
of traffic fatalities show that in 2010 an estimated 32788 people died in motor
vehicle traffic crashes This is a 3 reduction over 2009 levels If these
Page 6 of 45
projections are realized highway traffic fatalities will be lowest on record
(since 1949)
The graphical representation of the traffic fatality data compiled annually by
the National Highway Traffic Safety Administration (NHTSA) as seen in
Figures 1 to 4 here tells its own story Indeed here a picture is certainly
worth a thousand words Let these graphs do the talking The detailed
captions attached with each figure permit an unbiased assessment of the
traffic fatality data and will hopefully lead to a repeal of the misguided
attempts to increase speed limits This also represents a simple and new
approach to analyzing the fatality data without excessive reliance on the
calculation of simple ratios such as the widely used fatality rate
As will become obvious the national speed limit of 55 mph instituted in
the historical year of 1973 yielded the twin benefits of improved fuel
economies and reduced traffic fatalities
The 1955 Cadilla available for tours of Memphis TN
httpeditorialautosmsncommost-unusual-tourist-vehicles2
Page 7 of 45
httpwwwugptiorgpubspdfDP188pdf
httpwwwlakecountypublichealthorgindexphpbuckle-up-montana
2 A brief review of historical traffic
fatality data compiled by NHTSA
The NHTSA uses the fatality rate as its single most important measure of
traffic safety The fatality rate is the ratio yx where x is the total vehicle miles
traveled (usually expressed in billions) by all US drivers and y is the absolute
number of highway fatalities To arrive at a simple tractable number the rate
is determined per 100 million vehicle miles traveled (acronym VMT)
Although this fatality rate yx has now reached a historical low in 2010
exclusive focus on this ratio while overlooking the underlying x-y trend might
be misleading as will become evident from the graphical representation of
the historical data being attempted here
Driver Behavior
Driver Drinking
Too Fast
Not Wearing
Seat Belts
Montanarsquos Likeliest
Fatal Crash Scenario
A Pick up
A Rural road
And Seat belts not
used
Page 8 of 45
Figure 1 Graph of the absolute number of US highway fatalities since 1957 The raw
data used to prepare this graph may be found in Table 1(relegated to the end of this
document) The absolute number of highway fatalities were quite low in the 1950s
and reached a peak in the late 1960s to early 1970s and have since decreased to
levels seen in the 1950s although the vehicle miles driven (in millions) has been
increasing from 646915 in 1957 to 2560373 in the year 2000 see also Figure 2
The fatality data from other government sources have also been studied by the author
and lead to the same conclusion of a peak in highway deaths around the late 1960s to
early 1970s
Page 9 of 45
Figure 2a Graphical representation of the absolute number of US highway fatalities
versus annual vehicle miles driven (in trillions) The number of miles driven by US
drivers has increased each year since 1957 as seen in Table 1 The absolute number
of highway fatalities has increased as well reaching a peak in the late 1960s to early
1970s The same peak is also seen here in the graph of the absolute number of
highway fatalities versus vehicle miles driven Improvements in vehicle safety devices
(notably seat belts and airbags) coupled with the institution of the national highway
speed limits (starting mid 1970s) and also improved highways are the primary
reasons for the decrease in fatalities These historical trends suggest that renewed
attempts to increase the speed limits on our highways would be counterproductive
and may eventually lead once again to an increase in fatalities with tragic
Page 10 of 45
consequences
Figure 2b Graphical representation of the US highway fatality data for the period
1921-1982 The first year for which a fatality rate yx could be computed is 1921 The
number of fatalities was 13253 and VMT was 5503 billion yielding a fatality rate of
2408 per 100 million VMT The fatality rate for any year is the slope of the ray ie
the straight line joining the (x y) data point back to the origin (00) of this graph see
dashed line for 1921 superimposed on to the graph The fatality rates (slopes of such
rays) had been declining quite consistently although the absolute number of fatalities
increased as seen here ultimately leading to the Congressional hearing in 1966 Is
VMT the single most important reason for the increasing fatalities
Page 11 of 45
Figure 3 Graphical representation of the traffic fatality data for the 15 year period
1994-2009 A sudden precipitous drop in the absolute number of fatalities (at least on
the magnified scale used here) and hence the fatality rate has been observed over
the three-year period 2007-2009 However it should be noted that the x-y scatter
graph here shows a general upward trend with fatalities actually increasing with
increasing VMT (as in the earlier era 1950s and 1960s) during the 12-year period
spanning 1994-2006 although the rate yx shows a misleading downward trend Why
is the rate yx going down
The reason is very simple and it may be just a mathematical artifact The equation of
the best-fit straight line through the most recent data points is of the form y = hx + c
= 2865 x + 34420 where h is the slope of the line and c the intercept (Note that x
here is VMT in billions The numerical value determined using this equation must be
divided by 10 to get the rate per 100 M VMT) Hence the fatality rate given by the
ratio yx = h + (cx) = 2865 + 34420x can actually decrease with increasing
values of x because of the nonzero intercept c Unlike the ray through the origin the
best-fit line does not pass through the origin (00) If we consider only the most
Page 12 of 45
recent data the intercept c is positive and fatality rates yx decrease with increasing
VMT and increasing fatalities In the earlier era both the slope h and intercept c had
very different values due to several factors being discussed here (speed limits
technology highway design etc)
Table 2 Traffic fatality data for the recent 15-year period
1994-2009 (Source NHTSA)
Year
Highway
fatalities y
Vehicle miles
traveled
VMT
(billions) x
Fatality rate
yx per 100
million VMT
Fatal crashes
1994 40716 2358 173 36254 1995 41817 2423 173 37241 1996 42065 2486 169 37494 1997 42013 2562 164 37324 1998 41501 2632 158 37107 1999 41717 2691 155 37140 2000 41945 2747 153 37526 2001 42196 2797 151 37862 2002 43005 2856 151 38491 2003 42884 2890 148 38477 2004 42836 2965 144 38444 2005 43510 2989 146 39252 2006 42708 3014 1 42 38648 2007 41259 3032 136 37435 2008 37423 2974 126 34172 2009 33808 2979 113 30797
Page 13 of 45
Figure 4 The most significant metric used by NHTSA is the fatality rate per 100
million vehicles miles traveled (VMT) This is now at a historical low of 113 for
2009 having declined year after year from 173 in 1994 The NHTSA however also
compiles other types of data on crashes There are three types of crashes fatal
injury but no death and property damage only A careful review of this crash data
for the period 1994-2009 reveals the obvious the lower the number of (fatal)
crashes x the lower the number of highway-accident-related fatalities y It is also
obvious that the number of fatalities per crash is greater than one ie more than one
person is being killed when one of more vehicles experience a crash
Clearly this is the single most important piece of information that one needs to
reduce the number of fatalities on our highways Vehicle design and engineering as
well as all other policy matters (legal political social environmental financial)
must be guided by this simple graph The best-fit line through the data derived using
simple linear regression has the equation y = hx + c = 114x ndash 10266 and is
Page 14 of 45
superimposed on to the data The design engineering goal and societal goal should
be to reduce the slope h of this statistically significant best-fit line to its ideal value of
h = 1 A fatal crash by definition is one where at least one person dies either an
occupant or a non-motorist in the path of the vehicle Hence the ideal slope h = 1
Photograph of an accident scene from the period 1955-1965
httpwwwcorinthsocialhistoryprojectorghtmlhighwaytollshtml
3 A Brief History of Traffic Safety Legislation
The following is extracted from the Wikipedia article on National Highway
Traffic Safety Administration (NHTSA)
httpenwikipediaorgwikiNational_Highway_Traffic_Safety_Administration
In 1965 and 1966 public pressure grew in the US to increase the safety of
cars The number of deaths on US highways were increasing year after year
Page 15 of 45
see Figure 1 and in 1966 Congress held a series of highly publicized
hearings on highway safety This led to the legislation for mandatory
installation of seat belts which also created the US Department of
Transportation (on Oct 15 1966)
httpwwwemsgovpdf2011EMSWeek2011_Stricklandpdf
The following is extracted from a Washington Post article on
NHTSA dated April 2 2002
httpwwwwashingtonpostcomwp-srvbusinessincludesnhtsa_primerhtm
In 1966 after decades of rising traffic fatalities (also vividly illustrated in
Figures 1 and 2 here) the publication of Ralph Naders Unsafe at Any
Speed and increasing public outcry for safer automobiles Congress held a
series of highly publicized hearings on creating a regulatory agency for traffic
safety Among the witnesses was William Haddon an epidemiologist who
introduced the idea that traffic accidents could be analyzed scientifically and
injuries reduced by changing auto design such as installing collapsible
steering columns safety glass head rests and seat belts
Congress passed the Highway Safety Act of 1966 creating the National
Highway Safety Bureau with Haddon as its first administrator The bureau
became NHTSA in 1970 under the newly established Department of
Transportation An early Nader convert Joan Claybrook headed NHTSA
under President Carter and now runs Naders organization Public Citizen
National Traffic and Motor Vehicle Safety Act
httpwwwanswerscomtopicnational-traffic-and-motor-vehicle-safety-act
Signed into law by President Lyndon Johnson on September 9 1966 this act
created the first mandatory federal safety standards for motor vehicles The
act was motivated by a variety of factors First and foremost the public was
growing increasingly concerned over the rising number of traffic fatalities on
the nations roads Such fatalities had increased by nearly 30 percent
between 1960 and 1965 and experts forecasted 100000 such deaths
Page 16 of 45
annually by 1975 unless something was done to improve traffic safety
Adding fuel to the fire Ralph Naders Unsafe at Any Speed published in
November 1965 criticized the automobile industry for neglecting safety in
favor of power and styling when designing new vehicles
4 The reason for the historical
decrease in highway fatalities
A recent news item see link given below regarding renewed attempts to
increase the speed limit by many states prompted this write up by the
present author who has studied traffic fatality data extensively and analyzed
them very carefully over the last several years
httpmoneymsncomauto-insurancewhy-speed-limits-are-
risingaspxGT1=33033
Residents of Metro Detroit area who frequently cross into Ohio from
Michigan notice that the speed limit has now increased in Ohio The speed
limit on Michigan highways was increased to 70 mph in the late 1990s but
Ohio retained its lower speed limit for many years leading Michigan drivers to
experience a ―speed trap of sorts The speed limit is also increasing in many
other states notably Texas where it is proposed to increase it to 85 mph at
least in West Texas
Historically speaking from a traffic fatality standpoint we must consider two
important dates 1966 and 1973 Only 1973 the year of the Arab oil embargo
following the Arab-Israeli war (that led to what President Obama has recently
called the pre-1967 border for Middle East peace) is mentioned in the above
article It fails to mention the significance of the year 1966
Prior to 1966 there was actually NO speed limit in many Western states and
deaths due to highway accidents were increasing year after year The
Page 17 of 45
number of highway fatalities went up from 38702 in 1957 to 51524 in 1965
a 33 increase over the 1957 level and an additional 12822 deaths in 1965
compared to 1957 It was this carnage on the US highways that forced
Congress to hold its hearings on highway traffic fatalities in 1966
Nonetheless a careful examination of the fatality data in Table 1 shows that
notwithstanding the highly publicized Congressional hearings of 1966 and
new safety legislation that was enacted the absolute number of fatalities
continued to increase after 1966 and only started decreasing after 1973
Vehicle designs especially the introduction of safety features (even the
simplest like safety belts) did not change significantly between 1966 and
1973 Nonetheless post-1973 we begin to see a dramatic turnaround
Why
After the 1973 Arab oil embargo a nationwide maximum speed limit (NMSL)
of 55 mph was imposed and accepted in the USA (effective Jan 1 1974)
during the Nixon administration primarily as an effort to conserve fuel and
reduce the US vulnerability to oil imports The unintended and indeed
fortunate consequence of this reduced speed limit was the immediate
reduction in the fatalities revealed in Figures 2 and 3 This is the real reason
for the peaks in highway fatalities observed in these two graphs
The Congressional hearings of 1966 did eventually have an impact but it was
a delayed one The impact of the 1973 nationwide speed limit of 55 mph was
however immediate as we see from the magnified plot of the same data in
Figure 5 and a closer examination of the raw fatality data in Table 1
The number of highway-accident-related fatalities decreased immediately
from a high of 55704 in 1972 to just 46078 in 1974 a 173 drop see
arrows There were 9626 fewer deaths annually even with a slight increase
in the vehicle miles driven (see Table 1) Indeed the number of highway
death reached its absolute peak value in 1972 never to be seen again
Fatalities have been decreasing every since with slight fluctuations about
each new low value
Page 18 of 45
Figure 5 Expanded view of the fatality data showing the immediate impact of the
national speed limit of 55 mph following the Arab oil embargo of 1973 Note that
fatalities continued to rise between 1966 and 1973 in spite of the highly publicized
Congressional hearings in 1966 and the traffic safety legislation enacted soon after
Each new low is probably associated with vehicle safety innovations and the
improvements in vehicle design and engineering The combined beneficial
effect of improved vehicle designs primarily the introduction of seat belts
and the laws enforcing usage of seat belts aided by the reduced speed
limits contributed to the continued decline in the absolute number of fatalities
that started since 1973 and has continued to this day The subsequent
introduction of other safety features notably air bags has contributed to a
further reduction in highway fatalities
Page 19 of 45
State police Trooper First Class Jeffrey Flowers looking at a car in which a Boswell
Pennsylvania woman was injured Tuesday (May 31 2011) The accident occurred at
an intersection when a truck (seen behind the wrecked car) entered this accident
prone intersection (part of a highway safety corridor where signs are posted to
reduce unsafe driver behavior) There have been four accidents at this intersection
since 2006 none fatal httpwwwdailyamericancomnewssomersetda-ot-woman-
injured-in-route-30-wreck-2011053104165420story
5 Numerical calculations of decline in
fatalities and the impact of NMSL post-1973
Letlsquos consider the decline in fatalities between 1972 the last year before the
adoption of the NMSL and 1974 the first year following its adoption after the
Arab oil embargo There was an immediate decrease in the number of
fatalities by 9393 ie y = -9393 with a slight increase in the VMT ie x
= 20758 millions The NHTSA data used here may be found in the table at
the end of this document The numerical value of the rate of change per
billion VMT (ie neglecting the sign) was therefore
yx = 4525 fatalitiesbillion VMT (1972-1974)
Page 20 of 45
It is instructive to compare this rate of change in fatalities with similar short
periods of a decline in fatalities in the pre-1973 era when speed limits were
much higher The absolute number of fatalities declined over a relatively
short period with both an increase and a decrease in VMT The results are
given below and are self-explanatory
yx = 454 fatalitiesbillion VMT (1953-54) decline with increase in VMT
yx = 655 fatalitiesbillion VMT (1942-43) decline with decrease in VMT
yx = 1739 fatalitiesbillion VMT (1941-42) decline with decrease in VMT
yx = 4528 fatalitiesbillion VMT (1937-39) decline with increase in VMT
yx = 2548 fatalitiesbillion VMT (1931-32) decline with decrease in VMT
The rate of decline observed between 1953 and 1954 with an increase in
VMT was just one-tenth of that observed following the adoption of the 55
mph speed limit The war years (1941-43 WWII) and the Great Depression
era (1931-32) were accompanied by big declines in fatalities with decreasing
VMT but the rate of change was still significantly lower than observed after
the adoption of the NMSL
The only apparently inexplicable decline is that between 1937 and 1939
where a nearly identical high rate of decline was observed Notice also the
big drop in the traditional fatality rate between 1937 and 1938 This large drop
appears to coincide with the creation of the National Safety Council (NSC) by
William H Cameron in June 1937 (see link below) with its far-flung campaign
of education legislation research highway engineering and traffic training
undertaken by the NSC and some two dozen other groups with the backing of the
automotive industry through its Automotive Safety Foundation Other factors
unknown to the present author probably also played a role
httpwwwtimecomtimemagazinearticle0917188379700htmlixzz1O2G
7rnUg
Page 21 of 45
These simple computations here however reveal the significant effect of
reduced speed limits on highway fatalities much more so than other factors
6 Further Considerations Pros and Cons
The singular effect of increased speeds (or speeding) on highway fatalities
has been studied and demonstrated by a number of industry sources such
as the Insurance Institute for Highway Safety (IIHS) Consumers Union and
also by government researchers
httpwwwsmartmotoristcomtraffic-and-safety-guidelineexcessive-speed-is-
a-factor-in-one-third-of-all-fatal-crasheshtml
httpwwwconsumersunionorgotherspeedlimitsspeed031500a2htm
Speed ndash defined as exceeding the posted speed limit or driving too fast for
given conditions ndash is a factor in nearly one-third of all fatal crashes Besides
fatality in 1998 nearly 40000 people were critically injured in speed-related
crashes and nearly 72000 were moderately injured
The salutary and immediate beneficial effect of the nationwide 55 mph speed
limit has been noted by other researchers (see Susan Ferguson link below)
httpwwwnhtsagovpeopleinjuryenforcespeed_forum_presentationsfergu
sonpdf
After a partial repeal of this law in 1987 which granted states the authority to
increase speed limit (especially in rural interstates) a 1989 study showed a
15 increase in fatalities in rural interstates and a 5 increase in non-rural
interstates Unfortunately such studies often tend to be discounted by
advocates of increasing the speed limits as being produced by biased
industry sources
Similar conclusions were also presented by NHTSA in February 1998 in its
report to the Congress entitled ―Report to Congress The Effect of Increased
Speed Limits in the Post-NMSL Era see link given below Among its key
Page 22 of 45
findings is the following quoted in its entirety NMSL refers to the National
Maximum Speed Limit legislated after the Arab oil embargo of 1973
httpwww-nrdnhtsadotgovPubs808-637PDF
hellip Nevertheless it is important to note that data currently available from the
National Highway Traffic Safety Administrationrsquos (NHTSA) Fatality Analysis
Reporting System (FARS) shows that states that increased speed limits in 1996
experienced approximately 350 more Interstate fatalities than would have been
expected based on historical trends -- about 9 percent above expectations
Concurrently the Interstate fatalities experienced in states that did not increase speed
limits in 1996 was consistent with pre-1996 trends The estimated increase in
Interstate fatalities found in this study while smaller in magnitude compared to the
estimated change in fatalities found in 1987 following the increase of speed limits on
rural Interstates does follow the historical pattern of increases in fatalities being
associated with increases in posted speed limits
The annual crash reports compiled by NHTSA see Table 3 indicate that the
number of fatal crashes (and hence fatalities using the regression equation
developed in Figure 4) increase as the posted speed limits increase
Page 23 of 45
Table 3 Posted speed limits and number of crashes
Speed Limit Crashes (2008) Crashes (2009)
30 mph or less 3705 3277 35 or 40 mph 6115 5516 45 or 50 mph 6461 6074
55 mph 9794 8847 60 mph or higher 6908 6124
Total 34017 30797
Source httpwww-nrdnhtsadotgovPubs811402EEpdf
61 Studies cited in favor of lower speed limits
A detailed analysis of speeding related fatalities (see link below) by NHTSA
shows that a third of all crashes involve speeding ie at least one driver was
speeding
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Furthermore the above report which covers the period 1983-2002
indicates that immediately after the NMSL was completely abolished in
December 1995 the number of speeding related fatalities at speeds
above 65 mph increased from just 15 in 1995 to a 677 in 1996 (see Table
62 on page 43 of above report) It continued to increase in the years
since climbing to 930 in 2000
More detailed studies similar to that noted above by researchers at the
University of Illinois Chicago led by Lee S Friedman again lead to the
conclusion that higher speed limits lead to an increase in the number of
fatalities (see American Journal of Public Health online July 16 2009)
httphealthusnewscomhealth-newsmanaging-your-
healthcarearticles20090716deaths-injuries-increase-with-higher-speed-
limits
Page 24 of 45
httpwwwmedpagetodaycomPublicHealthPolicyPublicHealth15122
httpwwwamericaneercomspeed-limits
httpwwwactuarialoutpostcomactuarial_discussion_forumarchiveindexph
pt-171870html
For the study period 1995-2005 these researchers found that 12545 deaths
and 36582 injuries could be attributed to the increased speed limits The
benefits of reduced speed limits are stated quite eloquently by Dr Friedman
and are reproduced below (from above news article see link)
Reduced speed limits would save lives Friedman said They would also reduce
gas consumption cut emissions of air pollutants save valuable years of productivity
(lost due to injuries)and reduce the societal cost of motor vehicle crashes (due to
both fatal crashes and due to nonfatal and severe life-changing injuries) he added
Friedman and coworkers have also shown that increasing the speed limit led
to an immediate increase in the number of fatalities on Israeli roadways (see
link below)
httpinjurypreventionbmjcomcontent133156
The effect of speeding is very significant especially in rural areas resulting
in significantly higher fatalities Fatality rates are frequently double or triple
that in urban areas (see link below)
httpsafetyfhwadotgovspeedmgtdata_factsdocsspeeding_ruralpdf
As of Jan 1 2005 five Midwestern states had increased the speed limits to
above 65 mph (Illinois Iowa Kansas Minnesota Missouri Nebraska and
South Dakota) whereas three (Illinois Iowa and Wisconsin) had not All the
five states with increased speed limits showed a 7 to 13 increase in
fatalities The NHTSA study considered an eight year period before and after
the change in Dec 1995 (see Table 1 in link below) The collective experience
of the states that did NOT increase the speed limit was a 7 decline in
fatalities (see Table 2 of link below)
httpwwwiowadotgovmvdodsstats2006speedstudypdf
Page 25 of 45
Moreover Table 5 in the above study shows the effect of imposing the NMSL
of 55 mph in Iowa and its repeal in 1995 Considering a four-year average
before 1974 when the speed limit was 75 mph there were 35 fatal crashes
with 43 fatalities In the first four years after the 55 mph there were only 23
fatal crashes and 28 fatalities In the last four years before the repeal of 55
mph in 1995 there was a further decline to 14 fatal crashes with 17 fatalities
The Iowa fatality data will be discussed in more detail separately (in a later report)
since it provides the opportunity to assess the effect of a change in the speed limit
on the relationship between number of fatalities and fatal crashes (as seen in
Figure 4 for the US as a whole)
North of the US border Canadians seem to be citing the ―shocking increase
in highway fatalities in the US states where the speed limits were raised to
curb their own speed limits
httparchivesafety-councilorginfotrafficspeed-02html
httparchivesafety-councilorginfotrafficspeedhtml
Speed kills but speed also sells notes the second of the above news items
Manufacturers are producing more high performance cars (with higher horse
power to weight ratio) and ads feature enticing cars that race and swerve in
miraculous ways on empty roads These subliminal messages encourage
drivers especially young drivers to break the speed limit leading to the
absolute increase in highway fatalities (although the rate itself is going
down) The article emphasizes the need to enforce the speed limit on
Canadian highways and in cities where street racing is becoming a problem
62 Studies cited by opponents of lower speed limits
In fairness to quote the opponents on the other side of this debate Montana
reverted back to Reasonable and Prudent speed limits when the National
Maximum Speed Limit was repealed in 1995 and appears to have
experienced no significant increase in fatalities
Page 26 of 45
httpwwwhwysafetycomhwy_montanahtm
httpwwwmotoristsorgpressmontana-no-speed-limit-safety-paradox
httpwwwsouthbayriderscomforumsshowthreadphpt=81453amppage=1
Likewise studies in the state of Maryland showed no significant increase in
highway fatalities when the speed limit was increased from 55 mph to 75
mph The reason might simply be that drivers were already speeding much
more so when the speed limit was 55 mph than after the increase to 75 mph
In other words the fatalities data already reflects the effect of higher speeds
(not speed limits) on the number of fatalities
In Utah the experimental increase in the speed limit to 80 mph was
considered to be a success in terms of safety
httpautosaolcomarticleutah-speed-limit-tests
The UDOT Director noted that there was no increase in the number of
accidents on Interstate 15 But what happens in the event of an accident
when the speed limits are higher and drivers are driving at higher speeds and
two objects collide at this higher speed However no increase in the number
of accidents is not the same as no increase in fatalities due to the higher
speeds When accidents do occur do fatalities increase
Likewise in California when the speed limit went up from 55 mph to 65
mph in 1995 (after repeal of NMSL) fewer deaths were reported in 1998
compared to the peak year of 1979 or even 1987 Again the explanation
seems to be that motorists were already speeding when the limit was 55 mph
and that increasing the speed limit did not change driver behavior in any
significant way
httparticlessfgatecom1998-11-02news17735730_1_speed-limits-mph-
limit-death-rate
The National Motorists Association (NMA) a group which advocates higher
speed limits emphasizes the importance of considering fatality rates as
opposed to the raw fatalities The argument used is that fatality rates based
on the fatality per 100 million VMT is the legitimate way to look at the data
Page 27 of 45
This is a never ending debate Historically speaking fatality rates have been
going down ever since the compilation of traffic accidents data began Table
A1 in the appendix of a recent report by NHTSA (see link below) has highway
fatality rate data going back 1921
httpwww-nrdnhtsadotgovPubs811346pdf see appendix page 31
httpwwwmotoristsorgspeed-limitstruth
httpwwwmotoristsorgothercrash-data
httpwwwraisethespeedlimitorgmythshtml
httpwwwcatoorgpubspaspa346pdf
According to Stephen Moore of the Cato Institute (see last of the links above)
―All measures of highway safety show improvement not more deaths and
injuries since 1995 Despite the fact that 33 states raised their speed limits
immediately after the repeal of the mandatory federal speed limit the NHTSA
reported last October that the traffic death rate dropped to a record low level
in 1997lsquo Moreover the average fatality rate even fell in the states that raised
their speed limits
63 The Fatality rate Is it a reliable metric
In 1921 with fewer fatalities and fewer miles driven and the first year for
which the fatality rate could be computed the rate was 2408 It was down to
1479 in 1931 but the number of deaths had climbed to 31963 more than
double the 1921 absolute fatality number of 13253 It had dropped to 550 in
1966 the year of the highly publicized Congressional hearings but the
number of fatalities had climbed to 50984 in that fateful The Highway Safety
Act of 1966 ranks as one of the major acts of Congress and President
Johnson signed it saying that ―we have been tolerating a raging epidemic of
highway deathshellip see extract pasted below
httpwwwenotescommajor-acts-congresshighway-safety-act
Page 28 of 45
The act was motivated primarily by growing public concern over the rising number
of traffic fatalities in the United States Between 1960 and 1965 the annual number
of traffic fatalities increased by nearly thirty percent As President Lyndon B
Johnson stated at the signing of the act on September 9 1966 we have tolerated
a raging epidemic of highway death which has killed more of our youth than all
other diseases combined Through the Highway Safety Act we are going to find out
more about highway diseasemdashand we aim to cure it
Nonetheless highways fatalities continued to increase until the Arab oil
embargo of 1973 led to the NMSL of 55 mph all across the USA Do we just
ignore this undeniable historical record and focus only on the declining fatality
rate as the NMA and other proponents of higher speed limits seem to argue
(see links above)
The misleading nature of using fatality rates (per 100 M VMT) alone is also
obvious if one considers fatality data for individual states Take for example
the state of Montana which seems to have experienced no increase in
fatalities after repeal of NMSL
httpwww-nrdnhtsadotgovdepartmentsnrd-
30ncsaSTSI30_MT200930_MT_2009htm
For the period 2005-2009 the absolute number of fatalities for Montana
varied between a high of 277 in 2007 to a low of 229 in 2009 The fatality
rates per 100 M VMT on the other hand varied from a high of 245 for 2007
to a low of 201 for 2009 The corresponding US fatality rates varied from
136 to 114 Is the higher number for the fatality rate for Montana compared
to USA good or bad Likewise fatality rate per 100000 of population was
much higher for Montana than the US as a whole
This again highlights the pitfalls of using simple ratios to assess fatality statistics
without a full analysis of the underlying trends We will discuss this point
separately
As shown already the continuous decline in the fatality rate is a mathematical
artifact and essentially overlooks the unmistakable positive correlation
between the variables x and y of the type y = hx + c which becomes obvious
Page 29 of 45
only when we prepare the x-y scatter graph The ratio yx = h + (cx) can
decrease with increasing x (VMT) and increasing y (fatalities) since the
intercept c has a positive value when we consider only data spanning a short
period (such as 1994-2009 of more relevance to the current situation)
The debate between fatality rates and absolute number of fatalities is an
unending one A few years ago the Wall Street Journal carried an article
which was entitled (or something close) ―Unemployments rate in Ohio are
going down but why is the number of unemployed increasing The reason is
the same The graph of the number of unemployed (y) versus the number in
the labor market (x) is linear with a positive slope h and a positive intercept c
So the unemployment rate computed using the ratio yx keeps going down
year after year although the number unemployed keeps increasing Is it a
good thing that the unemployment rate is going down when more people
seem to be unable to find gainful unemployment
Or consider the situation with cancer death rates This too has been going
down in recent years but the actual number of cancer-related deaths has not
declined in any significant way Is it good that cancer death rates are going
down In all these situations the researchers or the socio-econo-politico
analysts involved in analyzing the trends in the data have failed to consider
the underlying x-y relation describing each problem
Hence it appears that the debate on the effect of increased speed limits
should not be focused on only the fatality rates (which have been decreasing
and proponents of higher speed limits cite this in their arguments) or even the
absolute number of fatalities (which has been the focus here) but on the
relationship between speed and the number of fatal crashes and the number
of fatalities within each speed segment (see Table 3 and also Figure 4)
Unfortunately details of number of fatalities and the number of fatal crashes
at each speed limit are not available even from NHTSA for detailed study
When a crash does occur (it is immaterial how many miles were driven) the
speed of the driver and vehicle design and engineering including safety
devices in place (seat belts airbags other impact absorbing technologies)
Page 30 of 45
determine if the occupants(s) will be killed One cannot argue that speed
does NOT kill That would be an absolute denial of the laws of physics
Studies show that setting the speed limit at the 85th percentile in any given
zone (this is the speed at or below which 85 of drivers are observed to
travel in traffic engineering studies) is the safest speed limit The majority of
drivers try to obey the posted speed limit while a few choose to drive at a
speed they consider is safe and prudent These are also perhaps the most
vociferous advocates of higher speed limits It is this tension caused due to
differences in speeds that leads to tailgating improper passing reckless
driving weaving from lane to lane and ultimately crashes and deaths in some
unfortunate cases
httpblogmotoristsorgspeed-limits-slower-safer
MARK TAYLOR
ANOTHER LOST A man was killed when his 4WD drive hit a tree east of Morrinsville (in New
Zealand) on Monday May 30 2011 The driver lost control of the vehicle on a bend probably tried
to correct his mistake and put the car into a ―yaw causing it to leave the road and smash sideways
into a tree Alerts to slow down had been posted since this was a high accident area but the driver
probably did not pay attention
64 Other factors
Many other factors besides speed no doubt affect highway fatalities The
vehicles of the 21st century are very different from the vehicles of the mid 20th
Page 31 of 45
century Technological innovations such as improvements in vehicle design
and engineering have greatly increased crash worthiness of vehicles even at
high speeds Environmental factors such as the weather also contribute to
accidents but not necessarily to increased fatalities Drivers actually tend to
slow down instinctively during adverse weather conditions (rain snow storms
etc) and although such weather may contribute to increased accidents the
lower speeds actually reduce fatalities
Yes technology has changed fundamentally from 1966 Drivers today are
more distracted by their cellmobile phone conversations (and also built-in
phones in luxury models) and text messaging than the drivers of the pre-1966
era High end cars now have many multimedia and internet features Again a
careful observation (even personal experience by the author) suggests that
such distracted drivers actually tend to (instinctively) drive more slowly and
hold up the traffic Perhaps such behavior leads to an increase in the number
of accidents but it does not necessarily lead to an increase in the number of
accident-related fatalities
Much talked about technological innovations such as automatic collision
avoidance systems and sensors (on the sides of vehicles) can indeed detect
vehicles in the front and neighboring lanes Furthermore vehicle-to-vehicle
communication systems vehicle-to-infrastructure communication systems
can no doubt avoid collisions and accidents Again such collision avoidance
systems work and are effective entirely because they automatically reduce
vehicle speeds - even if one of the offending vehicles is being at a super
high speed Also it must be remembered that such futuristic systems have
not yet been implemented widely nor can they be implemented widely since
the large majority of vehicles on the road are NOT luxury models Advanced
safety features come with a price and not all drivers can afford to pay that
price and ―buy that ―additional safety
Ultimately it is the laws of physics that govern what will happen when two or
more vehicles collide or even when a single vehicle collides with a stationary
infrastructural object (a bridge a wall a building or some impediment on the
road) The lower the number of crashes the lower the number of fatalities as
revealed by the 1994-2009 data graphed in Figure 5 The higher the speed of
Page 32 of 45
the object or objects that are involved in a collision the higher the kinetic
energy K that must be absorbed andor dissipated Increasing the posted
speed limit only increases the energy that must be absorbed when a crash
does occur This ultimately is the most important criterion determining the
number of fatalities
The kinetic energy increases as the square of the speed being given by the
well-known formula K = frac12 mv2 where m is the mass of the vehicle (in
laypersonlsquos language m increases directly with vehicle weight) and v is the
speed For the same vehicle mass an increase in the speed from 55 mph to
85 mph increases the kinetic energy K by a factor of 239 or roughly a 250
increase in the kinetic energy that must be absorbed in a collision
Ideally speaking the kinetic energy of the colliding object(s) is absorbed by
the vehicle infrastructure (a sturdy space frame the engine other vehicle
components etc) andor the surroundings However in the unfortunate
cases where this kinetic energy must be absorbed by the vehicle occupant(s)
the result is severe life-altering injuries andor death An unequivocal
relationship between an increase in vehicle speeds and fatal accidents can
be demonstrated by a careful examination of available traffic fatality data
This is a more involved discussion and is not the purpose of this short
communication These topics are no doubt very politically charged with many
social legal and financial implications with each interest group favoring a
different conclusion Nonetheless we cannot escape the laws of physics as
they govern the fundamental need to absorb higher and higher values of the
kinetic energy K with increasing vehicle speeds This same point is also
emphasized by Dr Friedman of the University of Illinois Chicago (see earlier
discussion)
Speed kills because of these energy transfer considerations and there can be
no doubt about it
Innovative 21st century solutions to speed management on the highways
such as strict enforcement of speed limits minimizing speed dispersion
(difference between speeds at which different drivers travel) while using
cameras to track the 15 of drivers who willfully violate the speed limit and
Page 33 of 45
create hazardous driving conditions is certainly recommended (Recall that
the optimum recommended speed limit is at or below which 85 of all drivers
travel ndash a policy also supported by NMA) Even on this score however the
results are confounding if we consider the Australian experience
httpwwwthenewspapercomnews282840asp
Up until 2007 there was no speed limit in the Northern Territory of
Australia Imposing a speed limit 130 kmph (80 mph) on some areas and
110 kmph (68 mph) in some others actually increased the number of deaths
The death toll in 2006 when there was no speed limit in this region was 44
and went up to 75 in 2009 see data table in link below
httpwwwthenewspapercomrlcdocs2009au-ntroadtollpdf
Furthermore it appears that installation of cameras to enforce speed limits
has proved to be a hazardous distraction to drivers and deaths actually
began to skyrocket between 2005 and 2007 in all Australian roadways
The main purpose here is to sound a cautionary note amid renewed attempts
in many states across the US to increase the speed limits on our highways by
calling attention to the historical facts regarding the ―epidemic levels of
highway traffic fatalities that engaged our national attention in the fateful year
of 1966 The graphical representation of the traffic fatality data in Figures 1
to 5 tells its own story
Indeed it would be tragic if highway-accident-related fatalities were to start
increasing once again and reach the historically high level that was last seen
in 1972 the year before the Arab oil embargo of 1973
Page 34 of 45
Conclusions
1 The graphical representation of the highway fatality data and the brief
summary of the historical facts of traffic safety legislation suggest that
recent attempts to increase the speed limits by various states (notably
Texas) may be misguided The distinct peak in the highway fatalities
observed in these graphs is highly alarming This appears to be related to
the enactment of the National Maximum Speed Limit (NSML) in 1974
following the 1973 Arab oil embargo Although NSML was motivated by a
desire to reduce gasoline consumption an unintended benefit might have
been a dramatic reduction in fatalities The fundamental reasons for the
peak in the fatalities-VMT curve must be examined carefully without
political posturing
2 The widely used fatality rate fatalities per 100 M vehicle miles traveled
has been declining since 1921 the first year for which a fatality rate could
be computed and has now reached a historical low The absolute number
of fatalities on the other hand was increasing in the 1950s and 1960s at
an alarming rate and the public outcry that ensued led to the highly
publicized Congressional hearing of 1966 and the subsequent traffic safety
legislations The fatality rate has been decreasing even in the most recent
15-year period (1994-2009) again with increasing fatalities although less
dramatically Thus it appears that fatality rate calculation based on vehicle
miles traveled (VMT) might not be a reliable indicator of the underlying
dynamics in the fatality trends
3 More detailed compilation of number of fatalities and the number of fatal
crashes within each speed limit segment is required to better understand
the effect of increasing speed limits on highway fatalities (and also fatality
rates) Such data is already available and is being compiled at the local
city and county levels in all jurisdictions and only needs to be reorganized
to highlight the effect of (posted) speed limits on the number of crashes
and fatalities This will require some minor rewriting and revisions to the
chapters named ―Crashes and ―States in the annual NHTSA reports
Page 35 of 45
Analysis of the fatalities-crashes data for several years with various
speed limits will be more revealing and meaningful than the current
fatality rates analysis and will be discussed separately in a follow up
report
4 One should not be lulled by the fact that vehicles of the 21st century are
now equipped with advanced safety features not available in the 1950s
and the 1960s In spite of these safety features the laws of physics dictate
that the higher the speed the higher kinetic energy of the colliding objects
and hence the greater the risk indeed near certainty of fatalities in a
higher speed collision compared to a lower speed one
5 The higher the speed at which the vehicle that is involved in a crash is
traveling the higher the kinetic energy that must be absorbed andor
dissipated without affecting the occupant(s) to avoid serious injuries andor
death This was true in the 1950s and the 1960s and will continue to be
true in the 21st century as well
Speed Kills for this just reason
6 It appears that higher fuel economies and reduced
highway fatalities were the twin societal benefits of 55
mph adopted after 1973 If so the current attempts to
increase the speed limits appear to be in conflict with
other important societal objectives
Page 36 of 45
Table 1 Annual US Street amp Highway
Fatalities from 1957
Year
Fatalities
Vehicle Miles
(millions)
Rate100M Vehicle Miles
1957 38702 646915 598
1958 36981 664915 556
1959 37910 700478 541
1960 38137 718845 531
1961 38091 737535 516
1962 40804 766852 532
1963 43564 805423 541
1964 47700 846500 563
1965 49163 887640 554
1966 51524 927915 555
1967 51559 965132 534
1968 53831 1019726 528
1969 55032 1066108 516
1970 53672 1114098 482
1971 53761 1183524 454
1972 55704 1264614 440
1973 55113 1316207 419
1974 46078 1282790 359
1975 45500 1330074 342
1976 45523 1402380 325
1977 47878 1467027 326
1978 50331 1544704 326
1979 51103 1529133 334
1980 51091 1527295 335
1981 49301 1552803 317
1982 43945 1595010 276
1983 42589 1652788 258
1984 44257 1720269 257
1985 43795 1774179 247
Page 37 of 45
1986 46056 1835000 251
1987 46385 1921000 241
1988 47093 2026000 232
1989 45555 2107040 216
1990 44529 2147501 207
1991 41162 2172214 189
1992 39235 2239828 175
1993 40115 2296585 175
1994 40676 2359984 172
1995 41798 2422696 173
1996 41907 2485848 169
1997 41967 2560373 164
Data from Federal Highway Administration
Source httpwwwpublicpurposecomhwy-fatal57+htm
Telephone +16186328507 - Facsimile +16186328538
WENDELL COX CONSULTANCY P O Box 841 - Belleville IL 62269 USA
Page 38 of 45
Fatality data for 1921-1982 compiled by NHTSA
Year
VMT
(Millions)
VMT
(Billions)
Fatalities
Fatality rate
per 100 M VMT
1921 55027 5503 13253 241 1922 67697 6770 14859 219 1923 84995 8500 17870 210 1924 104838 10484 18400 176 1925 122346 12235 20771 170 1926 140735 14074 22194 158 1927 158453 15845 24470 154 1928 172856 17286 26557 154 1929 197720 19772 29592 150 1930 206320 20632 31204 151 1931 216151 21615 31963 148 1932 200517 20052 27979 140 1933 200642 20064 29746 148 1934 215563 21556 34240 159 1935 228568 22857 34494 151 1936 252128 25213 36126 143 1937 270110 27011 37819 140 1938 271177 27118 31083 115 1939 285402 28540 30895 108 1940 302188 30219 32914 109 1941 333612 33361 38142 114 1942 268224 26822 27007 101 1943 208192 20819 22727 109 1944 212713 21271 23165 109 1945 250173 25017 26785 107 1946 340880 34088 31874 94 1947 370894 37089 31193 84 1948 397957 39796 30775 77 1949 424461 42446 30246 71 1950 458246 45825 33186 72 1951 491093 49109 35309 72
1952 513581 51358 36088 70
Page 39 of 45
1953 544433 54443 36190 66 1954 561963 56196 33890 60 1955 605646 60565 36688 61 1956 627843 62784 37965 60 1957 647004 64700 36932 57 1958 664653 66465 35331 53 1959 700480 70048 36223 52 1960 718762 71876 36399 51 1961 737421 73742 36285 49 1962 766734 76673 38980 51 1963 805249 80525 41723 52 1964 846298 84630 45645 54 1965 887812 88781 47089 53 1966 925899 92590 50894 55 1967 964005 96401 50724 53 1968 1015869 101587 52725 52 1969 1061791 106179 53543 50 1970 1109724 110972 52627 47 1971 1178811 117881 52542 45 1972 1259786 125979 54589 43 1973 1313110 131311 54052 41 1974 1280544 128054 45196 35 1975 1327664 132766 44525 34 1976 1402380 140238 45523 32 1977 1467027 146703 47878 33 1978 1544704 154470 50331 33 1979 1529133 152913 51093 33 1980 1527295 152730 51091 33 1981 1555308 155531 49301 32 1982 1595010 159501 43945 28
Source Analysis of Significant Decline in Motor Vehicle Traffic Fatalities in
2008 httpwww-nrdnhtsadotgovPubs811346pdf see Table A1 page 31
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Page 40 of 45
Acknowledgements
The author is grateful for thoughtful comments provided by friends and colleagues
with whom this document was shared via email prior to it being uploaded as a
publicly available document for wider dissemination and study The comments
offered by Prof Subra Ganesan of Oakland University Electrical and Computer
Engineering Department are reproduced with permission in their entirety
About the author
The author obtained his Masterrsquos (S M) and Doctoral (Sc D) degrees in Materials Engineering
from the Massachusetts Institute of Technology Cambridge USA He then spent his entire
professional career at leading US research institutions (MIT NASA Case Western Reserve
University and General Motors R amp D Center in Warren MI) He holds four patents in advanced
materials processing has co-authored two books and has published several scientific papers in
leading peer-reviewed international journals His expertise includes developing simple
mathematical models to explain the behavior of complex systems He can be reached by email at
vlaxmananhotmailcom
Page 41 of 45
Please Buckle Up
httpwwwlakecountypublichealthorgindexphpbuckle-up-montana
Public Awareness
Respect the Cage Exhibit
The Department of Transportation hopes that showing the reality of the crash will reduce traffic
fatalities A crushed car crash dummies and a sobering message ndash all part of the ―Respect The
Cage exhibit that is traveling across Montana The exhibit sponsored by the Montana Department
of Transportation stopped in Ronan on November 6th and is aimed at raising awareness about the
importance of wearing seat belts
The car in the exhibit was in an actual wreck many years ago
the passenger in the vehicle died because he was not wearing a
seat belt the driver who was wearing his seat belt survived
Montanarsquos likeliest crash fatality scenario
A Pickup
A Rural road
And Seat belts that
arenrsquot used
Page 42 of 45
Occupants of pickups are less likely to wear seat belts and pickups are more likely to
roll over than passenger cars
Seat belts reduce the risk of death by 60 percent in pickups and SUVs
In Montana from 2006-2008 81 of those killed in a crash while riding in a pickup were not wearing seat belts
In Montana pickups make up 401 of the vehicle population
For more information on Respect the Cage click here
Page 43 of 45
Appendix 1
Lack of seat belts leading cause of Louisiana highway deaths
1251 AM May 28 2011 |
Written by Adam Duvernay
Crashes involving unbuckled motorists were the leading cause of highway fatalities
in Louisiana last year and cost $9888 million according to recent reports The
Louisiana Highway Safety Commission reported 59 percent of vehicle occupants
killed in Louisiana crashes last year mdash about one in four mdash werent wearing seat
belts
httpwwwshreveporttimescomarticle20110528NEWS01105280354Lack-seat-
belts-leading-cause-La-highway-deathsodyssey=tab|topnews|text|FRONTPAGE
Crash bull Stats Published by NHTSAlsquos National Center for Statistics and Analysis 1200 New Jersey Avenue SE Washington DC 20590
DOT HS 811 451
Early Estimate of Motor Vehicle Traffic Fatalities in 2010
httpwww-nrdnhtsadotgovPubs811451pdf
Summary
A statistical projection of traffic fatalities in 2010 shows that an estimated 32788
people died in motor vehicle traffic crashes This represents a decline of about 3
percent as compared to the 33808 fatalities in 2009 as shown in Table 1 If these
projections are realized fatalities will be lowest on record (since 1949)
Traffic Safety Facts Overview 2009 Data
httpwww-nrdnhtsadotgovPubs811392pdf
In 2009 33808 people were killed in the estimated 5505000 police-reported
motor vehicle traffic crashes 2217000 people were injured and 3957000
crashes involved property damage only Compared to 2008 this is a 10-
percent decrease in the number of fatalities and a 5-percent decrease in the
Page 44 of 45
number of police-reported motor vehicle traffic crashes people injured and
crashes involving property damage
An average of 93 people died each day in motor vehicle crashes in 2009 mdash
an average of one every 16 minutes
Traffic Safety Facts Overview 2008 Data
httpwww-nrdnhtsadotgovPubs811162pdf
In 2008 37261 people were killed in the estimated 5811000 police-reported
motor vehicle traffic crashes 2346000 people were injured and 4146000
crashes involved property damage only
Some comments and Feedback
The following comments were received from Prof Ganesan after his review of the
first draft of this document It was subsequently revised thanks to this input to
address some of the very important issues raised here
Dear Laxman
The write up is not enough
You are emphasizing that the speed limit reduces the fatal accidents (comparing 1966
to 2000 accident numbers)
Can you also add a few sentences why the number is decreasing from 1980 to 2000
values (May be due to better design of vehicles)
Can you say anything about the fuel consumption with the speed for any typical
vehicle in 2011 or 2010 (do not consider the fatalities issue)
Probably a speed between 55 and 60 mph gives a better mileage If so this is a
compelling reason to keep the speed limit low But cars probably can be tuned to
give better mileage at any high speed also
Page 45 of 45
Weather is also a major factor in fatal accidents Speed limit may be kept low during
winter and kept higher in summer Give your comments on this too
Driver distractions can cause more accidents Now cars have many multimedia and
internet features Automatic collision avoidance systems and sensors on the sides can
detect vehicles in the front and neighboring lanes and it can automatically decrease
speed even if the driver speeds at super high speeds
Give some comments on this too There is also Vehicle to Vehicle communications
vehicle to infrastructure communications and they can avoid collisions and accidents
Technology has changed from 1966 I cannot agree with you on the speed limit
without any discussion on the above and other factors
Have a great day
Subra Ganesan
Professor Subramaniam Ganesan
Director Real Time amp DSP Lab
Electrical and Computer Engineering Department
2200 Squirrel Road Dodge Hall Room 105
Oakland University Rochester MI 48309 USA
Phone 248 370 2206 Fax 248 370 4633
wwwsecsoaklandedu~ganesan
IEEE Distinguished Visiting Speaker (2005-2009) Coordinator
IEEE SEM CS chapter Chair Region 4 and CS Society Board member
SAE ASEE ACM member
Page 3 of 45
Summary
A brief review of the historical trends in US traffic fatalities since 1929 is
presented here within the context of the recent attempts to increase the
posted speed limits on US highways most notably in Texas The public
outrage due to the ―epidemic of US highway deaths in the 1950s and the
1960s prompted Congress to hold its highly publicized hearings in 1966 and
the enactment of safey legislation signed by President Johnson later that
year However it appears that the National Maximum Speed Limit (NSML) of
55 mph enacted as an energy saving measure in 1973 following the Arab oil
embargo had a greater and immediate impact on the reduction in highway
traffic fatalities than the traffic safety legislations which no dobut had a
delayed and longer term effect (via the introdcution of vehicle safety features
like seat belts and airbags)
Some pros and cons in the debate on increasing speed limits and the impact
on fatalities and crashworthiness of vehicles have been discussed briefly A
more detailed discussion of the specific effect of speed limits (on fatalities)
may be found in a companion document where it is shown that the universal
mathematical law y = hx + c relating the number of fatal crashes (x) and the
number of fatalities (y) can be used to assess the effect of increasing or
decreasing the speed limits
A Fresh look at the Iowa Kansas Montana and Txas motor vehicle fatalities
data Effect of Speed Limits on Fatalities Texas Proofing of Vehicles
httpwwwscribdcomdoc59153773Effect-of-Speed-Limits-on-Fatalities-
Texas-Proofing-of-Vehciles
Page 4 of 45
1 Introduction
In traffic safety research we encounter two important dates or years 1966
and 1973 The main purpose here is to call attention to the historical facts
regarding the ―epidemic levels of highway traffic fatalities that engaged our
national attention in the fateful year of 1966
Does Speed Kill This is no doubt a politically charged topic with different
interest groups drawing their own conclusions and pulling in different
directions even when confronted with exactly the same facts Nonetheless
here is a humble attempt by a lone citizen to sound a cautionary note amid
the renewed attempts in many states across the US to increase the speed
limits on our highways
Page 5 of 45
The 1927 Durant Motor Star produced by William Durant the founder and the first
CEO of General Motors This car can be rented to tour San Diego for $50 to $70 per
hour plus $150 to $200 for the first half-hour httpeditorialautosmsncommost-
unusual-tourist-vehicles4
Also for the first time the Center for Disease Control (CDC) has recently
released the state-by-state societal costs of motor vehicle crashes Highway
fatalities cost $41 billion annually The CDC announcement coincides with the
kickoff of the United Nations Decade of Action an international effort aimed
at saving 5 million lives though 2020 by working cooperatively towards
greater road safety
httpwwwthecarconnectioncomnews1059966_cdc-highway-fatalities-cost-
41-billion-annually
Indeed it would be tragic if highway-accident-related fatalities were to start
increasing once again and reach the historically high level that was last seen
in 1972 the year before the Arab oil embargo of 1973 Statistical projections
of traffic fatalities show that in 2010 an estimated 32788 people died in motor
vehicle traffic crashes This is a 3 reduction over 2009 levels If these
Page 6 of 45
projections are realized highway traffic fatalities will be lowest on record
(since 1949)
The graphical representation of the traffic fatality data compiled annually by
the National Highway Traffic Safety Administration (NHTSA) as seen in
Figures 1 to 4 here tells its own story Indeed here a picture is certainly
worth a thousand words Let these graphs do the talking The detailed
captions attached with each figure permit an unbiased assessment of the
traffic fatality data and will hopefully lead to a repeal of the misguided
attempts to increase speed limits This also represents a simple and new
approach to analyzing the fatality data without excessive reliance on the
calculation of simple ratios such as the widely used fatality rate
As will become obvious the national speed limit of 55 mph instituted in
the historical year of 1973 yielded the twin benefits of improved fuel
economies and reduced traffic fatalities
The 1955 Cadilla available for tours of Memphis TN
httpeditorialautosmsncommost-unusual-tourist-vehicles2
Page 7 of 45
httpwwwugptiorgpubspdfDP188pdf
httpwwwlakecountypublichealthorgindexphpbuckle-up-montana
2 A brief review of historical traffic
fatality data compiled by NHTSA
The NHTSA uses the fatality rate as its single most important measure of
traffic safety The fatality rate is the ratio yx where x is the total vehicle miles
traveled (usually expressed in billions) by all US drivers and y is the absolute
number of highway fatalities To arrive at a simple tractable number the rate
is determined per 100 million vehicle miles traveled (acronym VMT)
Although this fatality rate yx has now reached a historical low in 2010
exclusive focus on this ratio while overlooking the underlying x-y trend might
be misleading as will become evident from the graphical representation of
the historical data being attempted here
Driver Behavior
Driver Drinking
Too Fast
Not Wearing
Seat Belts
Montanarsquos Likeliest
Fatal Crash Scenario
A Pick up
A Rural road
And Seat belts not
used
Page 8 of 45
Figure 1 Graph of the absolute number of US highway fatalities since 1957 The raw
data used to prepare this graph may be found in Table 1(relegated to the end of this
document) The absolute number of highway fatalities were quite low in the 1950s
and reached a peak in the late 1960s to early 1970s and have since decreased to
levels seen in the 1950s although the vehicle miles driven (in millions) has been
increasing from 646915 in 1957 to 2560373 in the year 2000 see also Figure 2
The fatality data from other government sources have also been studied by the author
and lead to the same conclusion of a peak in highway deaths around the late 1960s to
early 1970s
Page 9 of 45
Figure 2a Graphical representation of the absolute number of US highway fatalities
versus annual vehicle miles driven (in trillions) The number of miles driven by US
drivers has increased each year since 1957 as seen in Table 1 The absolute number
of highway fatalities has increased as well reaching a peak in the late 1960s to early
1970s The same peak is also seen here in the graph of the absolute number of
highway fatalities versus vehicle miles driven Improvements in vehicle safety devices
(notably seat belts and airbags) coupled with the institution of the national highway
speed limits (starting mid 1970s) and also improved highways are the primary
reasons for the decrease in fatalities These historical trends suggest that renewed
attempts to increase the speed limits on our highways would be counterproductive
and may eventually lead once again to an increase in fatalities with tragic
Page 10 of 45
consequences
Figure 2b Graphical representation of the US highway fatality data for the period
1921-1982 The first year for which a fatality rate yx could be computed is 1921 The
number of fatalities was 13253 and VMT was 5503 billion yielding a fatality rate of
2408 per 100 million VMT The fatality rate for any year is the slope of the ray ie
the straight line joining the (x y) data point back to the origin (00) of this graph see
dashed line for 1921 superimposed on to the graph The fatality rates (slopes of such
rays) had been declining quite consistently although the absolute number of fatalities
increased as seen here ultimately leading to the Congressional hearing in 1966 Is
VMT the single most important reason for the increasing fatalities
Page 11 of 45
Figure 3 Graphical representation of the traffic fatality data for the 15 year period
1994-2009 A sudden precipitous drop in the absolute number of fatalities (at least on
the magnified scale used here) and hence the fatality rate has been observed over
the three-year period 2007-2009 However it should be noted that the x-y scatter
graph here shows a general upward trend with fatalities actually increasing with
increasing VMT (as in the earlier era 1950s and 1960s) during the 12-year period
spanning 1994-2006 although the rate yx shows a misleading downward trend Why
is the rate yx going down
The reason is very simple and it may be just a mathematical artifact The equation of
the best-fit straight line through the most recent data points is of the form y = hx + c
= 2865 x + 34420 where h is the slope of the line and c the intercept (Note that x
here is VMT in billions The numerical value determined using this equation must be
divided by 10 to get the rate per 100 M VMT) Hence the fatality rate given by the
ratio yx = h + (cx) = 2865 + 34420x can actually decrease with increasing
values of x because of the nonzero intercept c Unlike the ray through the origin the
best-fit line does not pass through the origin (00) If we consider only the most
Page 12 of 45
recent data the intercept c is positive and fatality rates yx decrease with increasing
VMT and increasing fatalities In the earlier era both the slope h and intercept c had
very different values due to several factors being discussed here (speed limits
technology highway design etc)
Table 2 Traffic fatality data for the recent 15-year period
1994-2009 (Source NHTSA)
Year
Highway
fatalities y
Vehicle miles
traveled
VMT
(billions) x
Fatality rate
yx per 100
million VMT
Fatal crashes
1994 40716 2358 173 36254 1995 41817 2423 173 37241 1996 42065 2486 169 37494 1997 42013 2562 164 37324 1998 41501 2632 158 37107 1999 41717 2691 155 37140 2000 41945 2747 153 37526 2001 42196 2797 151 37862 2002 43005 2856 151 38491 2003 42884 2890 148 38477 2004 42836 2965 144 38444 2005 43510 2989 146 39252 2006 42708 3014 1 42 38648 2007 41259 3032 136 37435 2008 37423 2974 126 34172 2009 33808 2979 113 30797
Page 13 of 45
Figure 4 The most significant metric used by NHTSA is the fatality rate per 100
million vehicles miles traveled (VMT) This is now at a historical low of 113 for
2009 having declined year after year from 173 in 1994 The NHTSA however also
compiles other types of data on crashes There are three types of crashes fatal
injury but no death and property damage only A careful review of this crash data
for the period 1994-2009 reveals the obvious the lower the number of (fatal)
crashes x the lower the number of highway-accident-related fatalities y It is also
obvious that the number of fatalities per crash is greater than one ie more than one
person is being killed when one of more vehicles experience a crash
Clearly this is the single most important piece of information that one needs to
reduce the number of fatalities on our highways Vehicle design and engineering as
well as all other policy matters (legal political social environmental financial)
must be guided by this simple graph The best-fit line through the data derived using
simple linear regression has the equation y = hx + c = 114x ndash 10266 and is
Page 14 of 45
superimposed on to the data The design engineering goal and societal goal should
be to reduce the slope h of this statistically significant best-fit line to its ideal value of
h = 1 A fatal crash by definition is one where at least one person dies either an
occupant or a non-motorist in the path of the vehicle Hence the ideal slope h = 1
Photograph of an accident scene from the period 1955-1965
httpwwwcorinthsocialhistoryprojectorghtmlhighwaytollshtml
3 A Brief History of Traffic Safety Legislation
The following is extracted from the Wikipedia article on National Highway
Traffic Safety Administration (NHTSA)
httpenwikipediaorgwikiNational_Highway_Traffic_Safety_Administration
In 1965 and 1966 public pressure grew in the US to increase the safety of
cars The number of deaths on US highways were increasing year after year
Page 15 of 45
see Figure 1 and in 1966 Congress held a series of highly publicized
hearings on highway safety This led to the legislation for mandatory
installation of seat belts which also created the US Department of
Transportation (on Oct 15 1966)
httpwwwemsgovpdf2011EMSWeek2011_Stricklandpdf
The following is extracted from a Washington Post article on
NHTSA dated April 2 2002
httpwwwwashingtonpostcomwp-srvbusinessincludesnhtsa_primerhtm
In 1966 after decades of rising traffic fatalities (also vividly illustrated in
Figures 1 and 2 here) the publication of Ralph Naders Unsafe at Any
Speed and increasing public outcry for safer automobiles Congress held a
series of highly publicized hearings on creating a regulatory agency for traffic
safety Among the witnesses was William Haddon an epidemiologist who
introduced the idea that traffic accidents could be analyzed scientifically and
injuries reduced by changing auto design such as installing collapsible
steering columns safety glass head rests and seat belts
Congress passed the Highway Safety Act of 1966 creating the National
Highway Safety Bureau with Haddon as its first administrator The bureau
became NHTSA in 1970 under the newly established Department of
Transportation An early Nader convert Joan Claybrook headed NHTSA
under President Carter and now runs Naders organization Public Citizen
National Traffic and Motor Vehicle Safety Act
httpwwwanswerscomtopicnational-traffic-and-motor-vehicle-safety-act
Signed into law by President Lyndon Johnson on September 9 1966 this act
created the first mandatory federal safety standards for motor vehicles The
act was motivated by a variety of factors First and foremost the public was
growing increasingly concerned over the rising number of traffic fatalities on
the nations roads Such fatalities had increased by nearly 30 percent
between 1960 and 1965 and experts forecasted 100000 such deaths
Page 16 of 45
annually by 1975 unless something was done to improve traffic safety
Adding fuel to the fire Ralph Naders Unsafe at Any Speed published in
November 1965 criticized the automobile industry for neglecting safety in
favor of power and styling when designing new vehicles
4 The reason for the historical
decrease in highway fatalities
A recent news item see link given below regarding renewed attempts to
increase the speed limit by many states prompted this write up by the
present author who has studied traffic fatality data extensively and analyzed
them very carefully over the last several years
httpmoneymsncomauto-insurancewhy-speed-limits-are-
risingaspxGT1=33033
Residents of Metro Detroit area who frequently cross into Ohio from
Michigan notice that the speed limit has now increased in Ohio The speed
limit on Michigan highways was increased to 70 mph in the late 1990s but
Ohio retained its lower speed limit for many years leading Michigan drivers to
experience a ―speed trap of sorts The speed limit is also increasing in many
other states notably Texas where it is proposed to increase it to 85 mph at
least in West Texas
Historically speaking from a traffic fatality standpoint we must consider two
important dates 1966 and 1973 Only 1973 the year of the Arab oil embargo
following the Arab-Israeli war (that led to what President Obama has recently
called the pre-1967 border for Middle East peace) is mentioned in the above
article It fails to mention the significance of the year 1966
Prior to 1966 there was actually NO speed limit in many Western states and
deaths due to highway accidents were increasing year after year The
Page 17 of 45
number of highway fatalities went up from 38702 in 1957 to 51524 in 1965
a 33 increase over the 1957 level and an additional 12822 deaths in 1965
compared to 1957 It was this carnage on the US highways that forced
Congress to hold its hearings on highway traffic fatalities in 1966
Nonetheless a careful examination of the fatality data in Table 1 shows that
notwithstanding the highly publicized Congressional hearings of 1966 and
new safety legislation that was enacted the absolute number of fatalities
continued to increase after 1966 and only started decreasing after 1973
Vehicle designs especially the introduction of safety features (even the
simplest like safety belts) did not change significantly between 1966 and
1973 Nonetheless post-1973 we begin to see a dramatic turnaround
Why
After the 1973 Arab oil embargo a nationwide maximum speed limit (NMSL)
of 55 mph was imposed and accepted in the USA (effective Jan 1 1974)
during the Nixon administration primarily as an effort to conserve fuel and
reduce the US vulnerability to oil imports The unintended and indeed
fortunate consequence of this reduced speed limit was the immediate
reduction in the fatalities revealed in Figures 2 and 3 This is the real reason
for the peaks in highway fatalities observed in these two graphs
The Congressional hearings of 1966 did eventually have an impact but it was
a delayed one The impact of the 1973 nationwide speed limit of 55 mph was
however immediate as we see from the magnified plot of the same data in
Figure 5 and a closer examination of the raw fatality data in Table 1
The number of highway-accident-related fatalities decreased immediately
from a high of 55704 in 1972 to just 46078 in 1974 a 173 drop see
arrows There were 9626 fewer deaths annually even with a slight increase
in the vehicle miles driven (see Table 1) Indeed the number of highway
death reached its absolute peak value in 1972 never to be seen again
Fatalities have been decreasing every since with slight fluctuations about
each new low value
Page 18 of 45
Figure 5 Expanded view of the fatality data showing the immediate impact of the
national speed limit of 55 mph following the Arab oil embargo of 1973 Note that
fatalities continued to rise between 1966 and 1973 in spite of the highly publicized
Congressional hearings in 1966 and the traffic safety legislation enacted soon after
Each new low is probably associated with vehicle safety innovations and the
improvements in vehicle design and engineering The combined beneficial
effect of improved vehicle designs primarily the introduction of seat belts
and the laws enforcing usage of seat belts aided by the reduced speed
limits contributed to the continued decline in the absolute number of fatalities
that started since 1973 and has continued to this day The subsequent
introduction of other safety features notably air bags has contributed to a
further reduction in highway fatalities
Page 19 of 45
State police Trooper First Class Jeffrey Flowers looking at a car in which a Boswell
Pennsylvania woman was injured Tuesday (May 31 2011) The accident occurred at
an intersection when a truck (seen behind the wrecked car) entered this accident
prone intersection (part of a highway safety corridor where signs are posted to
reduce unsafe driver behavior) There have been four accidents at this intersection
since 2006 none fatal httpwwwdailyamericancomnewssomersetda-ot-woman-
injured-in-route-30-wreck-2011053104165420story
5 Numerical calculations of decline in
fatalities and the impact of NMSL post-1973
Letlsquos consider the decline in fatalities between 1972 the last year before the
adoption of the NMSL and 1974 the first year following its adoption after the
Arab oil embargo There was an immediate decrease in the number of
fatalities by 9393 ie y = -9393 with a slight increase in the VMT ie x
= 20758 millions The NHTSA data used here may be found in the table at
the end of this document The numerical value of the rate of change per
billion VMT (ie neglecting the sign) was therefore
yx = 4525 fatalitiesbillion VMT (1972-1974)
Page 20 of 45
It is instructive to compare this rate of change in fatalities with similar short
periods of a decline in fatalities in the pre-1973 era when speed limits were
much higher The absolute number of fatalities declined over a relatively
short period with both an increase and a decrease in VMT The results are
given below and are self-explanatory
yx = 454 fatalitiesbillion VMT (1953-54) decline with increase in VMT
yx = 655 fatalitiesbillion VMT (1942-43) decline with decrease in VMT
yx = 1739 fatalitiesbillion VMT (1941-42) decline with decrease in VMT
yx = 4528 fatalitiesbillion VMT (1937-39) decline with increase in VMT
yx = 2548 fatalitiesbillion VMT (1931-32) decline with decrease in VMT
The rate of decline observed between 1953 and 1954 with an increase in
VMT was just one-tenth of that observed following the adoption of the 55
mph speed limit The war years (1941-43 WWII) and the Great Depression
era (1931-32) were accompanied by big declines in fatalities with decreasing
VMT but the rate of change was still significantly lower than observed after
the adoption of the NMSL
The only apparently inexplicable decline is that between 1937 and 1939
where a nearly identical high rate of decline was observed Notice also the
big drop in the traditional fatality rate between 1937 and 1938 This large drop
appears to coincide with the creation of the National Safety Council (NSC) by
William H Cameron in June 1937 (see link below) with its far-flung campaign
of education legislation research highway engineering and traffic training
undertaken by the NSC and some two dozen other groups with the backing of the
automotive industry through its Automotive Safety Foundation Other factors
unknown to the present author probably also played a role
httpwwwtimecomtimemagazinearticle0917188379700htmlixzz1O2G
7rnUg
Page 21 of 45
These simple computations here however reveal the significant effect of
reduced speed limits on highway fatalities much more so than other factors
6 Further Considerations Pros and Cons
The singular effect of increased speeds (or speeding) on highway fatalities
has been studied and demonstrated by a number of industry sources such
as the Insurance Institute for Highway Safety (IIHS) Consumers Union and
also by government researchers
httpwwwsmartmotoristcomtraffic-and-safety-guidelineexcessive-speed-is-
a-factor-in-one-third-of-all-fatal-crasheshtml
httpwwwconsumersunionorgotherspeedlimitsspeed031500a2htm
Speed ndash defined as exceeding the posted speed limit or driving too fast for
given conditions ndash is a factor in nearly one-third of all fatal crashes Besides
fatality in 1998 nearly 40000 people were critically injured in speed-related
crashes and nearly 72000 were moderately injured
The salutary and immediate beneficial effect of the nationwide 55 mph speed
limit has been noted by other researchers (see Susan Ferguson link below)
httpwwwnhtsagovpeopleinjuryenforcespeed_forum_presentationsfergu
sonpdf
After a partial repeal of this law in 1987 which granted states the authority to
increase speed limit (especially in rural interstates) a 1989 study showed a
15 increase in fatalities in rural interstates and a 5 increase in non-rural
interstates Unfortunately such studies often tend to be discounted by
advocates of increasing the speed limits as being produced by biased
industry sources
Similar conclusions were also presented by NHTSA in February 1998 in its
report to the Congress entitled ―Report to Congress The Effect of Increased
Speed Limits in the Post-NMSL Era see link given below Among its key
Page 22 of 45
findings is the following quoted in its entirety NMSL refers to the National
Maximum Speed Limit legislated after the Arab oil embargo of 1973
httpwww-nrdnhtsadotgovPubs808-637PDF
hellip Nevertheless it is important to note that data currently available from the
National Highway Traffic Safety Administrationrsquos (NHTSA) Fatality Analysis
Reporting System (FARS) shows that states that increased speed limits in 1996
experienced approximately 350 more Interstate fatalities than would have been
expected based on historical trends -- about 9 percent above expectations
Concurrently the Interstate fatalities experienced in states that did not increase speed
limits in 1996 was consistent with pre-1996 trends The estimated increase in
Interstate fatalities found in this study while smaller in magnitude compared to the
estimated change in fatalities found in 1987 following the increase of speed limits on
rural Interstates does follow the historical pattern of increases in fatalities being
associated with increases in posted speed limits
The annual crash reports compiled by NHTSA see Table 3 indicate that the
number of fatal crashes (and hence fatalities using the regression equation
developed in Figure 4) increase as the posted speed limits increase
Page 23 of 45
Table 3 Posted speed limits and number of crashes
Speed Limit Crashes (2008) Crashes (2009)
30 mph or less 3705 3277 35 or 40 mph 6115 5516 45 or 50 mph 6461 6074
55 mph 9794 8847 60 mph or higher 6908 6124
Total 34017 30797
Source httpwww-nrdnhtsadotgovPubs811402EEpdf
61 Studies cited in favor of lower speed limits
A detailed analysis of speeding related fatalities (see link below) by NHTSA
shows that a third of all crashes involve speeding ie at least one driver was
speeding
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Furthermore the above report which covers the period 1983-2002
indicates that immediately after the NMSL was completely abolished in
December 1995 the number of speeding related fatalities at speeds
above 65 mph increased from just 15 in 1995 to a 677 in 1996 (see Table
62 on page 43 of above report) It continued to increase in the years
since climbing to 930 in 2000
More detailed studies similar to that noted above by researchers at the
University of Illinois Chicago led by Lee S Friedman again lead to the
conclusion that higher speed limits lead to an increase in the number of
fatalities (see American Journal of Public Health online July 16 2009)
httphealthusnewscomhealth-newsmanaging-your-
healthcarearticles20090716deaths-injuries-increase-with-higher-speed-
limits
Page 24 of 45
httpwwwmedpagetodaycomPublicHealthPolicyPublicHealth15122
httpwwwamericaneercomspeed-limits
httpwwwactuarialoutpostcomactuarial_discussion_forumarchiveindexph
pt-171870html
For the study period 1995-2005 these researchers found that 12545 deaths
and 36582 injuries could be attributed to the increased speed limits The
benefits of reduced speed limits are stated quite eloquently by Dr Friedman
and are reproduced below (from above news article see link)
Reduced speed limits would save lives Friedman said They would also reduce
gas consumption cut emissions of air pollutants save valuable years of productivity
(lost due to injuries)and reduce the societal cost of motor vehicle crashes (due to
both fatal crashes and due to nonfatal and severe life-changing injuries) he added
Friedman and coworkers have also shown that increasing the speed limit led
to an immediate increase in the number of fatalities on Israeli roadways (see
link below)
httpinjurypreventionbmjcomcontent133156
The effect of speeding is very significant especially in rural areas resulting
in significantly higher fatalities Fatality rates are frequently double or triple
that in urban areas (see link below)
httpsafetyfhwadotgovspeedmgtdata_factsdocsspeeding_ruralpdf
As of Jan 1 2005 five Midwestern states had increased the speed limits to
above 65 mph (Illinois Iowa Kansas Minnesota Missouri Nebraska and
South Dakota) whereas three (Illinois Iowa and Wisconsin) had not All the
five states with increased speed limits showed a 7 to 13 increase in
fatalities The NHTSA study considered an eight year period before and after
the change in Dec 1995 (see Table 1 in link below) The collective experience
of the states that did NOT increase the speed limit was a 7 decline in
fatalities (see Table 2 of link below)
httpwwwiowadotgovmvdodsstats2006speedstudypdf
Page 25 of 45
Moreover Table 5 in the above study shows the effect of imposing the NMSL
of 55 mph in Iowa and its repeal in 1995 Considering a four-year average
before 1974 when the speed limit was 75 mph there were 35 fatal crashes
with 43 fatalities In the first four years after the 55 mph there were only 23
fatal crashes and 28 fatalities In the last four years before the repeal of 55
mph in 1995 there was a further decline to 14 fatal crashes with 17 fatalities
The Iowa fatality data will be discussed in more detail separately (in a later report)
since it provides the opportunity to assess the effect of a change in the speed limit
on the relationship between number of fatalities and fatal crashes (as seen in
Figure 4 for the US as a whole)
North of the US border Canadians seem to be citing the ―shocking increase
in highway fatalities in the US states where the speed limits were raised to
curb their own speed limits
httparchivesafety-councilorginfotrafficspeed-02html
httparchivesafety-councilorginfotrafficspeedhtml
Speed kills but speed also sells notes the second of the above news items
Manufacturers are producing more high performance cars (with higher horse
power to weight ratio) and ads feature enticing cars that race and swerve in
miraculous ways on empty roads These subliminal messages encourage
drivers especially young drivers to break the speed limit leading to the
absolute increase in highway fatalities (although the rate itself is going
down) The article emphasizes the need to enforce the speed limit on
Canadian highways and in cities where street racing is becoming a problem
62 Studies cited by opponents of lower speed limits
In fairness to quote the opponents on the other side of this debate Montana
reverted back to Reasonable and Prudent speed limits when the National
Maximum Speed Limit was repealed in 1995 and appears to have
experienced no significant increase in fatalities
Page 26 of 45
httpwwwhwysafetycomhwy_montanahtm
httpwwwmotoristsorgpressmontana-no-speed-limit-safety-paradox
httpwwwsouthbayriderscomforumsshowthreadphpt=81453amppage=1
Likewise studies in the state of Maryland showed no significant increase in
highway fatalities when the speed limit was increased from 55 mph to 75
mph The reason might simply be that drivers were already speeding much
more so when the speed limit was 55 mph than after the increase to 75 mph
In other words the fatalities data already reflects the effect of higher speeds
(not speed limits) on the number of fatalities
In Utah the experimental increase in the speed limit to 80 mph was
considered to be a success in terms of safety
httpautosaolcomarticleutah-speed-limit-tests
The UDOT Director noted that there was no increase in the number of
accidents on Interstate 15 But what happens in the event of an accident
when the speed limits are higher and drivers are driving at higher speeds and
two objects collide at this higher speed However no increase in the number
of accidents is not the same as no increase in fatalities due to the higher
speeds When accidents do occur do fatalities increase
Likewise in California when the speed limit went up from 55 mph to 65
mph in 1995 (after repeal of NMSL) fewer deaths were reported in 1998
compared to the peak year of 1979 or even 1987 Again the explanation
seems to be that motorists were already speeding when the limit was 55 mph
and that increasing the speed limit did not change driver behavior in any
significant way
httparticlessfgatecom1998-11-02news17735730_1_speed-limits-mph-
limit-death-rate
The National Motorists Association (NMA) a group which advocates higher
speed limits emphasizes the importance of considering fatality rates as
opposed to the raw fatalities The argument used is that fatality rates based
on the fatality per 100 million VMT is the legitimate way to look at the data
Page 27 of 45
This is a never ending debate Historically speaking fatality rates have been
going down ever since the compilation of traffic accidents data began Table
A1 in the appendix of a recent report by NHTSA (see link below) has highway
fatality rate data going back 1921
httpwww-nrdnhtsadotgovPubs811346pdf see appendix page 31
httpwwwmotoristsorgspeed-limitstruth
httpwwwmotoristsorgothercrash-data
httpwwwraisethespeedlimitorgmythshtml
httpwwwcatoorgpubspaspa346pdf
According to Stephen Moore of the Cato Institute (see last of the links above)
―All measures of highway safety show improvement not more deaths and
injuries since 1995 Despite the fact that 33 states raised their speed limits
immediately after the repeal of the mandatory federal speed limit the NHTSA
reported last October that the traffic death rate dropped to a record low level
in 1997lsquo Moreover the average fatality rate even fell in the states that raised
their speed limits
63 The Fatality rate Is it a reliable metric
In 1921 with fewer fatalities and fewer miles driven and the first year for
which the fatality rate could be computed the rate was 2408 It was down to
1479 in 1931 but the number of deaths had climbed to 31963 more than
double the 1921 absolute fatality number of 13253 It had dropped to 550 in
1966 the year of the highly publicized Congressional hearings but the
number of fatalities had climbed to 50984 in that fateful The Highway Safety
Act of 1966 ranks as one of the major acts of Congress and President
Johnson signed it saying that ―we have been tolerating a raging epidemic of
highway deathshellip see extract pasted below
httpwwwenotescommajor-acts-congresshighway-safety-act
Page 28 of 45
The act was motivated primarily by growing public concern over the rising number
of traffic fatalities in the United States Between 1960 and 1965 the annual number
of traffic fatalities increased by nearly thirty percent As President Lyndon B
Johnson stated at the signing of the act on September 9 1966 we have tolerated
a raging epidemic of highway death which has killed more of our youth than all
other diseases combined Through the Highway Safety Act we are going to find out
more about highway diseasemdashand we aim to cure it
Nonetheless highways fatalities continued to increase until the Arab oil
embargo of 1973 led to the NMSL of 55 mph all across the USA Do we just
ignore this undeniable historical record and focus only on the declining fatality
rate as the NMA and other proponents of higher speed limits seem to argue
(see links above)
The misleading nature of using fatality rates (per 100 M VMT) alone is also
obvious if one considers fatality data for individual states Take for example
the state of Montana which seems to have experienced no increase in
fatalities after repeal of NMSL
httpwww-nrdnhtsadotgovdepartmentsnrd-
30ncsaSTSI30_MT200930_MT_2009htm
For the period 2005-2009 the absolute number of fatalities for Montana
varied between a high of 277 in 2007 to a low of 229 in 2009 The fatality
rates per 100 M VMT on the other hand varied from a high of 245 for 2007
to a low of 201 for 2009 The corresponding US fatality rates varied from
136 to 114 Is the higher number for the fatality rate for Montana compared
to USA good or bad Likewise fatality rate per 100000 of population was
much higher for Montana than the US as a whole
This again highlights the pitfalls of using simple ratios to assess fatality statistics
without a full analysis of the underlying trends We will discuss this point
separately
As shown already the continuous decline in the fatality rate is a mathematical
artifact and essentially overlooks the unmistakable positive correlation
between the variables x and y of the type y = hx + c which becomes obvious
Page 29 of 45
only when we prepare the x-y scatter graph The ratio yx = h + (cx) can
decrease with increasing x (VMT) and increasing y (fatalities) since the
intercept c has a positive value when we consider only data spanning a short
period (such as 1994-2009 of more relevance to the current situation)
The debate between fatality rates and absolute number of fatalities is an
unending one A few years ago the Wall Street Journal carried an article
which was entitled (or something close) ―Unemployments rate in Ohio are
going down but why is the number of unemployed increasing The reason is
the same The graph of the number of unemployed (y) versus the number in
the labor market (x) is linear with a positive slope h and a positive intercept c
So the unemployment rate computed using the ratio yx keeps going down
year after year although the number unemployed keeps increasing Is it a
good thing that the unemployment rate is going down when more people
seem to be unable to find gainful unemployment
Or consider the situation with cancer death rates This too has been going
down in recent years but the actual number of cancer-related deaths has not
declined in any significant way Is it good that cancer death rates are going
down In all these situations the researchers or the socio-econo-politico
analysts involved in analyzing the trends in the data have failed to consider
the underlying x-y relation describing each problem
Hence it appears that the debate on the effect of increased speed limits
should not be focused on only the fatality rates (which have been decreasing
and proponents of higher speed limits cite this in their arguments) or even the
absolute number of fatalities (which has been the focus here) but on the
relationship between speed and the number of fatal crashes and the number
of fatalities within each speed segment (see Table 3 and also Figure 4)
Unfortunately details of number of fatalities and the number of fatal crashes
at each speed limit are not available even from NHTSA for detailed study
When a crash does occur (it is immaterial how many miles were driven) the
speed of the driver and vehicle design and engineering including safety
devices in place (seat belts airbags other impact absorbing technologies)
Page 30 of 45
determine if the occupants(s) will be killed One cannot argue that speed
does NOT kill That would be an absolute denial of the laws of physics
Studies show that setting the speed limit at the 85th percentile in any given
zone (this is the speed at or below which 85 of drivers are observed to
travel in traffic engineering studies) is the safest speed limit The majority of
drivers try to obey the posted speed limit while a few choose to drive at a
speed they consider is safe and prudent These are also perhaps the most
vociferous advocates of higher speed limits It is this tension caused due to
differences in speeds that leads to tailgating improper passing reckless
driving weaving from lane to lane and ultimately crashes and deaths in some
unfortunate cases
httpblogmotoristsorgspeed-limits-slower-safer
MARK TAYLOR
ANOTHER LOST A man was killed when his 4WD drive hit a tree east of Morrinsville (in New
Zealand) on Monday May 30 2011 The driver lost control of the vehicle on a bend probably tried
to correct his mistake and put the car into a ―yaw causing it to leave the road and smash sideways
into a tree Alerts to slow down had been posted since this was a high accident area but the driver
probably did not pay attention
64 Other factors
Many other factors besides speed no doubt affect highway fatalities The
vehicles of the 21st century are very different from the vehicles of the mid 20th
Page 31 of 45
century Technological innovations such as improvements in vehicle design
and engineering have greatly increased crash worthiness of vehicles even at
high speeds Environmental factors such as the weather also contribute to
accidents but not necessarily to increased fatalities Drivers actually tend to
slow down instinctively during adverse weather conditions (rain snow storms
etc) and although such weather may contribute to increased accidents the
lower speeds actually reduce fatalities
Yes technology has changed fundamentally from 1966 Drivers today are
more distracted by their cellmobile phone conversations (and also built-in
phones in luxury models) and text messaging than the drivers of the pre-1966
era High end cars now have many multimedia and internet features Again a
careful observation (even personal experience by the author) suggests that
such distracted drivers actually tend to (instinctively) drive more slowly and
hold up the traffic Perhaps such behavior leads to an increase in the number
of accidents but it does not necessarily lead to an increase in the number of
accident-related fatalities
Much talked about technological innovations such as automatic collision
avoidance systems and sensors (on the sides of vehicles) can indeed detect
vehicles in the front and neighboring lanes Furthermore vehicle-to-vehicle
communication systems vehicle-to-infrastructure communication systems
can no doubt avoid collisions and accidents Again such collision avoidance
systems work and are effective entirely because they automatically reduce
vehicle speeds - even if one of the offending vehicles is being at a super
high speed Also it must be remembered that such futuristic systems have
not yet been implemented widely nor can they be implemented widely since
the large majority of vehicles on the road are NOT luxury models Advanced
safety features come with a price and not all drivers can afford to pay that
price and ―buy that ―additional safety
Ultimately it is the laws of physics that govern what will happen when two or
more vehicles collide or even when a single vehicle collides with a stationary
infrastructural object (a bridge a wall a building or some impediment on the
road) The lower the number of crashes the lower the number of fatalities as
revealed by the 1994-2009 data graphed in Figure 5 The higher the speed of
Page 32 of 45
the object or objects that are involved in a collision the higher the kinetic
energy K that must be absorbed andor dissipated Increasing the posted
speed limit only increases the energy that must be absorbed when a crash
does occur This ultimately is the most important criterion determining the
number of fatalities
The kinetic energy increases as the square of the speed being given by the
well-known formula K = frac12 mv2 where m is the mass of the vehicle (in
laypersonlsquos language m increases directly with vehicle weight) and v is the
speed For the same vehicle mass an increase in the speed from 55 mph to
85 mph increases the kinetic energy K by a factor of 239 or roughly a 250
increase in the kinetic energy that must be absorbed in a collision
Ideally speaking the kinetic energy of the colliding object(s) is absorbed by
the vehicle infrastructure (a sturdy space frame the engine other vehicle
components etc) andor the surroundings However in the unfortunate
cases where this kinetic energy must be absorbed by the vehicle occupant(s)
the result is severe life-altering injuries andor death An unequivocal
relationship between an increase in vehicle speeds and fatal accidents can
be demonstrated by a careful examination of available traffic fatality data
This is a more involved discussion and is not the purpose of this short
communication These topics are no doubt very politically charged with many
social legal and financial implications with each interest group favoring a
different conclusion Nonetheless we cannot escape the laws of physics as
they govern the fundamental need to absorb higher and higher values of the
kinetic energy K with increasing vehicle speeds This same point is also
emphasized by Dr Friedman of the University of Illinois Chicago (see earlier
discussion)
Speed kills because of these energy transfer considerations and there can be
no doubt about it
Innovative 21st century solutions to speed management on the highways
such as strict enforcement of speed limits minimizing speed dispersion
(difference between speeds at which different drivers travel) while using
cameras to track the 15 of drivers who willfully violate the speed limit and
Page 33 of 45
create hazardous driving conditions is certainly recommended (Recall that
the optimum recommended speed limit is at or below which 85 of all drivers
travel ndash a policy also supported by NMA) Even on this score however the
results are confounding if we consider the Australian experience
httpwwwthenewspapercomnews282840asp
Up until 2007 there was no speed limit in the Northern Territory of
Australia Imposing a speed limit 130 kmph (80 mph) on some areas and
110 kmph (68 mph) in some others actually increased the number of deaths
The death toll in 2006 when there was no speed limit in this region was 44
and went up to 75 in 2009 see data table in link below
httpwwwthenewspapercomrlcdocs2009au-ntroadtollpdf
Furthermore it appears that installation of cameras to enforce speed limits
has proved to be a hazardous distraction to drivers and deaths actually
began to skyrocket between 2005 and 2007 in all Australian roadways
The main purpose here is to sound a cautionary note amid renewed attempts
in many states across the US to increase the speed limits on our highways by
calling attention to the historical facts regarding the ―epidemic levels of
highway traffic fatalities that engaged our national attention in the fateful year
of 1966 The graphical representation of the traffic fatality data in Figures 1
to 5 tells its own story
Indeed it would be tragic if highway-accident-related fatalities were to start
increasing once again and reach the historically high level that was last seen
in 1972 the year before the Arab oil embargo of 1973
Page 34 of 45
Conclusions
1 The graphical representation of the highway fatality data and the brief
summary of the historical facts of traffic safety legislation suggest that
recent attempts to increase the speed limits by various states (notably
Texas) may be misguided The distinct peak in the highway fatalities
observed in these graphs is highly alarming This appears to be related to
the enactment of the National Maximum Speed Limit (NSML) in 1974
following the 1973 Arab oil embargo Although NSML was motivated by a
desire to reduce gasoline consumption an unintended benefit might have
been a dramatic reduction in fatalities The fundamental reasons for the
peak in the fatalities-VMT curve must be examined carefully without
political posturing
2 The widely used fatality rate fatalities per 100 M vehicle miles traveled
has been declining since 1921 the first year for which a fatality rate could
be computed and has now reached a historical low The absolute number
of fatalities on the other hand was increasing in the 1950s and 1960s at
an alarming rate and the public outcry that ensued led to the highly
publicized Congressional hearing of 1966 and the subsequent traffic safety
legislations The fatality rate has been decreasing even in the most recent
15-year period (1994-2009) again with increasing fatalities although less
dramatically Thus it appears that fatality rate calculation based on vehicle
miles traveled (VMT) might not be a reliable indicator of the underlying
dynamics in the fatality trends
3 More detailed compilation of number of fatalities and the number of fatal
crashes within each speed limit segment is required to better understand
the effect of increasing speed limits on highway fatalities (and also fatality
rates) Such data is already available and is being compiled at the local
city and county levels in all jurisdictions and only needs to be reorganized
to highlight the effect of (posted) speed limits on the number of crashes
and fatalities This will require some minor rewriting and revisions to the
chapters named ―Crashes and ―States in the annual NHTSA reports
Page 35 of 45
Analysis of the fatalities-crashes data for several years with various
speed limits will be more revealing and meaningful than the current
fatality rates analysis and will be discussed separately in a follow up
report
4 One should not be lulled by the fact that vehicles of the 21st century are
now equipped with advanced safety features not available in the 1950s
and the 1960s In spite of these safety features the laws of physics dictate
that the higher the speed the higher kinetic energy of the colliding objects
and hence the greater the risk indeed near certainty of fatalities in a
higher speed collision compared to a lower speed one
5 The higher the speed at which the vehicle that is involved in a crash is
traveling the higher the kinetic energy that must be absorbed andor
dissipated without affecting the occupant(s) to avoid serious injuries andor
death This was true in the 1950s and the 1960s and will continue to be
true in the 21st century as well
Speed Kills for this just reason
6 It appears that higher fuel economies and reduced
highway fatalities were the twin societal benefits of 55
mph adopted after 1973 If so the current attempts to
increase the speed limits appear to be in conflict with
other important societal objectives
Page 36 of 45
Table 1 Annual US Street amp Highway
Fatalities from 1957
Year
Fatalities
Vehicle Miles
(millions)
Rate100M Vehicle Miles
1957 38702 646915 598
1958 36981 664915 556
1959 37910 700478 541
1960 38137 718845 531
1961 38091 737535 516
1962 40804 766852 532
1963 43564 805423 541
1964 47700 846500 563
1965 49163 887640 554
1966 51524 927915 555
1967 51559 965132 534
1968 53831 1019726 528
1969 55032 1066108 516
1970 53672 1114098 482
1971 53761 1183524 454
1972 55704 1264614 440
1973 55113 1316207 419
1974 46078 1282790 359
1975 45500 1330074 342
1976 45523 1402380 325
1977 47878 1467027 326
1978 50331 1544704 326
1979 51103 1529133 334
1980 51091 1527295 335
1981 49301 1552803 317
1982 43945 1595010 276
1983 42589 1652788 258
1984 44257 1720269 257
1985 43795 1774179 247
Page 37 of 45
1986 46056 1835000 251
1987 46385 1921000 241
1988 47093 2026000 232
1989 45555 2107040 216
1990 44529 2147501 207
1991 41162 2172214 189
1992 39235 2239828 175
1993 40115 2296585 175
1994 40676 2359984 172
1995 41798 2422696 173
1996 41907 2485848 169
1997 41967 2560373 164
Data from Federal Highway Administration
Source httpwwwpublicpurposecomhwy-fatal57+htm
Telephone +16186328507 - Facsimile +16186328538
WENDELL COX CONSULTANCY P O Box 841 - Belleville IL 62269 USA
Page 38 of 45
Fatality data for 1921-1982 compiled by NHTSA
Year
VMT
(Millions)
VMT
(Billions)
Fatalities
Fatality rate
per 100 M VMT
1921 55027 5503 13253 241 1922 67697 6770 14859 219 1923 84995 8500 17870 210 1924 104838 10484 18400 176 1925 122346 12235 20771 170 1926 140735 14074 22194 158 1927 158453 15845 24470 154 1928 172856 17286 26557 154 1929 197720 19772 29592 150 1930 206320 20632 31204 151 1931 216151 21615 31963 148 1932 200517 20052 27979 140 1933 200642 20064 29746 148 1934 215563 21556 34240 159 1935 228568 22857 34494 151 1936 252128 25213 36126 143 1937 270110 27011 37819 140 1938 271177 27118 31083 115 1939 285402 28540 30895 108 1940 302188 30219 32914 109 1941 333612 33361 38142 114 1942 268224 26822 27007 101 1943 208192 20819 22727 109 1944 212713 21271 23165 109 1945 250173 25017 26785 107 1946 340880 34088 31874 94 1947 370894 37089 31193 84 1948 397957 39796 30775 77 1949 424461 42446 30246 71 1950 458246 45825 33186 72 1951 491093 49109 35309 72
1952 513581 51358 36088 70
Page 39 of 45
1953 544433 54443 36190 66 1954 561963 56196 33890 60 1955 605646 60565 36688 61 1956 627843 62784 37965 60 1957 647004 64700 36932 57 1958 664653 66465 35331 53 1959 700480 70048 36223 52 1960 718762 71876 36399 51 1961 737421 73742 36285 49 1962 766734 76673 38980 51 1963 805249 80525 41723 52 1964 846298 84630 45645 54 1965 887812 88781 47089 53 1966 925899 92590 50894 55 1967 964005 96401 50724 53 1968 1015869 101587 52725 52 1969 1061791 106179 53543 50 1970 1109724 110972 52627 47 1971 1178811 117881 52542 45 1972 1259786 125979 54589 43 1973 1313110 131311 54052 41 1974 1280544 128054 45196 35 1975 1327664 132766 44525 34 1976 1402380 140238 45523 32 1977 1467027 146703 47878 33 1978 1544704 154470 50331 33 1979 1529133 152913 51093 33 1980 1527295 152730 51091 33 1981 1555308 155531 49301 32 1982 1595010 159501 43945 28
Source Analysis of Significant Decline in Motor Vehicle Traffic Fatalities in
2008 httpwww-nrdnhtsadotgovPubs811346pdf see Table A1 page 31
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Page 40 of 45
Acknowledgements
The author is grateful for thoughtful comments provided by friends and colleagues
with whom this document was shared via email prior to it being uploaded as a
publicly available document for wider dissemination and study The comments
offered by Prof Subra Ganesan of Oakland University Electrical and Computer
Engineering Department are reproduced with permission in their entirety
About the author
The author obtained his Masterrsquos (S M) and Doctoral (Sc D) degrees in Materials Engineering
from the Massachusetts Institute of Technology Cambridge USA He then spent his entire
professional career at leading US research institutions (MIT NASA Case Western Reserve
University and General Motors R amp D Center in Warren MI) He holds four patents in advanced
materials processing has co-authored two books and has published several scientific papers in
leading peer-reviewed international journals His expertise includes developing simple
mathematical models to explain the behavior of complex systems He can be reached by email at
vlaxmananhotmailcom
Page 41 of 45
Please Buckle Up
httpwwwlakecountypublichealthorgindexphpbuckle-up-montana
Public Awareness
Respect the Cage Exhibit
The Department of Transportation hopes that showing the reality of the crash will reduce traffic
fatalities A crushed car crash dummies and a sobering message ndash all part of the ―Respect The
Cage exhibit that is traveling across Montana The exhibit sponsored by the Montana Department
of Transportation stopped in Ronan on November 6th and is aimed at raising awareness about the
importance of wearing seat belts
The car in the exhibit was in an actual wreck many years ago
the passenger in the vehicle died because he was not wearing a
seat belt the driver who was wearing his seat belt survived
Montanarsquos likeliest crash fatality scenario
A Pickup
A Rural road
And Seat belts that
arenrsquot used
Page 42 of 45
Occupants of pickups are less likely to wear seat belts and pickups are more likely to
roll over than passenger cars
Seat belts reduce the risk of death by 60 percent in pickups and SUVs
In Montana from 2006-2008 81 of those killed in a crash while riding in a pickup were not wearing seat belts
In Montana pickups make up 401 of the vehicle population
For more information on Respect the Cage click here
Page 43 of 45
Appendix 1
Lack of seat belts leading cause of Louisiana highway deaths
1251 AM May 28 2011 |
Written by Adam Duvernay
Crashes involving unbuckled motorists were the leading cause of highway fatalities
in Louisiana last year and cost $9888 million according to recent reports The
Louisiana Highway Safety Commission reported 59 percent of vehicle occupants
killed in Louisiana crashes last year mdash about one in four mdash werent wearing seat
belts
httpwwwshreveporttimescomarticle20110528NEWS01105280354Lack-seat-
belts-leading-cause-La-highway-deathsodyssey=tab|topnews|text|FRONTPAGE
Crash bull Stats Published by NHTSAlsquos National Center for Statistics and Analysis 1200 New Jersey Avenue SE Washington DC 20590
DOT HS 811 451
Early Estimate of Motor Vehicle Traffic Fatalities in 2010
httpwww-nrdnhtsadotgovPubs811451pdf
Summary
A statistical projection of traffic fatalities in 2010 shows that an estimated 32788
people died in motor vehicle traffic crashes This represents a decline of about 3
percent as compared to the 33808 fatalities in 2009 as shown in Table 1 If these
projections are realized fatalities will be lowest on record (since 1949)
Traffic Safety Facts Overview 2009 Data
httpwww-nrdnhtsadotgovPubs811392pdf
In 2009 33808 people were killed in the estimated 5505000 police-reported
motor vehicle traffic crashes 2217000 people were injured and 3957000
crashes involved property damage only Compared to 2008 this is a 10-
percent decrease in the number of fatalities and a 5-percent decrease in the
Page 44 of 45
number of police-reported motor vehicle traffic crashes people injured and
crashes involving property damage
An average of 93 people died each day in motor vehicle crashes in 2009 mdash
an average of one every 16 minutes
Traffic Safety Facts Overview 2008 Data
httpwww-nrdnhtsadotgovPubs811162pdf
In 2008 37261 people were killed in the estimated 5811000 police-reported
motor vehicle traffic crashes 2346000 people were injured and 4146000
crashes involved property damage only
Some comments and Feedback
The following comments were received from Prof Ganesan after his review of the
first draft of this document It was subsequently revised thanks to this input to
address some of the very important issues raised here
Dear Laxman
The write up is not enough
You are emphasizing that the speed limit reduces the fatal accidents (comparing 1966
to 2000 accident numbers)
Can you also add a few sentences why the number is decreasing from 1980 to 2000
values (May be due to better design of vehicles)
Can you say anything about the fuel consumption with the speed for any typical
vehicle in 2011 or 2010 (do not consider the fatalities issue)
Probably a speed between 55 and 60 mph gives a better mileage If so this is a
compelling reason to keep the speed limit low But cars probably can be tuned to
give better mileage at any high speed also
Page 45 of 45
Weather is also a major factor in fatal accidents Speed limit may be kept low during
winter and kept higher in summer Give your comments on this too
Driver distractions can cause more accidents Now cars have many multimedia and
internet features Automatic collision avoidance systems and sensors on the sides can
detect vehicles in the front and neighboring lanes and it can automatically decrease
speed even if the driver speeds at super high speeds
Give some comments on this too There is also Vehicle to Vehicle communications
vehicle to infrastructure communications and they can avoid collisions and accidents
Technology has changed from 1966 I cannot agree with you on the speed limit
without any discussion on the above and other factors
Have a great day
Subra Ganesan
Professor Subramaniam Ganesan
Director Real Time amp DSP Lab
Electrical and Computer Engineering Department
2200 Squirrel Road Dodge Hall Room 105
Oakland University Rochester MI 48309 USA
Phone 248 370 2206 Fax 248 370 4633
wwwsecsoaklandedu~ganesan
IEEE Distinguished Visiting Speaker (2005-2009) Coordinator
IEEE SEM CS chapter Chair Region 4 and CS Society Board member
SAE ASEE ACM member
Page 4 of 45
1 Introduction
In traffic safety research we encounter two important dates or years 1966
and 1973 The main purpose here is to call attention to the historical facts
regarding the ―epidemic levels of highway traffic fatalities that engaged our
national attention in the fateful year of 1966
Does Speed Kill This is no doubt a politically charged topic with different
interest groups drawing their own conclusions and pulling in different
directions even when confronted with exactly the same facts Nonetheless
here is a humble attempt by a lone citizen to sound a cautionary note amid
the renewed attempts in many states across the US to increase the speed
limits on our highways
Page 5 of 45
The 1927 Durant Motor Star produced by William Durant the founder and the first
CEO of General Motors This car can be rented to tour San Diego for $50 to $70 per
hour plus $150 to $200 for the first half-hour httpeditorialautosmsncommost-
unusual-tourist-vehicles4
Also for the first time the Center for Disease Control (CDC) has recently
released the state-by-state societal costs of motor vehicle crashes Highway
fatalities cost $41 billion annually The CDC announcement coincides with the
kickoff of the United Nations Decade of Action an international effort aimed
at saving 5 million lives though 2020 by working cooperatively towards
greater road safety
httpwwwthecarconnectioncomnews1059966_cdc-highway-fatalities-cost-
41-billion-annually
Indeed it would be tragic if highway-accident-related fatalities were to start
increasing once again and reach the historically high level that was last seen
in 1972 the year before the Arab oil embargo of 1973 Statistical projections
of traffic fatalities show that in 2010 an estimated 32788 people died in motor
vehicle traffic crashes This is a 3 reduction over 2009 levels If these
Page 6 of 45
projections are realized highway traffic fatalities will be lowest on record
(since 1949)
The graphical representation of the traffic fatality data compiled annually by
the National Highway Traffic Safety Administration (NHTSA) as seen in
Figures 1 to 4 here tells its own story Indeed here a picture is certainly
worth a thousand words Let these graphs do the talking The detailed
captions attached with each figure permit an unbiased assessment of the
traffic fatality data and will hopefully lead to a repeal of the misguided
attempts to increase speed limits This also represents a simple and new
approach to analyzing the fatality data without excessive reliance on the
calculation of simple ratios such as the widely used fatality rate
As will become obvious the national speed limit of 55 mph instituted in
the historical year of 1973 yielded the twin benefits of improved fuel
economies and reduced traffic fatalities
The 1955 Cadilla available for tours of Memphis TN
httpeditorialautosmsncommost-unusual-tourist-vehicles2
Page 7 of 45
httpwwwugptiorgpubspdfDP188pdf
httpwwwlakecountypublichealthorgindexphpbuckle-up-montana
2 A brief review of historical traffic
fatality data compiled by NHTSA
The NHTSA uses the fatality rate as its single most important measure of
traffic safety The fatality rate is the ratio yx where x is the total vehicle miles
traveled (usually expressed in billions) by all US drivers and y is the absolute
number of highway fatalities To arrive at a simple tractable number the rate
is determined per 100 million vehicle miles traveled (acronym VMT)
Although this fatality rate yx has now reached a historical low in 2010
exclusive focus on this ratio while overlooking the underlying x-y trend might
be misleading as will become evident from the graphical representation of
the historical data being attempted here
Driver Behavior
Driver Drinking
Too Fast
Not Wearing
Seat Belts
Montanarsquos Likeliest
Fatal Crash Scenario
A Pick up
A Rural road
And Seat belts not
used
Page 8 of 45
Figure 1 Graph of the absolute number of US highway fatalities since 1957 The raw
data used to prepare this graph may be found in Table 1(relegated to the end of this
document) The absolute number of highway fatalities were quite low in the 1950s
and reached a peak in the late 1960s to early 1970s and have since decreased to
levels seen in the 1950s although the vehicle miles driven (in millions) has been
increasing from 646915 in 1957 to 2560373 in the year 2000 see also Figure 2
The fatality data from other government sources have also been studied by the author
and lead to the same conclusion of a peak in highway deaths around the late 1960s to
early 1970s
Page 9 of 45
Figure 2a Graphical representation of the absolute number of US highway fatalities
versus annual vehicle miles driven (in trillions) The number of miles driven by US
drivers has increased each year since 1957 as seen in Table 1 The absolute number
of highway fatalities has increased as well reaching a peak in the late 1960s to early
1970s The same peak is also seen here in the graph of the absolute number of
highway fatalities versus vehicle miles driven Improvements in vehicle safety devices
(notably seat belts and airbags) coupled with the institution of the national highway
speed limits (starting mid 1970s) and also improved highways are the primary
reasons for the decrease in fatalities These historical trends suggest that renewed
attempts to increase the speed limits on our highways would be counterproductive
and may eventually lead once again to an increase in fatalities with tragic
Page 10 of 45
consequences
Figure 2b Graphical representation of the US highway fatality data for the period
1921-1982 The first year for which a fatality rate yx could be computed is 1921 The
number of fatalities was 13253 and VMT was 5503 billion yielding a fatality rate of
2408 per 100 million VMT The fatality rate for any year is the slope of the ray ie
the straight line joining the (x y) data point back to the origin (00) of this graph see
dashed line for 1921 superimposed on to the graph The fatality rates (slopes of such
rays) had been declining quite consistently although the absolute number of fatalities
increased as seen here ultimately leading to the Congressional hearing in 1966 Is
VMT the single most important reason for the increasing fatalities
Page 11 of 45
Figure 3 Graphical representation of the traffic fatality data for the 15 year period
1994-2009 A sudden precipitous drop in the absolute number of fatalities (at least on
the magnified scale used here) and hence the fatality rate has been observed over
the three-year period 2007-2009 However it should be noted that the x-y scatter
graph here shows a general upward trend with fatalities actually increasing with
increasing VMT (as in the earlier era 1950s and 1960s) during the 12-year period
spanning 1994-2006 although the rate yx shows a misleading downward trend Why
is the rate yx going down
The reason is very simple and it may be just a mathematical artifact The equation of
the best-fit straight line through the most recent data points is of the form y = hx + c
= 2865 x + 34420 where h is the slope of the line and c the intercept (Note that x
here is VMT in billions The numerical value determined using this equation must be
divided by 10 to get the rate per 100 M VMT) Hence the fatality rate given by the
ratio yx = h + (cx) = 2865 + 34420x can actually decrease with increasing
values of x because of the nonzero intercept c Unlike the ray through the origin the
best-fit line does not pass through the origin (00) If we consider only the most
Page 12 of 45
recent data the intercept c is positive and fatality rates yx decrease with increasing
VMT and increasing fatalities In the earlier era both the slope h and intercept c had
very different values due to several factors being discussed here (speed limits
technology highway design etc)
Table 2 Traffic fatality data for the recent 15-year period
1994-2009 (Source NHTSA)
Year
Highway
fatalities y
Vehicle miles
traveled
VMT
(billions) x
Fatality rate
yx per 100
million VMT
Fatal crashes
1994 40716 2358 173 36254 1995 41817 2423 173 37241 1996 42065 2486 169 37494 1997 42013 2562 164 37324 1998 41501 2632 158 37107 1999 41717 2691 155 37140 2000 41945 2747 153 37526 2001 42196 2797 151 37862 2002 43005 2856 151 38491 2003 42884 2890 148 38477 2004 42836 2965 144 38444 2005 43510 2989 146 39252 2006 42708 3014 1 42 38648 2007 41259 3032 136 37435 2008 37423 2974 126 34172 2009 33808 2979 113 30797
Page 13 of 45
Figure 4 The most significant metric used by NHTSA is the fatality rate per 100
million vehicles miles traveled (VMT) This is now at a historical low of 113 for
2009 having declined year after year from 173 in 1994 The NHTSA however also
compiles other types of data on crashes There are three types of crashes fatal
injury but no death and property damage only A careful review of this crash data
for the period 1994-2009 reveals the obvious the lower the number of (fatal)
crashes x the lower the number of highway-accident-related fatalities y It is also
obvious that the number of fatalities per crash is greater than one ie more than one
person is being killed when one of more vehicles experience a crash
Clearly this is the single most important piece of information that one needs to
reduce the number of fatalities on our highways Vehicle design and engineering as
well as all other policy matters (legal political social environmental financial)
must be guided by this simple graph The best-fit line through the data derived using
simple linear regression has the equation y = hx + c = 114x ndash 10266 and is
Page 14 of 45
superimposed on to the data The design engineering goal and societal goal should
be to reduce the slope h of this statistically significant best-fit line to its ideal value of
h = 1 A fatal crash by definition is one where at least one person dies either an
occupant or a non-motorist in the path of the vehicle Hence the ideal slope h = 1
Photograph of an accident scene from the period 1955-1965
httpwwwcorinthsocialhistoryprojectorghtmlhighwaytollshtml
3 A Brief History of Traffic Safety Legislation
The following is extracted from the Wikipedia article on National Highway
Traffic Safety Administration (NHTSA)
httpenwikipediaorgwikiNational_Highway_Traffic_Safety_Administration
In 1965 and 1966 public pressure grew in the US to increase the safety of
cars The number of deaths on US highways were increasing year after year
Page 15 of 45
see Figure 1 and in 1966 Congress held a series of highly publicized
hearings on highway safety This led to the legislation for mandatory
installation of seat belts which also created the US Department of
Transportation (on Oct 15 1966)
httpwwwemsgovpdf2011EMSWeek2011_Stricklandpdf
The following is extracted from a Washington Post article on
NHTSA dated April 2 2002
httpwwwwashingtonpostcomwp-srvbusinessincludesnhtsa_primerhtm
In 1966 after decades of rising traffic fatalities (also vividly illustrated in
Figures 1 and 2 here) the publication of Ralph Naders Unsafe at Any
Speed and increasing public outcry for safer automobiles Congress held a
series of highly publicized hearings on creating a regulatory agency for traffic
safety Among the witnesses was William Haddon an epidemiologist who
introduced the idea that traffic accidents could be analyzed scientifically and
injuries reduced by changing auto design such as installing collapsible
steering columns safety glass head rests and seat belts
Congress passed the Highway Safety Act of 1966 creating the National
Highway Safety Bureau with Haddon as its first administrator The bureau
became NHTSA in 1970 under the newly established Department of
Transportation An early Nader convert Joan Claybrook headed NHTSA
under President Carter and now runs Naders organization Public Citizen
National Traffic and Motor Vehicle Safety Act
httpwwwanswerscomtopicnational-traffic-and-motor-vehicle-safety-act
Signed into law by President Lyndon Johnson on September 9 1966 this act
created the first mandatory federal safety standards for motor vehicles The
act was motivated by a variety of factors First and foremost the public was
growing increasingly concerned over the rising number of traffic fatalities on
the nations roads Such fatalities had increased by nearly 30 percent
between 1960 and 1965 and experts forecasted 100000 such deaths
Page 16 of 45
annually by 1975 unless something was done to improve traffic safety
Adding fuel to the fire Ralph Naders Unsafe at Any Speed published in
November 1965 criticized the automobile industry for neglecting safety in
favor of power and styling when designing new vehicles
4 The reason for the historical
decrease in highway fatalities
A recent news item see link given below regarding renewed attempts to
increase the speed limit by many states prompted this write up by the
present author who has studied traffic fatality data extensively and analyzed
them very carefully over the last several years
httpmoneymsncomauto-insurancewhy-speed-limits-are-
risingaspxGT1=33033
Residents of Metro Detroit area who frequently cross into Ohio from
Michigan notice that the speed limit has now increased in Ohio The speed
limit on Michigan highways was increased to 70 mph in the late 1990s but
Ohio retained its lower speed limit for many years leading Michigan drivers to
experience a ―speed trap of sorts The speed limit is also increasing in many
other states notably Texas where it is proposed to increase it to 85 mph at
least in West Texas
Historically speaking from a traffic fatality standpoint we must consider two
important dates 1966 and 1973 Only 1973 the year of the Arab oil embargo
following the Arab-Israeli war (that led to what President Obama has recently
called the pre-1967 border for Middle East peace) is mentioned in the above
article It fails to mention the significance of the year 1966
Prior to 1966 there was actually NO speed limit in many Western states and
deaths due to highway accidents were increasing year after year The
Page 17 of 45
number of highway fatalities went up from 38702 in 1957 to 51524 in 1965
a 33 increase over the 1957 level and an additional 12822 deaths in 1965
compared to 1957 It was this carnage on the US highways that forced
Congress to hold its hearings on highway traffic fatalities in 1966
Nonetheless a careful examination of the fatality data in Table 1 shows that
notwithstanding the highly publicized Congressional hearings of 1966 and
new safety legislation that was enacted the absolute number of fatalities
continued to increase after 1966 and only started decreasing after 1973
Vehicle designs especially the introduction of safety features (even the
simplest like safety belts) did not change significantly between 1966 and
1973 Nonetheless post-1973 we begin to see a dramatic turnaround
Why
After the 1973 Arab oil embargo a nationwide maximum speed limit (NMSL)
of 55 mph was imposed and accepted in the USA (effective Jan 1 1974)
during the Nixon administration primarily as an effort to conserve fuel and
reduce the US vulnerability to oil imports The unintended and indeed
fortunate consequence of this reduced speed limit was the immediate
reduction in the fatalities revealed in Figures 2 and 3 This is the real reason
for the peaks in highway fatalities observed in these two graphs
The Congressional hearings of 1966 did eventually have an impact but it was
a delayed one The impact of the 1973 nationwide speed limit of 55 mph was
however immediate as we see from the magnified plot of the same data in
Figure 5 and a closer examination of the raw fatality data in Table 1
The number of highway-accident-related fatalities decreased immediately
from a high of 55704 in 1972 to just 46078 in 1974 a 173 drop see
arrows There were 9626 fewer deaths annually even with a slight increase
in the vehicle miles driven (see Table 1) Indeed the number of highway
death reached its absolute peak value in 1972 never to be seen again
Fatalities have been decreasing every since with slight fluctuations about
each new low value
Page 18 of 45
Figure 5 Expanded view of the fatality data showing the immediate impact of the
national speed limit of 55 mph following the Arab oil embargo of 1973 Note that
fatalities continued to rise between 1966 and 1973 in spite of the highly publicized
Congressional hearings in 1966 and the traffic safety legislation enacted soon after
Each new low is probably associated with vehicle safety innovations and the
improvements in vehicle design and engineering The combined beneficial
effect of improved vehicle designs primarily the introduction of seat belts
and the laws enforcing usage of seat belts aided by the reduced speed
limits contributed to the continued decline in the absolute number of fatalities
that started since 1973 and has continued to this day The subsequent
introduction of other safety features notably air bags has contributed to a
further reduction in highway fatalities
Page 19 of 45
State police Trooper First Class Jeffrey Flowers looking at a car in which a Boswell
Pennsylvania woman was injured Tuesday (May 31 2011) The accident occurred at
an intersection when a truck (seen behind the wrecked car) entered this accident
prone intersection (part of a highway safety corridor where signs are posted to
reduce unsafe driver behavior) There have been four accidents at this intersection
since 2006 none fatal httpwwwdailyamericancomnewssomersetda-ot-woman-
injured-in-route-30-wreck-2011053104165420story
5 Numerical calculations of decline in
fatalities and the impact of NMSL post-1973
Letlsquos consider the decline in fatalities between 1972 the last year before the
adoption of the NMSL and 1974 the first year following its adoption after the
Arab oil embargo There was an immediate decrease in the number of
fatalities by 9393 ie y = -9393 with a slight increase in the VMT ie x
= 20758 millions The NHTSA data used here may be found in the table at
the end of this document The numerical value of the rate of change per
billion VMT (ie neglecting the sign) was therefore
yx = 4525 fatalitiesbillion VMT (1972-1974)
Page 20 of 45
It is instructive to compare this rate of change in fatalities with similar short
periods of a decline in fatalities in the pre-1973 era when speed limits were
much higher The absolute number of fatalities declined over a relatively
short period with both an increase and a decrease in VMT The results are
given below and are self-explanatory
yx = 454 fatalitiesbillion VMT (1953-54) decline with increase in VMT
yx = 655 fatalitiesbillion VMT (1942-43) decline with decrease in VMT
yx = 1739 fatalitiesbillion VMT (1941-42) decline with decrease in VMT
yx = 4528 fatalitiesbillion VMT (1937-39) decline with increase in VMT
yx = 2548 fatalitiesbillion VMT (1931-32) decline with decrease in VMT
The rate of decline observed between 1953 and 1954 with an increase in
VMT was just one-tenth of that observed following the adoption of the 55
mph speed limit The war years (1941-43 WWII) and the Great Depression
era (1931-32) were accompanied by big declines in fatalities with decreasing
VMT but the rate of change was still significantly lower than observed after
the adoption of the NMSL
The only apparently inexplicable decline is that between 1937 and 1939
where a nearly identical high rate of decline was observed Notice also the
big drop in the traditional fatality rate between 1937 and 1938 This large drop
appears to coincide with the creation of the National Safety Council (NSC) by
William H Cameron in June 1937 (see link below) with its far-flung campaign
of education legislation research highway engineering and traffic training
undertaken by the NSC and some two dozen other groups with the backing of the
automotive industry through its Automotive Safety Foundation Other factors
unknown to the present author probably also played a role
httpwwwtimecomtimemagazinearticle0917188379700htmlixzz1O2G
7rnUg
Page 21 of 45
These simple computations here however reveal the significant effect of
reduced speed limits on highway fatalities much more so than other factors
6 Further Considerations Pros and Cons
The singular effect of increased speeds (or speeding) on highway fatalities
has been studied and demonstrated by a number of industry sources such
as the Insurance Institute for Highway Safety (IIHS) Consumers Union and
also by government researchers
httpwwwsmartmotoristcomtraffic-and-safety-guidelineexcessive-speed-is-
a-factor-in-one-third-of-all-fatal-crasheshtml
httpwwwconsumersunionorgotherspeedlimitsspeed031500a2htm
Speed ndash defined as exceeding the posted speed limit or driving too fast for
given conditions ndash is a factor in nearly one-third of all fatal crashes Besides
fatality in 1998 nearly 40000 people were critically injured in speed-related
crashes and nearly 72000 were moderately injured
The salutary and immediate beneficial effect of the nationwide 55 mph speed
limit has been noted by other researchers (see Susan Ferguson link below)
httpwwwnhtsagovpeopleinjuryenforcespeed_forum_presentationsfergu
sonpdf
After a partial repeal of this law in 1987 which granted states the authority to
increase speed limit (especially in rural interstates) a 1989 study showed a
15 increase in fatalities in rural interstates and a 5 increase in non-rural
interstates Unfortunately such studies often tend to be discounted by
advocates of increasing the speed limits as being produced by biased
industry sources
Similar conclusions were also presented by NHTSA in February 1998 in its
report to the Congress entitled ―Report to Congress The Effect of Increased
Speed Limits in the Post-NMSL Era see link given below Among its key
Page 22 of 45
findings is the following quoted in its entirety NMSL refers to the National
Maximum Speed Limit legislated after the Arab oil embargo of 1973
httpwww-nrdnhtsadotgovPubs808-637PDF
hellip Nevertheless it is important to note that data currently available from the
National Highway Traffic Safety Administrationrsquos (NHTSA) Fatality Analysis
Reporting System (FARS) shows that states that increased speed limits in 1996
experienced approximately 350 more Interstate fatalities than would have been
expected based on historical trends -- about 9 percent above expectations
Concurrently the Interstate fatalities experienced in states that did not increase speed
limits in 1996 was consistent with pre-1996 trends The estimated increase in
Interstate fatalities found in this study while smaller in magnitude compared to the
estimated change in fatalities found in 1987 following the increase of speed limits on
rural Interstates does follow the historical pattern of increases in fatalities being
associated with increases in posted speed limits
The annual crash reports compiled by NHTSA see Table 3 indicate that the
number of fatal crashes (and hence fatalities using the regression equation
developed in Figure 4) increase as the posted speed limits increase
Page 23 of 45
Table 3 Posted speed limits and number of crashes
Speed Limit Crashes (2008) Crashes (2009)
30 mph or less 3705 3277 35 or 40 mph 6115 5516 45 or 50 mph 6461 6074
55 mph 9794 8847 60 mph or higher 6908 6124
Total 34017 30797
Source httpwww-nrdnhtsadotgovPubs811402EEpdf
61 Studies cited in favor of lower speed limits
A detailed analysis of speeding related fatalities (see link below) by NHTSA
shows that a third of all crashes involve speeding ie at least one driver was
speeding
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Furthermore the above report which covers the period 1983-2002
indicates that immediately after the NMSL was completely abolished in
December 1995 the number of speeding related fatalities at speeds
above 65 mph increased from just 15 in 1995 to a 677 in 1996 (see Table
62 on page 43 of above report) It continued to increase in the years
since climbing to 930 in 2000
More detailed studies similar to that noted above by researchers at the
University of Illinois Chicago led by Lee S Friedman again lead to the
conclusion that higher speed limits lead to an increase in the number of
fatalities (see American Journal of Public Health online July 16 2009)
httphealthusnewscomhealth-newsmanaging-your-
healthcarearticles20090716deaths-injuries-increase-with-higher-speed-
limits
Page 24 of 45
httpwwwmedpagetodaycomPublicHealthPolicyPublicHealth15122
httpwwwamericaneercomspeed-limits
httpwwwactuarialoutpostcomactuarial_discussion_forumarchiveindexph
pt-171870html
For the study period 1995-2005 these researchers found that 12545 deaths
and 36582 injuries could be attributed to the increased speed limits The
benefits of reduced speed limits are stated quite eloquently by Dr Friedman
and are reproduced below (from above news article see link)
Reduced speed limits would save lives Friedman said They would also reduce
gas consumption cut emissions of air pollutants save valuable years of productivity
(lost due to injuries)and reduce the societal cost of motor vehicle crashes (due to
both fatal crashes and due to nonfatal and severe life-changing injuries) he added
Friedman and coworkers have also shown that increasing the speed limit led
to an immediate increase in the number of fatalities on Israeli roadways (see
link below)
httpinjurypreventionbmjcomcontent133156
The effect of speeding is very significant especially in rural areas resulting
in significantly higher fatalities Fatality rates are frequently double or triple
that in urban areas (see link below)
httpsafetyfhwadotgovspeedmgtdata_factsdocsspeeding_ruralpdf
As of Jan 1 2005 five Midwestern states had increased the speed limits to
above 65 mph (Illinois Iowa Kansas Minnesota Missouri Nebraska and
South Dakota) whereas three (Illinois Iowa and Wisconsin) had not All the
five states with increased speed limits showed a 7 to 13 increase in
fatalities The NHTSA study considered an eight year period before and after
the change in Dec 1995 (see Table 1 in link below) The collective experience
of the states that did NOT increase the speed limit was a 7 decline in
fatalities (see Table 2 of link below)
httpwwwiowadotgovmvdodsstats2006speedstudypdf
Page 25 of 45
Moreover Table 5 in the above study shows the effect of imposing the NMSL
of 55 mph in Iowa and its repeal in 1995 Considering a four-year average
before 1974 when the speed limit was 75 mph there were 35 fatal crashes
with 43 fatalities In the first four years after the 55 mph there were only 23
fatal crashes and 28 fatalities In the last four years before the repeal of 55
mph in 1995 there was a further decline to 14 fatal crashes with 17 fatalities
The Iowa fatality data will be discussed in more detail separately (in a later report)
since it provides the opportunity to assess the effect of a change in the speed limit
on the relationship between number of fatalities and fatal crashes (as seen in
Figure 4 for the US as a whole)
North of the US border Canadians seem to be citing the ―shocking increase
in highway fatalities in the US states where the speed limits were raised to
curb their own speed limits
httparchivesafety-councilorginfotrafficspeed-02html
httparchivesafety-councilorginfotrafficspeedhtml
Speed kills but speed also sells notes the second of the above news items
Manufacturers are producing more high performance cars (with higher horse
power to weight ratio) and ads feature enticing cars that race and swerve in
miraculous ways on empty roads These subliminal messages encourage
drivers especially young drivers to break the speed limit leading to the
absolute increase in highway fatalities (although the rate itself is going
down) The article emphasizes the need to enforce the speed limit on
Canadian highways and in cities where street racing is becoming a problem
62 Studies cited by opponents of lower speed limits
In fairness to quote the opponents on the other side of this debate Montana
reverted back to Reasonable and Prudent speed limits when the National
Maximum Speed Limit was repealed in 1995 and appears to have
experienced no significant increase in fatalities
Page 26 of 45
httpwwwhwysafetycomhwy_montanahtm
httpwwwmotoristsorgpressmontana-no-speed-limit-safety-paradox
httpwwwsouthbayriderscomforumsshowthreadphpt=81453amppage=1
Likewise studies in the state of Maryland showed no significant increase in
highway fatalities when the speed limit was increased from 55 mph to 75
mph The reason might simply be that drivers were already speeding much
more so when the speed limit was 55 mph than after the increase to 75 mph
In other words the fatalities data already reflects the effect of higher speeds
(not speed limits) on the number of fatalities
In Utah the experimental increase in the speed limit to 80 mph was
considered to be a success in terms of safety
httpautosaolcomarticleutah-speed-limit-tests
The UDOT Director noted that there was no increase in the number of
accidents on Interstate 15 But what happens in the event of an accident
when the speed limits are higher and drivers are driving at higher speeds and
two objects collide at this higher speed However no increase in the number
of accidents is not the same as no increase in fatalities due to the higher
speeds When accidents do occur do fatalities increase
Likewise in California when the speed limit went up from 55 mph to 65
mph in 1995 (after repeal of NMSL) fewer deaths were reported in 1998
compared to the peak year of 1979 or even 1987 Again the explanation
seems to be that motorists were already speeding when the limit was 55 mph
and that increasing the speed limit did not change driver behavior in any
significant way
httparticlessfgatecom1998-11-02news17735730_1_speed-limits-mph-
limit-death-rate
The National Motorists Association (NMA) a group which advocates higher
speed limits emphasizes the importance of considering fatality rates as
opposed to the raw fatalities The argument used is that fatality rates based
on the fatality per 100 million VMT is the legitimate way to look at the data
Page 27 of 45
This is a never ending debate Historically speaking fatality rates have been
going down ever since the compilation of traffic accidents data began Table
A1 in the appendix of a recent report by NHTSA (see link below) has highway
fatality rate data going back 1921
httpwww-nrdnhtsadotgovPubs811346pdf see appendix page 31
httpwwwmotoristsorgspeed-limitstruth
httpwwwmotoristsorgothercrash-data
httpwwwraisethespeedlimitorgmythshtml
httpwwwcatoorgpubspaspa346pdf
According to Stephen Moore of the Cato Institute (see last of the links above)
―All measures of highway safety show improvement not more deaths and
injuries since 1995 Despite the fact that 33 states raised their speed limits
immediately after the repeal of the mandatory federal speed limit the NHTSA
reported last October that the traffic death rate dropped to a record low level
in 1997lsquo Moreover the average fatality rate even fell in the states that raised
their speed limits
63 The Fatality rate Is it a reliable metric
In 1921 with fewer fatalities and fewer miles driven and the first year for
which the fatality rate could be computed the rate was 2408 It was down to
1479 in 1931 but the number of deaths had climbed to 31963 more than
double the 1921 absolute fatality number of 13253 It had dropped to 550 in
1966 the year of the highly publicized Congressional hearings but the
number of fatalities had climbed to 50984 in that fateful The Highway Safety
Act of 1966 ranks as one of the major acts of Congress and President
Johnson signed it saying that ―we have been tolerating a raging epidemic of
highway deathshellip see extract pasted below
httpwwwenotescommajor-acts-congresshighway-safety-act
Page 28 of 45
The act was motivated primarily by growing public concern over the rising number
of traffic fatalities in the United States Between 1960 and 1965 the annual number
of traffic fatalities increased by nearly thirty percent As President Lyndon B
Johnson stated at the signing of the act on September 9 1966 we have tolerated
a raging epidemic of highway death which has killed more of our youth than all
other diseases combined Through the Highway Safety Act we are going to find out
more about highway diseasemdashand we aim to cure it
Nonetheless highways fatalities continued to increase until the Arab oil
embargo of 1973 led to the NMSL of 55 mph all across the USA Do we just
ignore this undeniable historical record and focus only on the declining fatality
rate as the NMA and other proponents of higher speed limits seem to argue
(see links above)
The misleading nature of using fatality rates (per 100 M VMT) alone is also
obvious if one considers fatality data for individual states Take for example
the state of Montana which seems to have experienced no increase in
fatalities after repeal of NMSL
httpwww-nrdnhtsadotgovdepartmentsnrd-
30ncsaSTSI30_MT200930_MT_2009htm
For the period 2005-2009 the absolute number of fatalities for Montana
varied between a high of 277 in 2007 to a low of 229 in 2009 The fatality
rates per 100 M VMT on the other hand varied from a high of 245 for 2007
to a low of 201 for 2009 The corresponding US fatality rates varied from
136 to 114 Is the higher number for the fatality rate for Montana compared
to USA good or bad Likewise fatality rate per 100000 of population was
much higher for Montana than the US as a whole
This again highlights the pitfalls of using simple ratios to assess fatality statistics
without a full analysis of the underlying trends We will discuss this point
separately
As shown already the continuous decline in the fatality rate is a mathematical
artifact and essentially overlooks the unmistakable positive correlation
between the variables x and y of the type y = hx + c which becomes obvious
Page 29 of 45
only when we prepare the x-y scatter graph The ratio yx = h + (cx) can
decrease with increasing x (VMT) and increasing y (fatalities) since the
intercept c has a positive value when we consider only data spanning a short
period (such as 1994-2009 of more relevance to the current situation)
The debate between fatality rates and absolute number of fatalities is an
unending one A few years ago the Wall Street Journal carried an article
which was entitled (or something close) ―Unemployments rate in Ohio are
going down but why is the number of unemployed increasing The reason is
the same The graph of the number of unemployed (y) versus the number in
the labor market (x) is linear with a positive slope h and a positive intercept c
So the unemployment rate computed using the ratio yx keeps going down
year after year although the number unemployed keeps increasing Is it a
good thing that the unemployment rate is going down when more people
seem to be unable to find gainful unemployment
Or consider the situation with cancer death rates This too has been going
down in recent years but the actual number of cancer-related deaths has not
declined in any significant way Is it good that cancer death rates are going
down In all these situations the researchers or the socio-econo-politico
analysts involved in analyzing the trends in the data have failed to consider
the underlying x-y relation describing each problem
Hence it appears that the debate on the effect of increased speed limits
should not be focused on only the fatality rates (which have been decreasing
and proponents of higher speed limits cite this in their arguments) or even the
absolute number of fatalities (which has been the focus here) but on the
relationship between speed and the number of fatal crashes and the number
of fatalities within each speed segment (see Table 3 and also Figure 4)
Unfortunately details of number of fatalities and the number of fatal crashes
at each speed limit are not available even from NHTSA for detailed study
When a crash does occur (it is immaterial how many miles were driven) the
speed of the driver and vehicle design and engineering including safety
devices in place (seat belts airbags other impact absorbing technologies)
Page 30 of 45
determine if the occupants(s) will be killed One cannot argue that speed
does NOT kill That would be an absolute denial of the laws of physics
Studies show that setting the speed limit at the 85th percentile in any given
zone (this is the speed at or below which 85 of drivers are observed to
travel in traffic engineering studies) is the safest speed limit The majority of
drivers try to obey the posted speed limit while a few choose to drive at a
speed they consider is safe and prudent These are also perhaps the most
vociferous advocates of higher speed limits It is this tension caused due to
differences in speeds that leads to tailgating improper passing reckless
driving weaving from lane to lane and ultimately crashes and deaths in some
unfortunate cases
httpblogmotoristsorgspeed-limits-slower-safer
MARK TAYLOR
ANOTHER LOST A man was killed when his 4WD drive hit a tree east of Morrinsville (in New
Zealand) on Monday May 30 2011 The driver lost control of the vehicle on a bend probably tried
to correct his mistake and put the car into a ―yaw causing it to leave the road and smash sideways
into a tree Alerts to slow down had been posted since this was a high accident area but the driver
probably did not pay attention
64 Other factors
Many other factors besides speed no doubt affect highway fatalities The
vehicles of the 21st century are very different from the vehicles of the mid 20th
Page 31 of 45
century Technological innovations such as improvements in vehicle design
and engineering have greatly increased crash worthiness of vehicles even at
high speeds Environmental factors such as the weather also contribute to
accidents but not necessarily to increased fatalities Drivers actually tend to
slow down instinctively during adverse weather conditions (rain snow storms
etc) and although such weather may contribute to increased accidents the
lower speeds actually reduce fatalities
Yes technology has changed fundamentally from 1966 Drivers today are
more distracted by their cellmobile phone conversations (and also built-in
phones in luxury models) and text messaging than the drivers of the pre-1966
era High end cars now have many multimedia and internet features Again a
careful observation (even personal experience by the author) suggests that
such distracted drivers actually tend to (instinctively) drive more slowly and
hold up the traffic Perhaps such behavior leads to an increase in the number
of accidents but it does not necessarily lead to an increase in the number of
accident-related fatalities
Much talked about technological innovations such as automatic collision
avoidance systems and sensors (on the sides of vehicles) can indeed detect
vehicles in the front and neighboring lanes Furthermore vehicle-to-vehicle
communication systems vehicle-to-infrastructure communication systems
can no doubt avoid collisions and accidents Again such collision avoidance
systems work and are effective entirely because they automatically reduce
vehicle speeds - even if one of the offending vehicles is being at a super
high speed Also it must be remembered that such futuristic systems have
not yet been implemented widely nor can they be implemented widely since
the large majority of vehicles on the road are NOT luxury models Advanced
safety features come with a price and not all drivers can afford to pay that
price and ―buy that ―additional safety
Ultimately it is the laws of physics that govern what will happen when two or
more vehicles collide or even when a single vehicle collides with a stationary
infrastructural object (a bridge a wall a building or some impediment on the
road) The lower the number of crashes the lower the number of fatalities as
revealed by the 1994-2009 data graphed in Figure 5 The higher the speed of
Page 32 of 45
the object or objects that are involved in a collision the higher the kinetic
energy K that must be absorbed andor dissipated Increasing the posted
speed limit only increases the energy that must be absorbed when a crash
does occur This ultimately is the most important criterion determining the
number of fatalities
The kinetic energy increases as the square of the speed being given by the
well-known formula K = frac12 mv2 where m is the mass of the vehicle (in
laypersonlsquos language m increases directly with vehicle weight) and v is the
speed For the same vehicle mass an increase in the speed from 55 mph to
85 mph increases the kinetic energy K by a factor of 239 or roughly a 250
increase in the kinetic energy that must be absorbed in a collision
Ideally speaking the kinetic energy of the colliding object(s) is absorbed by
the vehicle infrastructure (a sturdy space frame the engine other vehicle
components etc) andor the surroundings However in the unfortunate
cases where this kinetic energy must be absorbed by the vehicle occupant(s)
the result is severe life-altering injuries andor death An unequivocal
relationship between an increase in vehicle speeds and fatal accidents can
be demonstrated by a careful examination of available traffic fatality data
This is a more involved discussion and is not the purpose of this short
communication These topics are no doubt very politically charged with many
social legal and financial implications with each interest group favoring a
different conclusion Nonetheless we cannot escape the laws of physics as
they govern the fundamental need to absorb higher and higher values of the
kinetic energy K with increasing vehicle speeds This same point is also
emphasized by Dr Friedman of the University of Illinois Chicago (see earlier
discussion)
Speed kills because of these energy transfer considerations and there can be
no doubt about it
Innovative 21st century solutions to speed management on the highways
such as strict enforcement of speed limits minimizing speed dispersion
(difference between speeds at which different drivers travel) while using
cameras to track the 15 of drivers who willfully violate the speed limit and
Page 33 of 45
create hazardous driving conditions is certainly recommended (Recall that
the optimum recommended speed limit is at or below which 85 of all drivers
travel ndash a policy also supported by NMA) Even on this score however the
results are confounding if we consider the Australian experience
httpwwwthenewspapercomnews282840asp
Up until 2007 there was no speed limit in the Northern Territory of
Australia Imposing a speed limit 130 kmph (80 mph) on some areas and
110 kmph (68 mph) in some others actually increased the number of deaths
The death toll in 2006 when there was no speed limit in this region was 44
and went up to 75 in 2009 see data table in link below
httpwwwthenewspapercomrlcdocs2009au-ntroadtollpdf
Furthermore it appears that installation of cameras to enforce speed limits
has proved to be a hazardous distraction to drivers and deaths actually
began to skyrocket between 2005 and 2007 in all Australian roadways
The main purpose here is to sound a cautionary note amid renewed attempts
in many states across the US to increase the speed limits on our highways by
calling attention to the historical facts regarding the ―epidemic levels of
highway traffic fatalities that engaged our national attention in the fateful year
of 1966 The graphical representation of the traffic fatality data in Figures 1
to 5 tells its own story
Indeed it would be tragic if highway-accident-related fatalities were to start
increasing once again and reach the historically high level that was last seen
in 1972 the year before the Arab oil embargo of 1973
Page 34 of 45
Conclusions
1 The graphical representation of the highway fatality data and the brief
summary of the historical facts of traffic safety legislation suggest that
recent attempts to increase the speed limits by various states (notably
Texas) may be misguided The distinct peak in the highway fatalities
observed in these graphs is highly alarming This appears to be related to
the enactment of the National Maximum Speed Limit (NSML) in 1974
following the 1973 Arab oil embargo Although NSML was motivated by a
desire to reduce gasoline consumption an unintended benefit might have
been a dramatic reduction in fatalities The fundamental reasons for the
peak in the fatalities-VMT curve must be examined carefully without
political posturing
2 The widely used fatality rate fatalities per 100 M vehicle miles traveled
has been declining since 1921 the first year for which a fatality rate could
be computed and has now reached a historical low The absolute number
of fatalities on the other hand was increasing in the 1950s and 1960s at
an alarming rate and the public outcry that ensued led to the highly
publicized Congressional hearing of 1966 and the subsequent traffic safety
legislations The fatality rate has been decreasing even in the most recent
15-year period (1994-2009) again with increasing fatalities although less
dramatically Thus it appears that fatality rate calculation based on vehicle
miles traveled (VMT) might not be a reliable indicator of the underlying
dynamics in the fatality trends
3 More detailed compilation of number of fatalities and the number of fatal
crashes within each speed limit segment is required to better understand
the effect of increasing speed limits on highway fatalities (and also fatality
rates) Such data is already available and is being compiled at the local
city and county levels in all jurisdictions and only needs to be reorganized
to highlight the effect of (posted) speed limits on the number of crashes
and fatalities This will require some minor rewriting and revisions to the
chapters named ―Crashes and ―States in the annual NHTSA reports
Page 35 of 45
Analysis of the fatalities-crashes data for several years with various
speed limits will be more revealing and meaningful than the current
fatality rates analysis and will be discussed separately in a follow up
report
4 One should not be lulled by the fact that vehicles of the 21st century are
now equipped with advanced safety features not available in the 1950s
and the 1960s In spite of these safety features the laws of physics dictate
that the higher the speed the higher kinetic energy of the colliding objects
and hence the greater the risk indeed near certainty of fatalities in a
higher speed collision compared to a lower speed one
5 The higher the speed at which the vehicle that is involved in a crash is
traveling the higher the kinetic energy that must be absorbed andor
dissipated without affecting the occupant(s) to avoid serious injuries andor
death This was true in the 1950s and the 1960s and will continue to be
true in the 21st century as well
Speed Kills for this just reason
6 It appears that higher fuel economies and reduced
highway fatalities were the twin societal benefits of 55
mph adopted after 1973 If so the current attempts to
increase the speed limits appear to be in conflict with
other important societal objectives
Page 36 of 45
Table 1 Annual US Street amp Highway
Fatalities from 1957
Year
Fatalities
Vehicle Miles
(millions)
Rate100M Vehicle Miles
1957 38702 646915 598
1958 36981 664915 556
1959 37910 700478 541
1960 38137 718845 531
1961 38091 737535 516
1962 40804 766852 532
1963 43564 805423 541
1964 47700 846500 563
1965 49163 887640 554
1966 51524 927915 555
1967 51559 965132 534
1968 53831 1019726 528
1969 55032 1066108 516
1970 53672 1114098 482
1971 53761 1183524 454
1972 55704 1264614 440
1973 55113 1316207 419
1974 46078 1282790 359
1975 45500 1330074 342
1976 45523 1402380 325
1977 47878 1467027 326
1978 50331 1544704 326
1979 51103 1529133 334
1980 51091 1527295 335
1981 49301 1552803 317
1982 43945 1595010 276
1983 42589 1652788 258
1984 44257 1720269 257
1985 43795 1774179 247
Page 37 of 45
1986 46056 1835000 251
1987 46385 1921000 241
1988 47093 2026000 232
1989 45555 2107040 216
1990 44529 2147501 207
1991 41162 2172214 189
1992 39235 2239828 175
1993 40115 2296585 175
1994 40676 2359984 172
1995 41798 2422696 173
1996 41907 2485848 169
1997 41967 2560373 164
Data from Federal Highway Administration
Source httpwwwpublicpurposecomhwy-fatal57+htm
Telephone +16186328507 - Facsimile +16186328538
WENDELL COX CONSULTANCY P O Box 841 - Belleville IL 62269 USA
Page 38 of 45
Fatality data for 1921-1982 compiled by NHTSA
Year
VMT
(Millions)
VMT
(Billions)
Fatalities
Fatality rate
per 100 M VMT
1921 55027 5503 13253 241 1922 67697 6770 14859 219 1923 84995 8500 17870 210 1924 104838 10484 18400 176 1925 122346 12235 20771 170 1926 140735 14074 22194 158 1927 158453 15845 24470 154 1928 172856 17286 26557 154 1929 197720 19772 29592 150 1930 206320 20632 31204 151 1931 216151 21615 31963 148 1932 200517 20052 27979 140 1933 200642 20064 29746 148 1934 215563 21556 34240 159 1935 228568 22857 34494 151 1936 252128 25213 36126 143 1937 270110 27011 37819 140 1938 271177 27118 31083 115 1939 285402 28540 30895 108 1940 302188 30219 32914 109 1941 333612 33361 38142 114 1942 268224 26822 27007 101 1943 208192 20819 22727 109 1944 212713 21271 23165 109 1945 250173 25017 26785 107 1946 340880 34088 31874 94 1947 370894 37089 31193 84 1948 397957 39796 30775 77 1949 424461 42446 30246 71 1950 458246 45825 33186 72 1951 491093 49109 35309 72
1952 513581 51358 36088 70
Page 39 of 45
1953 544433 54443 36190 66 1954 561963 56196 33890 60 1955 605646 60565 36688 61 1956 627843 62784 37965 60 1957 647004 64700 36932 57 1958 664653 66465 35331 53 1959 700480 70048 36223 52 1960 718762 71876 36399 51 1961 737421 73742 36285 49 1962 766734 76673 38980 51 1963 805249 80525 41723 52 1964 846298 84630 45645 54 1965 887812 88781 47089 53 1966 925899 92590 50894 55 1967 964005 96401 50724 53 1968 1015869 101587 52725 52 1969 1061791 106179 53543 50 1970 1109724 110972 52627 47 1971 1178811 117881 52542 45 1972 1259786 125979 54589 43 1973 1313110 131311 54052 41 1974 1280544 128054 45196 35 1975 1327664 132766 44525 34 1976 1402380 140238 45523 32 1977 1467027 146703 47878 33 1978 1544704 154470 50331 33 1979 1529133 152913 51093 33 1980 1527295 152730 51091 33 1981 1555308 155531 49301 32 1982 1595010 159501 43945 28
Source Analysis of Significant Decline in Motor Vehicle Traffic Fatalities in
2008 httpwww-nrdnhtsadotgovPubs811346pdf see Table A1 page 31
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Page 40 of 45
Acknowledgements
The author is grateful for thoughtful comments provided by friends and colleagues
with whom this document was shared via email prior to it being uploaded as a
publicly available document for wider dissemination and study The comments
offered by Prof Subra Ganesan of Oakland University Electrical and Computer
Engineering Department are reproduced with permission in their entirety
About the author
The author obtained his Masterrsquos (S M) and Doctoral (Sc D) degrees in Materials Engineering
from the Massachusetts Institute of Technology Cambridge USA He then spent his entire
professional career at leading US research institutions (MIT NASA Case Western Reserve
University and General Motors R amp D Center in Warren MI) He holds four patents in advanced
materials processing has co-authored two books and has published several scientific papers in
leading peer-reviewed international journals His expertise includes developing simple
mathematical models to explain the behavior of complex systems He can be reached by email at
vlaxmananhotmailcom
Page 41 of 45
Please Buckle Up
httpwwwlakecountypublichealthorgindexphpbuckle-up-montana
Public Awareness
Respect the Cage Exhibit
The Department of Transportation hopes that showing the reality of the crash will reduce traffic
fatalities A crushed car crash dummies and a sobering message ndash all part of the ―Respect The
Cage exhibit that is traveling across Montana The exhibit sponsored by the Montana Department
of Transportation stopped in Ronan on November 6th and is aimed at raising awareness about the
importance of wearing seat belts
The car in the exhibit was in an actual wreck many years ago
the passenger in the vehicle died because he was not wearing a
seat belt the driver who was wearing his seat belt survived
Montanarsquos likeliest crash fatality scenario
A Pickup
A Rural road
And Seat belts that
arenrsquot used
Page 42 of 45
Occupants of pickups are less likely to wear seat belts and pickups are more likely to
roll over than passenger cars
Seat belts reduce the risk of death by 60 percent in pickups and SUVs
In Montana from 2006-2008 81 of those killed in a crash while riding in a pickup were not wearing seat belts
In Montana pickups make up 401 of the vehicle population
For more information on Respect the Cage click here
Page 43 of 45
Appendix 1
Lack of seat belts leading cause of Louisiana highway deaths
1251 AM May 28 2011 |
Written by Adam Duvernay
Crashes involving unbuckled motorists were the leading cause of highway fatalities
in Louisiana last year and cost $9888 million according to recent reports The
Louisiana Highway Safety Commission reported 59 percent of vehicle occupants
killed in Louisiana crashes last year mdash about one in four mdash werent wearing seat
belts
httpwwwshreveporttimescomarticle20110528NEWS01105280354Lack-seat-
belts-leading-cause-La-highway-deathsodyssey=tab|topnews|text|FRONTPAGE
Crash bull Stats Published by NHTSAlsquos National Center for Statistics and Analysis 1200 New Jersey Avenue SE Washington DC 20590
DOT HS 811 451
Early Estimate of Motor Vehicle Traffic Fatalities in 2010
httpwww-nrdnhtsadotgovPubs811451pdf
Summary
A statistical projection of traffic fatalities in 2010 shows that an estimated 32788
people died in motor vehicle traffic crashes This represents a decline of about 3
percent as compared to the 33808 fatalities in 2009 as shown in Table 1 If these
projections are realized fatalities will be lowest on record (since 1949)
Traffic Safety Facts Overview 2009 Data
httpwww-nrdnhtsadotgovPubs811392pdf
In 2009 33808 people were killed in the estimated 5505000 police-reported
motor vehicle traffic crashes 2217000 people were injured and 3957000
crashes involved property damage only Compared to 2008 this is a 10-
percent decrease in the number of fatalities and a 5-percent decrease in the
Page 44 of 45
number of police-reported motor vehicle traffic crashes people injured and
crashes involving property damage
An average of 93 people died each day in motor vehicle crashes in 2009 mdash
an average of one every 16 minutes
Traffic Safety Facts Overview 2008 Data
httpwww-nrdnhtsadotgovPubs811162pdf
In 2008 37261 people were killed in the estimated 5811000 police-reported
motor vehicle traffic crashes 2346000 people were injured and 4146000
crashes involved property damage only
Some comments and Feedback
The following comments were received from Prof Ganesan after his review of the
first draft of this document It was subsequently revised thanks to this input to
address some of the very important issues raised here
Dear Laxman
The write up is not enough
You are emphasizing that the speed limit reduces the fatal accidents (comparing 1966
to 2000 accident numbers)
Can you also add a few sentences why the number is decreasing from 1980 to 2000
values (May be due to better design of vehicles)
Can you say anything about the fuel consumption with the speed for any typical
vehicle in 2011 or 2010 (do not consider the fatalities issue)
Probably a speed between 55 and 60 mph gives a better mileage If so this is a
compelling reason to keep the speed limit low But cars probably can be tuned to
give better mileage at any high speed also
Page 45 of 45
Weather is also a major factor in fatal accidents Speed limit may be kept low during
winter and kept higher in summer Give your comments on this too
Driver distractions can cause more accidents Now cars have many multimedia and
internet features Automatic collision avoidance systems and sensors on the sides can
detect vehicles in the front and neighboring lanes and it can automatically decrease
speed even if the driver speeds at super high speeds
Give some comments on this too There is also Vehicle to Vehicle communications
vehicle to infrastructure communications and they can avoid collisions and accidents
Technology has changed from 1966 I cannot agree with you on the speed limit
without any discussion on the above and other factors
Have a great day
Subra Ganesan
Professor Subramaniam Ganesan
Director Real Time amp DSP Lab
Electrical and Computer Engineering Department
2200 Squirrel Road Dodge Hall Room 105
Oakland University Rochester MI 48309 USA
Phone 248 370 2206 Fax 248 370 4633
wwwsecsoaklandedu~ganesan
IEEE Distinguished Visiting Speaker (2005-2009) Coordinator
IEEE SEM CS chapter Chair Region 4 and CS Society Board member
SAE ASEE ACM member
Page 5 of 45
The 1927 Durant Motor Star produced by William Durant the founder and the first
CEO of General Motors This car can be rented to tour San Diego for $50 to $70 per
hour plus $150 to $200 for the first half-hour httpeditorialautosmsncommost-
unusual-tourist-vehicles4
Also for the first time the Center for Disease Control (CDC) has recently
released the state-by-state societal costs of motor vehicle crashes Highway
fatalities cost $41 billion annually The CDC announcement coincides with the
kickoff of the United Nations Decade of Action an international effort aimed
at saving 5 million lives though 2020 by working cooperatively towards
greater road safety
httpwwwthecarconnectioncomnews1059966_cdc-highway-fatalities-cost-
41-billion-annually
Indeed it would be tragic if highway-accident-related fatalities were to start
increasing once again and reach the historically high level that was last seen
in 1972 the year before the Arab oil embargo of 1973 Statistical projections
of traffic fatalities show that in 2010 an estimated 32788 people died in motor
vehicle traffic crashes This is a 3 reduction over 2009 levels If these
Page 6 of 45
projections are realized highway traffic fatalities will be lowest on record
(since 1949)
The graphical representation of the traffic fatality data compiled annually by
the National Highway Traffic Safety Administration (NHTSA) as seen in
Figures 1 to 4 here tells its own story Indeed here a picture is certainly
worth a thousand words Let these graphs do the talking The detailed
captions attached with each figure permit an unbiased assessment of the
traffic fatality data and will hopefully lead to a repeal of the misguided
attempts to increase speed limits This also represents a simple and new
approach to analyzing the fatality data without excessive reliance on the
calculation of simple ratios such as the widely used fatality rate
As will become obvious the national speed limit of 55 mph instituted in
the historical year of 1973 yielded the twin benefits of improved fuel
economies and reduced traffic fatalities
The 1955 Cadilla available for tours of Memphis TN
httpeditorialautosmsncommost-unusual-tourist-vehicles2
Page 7 of 45
httpwwwugptiorgpubspdfDP188pdf
httpwwwlakecountypublichealthorgindexphpbuckle-up-montana
2 A brief review of historical traffic
fatality data compiled by NHTSA
The NHTSA uses the fatality rate as its single most important measure of
traffic safety The fatality rate is the ratio yx where x is the total vehicle miles
traveled (usually expressed in billions) by all US drivers and y is the absolute
number of highway fatalities To arrive at a simple tractable number the rate
is determined per 100 million vehicle miles traveled (acronym VMT)
Although this fatality rate yx has now reached a historical low in 2010
exclusive focus on this ratio while overlooking the underlying x-y trend might
be misleading as will become evident from the graphical representation of
the historical data being attempted here
Driver Behavior
Driver Drinking
Too Fast
Not Wearing
Seat Belts
Montanarsquos Likeliest
Fatal Crash Scenario
A Pick up
A Rural road
And Seat belts not
used
Page 8 of 45
Figure 1 Graph of the absolute number of US highway fatalities since 1957 The raw
data used to prepare this graph may be found in Table 1(relegated to the end of this
document) The absolute number of highway fatalities were quite low in the 1950s
and reached a peak in the late 1960s to early 1970s and have since decreased to
levels seen in the 1950s although the vehicle miles driven (in millions) has been
increasing from 646915 in 1957 to 2560373 in the year 2000 see also Figure 2
The fatality data from other government sources have also been studied by the author
and lead to the same conclusion of a peak in highway deaths around the late 1960s to
early 1970s
Page 9 of 45
Figure 2a Graphical representation of the absolute number of US highway fatalities
versus annual vehicle miles driven (in trillions) The number of miles driven by US
drivers has increased each year since 1957 as seen in Table 1 The absolute number
of highway fatalities has increased as well reaching a peak in the late 1960s to early
1970s The same peak is also seen here in the graph of the absolute number of
highway fatalities versus vehicle miles driven Improvements in vehicle safety devices
(notably seat belts and airbags) coupled with the institution of the national highway
speed limits (starting mid 1970s) and also improved highways are the primary
reasons for the decrease in fatalities These historical trends suggest that renewed
attempts to increase the speed limits on our highways would be counterproductive
and may eventually lead once again to an increase in fatalities with tragic
Page 10 of 45
consequences
Figure 2b Graphical representation of the US highway fatality data for the period
1921-1982 The first year for which a fatality rate yx could be computed is 1921 The
number of fatalities was 13253 and VMT was 5503 billion yielding a fatality rate of
2408 per 100 million VMT The fatality rate for any year is the slope of the ray ie
the straight line joining the (x y) data point back to the origin (00) of this graph see
dashed line for 1921 superimposed on to the graph The fatality rates (slopes of such
rays) had been declining quite consistently although the absolute number of fatalities
increased as seen here ultimately leading to the Congressional hearing in 1966 Is
VMT the single most important reason for the increasing fatalities
Page 11 of 45
Figure 3 Graphical representation of the traffic fatality data for the 15 year period
1994-2009 A sudden precipitous drop in the absolute number of fatalities (at least on
the magnified scale used here) and hence the fatality rate has been observed over
the three-year period 2007-2009 However it should be noted that the x-y scatter
graph here shows a general upward trend with fatalities actually increasing with
increasing VMT (as in the earlier era 1950s and 1960s) during the 12-year period
spanning 1994-2006 although the rate yx shows a misleading downward trend Why
is the rate yx going down
The reason is very simple and it may be just a mathematical artifact The equation of
the best-fit straight line through the most recent data points is of the form y = hx + c
= 2865 x + 34420 where h is the slope of the line and c the intercept (Note that x
here is VMT in billions The numerical value determined using this equation must be
divided by 10 to get the rate per 100 M VMT) Hence the fatality rate given by the
ratio yx = h + (cx) = 2865 + 34420x can actually decrease with increasing
values of x because of the nonzero intercept c Unlike the ray through the origin the
best-fit line does not pass through the origin (00) If we consider only the most
Page 12 of 45
recent data the intercept c is positive and fatality rates yx decrease with increasing
VMT and increasing fatalities In the earlier era both the slope h and intercept c had
very different values due to several factors being discussed here (speed limits
technology highway design etc)
Table 2 Traffic fatality data for the recent 15-year period
1994-2009 (Source NHTSA)
Year
Highway
fatalities y
Vehicle miles
traveled
VMT
(billions) x
Fatality rate
yx per 100
million VMT
Fatal crashes
1994 40716 2358 173 36254 1995 41817 2423 173 37241 1996 42065 2486 169 37494 1997 42013 2562 164 37324 1998 41501 2632 158 37107 1999 41717 2691 155 37140 2000 41945 2747 153 37526 2001 42196 2797 151 37862 2002 43005 2856 151 38491 2003 42884 2890 148 38477 2004 42836 2965 144 38444 2005 43510 2989 146 39252 2006 42708 3014 1 42 38648 2007 41259 3032 136 37435 2008 37423 2974 126 34172 2009 33808 2979 113 30797
Page 13 of 45
Figure 4 The most significant metric used by NHTSA is the fatality rate per 100
million vehicles miles traveled (VMT) This is now at a historical low of 113 for
2009 having declined year after year from 173 in 1994 The NHTSA however also
compiles other types of data on crashes There are three types of crashes fatal
injury but no death and property damage only A careful review of this crash data
for the period 1994-2009 reveals the obvious the lower the number of (fatal)
crashes x the lower the number of highway-accident-related fatalities y It is also
obvious that the number of fatalities per crash is greater than one ie more than one
person is being killed when one of more vehicles experience a crash
Clearly this is the single most important piece of information that one needs to
reduce the number of fatalities on our highways Vehicle design and engineering as
well as all other policy matters (legal political social environmental financial)
must be guided by this simple graph The best-fit line through the data derived using
simple linear regression has the equation y = hx + c = 114x ndash 10266 and is
Page 14 of 45
superimposed on to the data The design engineering goal and societal goal should
be to reduce the slope h of this statistically significant best-fit line to its ideal value of
h = 1 A fatal crash by definition is one where at least one person dies either an
occupant or a non-motorist in the path of the vehicle Hence the ideal slope h = 1
Photograph of an accident scene from the period 1955-1965
httpwwwcorinthsocialhistoryprojectorghtmlhighwaytollshtml
3 A Brief History of Traffic Safety Legislation
The following is extracted from the Wikipedia article on National Highway
Traffic Safety Administration (NHTSA)
httpenwikipediaorgwikiNational_Highway_Traffic_Safety_Administration
In 1965 and 1966 public pressure grew in the US to increase the safety of
cars The number of deaths on US highways were increasing year after year
Page 15 of 45
see Figure 1 and in 1966 Congress held a series of highly publicized
hearings on highway safety This led to the legislation for mandatory
installation of seat belts which also created the US Department of
Transportation (on Oct 15 1966)
httpwwwemsgovpdf2011EMSWeek2011_Stricklandpdf
The following is extracted from a Washington Post article on
NHTSA dated April 2 2002
httpwwwwashingtonpostcomwp-srvbusinessincludesnhtsa_primerhtm
In 1966 after decades of rising traffic fatalities (also vividly illustrated in
Figures 1 and 2 here) the publication of Ralph Naders Unsafe at Any
Speed and increasing public outcry for safer automobiles Congress held a
series of highly publicized hearings on creating a regulatory agency for traffic
safety Among the witnesses was William Haddon an epidemiologist who
introduced the idea that traffic accidents could be analyzed scientifically and
injuries reduced by changing auto design such as installing collapsible
steering columns safety glass head rests and seat belts
Congress passed the Highway Safety Act of 1966 creating the National
Highway Safety Bureau with Haddon as its first administrator The bureau
became NHTSA in 1970 under the newly established Department of
Transportation An early Nader convert Joan Claybrook headed NHTSA
under President Carter and now runs Naders organization Public Citizen
National Traffic and Motor Vehicle Safety Act
httpwwwanswerscomtopicnational-traffic-and-motor-vehicle-safety-act
Signed into law by President Lyndon Johnson on September 9 1966 this act
created the first mandatory federal safety standards for motor vehicles The
act was motivated by a variety of factors First and foremost the public was
growing increasingly concerned over the rising number of traffic fatalities on
the nations roads Such fatalities had increased by nearly 30 percent
between 1960 and 1965 and experts forecasted 100000 such deaths
Page 16 of 45
annually by 1975 unless something was done to improve traffic safety
Adding fuel to the fire Ralph Naders Unsafe at Any Speed published in
November 1965 criticized the automobile industry for neglecting safety in
favor of power and styling when designing new vehicles
4 The reason for the historical
decrease in highway fatalities
A recent news item see link given below regarding renewed attempts to
increase the speed limit by many states prompted this write up by the
present author who has studied traffic fatality data extensively and analyzed
them very carefully over the last several years
httpmoneymsncomauto-insurancewhy-speed-limits-are-
risingaspxGT1=33033
Residents of Metro Detroit area who frequently cross into Ohio from
Michigan notice that the speed limit has now increased in Ohio The speed
limit on Michigan highways was increased to 70 mph in the late 1990s but
Ohio retained its lower speed limit for many years leading Michigan drivers to
experience a ―speed trap of sorts The speed limit is also increasing in many
other states notably Texas where it is proposed to increase it to 85 mph at
least in West Texas
Historically speaking from a traffic fatality standpoint we must consider two
important dates 1966 and 1973 Only 1973 the year of the Arab oil embargo
following the Arab-Israeli war (that led to what President Obama has recently
called the pre-1967 border for Middle East peace) is mentioned in the above
article It fails to mention the significance of the year 1966
Prior to 1966 there was actually NO speed limit in many Western states and
deaths due to highway accidents were increasing year after year The
Page 17 of 45
number of highway fatalities went up from 38702 in 1957 to 51524 in 1965
a 33 increase over the 1957 level and an additional 12822 deaths in 1965
compared to 1957 It was this carnage on the US highways that forced
Congress to hold its hearings on highway traffic fatalities in 1966
Nonetheless a careful examination of the fatality data in Table 1 shows that
notwithstanding the highly publicized Congressional hearings of 1966 and
new safety legislation that was enacted the absolute number of fatalities
continued to increase after 1966 and only started decreasing after 1973
Vehicle designs especially the introduction of safety features (even the
simplest like safety belts) did not change significantly between 1966 and
1973 Nonetheless post-1973 we begin to see a dramatic turnaround
Why
After the 1973 Arab oil embargo a nationwide maximum speed limit (NMSL)
of 55 mph was imposed and accepted in the USA (effective Jan 1 1974)
during the Nixon administration primarily as an effort to conserve fuel and
reduce the US vulnerability to oil imports The unintended and indeed
fortunate consequence of this reduced speed limit was the immediate
reduction in the fatalities revealed in Figures 2 and 3 This is the real reason
for the peaks in highway fatalities observed in these two graphs
The Congressional hearings of 1966 did eventually have an impact but it was
a delayed one The impact of the 1973 nationwide speed limit of 55 mph was
however immediate as we see from the magnified plot of the same data in
Figure 5 and a closer examination of the raw fatality data in Table 1
The number of highway-accident-related fatalities decreased immediately
from a high of 55704 in 1972 to just 46078 in 1974 a 173 drop see
arrows There were 9626 fewer deaths annually even with a slight increase
in the vehicle miles driven (see Table 1) Indeed the number of highway
death reached its absolute peak value in 1972 never to be seen again
Fatalities have been decreasing every since with slight fluctuations about
each new low value
Page 18 of 45
Figure 5 Expanded view of the fatality data showing the immediate impact of the
national speed limit of 55 mph following the Arab oil embargo of 1973 Note that
fatalities continued to rise between 1966 and 1973 in spite of the highly publicized
Congressional hearings in 1966 and the traffic safety legislation enacted soon after
Each new low is probably associated with vehicle safety innovations and the
improvements in vehicle design and engineering The combined beneficial
effect of improved vehicle designs primarily the introduction of seat belts
and the laws enforcing usage of seat belts aided by the reduced speed
limits contributed to the continued decline in the absolute number of fatalities
that started since 1973 and has continued to this day The subsequent
introduction of other safety features notably air bags has contributed to a
further reduction in highway fatalities
Page 19 of 45
State police Trooper First Class Jeffrey Flowers looking at a car in which a Boswell
Pennsylvania woman was injured Tuesday (May 31 2011) The accident occurred at
an intersection when a truck (seen behind the wrecked car) entered this accident
prone intersection (part of a highway safety corridor where signs are posted to
reduce unsafe driver behavior) There have been four accidents at this intersection
since 2006 none fatal httpwwwdailyamericancomnewssomersetda-ot-woman-
injured-in-route-30-wreck-2011053104165420story
5 Numerical calculations of decline in
fatalities and the impact of NMSL post-1973
Letlsquos consider the decline in fatalities between 1972 the last year before the
adoption of the NMSL and 1974 the first year following its adoption after the
Arab oil embargo There was an immediate decrease in the number of
fatalities by 9393 ie y = -9393 with a slight increase in the VMT ie x
= 20758 millions The NHTSA data used here may be found in the table at
the end of this document The numerical value of the rate of change per
billion VMT (ie neglecting the sign) was therefore
yx = 4525 fatalitiesbillion VMT (1972-1974)
Page 20 of 45
It is instructive to compare this rate of change in fatalities with similar short
periods of a decline in fatalities in the pre-1973 era when speed limits were
much higher The absolute number of fatalities declined over a relatively
short period with both an increase and a decrease in VMT The results are
given below and are self-explanatory
yx = 454 fatalitiesbillion VMT (1953-54) decline with increase in VMT
yx = 655 fatalitiesbillion VMT (1942-43) decline with decrease in VMT
yx = 1739 fatalitiesbillion VMT (1941-42) decline with decrease in VMT
yx = 4528 fatalitiesbillion VMT (1937-39) decline with increase in VMT
yx = 2548 fatalitiesbillion VMT (1931-32) decline with decrease in VMT
The rate of decline observed between 1953 and 1954 with an increase in
VMT was just one-tenth of that observed following the adoption of the 55
mph speed limit The war years (1941-43 WWII) and the Great Depression
era (1931-32) were accompanied by big declines in fatalities with decreasing
VMT but the rate of change was still significantly lower than observed after
the adoption of the NMSL
The only apparently inexplicable decline is that between 1937 and 1939
where a nearly identical high rate of decline was observed Notice also the
big drop in the traditional fatality rate between 1937 and 1938 This large drop
appears to coincide with the creation of the National Safety Council (NSC) by
William H Cameron in June 1937 (see link below) with its far-flung campaign
of education legislation research highway engineering and traffic training
undertaken by the NSC and some two dozen other groups with the backing of the
automotive industry through its Automotive Safety Foundation Other factors
unknown to the present author probably also played a role
httpwwwtimecomtimemagazinearticle0917188379700htmlixzz1O2G
7rnUg
Page 21 of 45
These simple computations here however reveal the significant effect of
reduced speed limits on highway fatalities much more so than other factors
6 Further Considerations Pros and Cons
The singular effect of increased speeds (or speeding) on highway fatalities
has been studied and demonstrated by a number of industry sources such
as the Insurance Institute for Highway Safety (IIHS) Consumers Union and
also by government researchers
httpwwwsmartmotoristcomtraffic-and-safety-guidelineexcessive-speed-is-
a-factor-in-one-third-of-all-fatal-crasheshtml
httpwwwconsumersunionorgotherspeedlimitsspeed031500a2htm
Speed ndash defined as exceeding the posted speed limit or driving too fast for
given conditions ndash is a factor in nearly one-third of all fatal crashes Besides
fatality in 1998 nearly 40000 people were critically injured in speed-related
crashes and nearly 72000 were moderately injured
The salutary and immediate beneficial effect of the nationwide 55 mph speed
limit has been noted by other researchers (see Susan Ferguson link below)
httpwwwnhtsagovpeopleinjuryenforcespeed_forum_presentationsfergu
sonpdf
After a partial repeal of this law in 1987 which granted states the authority to
increase speed limit (especially in rural interstates) a 1989 study showed a
15 increase in fatalities in rural interstates and a 5 increase in non-rural
interstates Unfortunately such studies often tend to be discounted by
advocates of increasing the speed limits as being produced by biased
industry sources
Similar conclusions were also presented by NHTSA in February 1998 in its
report to the Congress entitled ―Report to Congress The Effect of Increased
Speed Limits in the Post-NMSL Era see link given below Among its key
Page 22 of 45
findings is the following quoted in its entirety NMSL refers to the National
Maximum Speed Limit legislated after the Arab oil embargo of 1973
httpwww-nrdnhtsadotgovPubs808-637PDF
hellip Nevertheless it is important to note that data currently available from the
National Highway Traffic Safety Administrationrsquos (NHTSA) Fatality Analysis
Reporting System (FARS) shows that states that increased speed limits in 1996
experienced approximately 350 more Interstate fatalities than would have been
expected based on historical trends -- about 9 percent above expectations
Concurrently the Interstate fatalities experienced in states that did not increase speed
limits in 1996 was consistent with pre-1996 trends The estimated increase in
Interstate fatalities found in this study while smaller in magnitude compared to the
estimated change in fatalities found in 1987 following the increase of speed limits on
rural Interstates does follow the historical pattern of increases in fatalities being
associated with increases in posted speed limits
The annual crash reports compiled by NHTSA see Table 3 indicate that the
number of fatal crashes (and hence fatalities using the regression equation
developed in Figure 4) increase as the posted speed limits increase
Page 23 of 45
Table 3 Posted speed limits and number of crashes
Speed Limit Crashes (2008) Crashes (2009)
30 mph or less 3705 3277 35 or 40 mph 6115 5516 45 or 50 mph 6461 6074
55 mph 9794 8847 60 mph or higher 6908 6124
Total 34017 30797
Source httpwww-nrdnhtsadotgovPubs811402EEpdf
61 Studies cited in favor of lower speed limits
A detailed analysis of speeding related fatalities (see link below) by NHTSA
shows that a third of all crashes involve speeding ie at least one driver was
speeding
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Furthermore the above report which covers the period 1983-2002
indicates that immediately after the NMSL was completely abolished in
December 1995 the number of speeding related fatalities at speeds
above 65 mph increased from just 15 in 1995 to a 677 in 1996 (see Table
62 on page 43 of above report) It continued to increase in the years
since climbing to 930 in 2000
More detailed studies similar to that noted above by researchers at the
University of Illinois Chicago led by Lee S Friedman again lead to the
conclusion that higher speed limits lead to an increase in the number of
fatalities (see American Journal of Public Health online July 16 2009)
httphealthusnewscomhealth-newsmanaging-your-
healthcarearticles20090716deaths-injuries-increase-with-higher-speed-
limits
Page 24 of 45
httpwwwmedpagetodaycomPublicHealthPolicyPublicHealth15122
httpwwwamericaneercomspeed-limits
httpwwwactuarialoutpostcomactuarial_discussion_forumarchiveindexph
pt-171870html
For the study period 1995-2005 these researchers found that 12545 deaths
and 36582 injuries could be attributed to the increased speed limits The
benefits of reduced speed limits are stated quite eloquently by Dr Friedman
and are reproduced below (from above news article see link)
Reduced speed limits would save lives Friedman said They would also reduce
gas consumption cut emissions of air pollutants save valuable years of productivity
(lost due to injuries)and reduce the societal cost of motor vehicle crashes (due to
both fatal crashes and due to nonfatal and severe life-changing injuries) he added
Friedman and coworkers have also shown that increasing the speed limit led
to an immediate increase in the number of fatalities on Israeli roadways (see
link below)
httpinjurypreventionbmjcomcontent133156
The effect of speeding is very significant especially in rural areas resulting
in significantly higher fatalities Fatality rates are frequently double or triple
that in urban areas (see link below)
httpsafetyfhwadotgovspeedmgtdata_factsdocsspeeding_ruralpdf
As of Jan 1 2005 five Midwestern states had increased the speed limits to
above 65 mph (Illinois Iowa Kansas Minnesota Missouri Nebraska and
South Dakota) whereas three (Illinois Iowa and Wisconsin) had not All the
five states with increased speed limits showed a 7 to 13 increase in
fatalities The NHTSA study considered an eight year period before and after
the change in Dec 1995 (see Table 1 in link below) The collective experience
of the states that did NOT increase the speed limit was a 7 decline in
fatalities (see Table 2 of link below)
httpwwwiowadotgovmvdodsstats2006speedstudypdf
Page 25 of 45
Moreover Table 5 in the above study shows the effect of imposing the NMSL
of 55 mph in Iowa and its repeal in 1995 Considering a four-year average
before 1974 when the speed limit was 75 mph there were 35 fatal crashes
with 43 fatalities In the first four years after the 55 mph there were only 23
fatal crashes and 28 fatalities In the last four years before the repeal of 55
mph in 1995 there was a further decline to 14 fatal crashes with 17 fatalities
The Iowa fatality data will be discussed in more detail separately (in a later report)
since it provides the opportunity to assess the effect of a change in the speed limit
on the relationship between number of fatalities and fatal crashes (as seen in
Figure 4 for the US as a whole)
North of the US border Canadians seem to be citing the ―shocking increase
in highway fatalities in the US states where the speed limits were raised to
curb their own speed limits
httparchivesafety-councilorginfotrafficspeed-02html
httparchivesafety-councilorginfotrafficspeedhtml
Speed kills but speed also sells notes the second of the above news items
Manufacturers are producing more high performance cars (with higher horse
power to weight ratio) and ads feature enticing cars that race and swerve in
miraculous ways on empty roads These subliminal messages encourage
drivers especially young drivers to break the speed limit leading to the
absolute increase in highway fatalities (although the rate itself is going
down) The article emphasizes the need to enforce the speed limit on
Canadian highways and in cities where street racing is becoming a problem
62 Studies cited by opponents of lower speed limits
In fairness to quote the opponents on the other side of this debate Montana
reverted back to Reasonable and Prudent speed limits when the National
Maximum Speed Limit was repealed in 1995 and appears to have
experienced no significant increase in fatalities
Page 26 of 45
httpwwwhwysafetycomhwy_montanahtm
httpwwwmotoristsorgpressmontana-no-speed-limit-safety-paradox
httpwwwsouthbayriderscomforumsshowthreadphpt=81453amppage=1
Likewise studies in the state of Maryland showed no significant increase in
highway fatalities when the speed limit was increased from 55 mph to 75
mph The reason might simply be that drivers were already speeding much
more so when the speed limit was 55 mph than after the increase to 75 mph
In other words the fatalities data already reflects the effect of higher speeds
(not speed limits) on the number of fatalities
In Utah the experimental increase in the speed limit to 80 mph was
considered to be a success in terms of safety
httpautosaolcomarticleutah-speed-limit-tests
The UDOT Director noted that there was no increase in the number of
accidents on Interstate 15 But what happens in the event of an accident
when the speed limits are higher and drivers are driving at higher speeds and
two objects collide at this higher speed However no increase in the number
of accidents is not the same as no increase in fatalities due to the higher
speeds When accidents do occur do fatalities increase
Likewise in California when the speed limit went up from 55 mph to 65
mph in 1995 (after repeal of NMSL) fewer deaths were reported in 1998
compared to the peak year of 1979 or even 1987 Again the explanation
seems to be that motorists were already speeding when the limit was 55 mph
and that increasing the speed limit did not change driver behavior in any
significant way
httparticlessfgatecom1998-11-02news17735730_1_speed-limits-mph-
limit-death-rate
The National Motorists Association (NMA) a group which advocates higher
speed limits emphasizes the importance of considering fatality rates as
opposed to the raw fatalities The argument used is that fatality rates based
on the fatality per 100 million VMT is the legitimate way to look at the data
Page 27 of 45
This is a never ending debate Historically speaking fatality rates have been
going down ever since the compilation of traffic accidents data began Table
A1 in the appendix of a recent report by NHTSA (see link below) has highway
fatality rate data going back 1921
httpwww-nrdnhtsadotgovPubs811346pdf see appendix page 31
httpwwwmotoristsorgspeed-limitstruth
httpwwwmotoristsorgothercrash-data
httpwwwraisethespeedlimitorgmythshtml
httpwwwcatoorgpubspaspa346pdf
According to Stephen Moore of the Cato Institute (see last of the links above)
―All measures of highway safety show improvement not more deaths and
injuries since 1995 Despite the fact that 33 states raised their speed limits
immediately after the repeal of the mandatory federal speed limit the NHTSA
reported last October that the traffic death rate dropped to a record low level
in 1997lsquo Moreover the average fatality rate even fell in the states that raised
their speed limits
63 The Fatality rate Is it a reliable metric
In 1921 with fewer fatalities and fewer miles driven and the first year for
which the fatality rate could be computed the rate was 2408 It was down to
1479 in 1931 but the number of deaths had climbed to 31963 more than
double the 1921 absolute fatality number of 13253 It had dropped to 550 in
1966 the year of the highly publicized Congressional hearings but the
number of fatalities had climbed to 50984 in that fateful The Highway Safety
Act of 1966 ranks as one of the major acts of Congress and President
Johnson signed it saying that ―we have been tolerating a raging epidemic of
highway deathshellip see extract pasted below
httpwwwenotescommajor-acts-congresshighway-safety-act
Page 28 of 45
The act was motivated primarily by growing public concern over the rising number
of traffic fatalities in the United States Between 1960 and 1965 the annual number
of traffic fatalities increased by nearly thirty percent As President Lyndon B
Johnson stated at the signing of the act on September 9 1966 we have tolerated
a raging epidemic of highway death which has killed more of our youth than all
other diseases combined Through the Highway Safety Act we are going to find out
more about highway diseasemdashand we aim to cure it
Nonetheless highways fatalities continued to increase until the Arab oil
embargo of 1973 led to the NMSL of 55 mph all across the USA Do we just
ignore this undeniable historical record and focus only on the declining fatality
rate as the NMA and other proponents of higher speed limits seem to argue
(see links above)
The misleading nature of using fatality rates (per 100 M VMT) alone is also
obvious if one considers fatality data for individual states Take for example
the state of Montana which seems to have experienced no increase in
fatalities after repeal of NMSL
httpwww-nrdnhtsadotgovdepartmentsnrd-
30ncsaSTSI30_MT200930_MT_2009htm
For the period 2005-2009 the absolute number of fatalities for Montana
varied between a high of 277 in 2007 to a low of 229 in 2009 The fatality
rates per 100 M VMT on the other hand varied from a high of 245 for 2007
to a low of 201 for 2009 The corresponding US fatality rates varied from
136 to 114 Is the higher number for the fatality rate for Montana compared
to USA good or bad Likewise fatality rate per 100000 of population was
much higher for Montana than the US as a whole
This again highlights the pitfalls of using simple ratios to assess fatality statistics
without a full analysis of the underlying trends We will discuss this point
separately
As shown already the continuous decline in the fatality rate is a mathematical
artifact and essentially overlooks the unmistakable positive correlation
between the variables x and y of the type y = hx + c which becomes obvious
Page 29 of 45
only when we prepare the x-y scatter graph The ratio yx = h + (cx) can
decrease with increasing x (VMT) and increasing y (fatalities) since the
intercept c has a positive value when we consider only data spanning a short
period (such as 1994-2009 of more relevance to the current situation)
The debate between fatality rates and absolute number of fatalities is an
unending one A few years ago the Wall Street Journal carried an article
which was entitled (or something close) ―Unemployments rate in Ohio are
going down but why is the number of unemployed increasing The reason is
the same The graph of the number of unemployed (y) versus the number in
the labor market (x) is linear with a positive slope h and a positive intercept c
So the unemployment rate computed using the ratio yx keeps going down
year after year although the number unemployed keeps increasing Is it a
good thing that the unemployment rate is going down when more people
seem to be unable to find gainful unemployment
Or consider the situation with cancer death rates This too has been going
down in recent years but the actual number of cancer-related deaths has not
declined in any significant way Is it good that cancer death rates are going
down In all these situations the researchers or the socio-econo-politico
analysts involved in analyzing the trends in the data have failed to consider
the underlying x-y relation describing each problem
Hence it appears that the debate on the effect of increased speed limits
should not be focused on only the fatality rates (which have been decreasing
and proponents of higher speed limits cite this in their arguments) or even the
absolute number of fatalities (which has been the focus here) but on the
relationship between speed and the number of fatal crashes and the number
of fatalities within each speed segment (see Table 3 and also Figure 4)
Unfortunately details of number of fatalities and the number of fatal crashes
at each speed limit are not available even from NHTSA for detailed study
When a crash does occur (it is immaterial how many miles were driven) the
speed of the driver and vehicle design and engineering including safety
devices in place (seat belts airbags other impact absorbing technologies)
Page 30 of 45
determine if the occupants(s) will be killed One cannot argue that speed
does NOT kill That would be an absolute denial of the laws of physics
Studies show that setting the speed limit at the 85th percentile in any given
zone (this is the speed at or below which 85 of drivers are observed to
travel in traffic engineering studies) is the safest speed limit The majority of
drivers try to obey the posted speed limit while a few choose to drive at a
speed they consider is safe and prudent These are also perhaps the most
vociferous advocates of higher speed limits It is this tension caused due to
differences in speeds that leads to tailgating improper passing reckless
driving weaving from lane to lane and ultimately crashes and deaths in some
unfortunate cases
httpblogmotoristsorgspeed-limits-slower-safer
MARK TAYLOR
ANOTHER LOST A man was killed when his 4WD drive hit a tree east of Morrinsville (in New
Zealand) on Monday May 30 2011 The driver lost control of the vehicle on a bend probably tried
to correct his mistake and put the car into a ―yaw causing it to leave the road and smash sideways
into a tree Alerts to slow down had been posted since this was a high accident area but the driver
probably did not pay attention
64 Other factors
Many other factors besides speed no doubt affect highway fatalities The
vehicles of the 21st century are very different from the vehicles of the mid 20th
Page 31 of 45
century Technological innovations such as improvements in vehicle design
and engineering have greatly increased crash worthiness of vehicles even at
high speeds Environmental factors such as the weather also contribute to
accidents but not necessarily to increased fatalities Drivers actually tend to
slow down instinctively during adverse weather conditions (rain snow storms
etc) and although such weather may contribute to increased accidents the
lower speeds actually reduce fatalities
Yes technology has changed fundamentally from 1966 Drivers today are
more distracted by their cellmobile phone conversations (and also built-in
phones in luxury models) and text messaging than the drivers of the pre-1966
era High end cars now have many multimedia and internet features Again a
careful observation (even personal experience by the author) suggests that
such distracted drivers actually tend to (instinctively) drive more slowly and
hold up the traffic Perhaps such behavior leads to an increase in the number
of accidents but it does not necessarily lead to an increase in the number of
accident-related fatalities
Much talked about technological innovations such as automatic collision
avoidance systems and sensors (on the sides of vehicles) can indeed detect
vehicles in the front and neighboring lanes Furthermore vehicle-to-vehicle
communication systems vehicle-to-infrastructure communication systems
can no doubt avoid collisions and accidents Again such collision avoidance
systems work and are effective entirely because they automatically reduce
vehicle speeds - even if one of the offending vehicles is being at a super
high speed Also it must be remembered that such futuristic systems have
not yet been implemented widely nor can they be implemented widely since
the large majority of vehicles on the road are NOT luxury models Advanced
safety features come with a price and not all drivers can afford to pay that
price and ―buy that ―additional safety
Ultimately it is the laws of physics that govern what will happen when two or
more vehicles collide or even when a single vehicle collides with a stationary
infrastructural object (a bridge a wall a building or some impediment on the
road) The lower the number of crashes the lower the number of fatalities as
revealed by the 1994-2009 data graphed in Figure 5 The higher the speed of
Page 32 of 45
the object or objects that are involved in a collision the higher the kinetic
energy K that must be absorbed andor dissipated Increasing the posted
speed limit only increases the energy that must be absorbed when a crash
does occur This ultimately is the most important criterion determining the
number of fatalities
The kinetic energy increases as the square of the speed being given by the
well-known formula K = frac12 mv2 where m is the mass of the vehicle (in
laypersonlsquos language m increases directly with vehicle weight) and v is the
speed For the same vehicle mass an increase in the speed from 55 mph to
85 mph increases the kinetic energy K by a factor of 239 or roughly a 250
increase in the kinetic energy that must be absorbed in a collision
Ideally speaking the kinetic energy of the colliding object(s) is absorbed by
the vehicle infrastructure (a sturdy space frame the engine other vehicle
components etc) andor the surroundings However in the unfortunate
cases where this kinetic energy must be absorbed by the vehicle occupant(s)
the result is severe life-altering injuries andor death An unequivocal
relationship between an increase in vehicle speeds and fatal accidents can
be demonstrated by a careful examination of available traffic fatality data
This is a more involved discussion and is not the purpose of this short
communication These topics are no doubt very politically charged with many
social legal and financial implications with each interest group favoring a
different conclusion Nonetheless we cannot escape the laws of physics as
they govern the fundamental need to absorb higher and higher values of the
kinetic energy K with increasing vehicle speeds This same point is also
emphasized by Dr Friedman of the University of Illinois Chicago (see earlier
discussion)
Speed kills because of these energy transfer considerations and there can be
no doubt about it
Innovative 21st century solutions to speed management on the highways
such as strict enforcement of speed limits minimizing speed dispersion
(difference between speeds at which different drivers travel) while using
cameras to track the 15 of drivers who willfully violate the speed limit and
Page 33 of 45
create hazardous driving conditions is certainly recommended (Recall that
the optimum recommended speed limit is at or below which 85 of all drivers
travel ndash a policy also supported by NMA) Even on this score however the
results are confounding if we consider the Australian experience
httpwwwthenewspapercomnews282840asp
Up until 2007 there was no speed limit in the Northern Territory of
Australia Imposing a speed limit 130 kmph (80 mph) on some areas and
110 kmph (68 mph) in some others actually increased the number of deaths
The death toll in 2006 when there was no speed limit in this region was 44
and went up to 75 in 2009 see data table in link below
httpwwwthenewspapercomrlcdocs2009au-ntroadtollpdf
Furthermore it appears that installation of cameras to enforce speed limits
has proved to be a hazardous distraction to drivers and deaths actually
began to skyrocket between 2005 and 2007 in all Australian roadways
The main purpose here is to sound a cautionary note amid renewed attempts
in many states across the US to increase the speed limits on our highways by
calling attention to the historical facts regarding the ―epidemic levels of
highway traffic fatalities that engaged our national attention in the fateful year
of 1966 The graphical representation of the traffic fatality data in Figures 1
to 5 tells its own story
Indeed it would be tragic if highway-accident-related fatalities were to start
increasing once again and reach the historically high level that was last seen
in 1972 the year before the Arab oil embargo of 1973
Page 34 of 45
Conclusions
1 The graphical representation of the highway fatality data and the brief
summary of the historical facts of traffic safety legislation suggest that
recent attempts to increase the speed limits by various states (notably
Texas) may be misguided The distinct peak in the highway fatalities
observed in these graphs is highly alarming This appears to be related to
the enactment of the National Maximum Speed Limit (NSML) in 1974
following the 1973 Arab oil embargo Although NSML was motivated by a
desire to reduce gasoline consumption an unintended benefit might have
been a dramatic reduction in fatalities The fundamental reasons for the
peak in the fatalities-VMT curve must be examined carefully without
political posturing
2 The widely used fatality rate fatalities per 100 M vehicle miles traveled
has been declining since 1921 the first year for which a fatality rate could
be computed and has now reached a historical low The absolute number
of fatalities on the other hand was increasing in the 1950s and 1960s at
an alarming rate and the public outcry that ensued led to the highly
publicized Congressional hearing of 1966 and the subsequent traffic safety
legislations The fatality rate has been decreasing even in the most recent
15-year period (1994-2009) again with increasing fatalities although less
dramatically Thus it appears that fatality rate calculation based on vehicle
miles traveled (VMT) might not be a reliable indicator of the underlying
dynamics in the fatality trends
3 More detailed compilation of number of fatalities and the number of fatal
crashes within each speed limit segment is required to better understand
the effect of increasing speed limits on highway fatalities (and also fatality
rates) Such data is already available and is being compiled at the local
city and county levels in all jurisdictions and only needs to be reorganized
to highlight the effect of (posted) speed limits on the number of crashes
and fatalities This will require some minor rewriting and revisions to the
chapters named ―Crashes and ―States in the annual NHTSA reports
Page 35 of 45
Analysis of the fatalities-crashes data for several years with various
speed limits will be more revealing and meaningful than the current
fatality rates analysis and will be discussed separately in a follow up
report
4 One should not be lulled by the fact that vehicles of the 21st century are
now equipped with advanced safety features not available in the 1950s
and the 1960s In spite of these safety features the laws of physics dictate
that the higher the speed the higher kinetic energy of the colliding objects
and hence the greater the risk indeed near certainty of fatalities in a
higher speed collision compared to a lower speed one
5 The higher the speed at which the vehicle that is involved in a crash is
traveling the higher the kinetic energy that must be absorbed andor
dissipated without affecting the occupant(s) to avoid serious injuries andor
death This was true in the 1950s and the 1960s and will continue to be
true in the 21st century as well
Speed Kills for this just reason
6 It appears that higher fuel economies and reduced
highway fatalities were the twin societal benefits of 55
mph adopted after 1973 If so the current attempts to
increase the speed limits appear to be in conflict with
other important societal objectives
Page 36 of 45
Table 1 Annual US Street amp Highway
Fatalities from 1957
Year
Fatalities
Vehicle Miles
(millions)
Rate100M Vehicle Miles
1957 38702 646915 598
1958 36981 664915 556
1959 37910 700478 541
1960 38137 718845 531
1961 38091 737535 516
1962 40804 766852 532
1963 43564 805423 541
1964 47700 846500 563
1965 49163 887640 554
1966 51524 927915 555
1967 51559 965132 534
1968 53831 1019726 528
1969 55032 1066108 516
1970 53672 1114098 482
1971 53761 1183524 454
1972 55704 1264614 440
1973 55113 1316207 419
1974 46078 1282790 359
1975 45500 1330074 342
1976 45523 1402380 325
1977 47878 1467027 326
1978 50331 1544704 326
1979 51103 1529133 334
1980 51091 1527295 335
1981 49301 1552803 317
1982 43945 1595010 276
1983 42589 1652788 258
1984 44257 1720269 257
1985 43795 1774179 247
Page 37 of 45
1986 46056 1835000 251
1987 46385 1921000 241
1988 47093 2026000 232
1989 45555 2107040 216
1990 44529 2147501 207
1991 41162 2172214 189
1992 39235 2239828 175
1993 40115 2296585 175
1994 40676 2359984 172
1995 41798 2422696 173
1996 41907 2485848 169
1997 41967 2560373 164
Data from Federal Highway Administration
Source httpwwwpublicpurposecomhwy-fatal57+htm
Telephone +16186328507 - Facsimile +16186328538
WENDELL COX CONSULTANCY P O Box 841 - Belleville IL 62269 USA
Page 38 of 45
Fatality data for 1921-1982 compiled by NHTSA
Year
VMT
(Millions)
VMT
(Billions)
Fatalities
Fatality rate
per 100 M VMT
1921 55027 5503 13253 241 1922 67697 6770 14859 219 1923 84995 8500 17870 210 1924 104838 10484 18400 176 1925 122346 12235 20771 170 1926 140735 14074 22194 158 1927 158453 15845 24470 154 1928 172856 17286 26557 154 1929 197720 19772 29592 150 1930 206320 20632 31204 151 1931 216151 21615 31963 148 1932 200517 20052 27979 140 1933 200642 20064 29746 148 1934 215563 21556 34240 159 1935 228568 22857 34494 151 1936 252128 25213 36126 143 1937 270110 27011 37819 140 1938 271177 27118 31083 115 1939 285402 28540 30895 108 1940 302188 30219 32914 109 1941 333612 33361 38142 114 1942 268224 26822 27007 101 1943 208192 20819 22727 109 1944 212713 21271 23165 109 1945 250173 25017 26785 107 1946 340880 34088 31874 94 1947 370894 37089 31193 84 1948 397957 39796 30775 77 1949 424461 42446 30246 71 1950 458246 45825 33186 72 1951 491093 49109 35309 72
1952 513581 51358 36088 70
Page 39 of 45
1953 544433 54443 36190 66 1954 561963 56196 33890 60 1955 605646 60565 36688 61 1956 627843 62784 37965 60 1957 647004 64700 36932 57 1958 664653 66465 35331 53 1959 700480 70048 36223 52 1960 718762 71876 36399 51 1961 737421 73742 36285 49 1962 766734 76673 38980 51 1963 805249 80525 41723 52 1964 846298 84630 45645 54 1965 887812 88781 47089 53 1966 925899 92590 50894 55 1967 964005 96401 50724 53 1968 1015869 101587 52725 52 1969 1061791 106179 53543 50 1970 1109724 110972 52627 47 1971 1178811 117881 52542 45 1972 1259786 125979 54589 43 1973 1313110 131311 54052 41 1974 1280544 128054 45196 35 1975 1327664 132766 44525 34 1976 1402380 140238 45523 32 1977 1467027 146703 47878 33 1978 1544704 154470 50331 33 1979 1529133 152913 51093 33 1980 1527295 152730 51091 33 1981 1555308 155531 49301 32 1982 1595010 159501 43945 28
Source Analysis of Significant Decline in Motor Vehicle Traffic Fatalities in
2008 httpwww-nrdnhtsadotgovPubs811346pdf see Table A1 page 31
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Page 40 of 45
Acknowledgements
The author is grateful for thoughtful comments provided by friends and colleagues
with whom this document was shared via email prior to it being uploaded as a
publicly available document for wider dissemination and study The comments
offered by Prof Subra Ganesan of Oakland University Electrical and Computer
Engineering Department are reproduced with permission in their entirety
About the author
The author obtained his Masterrsquos (S M) and Doctoral (Sc D) degrees in Materials Engineering
from the Massachusetts Institute of Technology Cambridge USA He then spent his entire
professional career at leading US research institutions (MIT NASA Case Western Reserve
University and General Motors R amp D Center in Warren MI) He holds four patents in advanced
materials processing has co-authored two books and has published several scientific papers in
leading peer-reviewed international journals His expertise includes developing simple
mathematical models to explain the behavior of complex systems He can be reached by email at
vlaxmananhotmailcom
Page 41 of 45
Please Buckle Up
httpwwwlakecountypublichealthorgindexphpbuckle-up-montana
Public Awareness
Respect the Cage Exhibit
The Department of Transportation hopes that showing the reality of the crash will reduce traffic
fatalities A crushed car crash dummies and a sobering message ndash all part of the ―Respect The
Cage exhibit that is traveling across Montana The exhibit sponsored by the Montana Department
of Transportation stopped in Ronan on November 6th and is aimed at raising awareness about the
importance of wearing seat belts
The car in the exhibit was in an actual wreck many years ago
the passenger in the vehicle died because he was not wearing a
seat belt the driver who was wearing his seat belt survived
Montanarsquos likeliest crash fatality scenario
A Pickup
A Rural road
And Seat belts that
arenrsquot used
Page 42 of 45
Occupants of pickups are less likely to wear seat belts and pickups are more likely to
roll over than passenger cars
Seat belts reduce the risk of death by 60 percent in pickups and SUVs
In Montana from 2006-2008 81 of those killed in a crash while riding in a pickup were not wearing seat belts
In Montana pickups make up 401 of the vehicle population
For more information on Respect the Cage click here
Page 43 of 45
Appendix 1
Lack of seat belts leading cause of Louisiana highway deaths
1251 AM May 28 2011 |
Written by Adam Duvernay
Crashes involving unbuckled motorists were the leading cause of highway fatalities
in Louisiana last year and cost $9888 million according to recent reports The
Louisiana Highway Safety Commission reported 59 percent of vehicle occupants
killed in Louisiana crashes last year mdash about one in four mdash werent wearing seat
belts
httpwwwshreveporttimescomarticle20110528NEWS01105280354Lack-seat-
belts-leading-cause-La-highway-deathsodyssey=tab|topnews|text|FRONTPAGE
Crash bull Stats Published by NHTSAlsquos National Center for Statistics and Analysis 1200 New Jersey Avenue SE Washington DC 20590
DOT HS 811 451
Early Estimate of Motor Vehicle Traffic Fatalities in 2010
httpwww-nrdnhtsadotgovPubs811451pdf
Summary
A statistical projection of traffic fatalities in 2010 shows that an estimated 32788
people died in motor vehicle traffic crashes This represents a decline of about 3
percent as compared to the 33808 fatalities in 2009 as shown in Table 1 If these
projections are realized fatalities will be lowest on record (since 1949)
Traffic Safety Facts Overview 2009 Data
httpwww-nrdnhtsadotgovPubs811392pdf
In 2009 33808 people were killed in the estimated 5505000 police-reported
motor vehicle traffic crashes 2217000 people were injured and 3957000
crashes involved property damage only Compared to 2008 this is a 10-
percent decrease in the number of fatalities and a 5-percent decrease in the
Page 44 of 45
number of police-reported motor vehicle traffic crashes people injured and
crashes involving property damage
An average of 93 people died each day in motor vehicle crashes in 2009 mdash
an average of one every 16 minutes
Traffic Safety Facts Overview 2008 Data
httpwww-nrdnhtsadotgovPubs811162pdf
In 2008 37261 people were killed in the estimated 5811000 police-reported
motor vehicle traffic crashes 2346000 people were injured and 4146000
crashes involved property damage only
Some comments and Feedback
The following comments were received from Prof Ganesan after his review of the
first draft of this document It was subsequently revised thanks to this input to
address some of the very important issues raised here
Dear Laxman
The write up is not enough
You are emphasizing that the speed limit reduces the fatal accidents (comparing 1966
to 2000 accident numbers)
Can you also add a few sentences why the number is decreasing from 1980 to 2000
values (May be due to better design of vehicles)
Can you say anything about the fuel consumption with the speed for any typical
vehicle in 2011 or 2010 (do not consider the fatalities issue)
Probably a speed between 55 and 60 mph gives a better mileage If so this is a
compelling reason to keep the speed limit low But cars probably can be tuned to
give better mileage at any high speed also
Page 45 of 45
Weather is also a major factor in fatal accidents Speed limit may be kept low during
winter and kept higher in summer Give your comments on this too
Driver distractions can cause more accidents Now cars have many multimedia and
internet features Automatic collision avoidance systems and sensors on the sides can
detect vehicles in the front and neighboring lanes and it can automatically decrease
speed even if the driver speeds at super high speeds
Give some comments on this too There is also Vehicle to Vehicle communications
vehicle to infrastructure communications and they can avoid collisions and accidents
Technology has changed from 1966 I cannot agree with you on the speed limit
without any discussion on the above and other factors
Have a great day
Subra Ganesan
Professor Subramaniam Ganesan
Director Real Time amp DSP Lab
Electrical and Computer Engineering Department
2200 Squirrel Road Dodge Hall Room 105
Oakland University Rochester MI 48309 USA
Phone 248 370 2206 Fax 248 370 4633
wwwsecsoaklandedu~ganesan
IEEE Distinguished Visiting Speaker (2005-2009) Coordinator
IEEE SEM CS chapter Chair Region 4 and CS Society Board member
SAE ASEE ACM member
Page 6 of 45
projections are realized highway traffic fatalities will be lowest on record
(since 1949)
The graphical representation of the traffic fatality data compiled annually by
the National Highway Traffic Safety Administration (NHTSA) as seen in
Figures 1 to 4 here tells its own story Indeed here a picture is certainly
worth a thousand words Let these graphs do the talking The detailed
captions attached with each figure permit an unbiased assessment of the
traffic fatality data and will hopefully lead to a repeal of the misguided
attempts to increase speed limits This also represents a simple and new
approach to analyzing the fatality data without excessive reliance on the
calculation of simple ratios such as the widely used fatality rate
As will become obvious the national speed limit of 55 mph instituted in
the historical year of 1973 yielded the twin benefits of improved fuel
economies and reduced traffic fatalities
The 1955 Cadilla available for tours of Memphis TN
httpeditorialautosmsncommost-unusual-tourist-vehicles2
Page 7 of 45
httpwwwugptiorgpubspdfDP188pdf
httpwwwlakecountypublichealthorgindexphpbuckle-up-montana
2 A brief review of historical traffic
fatality data compiled by NHTSA
The NHTSA uses the fatality rate as its single most important measure of
traffic safety The fatality rate is the ratio yx where x is the total vehicle miles
traveled (usually expressed in billions) by all US drivers and y is the absolute
number of highway fatalities To arrive at a simple tractable number the rate
is determined per 100 million vehicle miles traveled (acronym VMT)
Although this fatality rate yx has now reached a historical low in 2010
exclusive focus on this ratio while overlooking the underlying x-y trend might
be misleading as will become evident from the graphical representation of
the historical data being attempted here
Driver Behavior
Driver Drinking
Too Fast
Not Wearing
Seat Belts
Montanarsquos Likeliest
Fatal Crash Scenario
A Pick up
A Rural road
And Seat belts not
used
Page 8 of 45
Figure 1 Graph of the absolute number of US highway fatalities since 1957 The raw
data used to prepare this graph may be found in Table 1(relegated to the end of this
document) The absolute number of highway fatalities were quite low in the 1950s
and reached a peak in the late 1960s to early 1970s and have since decreased to
levels seen in the 1950s although the vehicle miles driven (in millions) has been
increasing from 646915 in 1957 to 2560373 in the year 2000 see also Figure 2
The fatality data from other government sources have also been studied by the author
and lead to the same conclusion of a peak in highway deaths around the late 1960s to
early 1970s
Page 9 of 45
Figure 2a Graphical representation of the absolute number of US highway fatalities
versus annual vehicle miles driven (in trillions) The number of miles driven by US
drivers has increased each year since 1957 as seen in Table 1 The absolute number
of highway fatalities has increased as well reaching a peak in the late 1960s to early
1970s The same peak is also seen here in the graph of the absolute number of
highway fatalities versus vehicle miles driven Improvements in vehicle safety devices
(notably seat belts and airbags) coupled with the institution of the national highway
speed limits (starting mid 1970s) and also improved highways are the primary
reasons for the decrease in fatalities These historical trends suggest that renewed
attempts to increase the speed limits on our highways would be counterproductive
and may eventually lead once again to an increase in fatalities with tragic
Page 10 of 45
consequences
Figure 2b Graphical representation of the US highway fatality data for the period
1921-1982 The first year for which a fatality rate yx could be computed is 1921 The
number of fatalities was 13253 and VMT was 5503 billion yielding a fatality rate of
2408 per 100 million VMT The fatality rate for any year is the slope of the ray ie
the straight line joining the (x y) data point back to the origin (00) of this graph see
dashed line for 1921 superimposed on to the graph The fatality rates (slopes of such
rays) had been declining quite consistently although the absolute number of fatalities
increased as seen here ultimately leading to the Congressional hearing in 1966 Is
VMT the single most important reason for the increasing fatalities
Page 11 of 45
Figure 3 Graphical representation of the traffic fatality data for the 15 year period
1994-2009 A sudden precipitous drop in the absolute number of fatalities (at least on
the magnified scale used here) and hence the fatality rate has been observed over
the three-year period 2007-2009 However it should be noted that the x-y scatter
graph here shows a general upward trend with fatalities actually increasing with
increasing VMT (as in the earlier era 1950s and 1960s) during the 12-year period
spanning 1994-2006 although the rate yx shows a misleading downward trend Why
is the rate yx going down
The reason is very simple and it may be just a mathematical artifact The equation of
the best-fit straight line through the most recent data points is of the form y = hx + c
= 2865 x + 34420 where h is the slope of the line and c the intercept (Note that x
here is VMT in billions The numerical value determined using this equation must be
divided by 10 to get the rate per 100 M VMT) Hence the fatality rate given by the
ratio yx = h + (cx) = 2865 + 34420x can actually decrease with increasing
values of x because of the nonzero intercept c Unlike the ray through the origin the
best-fit line does not pass through the origin (00) If we consider only the most
Page 12 of 45
recent data the intercept c is positive and fatality rates yx decrease with increasing
VMT and increasing fatalities In the earlier era both the slope h and intercept c had
very different values due to several factors being discussed here (speed limits
technology highway design etc)
Table 2 Traffic fatality data for the recent 15-year period
1994-2009 (Source NHTSA)
Year
Highway
fatalities y
Vehicle miles
traveled
VMT
(billions) x
Fatality rate
yx per 100
million VMT
Fatal crashes
1994 40716 2358 173 36254 1995 41817 2423 173 37241 1996 42065 2486 169 37494 1997 42013 2562 164 37324 1998 41501 2632 158 37107 1999 41717 2691 155 37140 2000 41945 2747 153 37526 2001 42196 2797 151 37862 2002 43005 2856 151 38491 2003 42884 2890 148 38477 2004 42836 2965 144 38444 2005 43510 2989 146 39252 2006 42708 3014 1 42 38648 2007 41259 3032 136 37435 2008 37423 2974 126 34172 2009 33808 2979 113 30797
Page 13 of 45
Figure 4 The most significant metric used by NHTSA is the fatality rate per 100
million vehicles miles traveled (VMT) This is now at a historical low of 113 for
2009 having declined year after year from 173 in 1994 The NHTSA however also
compiles other types of data on crashes There are three types of crashes fatal
injury but no death and property damage only A careful review of this crash data
for the period 1994-2009 reveals the obvious the lower the number of (fatal)
crashes x the lower the number of highway-accident-related fatalities y It is also
obvious that the number of fatalities per crash is greater than one ie more than one
person is being killed when one of more vehicles experience a crash
Clearly this is the single most important piece of information that one needs to
reduce the number of fatalities on our highways Vehicle design and engineering as
well as all other policy matters (legal political social environmental financial)
must be guided by this simple graph The best-fit line through the data derived using
simple linear regression has the equation y = hx + c = 114x ndash 10266 and is
Page 14 of 45
superimposed on to the data The design engineering goal and societal goal should
be to reduce the slope h of this statistically significant best-fit line to its ideal value of
h = 1 A fatal crash by definition is one where at least one person dies either an
occupant or a non-motorist in the path of the vehicle Hence the ideal slope h = 1
Photograph of an accident scene from the period 1955-1965
httpwwwcorinthsocialhistoryprojectorghtmlhighwaytollshtml
3 A Brief History of Traffic Safety Legislation
The following is extracted from the Wikipedia article on National Highway
Traffic Safety Administration (NHTSA)
httpenwikipediaorgwikiNational_Highway_Traffic_Safety_Administration
In 1965 and 1966 public pressure grew in the US to increase the safety of
cars The number of deaths on US highways were increasing year after year
Page 15 of 45
see Figure 1 and in 1966 Congress held a series of highly publicized
hearings on highway safety This led to the legislation for mandatory
installation of seat belts which also created the US Department of
Transportation (on Oct 15 1966)
httpwwwemsgovpdf2011EMSWeek2011_Stricklandpdf
The following is extracted from a Washington Post article on
NHTSA dated April 2 2002
httpwwwwashingtonpostcomwp-srvbusinessincludesnhtsa_primerhtm
In 1966 after decades of rising traffic fatalities (also vividly illustrated in
Figures 1 and 2 here) the publication of Ralph Naders Unsafe at Any
Speed and increasing public outcry for safer automobiles Congress held a
series of highly publicized hearings on creating a regulatory agency for traffic
safety Among the witnesses was William Haddon an epidemiologist who
introduced the idea that traffic accidents could be analyzed scientifically and
injuries reduced by changing auto design such as installing collapsible
steering columns safety glass head rests and seat belts
Congress passed the Highway Safety Act of 1966 creating the National
Highway Safety Bureau with Haddon as its first administrator The bureau
became NHTSA in 1970 under the newly established Department of
Transportation An early Nader convert Joan Claybrook headed NHTSA
under President Carter and now runs Naders organization Public Citizen
National Traffic and Motor Vehicle Safety Act
httpwwwanswerscomtopicnational-traffic-and-motor-vehicle-safety-act
Signed into law by President Lyndon Johnson on September 9 1966 this act
created the first mandatory federal safety standards for motor vehicles The
act was motivated by a variety of factors First and foremost the public was
growing increasingly concerned over the rising number of traffic fatalities on
the nations roads Such fatalities had increased by nearly 30 percent
between 1960 and 1965 and experts forecasted 100000 such deaths
Page 16 of 45
annually by 1975 unless something was done to improve traffic safety
Adding fuel to the fire Ralph Naders Unsafe at Any Speed published in
November 1965 criticized the automobile industry for neglecting safety in
favor of power and styling when designing new vehicles
4 The reason for the historical
decrease in highway fatalities
A recent news item see link given below regarding renewed attempts to
increase the speed limit by many states prompted this write up by the
present author who has studied traffic fatality data extensively and analyzed
them very carefully over the last several years
httpmoneymsncomauto-insurancewhy-speed-limits-are-
risingaspxGT1=33033
Residents of Metro Detroit area who frequently cross into Ohio from
Michigan notice that the speed limit has now increased in Ohio The speed
limit on Michigan highways was increased to 70 mph in the late 1990s but
Ohio retained its lower speed limit for many years leading Michigan drivers to
experience a ―speed trap of sorts The speed limit is also increasing in many
other states notably Texas where it is proposed to increase it to 85 mph at
least in West Texas
Historically speaking from a traffic fatality standpoint we must consider two
important dates 1966 and 1973 Only 1973 the year of the Arab oil embargo
following the Arab-Israeli war (that led to what President Obama has recently
called the pre-1967 border for Middle East peace) is mentioned in the above
article It fails to mention the significance of the year 1966
Prior to 1966 there was actually NO speed limit in many Western states and
deaths due to highway accidents were increasing year after year The
Page 17 of 45
number of highway fatalities went up from 38702 in 1957 to 51524 in 1965
a 33 increase over the 1957 level and an additional 12822 deaths in 1965
compared to 1957 It was this carnage on the US highways that forced
Congress to hold its hearings on highway traffic fatalities in 1966
Nonetheless a careful examination of the fatality data in Table 1 shows that
notwithstanding the highly publicized Congressional hearings of 1966 and
new safety legislation that was enacted the absolute number of fatalities
continued to increase after 1966 and only started decreasing after 1973
Vehicle designs especially the introduction of safety features (even the
simplest like safety belts) did not change significantly between 1966 and
1973 Nonetheless post-1973 we begin to see a dramatic turnaround
Why
After the 1973 Arab oil embargo a nationwide maximum speed limit (NMSL)
of 55 mph was imposed and accepted in the USA (effective Jan 1 1974)
during the Nixon administration primarily as an effort to conserve fuel and
reduce the US vulnerability to oil imports The unintended and indeed
fortunate consequence of this reduced speed limit was the immediate
reduction in the fatalities revealed in Figures 2 and 3 This is the real reason
for the peaks in highway fatalities observed in these two graphs
The Congressional hearings of 1966 did eventually have an impact but it was
a delayed one The impact of the 1973 nationwide speed limit of 55 mph was
however immediate as we see from the magnified plot of the same data in
Figure 5 and a closer examination of the raw fatality data in Table 1
The number of highway-accident-related fatalities decreased immediately
from a high of 55704 in 1972 to just 46078 in 1974 a 173 drop see
arrows There were 9626 fewer deaths annually even with a slight increase
in the vehicle miles driven (see Table 1) Indeed the number of highway
death reached its absolute peak value in 1972 never to be seen again
Fatalities have been decreasing every since with slight fluctuations about
each new low value
Page 18 of 45
Figure 5 Expanded view of the fatality data showing the immediate impact of the
national speed limit of 55 mph following the Arab oil embargo of 1973 Note that
fatalities continued to rise between 1966 and 1973 in spite of the highly publicized
Congressional hearings in 1966 and the traffic safety legislation enacted soon after
Each new low is probably associated with vehicle safety innovations and the
improvements in vehicle design and engineering The combined beneficial
effect of improved vehicle designs primarily the introduction of seat belts
and the laws enforcing usage of seat belts aided by the reduced speed
limits contributed to the continued decline in the absolute number of fatalities
that started since 1973 and has continued to this day The subsequent
introduction of other safety features notably air bags has contributed to a
further reduction in highway fatalities
Page 19 of 45
State police Trooper First Class Jeffrey Flowers looking at a car in which a Boswell
Pennsylvania woman was injured Tuesday (May 31 2011) The accident occurred at
an intersection when a truck (seen behind the wrecked car) entered this accident
prone intersection (part of a highway safety corridor where signs are posted to
reduce unsafe driver behavior) There have been four accidents at this intersection
since 2006 none fatal httpwwwdailyamericancomnewssomersetda-ot-woman-
injured-in-route-30-wreck-2011053104165420story
5 Numerical calculations of decline in
fatalities and the impact of NMSL post-1973
Letlsquos consider the decline in fatalities between 1972 the last year before the
adoption of the NMSL and 1974 the first year following its adoption after the
Arab oil embargo There was an immediate decrease in the number of
fatalities by 9393 ie y = -9393 with a slight increase in the VMT ie x
= 20758 millions The NHTSA data used here may be found in the table at
the end of this document The numerical value of the rate of change per
billion VMT (ie neglecting the sign) was therefore
yx = 4525 fatalitiesbillion VMT (1972-1974)
Page 20 of 45
It is instructive to compare this rate of change in fatalities with similar short
periods of a decline in fatalities in the pre-1973 era when speed limits were
much higher The absolute number of fatalities declined over a relatively
short period with both an increase and a decrease in VMT The results are
given below and are self-explanatory
yx = 454 fatalitiesbillion VMT (1953-54) decline with increase in VMT
yx = 655 fatalitiesbillion VMT (1942-43) decline with decrease in VMT
yx = 1739 fatalitiesbillion VMT (1941-42) decline with decrease in VMT
yx = 4528 fatalitiesbillion VMT (1937-39) decline with increase in VMT
yx = 2548 fatalitiesbillion VMT (1931-32) decline with decrease in VMT
The rate of decline observed between 1953 and 1954 with an increase in
VMT was just one-tenth of that observed following the adoption of the 55
mph speed limit The war years (1941-43 WWII) and the Great Depression
era (1931-32) were accompanied by big declines in fatalities with decreasing
VMT but the rate of change was still significantly lower than observed after
the adoption of the NMSL
The only apparently inexplicable decline is that between 1937 and 1939
where a nearly identical high rate of decline was observed Notice also the
big drop in the traditional fatality rate between 1937 and 1938 This large drop
appears to coincide with the creation of the National Safety Council (NSC) by
William H Cameron in June 1937 (see link below) with its far-flung campaign
of education legislation research highway engineering and traffic training
undertaken by the NSC and some two dozen other groups with the backing of the
automotive industry through its Automotive Safety Foundation Other factors
unknown to the present author probably also played a role
httpwwwtimecomtimemagazinearticle0917188379700htmlixzz1O2G
7rnUg
Page 21 of 45
These simple computations here however reveal the significant effect of
reduced speed limits on highway fatalities much more so than other factors
6 Further Considerations Pros and Cons
The singular effect of increased speeds (or speeding) on highway fatalities
has been studied and demonstrated by a number of industry sources such
as the Insurance Institute for Highway Safety (IIHS) Consumers Union and
also by government researchers
httpwwwsmartmotoristcomtraffic-and-safety-guidelineexcessive-speed-is-
a-factor-in-one-third-of-all-fatal-crasheshtml
httpwwwconsumersunionorgotherspeedlimitsspeed031500a2htm
Speed ndash defined as exceeding the posted speed limit or driving too fast for
given conditions ndash is a factor in nearly one-third of all fatal crashes Besides
fatality in 1998 nearly 40000 people were critically injured in speed-related
crashes and nearly 72000 were moderately injured
The salutary and immediate beneficial effect of the nationwide 55 mph speed
limit has been noted by other researchers (see Susan Ferguson link below)
httpwwwnhtsagovpeopleinjuryenforcespeed_forum_presentationsfergu
sonpdf
After a partial repeal of this law in 1987 which granted states the authority to
increase speed limit (especially in rural interstates) a 1989 study showed a
15 increase in fatalities in rural interstates and a 5 increase in non-rural
interstates Unfortunately such studies often tend to be discounted by
advocates of increasing the speed limits as being produced by biased
industry sources
Similar conclusions were also presented by NHTSA in February 1998 in its
report to the Congress entitled ―Report to Congress The Effect of Increased
Speed Limits in the Post-NMSL Era see link given below Among its key
Page 22 of 45
findings is the following quoted in its entirety NMSL refers to the National
Maximum Speed Limit legislated after the Arab oil embargo of 1973
httpwww-nrdnhtsadotgovPubs808-637PDF
hellip Nevertheless it is important to note that data currently available from the
National Highway Traffic Safety Administrationrsquos (NHTSA) Fatality Analysis
Reporting System (FARS) shows that states that increased speed limits in 1996
experienced approximately 350 more Interstate fatalities than would have been
expected based on historical trends -- about 9 percent above expectations
Concurrently the Interstate fatalities experienced in states that did not increase speed
limits in 1996 was consistent with pre-1996 trends The estimated increase in
Interstate fatalities found in this study while smaller in magnitude compared to the
estimated change in fatalities found in 1987 following the increase of speed limits on
rural Interstates does follow the historical pattern of increases in fatalities being
associated with increases in posted speed limits
The annual crash reports compiled by NHTSA see Table 3 indicate that the
number of fatal crashes (and hence fatalities using the regression equation
developed in Figure 4) increase as the posted speed limits increase
Page 23 of 45
Table 3 Posted speed limits and number of crashes
Speed Limit Crashes (2008) Crashes (2009)
30 mph or less 3705 3277 35 or 40 mph 6115 5516 45 or 50 mph 6461 6074
55 mph 9794 8847 60 mph or higher 6908 6124
Total 34017 30797
Source httpwww-nrdnhtsadotgovPubs811402EEpdf
61 Studies cited in favor of lower speed limits
A detailed analysis of speeding related fatalities (see link below) by NHTSA
shows that a third of all crashes involve speeding ie at least one driver was
speeding
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Furthermore the above report which covers the period 1983-2002
indicates that immediately after the NMSL was completely abolished in
December 1995 the number of speeding related fatalities at speeds
above 65 mph increased from just 15 in 1995 to a 677 in 1996 (see Table
62 on page 43 of above report) It continued to increase in the years
since climbing to 930 in 2000
More detailed studies similar to that noted above by researchers at the
University of Illinois Chicago led by Lee S Friedman again lead to the
conclusion that higher speed limits lead to an increase in the number of
fatalities (see American Journal of Public Health online July 16 2009)
httphealthusnewscomhealth-newsmanaging-your-
healthcarearticles20090716deaths-injuries-increase-with-higher-speed-
limits
Page 24 of 45
httpwwwmedpagetodaycomPublicHealthPolicyPublicHealth15122
httpwwwamericaneercomspeed-limits
httpwwwactuarialoutpostcomactuarial_discussion_forumarchiveindexph
pt-171870html
For the study period 1995-2005 these researchers found that 12545 deaths
and 36582 injuries could be attributed to the increased speed limits The
benefits of reduced speed limits are stated quite eloquently by Dr Friedman
and are reproduced below (from above news article see link)
Reduced speed limits would save lives Friedman said They would also reduce
gas consumption cut emissions of air pollutants save valuable years of productivity
(lost due to injuries)and reduce the societal cost of motor vehicle crashes (due to
both fatal crashes and due to nonfatal and severe life-changing injuries) he added
Friedman and coworkers have also shown that increasing the speed limit led
to an immediate increase in the number of fatalities on Israeli roadways (see
link below)
httpinjurypreventionbmjcomcontent133156
The effect of speeding is very significant especially in rural areas resulting
in significantly higher fatalities Fatality rates are frequently double or triple
that in urban areas (see link below)
httpsafetyfhwadotgovspeedmgtdata_factsdocsspeeding_ruralpdf
As of Jan 1 2005 five Midwestern states had increased the speed limits to
above 65 mph (Illinois Iowa Kansas Minnesota Missouri Nebraska and
South Dakota) whereas three (Illinois Iowa and Wisconsin) had not All the
five states with increased speed limits showed a 7 to 13 increase in
fatalities The NHTSA study considered an eight year period before and after
the change in Dec 1995 (see Table 1 in link below) The collective experience
of the states that did NOT increase the speed limit was a 7 decline in
fatalities (see Table 2 of link below)
httpwwwiowadotgovmvdodsstats2006speedstudypdf
Page 25 of 45
Moreover Table 5 in the above study shows the effect of imposing the NMSL
of 55 mph in Iowa and its repeal in 1995 Considering a four-year average
before 1974 when the speed limit was 75 mph there were 35 fatal crashes
with 43 fatalities In the first four years after the 55 mph there were only 23
fatal crashes and 28 fatalities In the last four years before the repeal of 55
mph in 1995 there was a further decline to 14 fatal crashes with 17 fatalities
The Iowa fatality data will be discussed in more detail separately (in a later report)
since it provides the opportunity to assess the effect of a change in the speed limit
on the relationship between number of fatalities and fatal crashes (as seen in
Figure 4 for the US as a whole)
North of the US border Canadians seem to be citing the ―shocking increase
in highway fatalities in the US states where the speed limits were raised to
curb their own speed limits
httparchivesafety-councilorginfotrafficspeed-02html
httparchivesafety-councilorginfotrafficspeedhtml
Speed kills but speed also sells notes the second of the above news items
Manufacturers are producing more high performance cars (with higher horse
power to weight ratio) and ads feature enticing cars that race and swerve in
miraculous ways on empty roads These subliminal messages encourage
drivers especially young drivers to break the speed limit leading to the
absolute increase in highway fatalities (although the rate itself is going
down) The article emphasizes the need to enforce the speed limit on
Canadian highways and in cities where street racing is becoming a problem
62 Studies cited by opponents of lower speed limits
In fairness to quote the opponents on the other side of this debate Montana
reverted back to Reasonable and Prudent speed limits when the National
Maximum Speed Limit was repealed in 1995 and appears to have
experienced no significant increase in fatalities
Page 26 of 45
httpwwwhwysafetycomhwy_montanahtm
httpwwwmotoristsorgpressmontana-no-speed-limit-safety-paradox
httpwwwsouthbayriderscomforumsshowthreadphpt=81453amppage=1
Likewise studies in the state of Maryland showed no significant increase in
highway fatalities when the speed limit was increased from 55 mph to 75
mph The reason might simply be that drivers were already speeding much
more so when the speed limit was 55 mph than after the increase to 75 mph
In other words the fatalities data already reflects the effect of higher speeds
(not speed limits) on the number of fatalities
In Utah the experimental increase in the speed limit to 80 mph was
considered to be a success in terms of safety
httpautosaolcomarticleutah-speed-limit-tests
The UDOT Director noted that there was no increase in the number of
accidents on Interstate 15 But what happens in the event of an accident
when the speed limits are higher and drivers are driving at higher speeds and
two objects collide at this higher speed However no increase in the number
of accidents is not the same as no increase in fatalities due to the higher
speeds When accidents do occur do fatalities increase
Likewise in California when the speed limit went up from 55 mph to 65
mph in 1995 (after repeal of NMSL) fewer deaths were reported in 1998
compared to the peak year of 1979 or even 1987 Again the explanation
seems to be that motorists were already speeding when the limit was 55 mph
and that increasing the speed limit did not change driver behavior in any
significant way
httparticlessfgatecom1998-11-02news17735730_1_speed-limits-mph-
limit-death-rate
The National Motorists Association (NMA) a group which advocates higher
speed limits emphasizes the importance of considering fatality rates as
opposed to the raw fatalities The argument used is that fatality rates based
on the fatality per 100 million VMT is the legitimate way to look at the data
Page 27 of 45
This is a never ending debate Historically speaking fatality rates have been
going down ever since the compilation of traffic accidents data began Table
A1 in the appendix of a recent report by NHTSA (see link below) has highway
fatality rate data going back 1921
httpwww-nrdnhtsadotgovPubs811346pdf see appendix page 31
httpwwwmotoristsorgspeed-limitstruth
httpwwwmotoristsorgothercrash-data
httpwwwraisethespeedlimitorgmythshtml
httpwwwcatoorgpubspaspa346pdf
According to Stephen Moore of the Cato Institute (see last of the links above)
―All measures of highway safety show improvement not more deaths and
injuries since 1995 Despite the fact that 33 states raised their speed limits
immediately after the repeal of the mandatory federal speed limit the NHTSA
reported last October that the traffic death rate dropped to a record low level
in 1997lsquo Moreover the average fatality rate even fell in the states that raised
their speed limits
63 The Fatality rate Is it a reliable metric
In 1921 with fewer fatalities and fewer miles driven and the first year for
which the fatality rate could be computed the rate was 2408 It was down to
1479 in 1931 but the number of deaths had climbed to 31963 more than
double the 1921 absolute fatality number of 13253 It had dropped to 550 in
1966 the year of the highly publicized Congressional hearings but the
number of fatalities had climbed to 50984 in that fateful The Highway Safety
Act of 1966 ranks as one of the major acts of Congress and President
Johnson signed it saying that ―we have been tolerating a raging epidemic of
highway deathshellip see extract pasted below
httpwwwenotescommajor-acts-congresshighway-safety-act
Page 28 of 45
The act was motivated primarily by growing public concern over the rising number
of traffic fatalities in the United States Between 1960 and 1965 the annual number
of traffic fatalities increased by nearly thirty percent As President Lyndon B
Johnson stated at the signing of the act on September 9 1966 we have tolerated
a raging epidemic of highway death which has killed more of our youth than all
other diseases combined Through the Highway Safety Act we are going to find out
more about highway diseasemdashand we aim to cure it
Nonetheless highways fatalities continued to increase until the Arab oil
embargo of 1973 led to the NMSL of 55 mph all across the USA Do we just
ignore this undeniable historical record and focus only on the declining fatality
rate as the NMA and other proponents of higher speed limits seem to argue
(see links above)
The misleading nature of using fatality rates (per 100 M VMT) alone is also
obvious if one considers fatality data for individual states Take for example
the state of Montana which seems to have experienced no increase in
fatalities after repeal of NMSL
httpwww-nrdnhtsadotgovdepartmentsnrd-
30ncsaSTSI30_MT200930_MT_2009htm
For the period 2005-2009 the absolute number of fatalities for Montana
varied between a high of 277 in 2007 to a low of 229 in 2009 The fatality
rates per 100 M VMT on the other hand varied from a high of 245 for 2007
to a low of 201 for 2009 The corresponding US fatality rates varied from
136 to 114 Is the higher number for the fatality rate for Montana compared
to USA good or bad Likewise fatality rate per 100000 of population was
much higher for Montana than the US as a whole
This again highlights the pitfalls of using simple ratios to assess fatality statistics
without a full analysis of the underlying trends We will discuss this point
separately
As shown already the continuous decline in the fatality rate is a mathematical
artifact and essentially overlooks the unmistakable positive correlation
between the variables x and y of the type y = hx + c which becomes obvious
Page 29 of 45
only when we prepare the x-y scatter graph The ratio yx = h + (cx) can
decrease with increasing x (VMT) and increasing y (fatalities) since the
intercept c has a positive value when we consider only data spanning a short
period (such as 1994-2009 of more relevance to the current situation)
The debate between fatality rates and absolute number of fatalities is an
unending one A few years ago the Wall Street Journal carried an article
which was entitled (or something close) ―Unemployments rate in Ohio are
going down but why is the number of unemployed increasing The reason is
the same The graph of the number of unemployed (y) versus the number in
the labor market (x) is linear with a positive slope h and a positive intercept c
So the unemployment rate computed using the ratio yx keeps going down
year after year although the number unemployed keeps increasing Is it a
good thing that the unemployment rate is going down when more people
seem to be unable to find gainful unemployment
Or consider the situation with cancer death rates This too has been going
down in recent years but the actual number of cancer-related deaths has not
declined in any significant way Is it good that cancer death rates are going
down In all these situations the researchers or the socio-econo-politico
analysts involved in analyzing the trends in the data have failed to consider
the underlying x-y relation describing each problem
Hence it appears that the debate on the effect of increased speed limits
should not be focused on only the fatality rates (which have been decreasing
and proponents of higher speed limits cite this in their arguments) or even the
absolute number of fatalities (which has been the focus here) but on the
relationship between speed and the number of fatal crashes and the number
of fatalities within each speed segment (see Table 3 and also Figure 4)
Unfortunately details of number of fatalities and the number of fatal crashes
at each speed limit are not available even from NHTSA for detailed study
When a crash does occur (it is immaterial how many miles were driven) the
speed of the driver and vehicle design and engineering including safety
devices in place (seat belts airbags other impact absorbing technologies)
Page 30 of 45
determine if the occupants(s) will be killed One cannot argue that speed
does NOT kill That would be an absolute denial of the laws of physics
Studies show that setting the speed limit at the 85th percentile in any given
zone (this is the speed at or below which 85 of drivers are observed to
travel in traffic engineering studies) is the safest speed limit The majority of
drivers try to obey the posted speed limit while a few choose to drive at a
speed they consider is safe and prudent These are also perhaps the most
vociferous advocates of higher speed limits It is this tension caused due to
differences in speeds that leads to tailgating improper passing reckless
driving weaving from lane to lane and ultimately crashes and deaths in some
unfortunate cases
httpblogmotoristsorgspeed-limits-slower-safer
MARK TAYLOR
ANOTHER LOST A man was killed when his 4WD drive hit a tree east of Morrinsville (in New
Zealand) on Monday May 30 2011 The driver lost control of the vehicle on a bend probably tried
to correct his mistake and put the car into a ―yaw causing it to leave the road and smash sideways
into a tree Alerts to slow down had been posted since this was a high accident area but the driver
probably did not pay attention
64 Other factors
Many other factors besides speed no doubt affect highway fatalities The
vehicles of the 21st century are very different from the vehicles of the mid 20th
Page 31 of 45
century Technological innovations such as improvements in vehicle design
and engineering have greatly increased crash worthiness of vehicles even at
high speeds Environmental factors such as the weather also contribute to
accidents but not necessarily to increased fatalities Drivers actually tend to
slow down instinctively during adverse weather conditions (rain snow storms
etc) and although such weather may contribute to increased accidents the
lower speeds actually reduce fatalities
Yes technology has changed fundamentally from 1966 Drivers today are
more distracted by their cellmobile phone conversations (and also built-in
phones in luxury models) and text messaging than the drivers of the pre-1966
era High end cars now have many multimedia and internet features Again a
careful observation (even personal experience by the author) suggests that
such distracted drivers actually tend to (instinctively) drive more slowly and
hold up the traffic Perhaps such behavior leads to an increase in the number
of accidents but it does not necessarily lead to an increase in the number of
accident-related fatalities
Much talked about technological innovations such as automatic collision
avoidance systems and sensors (on the sides of vehicles) can indeed detect
vehicles in the front and neighboring lanes Furthermore vehicle-to-vehicle
communication systems vehicle-to-infrastructure communication systems
can no doubt avoid collisions and accidents Again such collision avoidance
systems work and are effective entirely because they automatically reduce
vehicle speeds - even if one of the offending vehicles is being at a super
high speed Also it must be remembered that such futuristic systems have
not yet been implemented widely nor can they be implemented widely since
the large majority of vehicles on the road are NOT luxury models Advanced
safety features come with a price and not all drivers can afford to pay that
price and ―buy that ―additional safety
Ultimately it is the laws of physics that govern what will happen when two or
more vehicles collide or even when a single vehicle collides with a stationary
infrastructural object (a bridge a wall a building or some impediment on the
road) The lower the number of crashes the lower the number of fatalities as
revealed by the 1994-2009 data graphed in Figure 5 The higher the speed of
Page 32 of 45
the object or objects that are involved in a collision the higher the kinetic
energy K that must be absorbed andor dissipated Increasing the posted
speed limit only increases the energy that must be absorbed when a crash
does occur This ultimately is the most important criterion determining the
number of fatalities
The kinetic energy increases as the square of the speed being given by the
well-known formula K = frac12 mv2 where m is the mass of the vehicle (in
laypersonlsquos language m increases directly with vehicle weight) and v is the
speed For the same vehicle mass an increase in the speed from 55 mph to
85 mph increases the kinetic energy K by a factor of 239 or roughly a 250
increase in the kinetic energy that must be absorbed in a collision
Ideally speaking the kinetic energy of the colliding object(s) is absorbed by
the vehicle infrastructure (a sturdy space frame the engine other vehicle
components etc) andor the surroundings However in the unfortunate
cases where this kinetic energy must be absorbed by the vehicle occupant(s)
the result is severe life-altering injuries andor death An unequivocal
relationship between an increase in vehicle speeds and fatal accidents can
be demonstrated by a careful examination of available traffic fatality data
This is a more involved discussion and is not the purpose of this short
communication These topics are no doubt very politically charged with many
social legal and financial implications with each interest group favoring a
different conclusion Nonetheless we cannot escape the laws of physics as
they govern the fundamental need to absorb higher and higher values of the
kinetic energy K with increasing vehicle speeds This same point is also
emphasized by Dr Friedman of the University of Illinois Chicago (see earlier
discussion)
Speed kills because of these energy transfer considerations and there can be
no doubt about it
Innovative 21st century solutions to speed management on the highways
such as strict enforcement of speed limits minimizing speed dispersion
(difference between speeds at which different drivers travel) while using
cameras to track the 15 of drivers who willfully violate the speed limit and
Page 33 of 45
create hazardous driving conditions is certainly recommended (Recall that
the optimum recommended speed limit is at or below which 85 of all drivers
travel ndash a policy also supported by NMA) Even on this score however the
results are confounding if we consider the Australian experience
httpwwwthenewspapercomnews282840asp
Up until 2007 there was no speed limit in the Northern Territory of
Australia Imposing a speed limit 130 kmph (80 mph) on some areas and
110 kmph (68 mph) in some others actually increased the number of deaths
The death toll in 2006 when there was no speed limit in this region was 44
and went up to 75 in 2009 see data table in link below
httpwwwthenewspapercomrlcdocs2009au-ntroadtollpdf
Furthermore it appears that installation of cameras to enforce speed limits
has proved to be a hazardous distraction to drivers and deaths actually
began to skyrocket between 2005 and 2007 in all Australian roadways
The main purpose here is to sound a cautionary note amid renewed attempts
in many states across the US to increase the speed limits on our highways by
calling attention to the historical facts regarding the ―epidemic levels of
highway traffic fatalities that engaged our national attention in the fateful year
of 1966 The graphical representation of the traffic fatality data in Figures 1
to 5 tells its own story
Indeed it would be tragic if highway-accident-related fatalities were to start
increasing once again and reach the historically high level that was last seen
in 1972 the year before the Arab oil embargo of 1973
Page 34 of 45
Conclusions
1 The graphical representation of the highway fatality data and the brief
summary of the historical facts of traffic safety legislation suggest that
recent attempts to increase the speed limits by various states (notably
Texas) may be misguided The distinct peak in the highway fatalities
observed in these graphs is highly alarming This appears to be related to
the enactment of the National Maximum Speed Limit (NSML) in 1974
following the 1973 Arab oil embargo Although NSML was motivated by a
desire to reduce gasoline consumption an unintended benefit might have
been a dramatic reduction in fatalities The fundamental reasons for the
peak in the fatalities-VMT curve must be examined carefully without
political posturing
2 The widely used fatality rate fatalities per 100 M vehicle miles traveled
has been declining since 1921 the first year for which a fatality rate could
be computed and has now reached a historical low The absolute number
of fatalities on the other hand was increasing in the 1950s and 1960s at
an alarming rate and the public outcry that ensued led to the highly
publicized Congressional hearing of 1966 and the subsequent traffic safety
legislations The fatality rate has been decreasing even in the most recent
15-year period (1994-2009) again with increasing fatalities although less
dramatically Thus it appears that fatality rate calculation based on vehicle
miles traveled (VMT) might not be a reliable indicator of the underlying
dynamics in the fatality trends
3 More detailed compilation of number of fatalities and the number of fatal
crashes within each speed limit segment is required to better understand
the effect of increasing speed limits on highway fatalities (and also fatality
rates) Such data is already available and is being compiled at the local
city and county levels in all jurisdictions and only needs to be reorganized
to highlight the effect of (posted) speed limits on the number of crashes
and fatalities This will require some minor rewriting and revisions to the
chapters named ―Crashes and ―States in the annual NHTSA reports
Page 35 of 45
Analysis of the fatalities-crashes data for several years with various
speed limits will be more revealing and meaningful than the current
fatality rates analysis and will be discussed separately in a follow up
report
4 One should not be lulled by the fact that vehicles of the 21st century are
now equipped with advanced safety features not available in the 1950s
and the 1960s In spite of these safety features the laws of physics dictate
that the higher the speed the higher kinetic energy of the colliding objects
and hence the greater the risk indeed near certainty of fatalities in a
higher speed collision compared to a lower speed one
5 The higher the speed at which the vehicle that is involved in a crash is
traveling the higher the kinetic energy that must be absorbed andor
dissipated without affecting the occupant(s) to avoid serious injuries andor
death This was true in the 1950s and the 1960s and will continue to be
true in the 21st century as well
Speed Kills for this just reason
6 It appears that higher fuel economies and reduced
highway fatalities were the twin societal benefits of 55
mph adopted after 1973 If so the current attempts to
increase the speed limits appear to be in conflict with
other important societal objectives
Page 36 of 45
Table 1 Annual US Street amp Highway
Fatalities from 1957
Year
Fatalities
Vehicle Miles
(millions)
Rate100M Vehicle Miles
1957 38702 646915 598
1958 36981 664915 556
1959 37910 700478 541
1960 38137 718845 531
1961 38091 737535 516
1962 40804 766852 532
1963 43564 805423 541
1964 47700 846500 563
1965 49163 887640 554
1966 51524 927915 555
1967 51559 965132 534
1968 53831 1019726 528
1969 55032 1066108 516
1970 53672 1114098 482
1971 53761 1183524 454
1972 55704 1264614 440
1973 55113 1316207 419
1974 46078 1282790 359
1975 45500 1330074 342
1976 45523 1402380 325
1977 47878 1467027 326
1978 50331 1544704 326
1979 51103 1529133 334
1980 51091 1527295 335
1981 49301 1552803 317
1982 43945 1595010 276
1983 42589 1652788 258
1984 44257 1720269 257
1985 43795 1774179 247
Page 37 of 45
1986 46056 1835000 251
1987 46385 1921000 241
1988 47093 2026000 232
1989 45555 2107040 216
1990 44529 2147501 207
1991 41162 2172214 189
1992 39235 2239828 175
1993 40115 2296585 175
1994 40676 2359984 172
1995 41798 2422696 173
1996 41907 2485848 169
1997 41967 2560373 164
Data from Federal Highway Administration
Source httpwwwpublicpurposecomhwy-fatal57+htm
Telephone +16186328507 - Facsimile +16186328538
WENDELL COX CONSULTANCY P O Box 841 - Belleville IL 62269 USA
Page 38 of 45
Fatality data for 1921-1982 compiled by NHTSA
Year
VMT
(Millions)
VMT
(Billions)
Fatalities
Fatality rate
per 100 M VMT
1921 55027 5503 13253 241 1922 67697 6770 14859 219 1923 84995 8500 17870 210 1924 104838 10484 18400 176 1925 122346 12235 20771 170 1926 140735 14074 22194 158 1927 158453 15845 24470 154 1928 172856 17286 26557 154 1929 197720 19772 29592 150 1930 206320 20632 31204 151 1931 216151 21615 31963 148 1932 200517 20052 27979 140 1933 200642 20064 29746 148 1934 215563 21556 34240 159 1935 228568 22857 34494 151 1936 252128 25213 36126 143 1937 270110 27011 37819 140 1938 271177 27118 31083 115 1939 285402 28540 30895 108 1940 302188 30219 32914 109 1941 333612 33361 38142 114 1942 268224 26822 27007 101 1943 208192 20819 22727 109 1944 212713 21271 23165 109 1945 250173 25017 26785 107 1946 340880 34088 31874 94 1947 370894 37089 31193 84 1948 397957 39796 30775 77 1949 424461 42446 30246 71 1950 458246 45825 33186 72 1951 491093 49109 35309 72
1952 513581 51358 36088 70
Page 39 of 45
1953 544433 54443 36190 66 1954 561963 56196 33890 60 1955 605646 60565 36688 61 1956 627843 62784 37965 60 1957 647004 64700 36932 57 1958 664653 66465 35331 53 1959 700480 70048 36223 52 1960 718762 71876 36399 51 1961 737421 73742 36285 49 1962 766734 76673 38980 51 1963 805249 80525 41723 52 1964 846298 84630 45645 54 1965 887812 88781 47089 53 1966 925899 92590 50894 55 1967 964005 96401 50724 53 1968 1015869 101587 52725 52 1969 1061791 106179 53543 50 1970 1109724 110972 52627 47 1971 1178811 117881 52542 45 1972 1259786 125979 54589 43 1973 1313110 131311 54052 41 1974 1280544 128054 45196 35 1975 1327664 132766 44525 34 1976 1402380 140238 45523 32 1977 1467027 146703 47878 33 1978 1544704 154470 50331 33 1979 1529133 152913 51093 33 1980 1527295 152730 51091 33 1981 1555308 155531 49301 32 1982 1595010 159501 43945 28
Source Analysis of Significant Decline in Motor Vehicle Traffic Fatalities in
2008 httpwww-nrdnhtsadotgovPubs811346pdf see Table A1 page 31
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Page 40 of 45
Acknowledgements
The author is grateful for thoughtful comments provided by friends and colleagues
with whom this document was shared via email prior to it being uploaded as a
publicly available document for wider dissemination and study The comments
offered by Prof Subra Ganesan of Oakland University Electrical and Computer
Engineering Department are reproduced with permission in their entirety
About the author
The author obtained his Masterrsquos (S M) and Doctoral (Sc D) degrees in Materials Engineering
from the Massachusetts Institute of Technology Cambridge USA He then spent his entire
professional career at leading US research institutions (MIT NASA Case Western Reserve
University and General Motors R amp D Center in Warren MI) He holds four patents in advanced
materials processing has co-authored two books and has published several scientific papers in
leading peer-reviewed international journals His expertise includes developing simple
mathematical models to explain the behavior of complex systems He can be reached by email at
vlaxmananhotmailcom
Page 41 of 45
Please Buckle Up
httpwwwlakecountypublichealthorgindexphpbuckle-up-montana
Public Awareness
Respect the Cage Exhibit
The Department of Transportation hopes that showing the reality of the crash will reduce traffic
fatalities A crushed car crash dummies and a sobering message ndash all part of the ―Respect The
Cage exhibit that is traveling across Montana The exhibit sponsored by the Montana Department
of Transportation stopped in Ronan on November 6th and is aimed at raising awareness about the
importance of wearing seat belts
The car in the exhibit was in an actual wreck many years ago
the passenger in the vehicle died because he was not wearing a
seat belt the driver who was wearing his seat belt survived
Montanarsquos likeliest crash fatality scenario
A Pickup
A Rural road
And Seat belts that
arenrsquot used
Page 42 of 45
Occupants of pickups are less likely to wear seat belts and pickups are more likely to
roll over than passenger cars
Seat belts reduce the risk of death by 60 percent in pickups and SUVs
In Montana from 2006-2008 81 of those killed in a crash while riding in a pickup were not wearing seat belts
In Montana pickups make up 401 of the vehicle population
For more information on Respect the Cage click here
Page 43 of 45
Appendix 1
Lack of seat belts leading cause of Louisiana highway deaths
1251 AM May 28 2011 |
Written by Adam Duvernay
Crashes involving unbuckled motorists were the leading cause of highway fatalities
in Louisiana last year and cost $9888 million according to recent reports The
Louisiana Highway Safety Commission reported 59 percent of vehicle occupants
killed in Louisiana crashes last year mdash about one in four mdash werent wearing seat
belts
httpwwwshreveporttimescomarticle20110528NEWS01105280354Lack-seat-
belts-leading-cause-La-highway-deathsodyssey=tab|topnews|text|FRONTPAGE
Crash bull Stats Published by NHTSAlsquos National Center for Statistics and Analysis 1200 New Jersey Avenue SE Washington DC 20590
DOT HS 811 451
Early Estimate of Motor Vehicle Traffic Fatalities in 2010
httpwww-nrdnhtsadotgovPubs811451pdf
Summary
A statistical projection of traffic fatalities in 2010 shows that an estimated 32788
people died in motor vehicle traffic crashes This represents a decline of about 3
percent as compared to the 33808 fatalities in 2009 as shown in Table 1 If these
projections are realized fatalities will be lowest on record (since 1949)
Traffic Safety Facts Overview 2009 Data
httpwww-nrdnhtsadotgovPubs811392pdf
In 2009 33808 people were killed in the estimated 5505000 police-reported
motor vehicle traffic crashes 2217000 people were injured and 3957000
crashes involved property damage only Compared to 2008 this is a 10-
percent decrease in the number of fatalities and a 5-percent decrease in the
Page 44 of 45
number of police-reported motor vehicle traffic crashes people injured and
crashes involving property damage
An average of 93 people died each day in motor vehicle crashes in 2009 mdash
an average of one every 16 minutes
Traffic Safety Facts Overview 2008 Data
httpwww-nrdnhtsadotgovPubs811162pdf
In 2008 37261 people were killed in the estimated 5811000 police-reported
motor vehicle traffic crashes 2346000 people were injured and 4146000
crashes involved property damage only
Some comments and Feedback
The following comments were received from Prof Ganesan after his review of the
first draft of this document It was subsequently revised thanks to this input to
address some of the very important issues raised here
Dear Laxman
The write up is not enough
You are emphasizing that the speed limit reduces the fatal accidents (comparing 1966
to 2000 accident numbers)
Can you also add a few sentences why the number is decreasing from 1980 to 2000
values (May be due to better design of vehicles)
Can you say anything about the fuel consumption with the speed for any typical
vehicle in 2011 or 2010 (do not consider the fatalities issue)
Probably a speed between 55 and 60 mph gives a better mileage If so this is a
compelling reason to keep the speed limit low But cars probably can be tuned to
give better mileage at any high speed also
Page 45 of 45
Weather is also a major factor in fatal accidents Speed limit may be kept low during
winter and kept higher in summer Give your comments on this too
Driver distractions can cause more accidents Now cars have many multimedia and
internet features Automatic collision avoidance systems and sensors on the sides can
detect vehicles in the front and neighboring lanes and it can automatically decrease
speed even if the driver speeds at super high speeds
Give some comments on this too There is also Vehicle to Vehicle communications
vehicle to infrastructure communications and they can avoid collisions and accidents
Technology has changed from 1966 I cannot agree with you on the speed limit
without any discussion on the above and other factors
Have a great day
Subra Ganesan
Professor Subramaniam Ganesan
Director Real Time amp DSP Lab
Electrical and Computer Engineering Department
2200 Squirrel Road Dodge Hall Room 105
Oakland University Rochester MI 48309 USA
Phone 248 370 2206 Fax 248 370 4633
wwwsecsoaklandedu~ganesan
IEEE Distinguished Visiting Speaker (2005-2009) Coordinator
IEEE SEM CS chapter Chair Region 4 and CS Society Board member
SAE ASEE ACM member
Page 7 of 45
httpwwwugptiorgpubspdfDP188pdf
httpwwwlakecountypublichealthorgindexphpbuckle-up-montana
2 A brief review of historical traffic
fatality data compiled by NHTSA
The NHTSA uses the fatality rate as its single most important measure of
traffic safety The fatality rate is the ratio yx where x is the total vehicle miles
traveled (usually expressed in billions) by all US drivers and y is the absolute
number of highway fatalities To arrive at a simple tractable number the rate
is determined per 100 million vehicle miles traveled (acronym VMT)
Although this fatality rate yx has now reached a historical low in 2010
exclusive focus on this ratio while overlooking the underlying x-y trend might
be misleading as will become evident from the graphical representation of
the historical data being attempted here
Driver Behavior
Driver Drinking
Too Fast
Not Wearing
Seat Belts
Montanarsquos Likeliest
Fatal Crash Scenario
A Pick up
A Rural road
And Seat belts not
used
Page 8 of 45
Figure 1 Graph of the absolute number of US highway fatalities since 1957 The raw
data used to prepare this graph may be found in Table 1(relegated to the end of this
document) The absolute number of highway fatalities were quite low in the 1950s
and reached a peak in the late 1960s to early 1970s and have since decreased to
levels seen in the 1950s although the vehicle miles driven (in millions) has been
increasing from 646915 in 1957 to 2560373 in the year 2000 see also Figure 2
The fatality data from other government sources have also been studied by the author
and lead to the same conclusion of a peak in highway deaths around the late 1960s to
early 1970s
Page 9 of 45
Figure 2a Graphical representation of the absolute number of US highway fatalities
versus annual vehicle miles driven (in trillions) The number of miles driven by US
drivers has increased each year since 1957 as seen in Table 1 The absolute number
of highway fatalities has increased as well reaching a peak in the late 1960s to early
1970s The same peak is also seen here in the graph of the absolute number of
highway fatalities versus vehicle miles driven Improvements in vehicle safety devices
(notably seat belts and airbags) coupled with the institution of the national highway
speed limits (starting mid 1970s) and also improved highways are the primary
reasons for the decrease in fatalities These historical trends suggest that renewed
attempts to increase the speed limits on our highways would be counterproductive
and may eventually lead once again to an increase in fatalities with tragic
Page 10 of 45
consequences
Figure 2b Graphical representation of the US highway fatality data for the period
1921-1982 The first year for which a fatality rate yx could be computed is 1921 The
number of fatalities was 13253 and VMT was 5503 billion yielding a fatality rate of
2408 per 100 million VMT The fatality rate for any year is the slope of the ray ie
the straight line joining the (x y) data point back to the origin (00) of this graph see
dashed line for 1921 superimposed on to the graph The fatality rates (slopes of such
rays) had been declining quite consistently although the absolute number of fatalities
increased as seen here ultimately leading to the Congressional hearing in 1966 Is
VMT the single most important reason for the increasing fatalities
Page 11 of 45
Figure 3 Graphical representation of the traffic fatality data for the 15 year period
1994-2009 A sudden precipitous drop in the absolute number of fatalities (at least on
the magnified scale used here) and hence the fatality rate has been observed over
the three-year period 2007-2009 However it should be noted that the x-y scatter
graph here shows a general upward trend with fatalities actually increasing with
increasing VMT (as in the earlier era 1950s and 1960s) during the 12-year period
spanning 1994-2006 although the rate yx shows a misleading downward trend Why
is the rate yx going down
The reason is very simple and it may be just a mathematical artifact The equation of
the best-fit straight line through the most recent data points is of the form y = hx + c
= 2865 x + 34420 where h is the slope of the line and c the intercept (Note that x
here is VMT in billions The numerical value determined using this equation must be
divided by 10 to get the rate per 100 M VMT) Hence the fatality rate given by the
ratio yx = h + (cx) = 2865 + 34420x can actually decrease with increasing
values of x because of the nonzero intercept c Unlike the ray through the origin the
best-fit line does not pass through the origin (00) If we consider only the most
Page 12 of 45
recent data the intercept c is positive and fatality rates yx decrease with increasing
VMT and increasing fatalities In the earlier era both the slope h and intercept c had
very different values due to several factors being discussed here (speed limits
technology highway design etc)
Table 2 Traffic fatality data for the recent 15-year period
1994-2009 (Source NHTSA)
Year
Highway
fatalities y
Vehicle miles
traveled
VMT
(billions) x
Fatality rate
yx per 100
million VMT
Fatal crashes
1994 40716 2358 173 36254 1995 41817 2423 173 37241 1996 42065 2486 169 37494 1997 42013 2562 164 37324 1998 41501 2632 158 37107 1999 41717 2691 155 37140 2000 41945 2747 153 37526 2001 42196 2797 151 37862 2002 43005 2856 151 38491 2003 42884 2890 148 38477 2004 42836 2965 144 38444 2005 43510 2989 146 39252 2006 42708 3014 1 42 38648 2007 41259 3032 136 37435 2008 37423 2974 126 34172 2009 33808 2979 113 30797
Page 13 of 45
Figure 4 The most significant metric used by NHTSA is the fatality rate per 100
million vehicles miles traveled (VMT) This is now at a historical low of 113 for
2009 having declined year after year from 173 in 1994 The NHTSA however also
compiles other types of data on crashes There are three types of crashes fatal
injury but no death and property damage only A careful review of this crash data
for the period 1994-2009 reveals the obvious the lower the number of (fatal)
crashes x the lower the number of highway-accident-related fatalities y It is also
obvious that the number of fatalities per crash is greater than one ie more than one
person is being killed when one of more vehicles experience a crash
Clearly this is the single most important piece of information that one needs to
reduce the number of fatalities on our highways Vehicle design and engineering as
well as all other policy matters (legal political social environmental financial)
must be guided by this simple graph The best-fit line through the data derived using
simple linear regression has the equation y = hx + c = 114x ndash 10266 and is
Page 14 of 45
superimposed on to the data The design engineering goal and societal goal should
be to reduce the slope h of this statistically significant best-fit line to its ideal value of
h = 1 A fatal crash by definition is one where at least one person dies either an
occupant or a non-motorist in the path of the vehicle Hence the ideal slope h = 1
Photograph of an accident scene from the period 1955-1965
httpwwwcorinthsocialhistoryprojectorghtmlhighwaytollshtml
3 A Brief History of Traffic Safety Legislation
The following is extracted from the Wikipedia article on National Highway
Traffic Safety Administration (NHTSA)
httpenwikipediaorgwikiNational_Highway_Traffic_Safety_Administration
In 1965 and 1966 public pressure grew in the US to increase the safety of
cars The number of deaths on US highways were increasing year after year
Page 15 of 45
see Figure 1 and in 1966 Congress held a series of highly publicized
hearings on highway safety This led to the legislation for mandatory
installation of seat belts which also created the US Department of
Transportation (on Oct 15 1966)
httpwwwemsgovpdf2011EMSWeek2011_Stricklandpdf
The following is extracted from a Washington Post article on
NHTSA dated April 2 2002
httpwwwwashingtonpostcomwp-srvbusinessincludesnhtsa_primerhtm
In 1966 after decades of rising traffic fatalities (also vividly illustrated in
Figures 1 and 2 here) the publication of Ralph Naders Unsafe at Any
Speed and increasing public outcry for safer automobiles Congress held a
series of highly publicized hearings on creating a regulatory agency for traffic
safety Among the witnesses was William Haddon an epidemiologist who
introduced the idea that traffic accidents could be analyzed scientifically and
injuries reduced by changing auto design such as installing collapsible
steering columns safety glass head rests and seat belts
Congress passed the Highway Safety Act of 1966 creating the National
Highway Safety Bureau with Haddon as its first administrator The bureau
became NHTSA in 1970 under the newly established Department of
Transportation An early Nader convert Joan Claybrook headed NHTSA
under President Carter and now runs Naders organization Public Citizen
National Traffic and Motor Vehicle Safety Act
httpwwwanswerscomtopicnational-traffic-and-motor-vehicle-safety-act
Signed into law by President Lyndon Johnson on September 9 1966 this act
created the first mandatory federal safety standards for motor vehicles The
act was motivated by a variety of factors First and foremost the public was
growing increasingly concerned over the rising number of traffic fatalities on
the nations roads Such fatalities had increased by nearly 30 percent
between 1960 and 1965 and experts forecasted 100000 such deaths
Page 16 of 45
annually by 1975 unless something was done to improve traffic safety
Adding fuel to the fire Ralph Naders Unsafe at Any Speed published in
November 1965 criticized the automobile industry for neglecting safety in
favor of power and styling when designing new vehicles
4 The reason for the historical
decrease in highway fatalities
A recent news item see link given below regarding renewed attempts to
increase the speed limit by many states prompted this write up by the
present author who has studied traffic fatality data extensively and analyzed
them very carefully over the last several years
httpmoneymsncomauto-insurancewhy-speed-limits-are-
risingaspxGT1=33033
Residents of Metro Detroit area who frequently cross into Ohio from
Michigan notice that the speed limit has now increased in Ohio The speed
limit on Michigan highways was increased to 70 mph in the late 1990s but
Ohio retained its lower speed limit for many years leading Michigan drivers to
experience a ―speed trap of sorts The speed limit is also increasing in many
other states notably Texas where it is proposed to increase it to 85 mph at
least in West Texas
Historically speaking from a traffic fatality standpoint we must consider two
important dates 1966 and 1973 Only 1973 the year of the Arab oil embargo
following the Arab-Israeli war (that led to what President Obama has recently
called the pre-1967 border for Middle East peace) is mentioned in the above
article It fails to mention the significance of the year 1966
Prior to 1966 there was actually NO speed limit in many Western states and
deaths due to highway accidents were increasing year after year The
Page 17 of 45
number of highway fatalities went up from 38702 in 1957 to 51524 in 1965
a 33 increase over the 1957 level and an additional 12822 deaths in 1965
compared to 1957 It was this carnage on the US highways that forced
Congress to hold its hearings on highway traffic fatalities in 1966
Nonetheless a careful examination of the fatality data in Table 1 shows that
notwithstanding the highly publicized Congressional hearings of 1966 and
new safety legislation that was enacted the absolute number of fatalities
continued to increase after 1966 and only started decreasing after 1973
Vehicle designs especially the introduction of safety features (even the
simplest like safety belts) did not change significantly between 1966 and
1973 Nonetheless post-1973 we begin to see a dramatic turnaround
Why
After the 1973 Arab oil embargo a nationwide maximum speed limit (NMSL)
of 55 mph was imposed and accepted in the USA (effective Jan 1 1974)
during the Nixon administration primarily as an effort to conserve fuel and
reduce the US vulnerability to oil imports The unintended and indeed
fortunate consequence of this reduced speed limit was the immediate
reduction in the fatalities revealed in Figures 2 and 3 This is the real reason
for the peaks in highway fatalities observed in these two graphs
The Congressional hearings of 1966 did eventually have an impact but it was
a delayed one The impact of the 1973 nationwide speed limit of 55 mph was
however immediate as we see from the magnified plot of the same data in
Figure 5 and a closer examination of the raw fatality data in Table 1
The number of highway-accident-related fatalities decreased immediately
from a high of 55704 in 1972 to just 46078 in 1974 a 173 drop see
arrows There were 9626 fewer deaths annually even with a slight increase
in the vehicle miles driven (see Table 1) Indeed the number of highway
death reached its absolute peak value in 1972 never to be seen again
Fatalities have been decreasing every since with slight fluctuations about
each new low value
Page 18 of 45
Figure 5 Expanded view of the fatality data showing the immediate impact of the
national speed limit of 55 mph following the Arab oil embargo of 1973 Note that
fatalities continued to rise between 1966 and 1973 in spite of the highly publicized
Congressional hearings in 1966 and the traffic safety legislation enacted soon after
Each new low is probably associated with vehicle safety innovations and the
improvements in vehicle design and engineering The combined beneficial
effect of improved vehicle designs primarily the introduction of seat belts
and the laws enforcing usage of seat belts aided by the reduced speed
limits contributed to the continued decline in the absolute number of fatalities
that started since 1973 and has continued to this day The subsequent
introduction of other safety features notably air bags has contributed to a
further reduction in highway fatalities
Page 19 of 45
State police Trooper First Class Jeffrey Flowers looking at a car in which a Boswell
Pennsylvania woman was injured Tuesday (May 31 2011) The accident occurred at
an intersection when a truck (seen behind the wrecked car) entered this accident
prone intersection (part of a highway safety corridor where signs are posted to
reduce unsafe driver behavior) There have been four accidents at this intersection
since 2006 none fatal httpwwwdailyamericancomnewssomersetda-ot-woman-
injured-in-route-30-wreck-2011053104165420story
5 Numerical calculations of decline in
fatalities and the impact of NMSL post-1973
Letlsquos consider the decline in fatalities between 1972 the last year before the
adoption of the NMSL and 1974 the first year following its adoption after the
Arab oil embargo There was an immediate decrease in the number of
fatalities by 9393 ie y = -9393 with a slight increase in the VMT ie x
= 20758 millions The NHTSA data used here may be found in the table at
the end of this document The numerical value of the rate of change per
billion VMT (ie neglecting the sign) was therefore
yx = 4525 fatalitiesbillion VMT (1972-1974)
Page 20 of 45
It is instructive to compare this rate of change in fatalities with similar short
periods of a decline in fatalities in the pre-1973 era when speed limits were
much higher The absolute number of fatalities declined over a relatively
short period with both an increase and a decrease in VMT The results are
given below and are self-explanatory
yx = 454 fatalitiesbillion VMT (1953-54) decline with increase in VMT
yx = 655 fatalitiesbillion VMT (1942-43) decline with decrease in VMT
yx = 1739 fatalitiesbillion VMT (1941-42) decline with decrease in VMT
yx = 4528 fatalitiesbillion VMT (1937-39) decline with increase in VMT
yx = 2548 fatalitiesbillion VMT (1931-32) decline with decrease in VMT
The rate of decline observed between 1953 and 1954 with an increase in
VMT was just one-tenth of that observed following the adoption of the 55
mph speed limit The war years (1941-43 WWII) and the Great Depression
era (1931-32) were accompanied by big declines in fatalities with decreasing
VMT but the rate of change was still significantly lower than observed after
the adoption of the NMSL
The only apparently inexplicable decline is that between 1937 and 1939
where a nearly identical high rate of decline was observed Notice also the
big drop in the traditional fatality rate between 1937 and 1938 This large drop
appears to coincide with the creation of the National Safety Council (NSC) by
William H Cameron in June 1937 (see link below) with its far-flung campaign
of education legislation research highway engineering and traffic training
undertaken by the NSC and some two dozen other groups with the backing of the
automotive industry through its Automotive Safety Foundation Other factors
unknown to the present author probably also played a role
httpwwwtimecomtimemagazinearticle0917188379700htmlixzz1O2G
7rnUg
Page 21 of 45
These simple computations here however reveal the significant effect of
reduced speed limits on highway fatalities much more so than other factors
6 Further Considerations Pros and Cons
The singular effect of increased speeds (or speeding) on highway fatalities
has been studied and demonstrated by a number of industry sources such
as the Insurance Institute for Highway Safety (IIHS) Consumers Union and
also by government researchers
httpwwwsmartmotoristcomtraffic-and-safety-guidelineexcessive-speed-is-
a-factor-in-one-third-of-all-fatal-crasheshtml
httpwwwconsumersunionorgotherspeedlimitsspeed031500a2htm
Speed ndash defined as exceeding the posted speed limit or driving too fast for
given conditions ndash is a factor in nearly one-third of all fatal crashes Besides
fatality in 1998 nearly 40000 people were critically injured in speed-related
crashes and nearly 72000 were moderately injured
The salutary and immediate beneficial effect of the nationwide 55 mph speed
limit has been noted by other researchers (see Susan Ferguson link below)
httpwwwnhtsagovpeopleinjuryenforcespeed_forum_presentationsfergu
sonpdf
After a partial repeal of this law in 1987 which granted states the authority to
increase speed limit (especially in rural interstates) a 1989 study showed a
15 increase in fatalities in rural interstates and a 5 increase in non-rural
interstates Unfortunately such studies often tend to be discounted by
advocates of increasing the speed limits as being produced by biased
industry sources
Similar conclusions were also presented by NHTSA in February 1998 in its
report to the Congress entitled ―Report to Congress The Effect of Increased
Speed Limits in the Post-NMSL Era see link given below Among its key
Page 22 of 45
findings is the following quoted in its entirety NMSL refers to the National
Maximum Speed Limit legislated after the Arab oil embargo of 1973
httpwww-nrdnhtsadotgovPubs808-637PDF
hellip Nevertheless it is important to note that data currently available from the
National Highway Traffic Safety Administrationrsquos (NHTSA) Fatality Analysis
Reporting System (FARS) shows that states that increased speed limits in 1996
experienced approximately 350 more Interstate fatalities than would have been
expected based on historical trends -- about 9 percent above expectations
Concurrently the Interstate fatalities experienced in states that did not increase speed
limits in 1996 was consistent with pre-1996 trends The estimated increase in
Interstate fatalities found in this study while smaller in magnitude compared to the
estimated change in fatalities found in 1987 following the increase of speed limits on
rural Interstates does follow the historical pattern of increases in fatalities being
associated with increases in posted speed limits
The annual crash reports compiled by NHTSA see Table 3 indicate that the
number of fatal crashes (and hence fatalities using the regression equation
developed in Figure 4) increase as the posted speed limits increase
Page 23 of 45
Table 3 Posted speed limits and number of crashes
Speed Limit Crashes (2008) Crashes (2009)
30 mph or less 3705 3277 35 or 40 mph 6115 5516 45 or 50 mph 6461 6074
55 mph 9794 8847 60 mph or higher 6908 6124
Total 34017 30797
Source httpwww-nrdnhtsadotgovPubs811402EEpdf
61 Studies cited in favor of lower speed limits
A detailed analysis of speeding related fatalities (see link below) by NHTSA
shows that a third of all crashes involve speeding ie at least one driver was
speeding
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Furthermore the above report which covers the period 1983-2002
indicates that immediately after the NMSL was completely abolished in
December 1995 the number of speeding related fatalities at speeds
above 65 mph increased from just 15 in 1995 to a 677 in 1996 (see Table
62 on page 43 of above report) It continued to increase in the years
since climbing to 930 in 2000
More detailed studies similar to that noted above by researchers at the
University of Illinois Chicago led by Lee S Friedman again lead to the
conclusion that higher speed limits lead to an increase in the number of
fatalities (see American Journal of Public Health online July 16 2009)
httphealthusnewscomhealth-newsmanaging-your-
healthcarearticles20090716deaths-injuries-increase-with-higher-speed-
limits
Page 24 of 45
httpwwwmedpagetodaycomPublicHealthPolicyPublicHealth15122
httpwwwamericaneercomspeed-limits
httpwwwactuarialoutpostcomactuarial_discussion_forumarchiveindexph
pt-171870html
For the study period 1995-2005 these researchers found that 12545 deaths
and 36582 injuries could be attributed to the increased speed limits The
benefits of reduced speed limits are stated quite eloquently by Dr Friedman
and are reproduced below (from above news article see link)
Reduced speed limits would save lives Friedman said They would also reduce
gas consumption cut emissions of air pollutants save valuable years of productivity
(lost due to injuries)and reduce the societal cost of motor vehicle crashes (due to
both fatal crashes and due to nonfatal and severe life-changing injuries) he added
Friedman and coworkers have also shown that increasing the speed limit led
to an immediate increase in the number of fatalities on Israeli roadways (see
link below)
httpinjurypreventionbmjcomcontent133156
The effect of speeding is very significant especially in rural areas resulting
in significantly higher fatalities Fatality rates are frequently double or triple
that in urban areas (see link below)
httpsafetyfhwadotgovspeedmgtdata_factsdocsspeeding_ruralpdf
As of Jan 1 2005 five Midwestern states had increased the speed limits to
above 65 mph (Illinois Iowa Kansas Minnesota Missouri Nebraska and
South Dakota) whereas three (Illinois Iowa and Wisconsin) had not All the
five states with increased speed limits showed a 7 to 13 increase in
fatalities The NHTSA study considered an eight year period before and after
the change in Dec 1995 (see Table 1 in link below) The collective experience
of the states that did NOT increase the speed limit was a 7 decline in
fatalities (see Table 2 of link below)
httpwwwiowadotgovmvdodsstats2006speedstudypdf
Page 25 of 45
Moreover Table 5 in the above study shows the effect of imposing the NMSL
of 55 mph in Iowa and its repeal in 1995 Considering a four-year average
before 1974 when the speed limit was 75 mph there were 35 fatal crashes
with 43 fatalities In the first four years after the 55 mph there were only 23
fatal crashes and 28 fatalities In the last four years before the repeal of 55
mph in 1995 there was a further decline to 14 fatal crashes with 17 fatalities
The Iowa fatality data will be discussed in more detail separately (in a later report)
since it provides the opportunity to assess the effect of a change in the speed limit
on the relationship between number of fatalities and fatal crashes (as seen in
Figure 4 for the US as a whole)
North of the US border Canadians seem to be citing the ―shocking increase
in highway fatalities in the US states where the speed limits were raised to
curb their own speed limits
httparchivesafety-councilorginfotrafficspeed-02html
httparchivesafety-councilorginfotrafficspeedhtml
Speed kills but speed also sells notes the second of the above news items
Manufacturers are producing more high performance cars (with higher horse
power to weight ratio) and ads feature enticing cars that race and swerve in
miraculous ways on empty roads These subliminal messages encourage
drivers especially young drivers to break the speed limit leading to the
absolute increase in highway fatalities (although the rate itself is going
down) The article emphasizes the need to enforce the speed limit on
Canadian highways and in cities where street racing is becoming a problem
62 Studies cited by opponents of lower speed limits
In fairness to quote the opponents on the other side of this debate Montana
reverted back to Reasonable and Prudent speed limits when the National
Maximum Speed Limit was repealed in 1995 and appears to have
experienced no significant increase in fatalities
Page 26 of 45
httpwwwhwysafetycomhwy_montanahtm
httpwwwmotoristsorgpressmontana-no-speed-limit-safety-paradox
httpwwwsouthbayriderscomforumsshowthreadphpt=81453amppage=1
Likewise studies in the state of Maryland showed no significant increase in
highway fatalities when the speed limit was increased from 55 mph to 75
mph The reason might simply be that drivers were already speeding much
more so when the speed limit was 55 mph than after the increase to 75 mph
In other words the fatalities data already reflects the effect of higher speeds
(not speed limits) on the number of fatalities
In Utah the experimental increase in the speed limit to 80 mph was
considered to be a success in terms of safety
httpautosaolcomarticleutah-speed-limit-tests
The UDOT Director noted that there was no increase in the number of
accidents on Interstate 15 But what happens in the event of an accident
when the speed limits are higher and drivers are driving at higher speeds and
two objects collide at this higher speed However no increase in the number
of accidents is not the same as no increase in fatalities due to the higher
speeds When accidents do occur do fatalities increase
Likewise in California when the speed limit went up from 55 mph to 65
mph in 1995 (after repeal of NMSL) fewer deaths were reported in 1998
compared to the peak year of 1979 or even 1987 Again the explanation
seems to be that motorists were already speeding when the limit was 55 mph
and that increasing the speed limit did not change driver behavior in any
significant way
httparticlessfgatecom1998-11-02news17735730_1_speed-limits-mph-
limit-death-rate
The National Motorists Association (NMA) a group which advocates higher
speed limits emphasizes the importance of considering fatality rates as
opposed to the raw fatalities The argument used is that fatality rates based
on the fatality per 100 million VMT is the legitimate way to look at the data
Page 27 of 45
This is a never ending debate Historically speaking fatality rates have been
going down ever since the compilation of traffic accidents data began Table
A1 in the appendix of a recent report by NHTSA (see link below) has highway
fatality rate data going back 1921
httpwww-nrdnhtsadotgovPubs811346pdf see appendix page 31
httpwwwmotoristsorgspeed-limitstruth
httpwwwmotoristsorgothercrash-data
httpwwwraisethespeedlimitorgmythshtml
httpwwwcatoorgpubspaspa346pdf
According to Stephen Moore of the Cato Institute (see last of the links above)
―All measures of highway safety show improvement not more deaths and
injuries since 1995 Despite the fact that 33 states raised their speed limits
immediately after the repeal of the mandatory federal speed limit the NHTSA
reported last October that the traffic death rate dropped to a record low level
in 1997lsquo Moreover the average fatality rate even fell in the states that raised
their speed limits
63 The Fatality rate Is it a reliable metric
In 1921 with fewer fatalities and fewer miles driven and the first year for
which the fatality rate could be computed the rate was 2408 It was down to
1479 in 1931 but the number of deaths had climbed to 31963 more than
double the 1921 absolute fatality number of 13253 It had dropped to 550 in
1966 the year of the highly publicized Congressional hearings but the
number of fatalities had climbed to 50984 in that fateful The Highway Safety
Act of 1966 ranks as one of the major acts of Congress and President
Johnson signed it saying that ―we have been tolerating a raging epidemic of
highway deathshellip see extract pasted below
httpwwwenotescommajor-acts-congresshighway-safety-act
Page 28 of 45
The act was motivated primarily by growing public concern over the rising number
of traffic fatalities in the United States Between 1960 and 1965 the annual number
of traffic fatalities increased by nearly thirty percent As President Lyndon B
Johnson stated at the signing of the act on September 9 1966 we have tolerated
a raging epidemic of highway death which has killed more of our youth than all
other diseases combined Through the Highway Safety Act we are going to find out
more about highway diseasemdashand we aim to cure it
Nonetheless highways fatalities continued to increase until the Arab oil
embargo of 1973 led to the NMSL of 55 mph all across the USA Do we just
ignore this undeniable historical record and focus only on the declining fatality
rate as the NMA and other proponents of higher speed limits seem to argue
(see links above)
The misleading nature of using fatality rates (per 100 M VMT) alone is also
obvious if one considers fatality data for individual states Take for example
the state of Montana which seems to have experienced no increase in
fatalities after repeal of NMSL
httpwww-nrdnhtsadotgovdepartmentsnrd-
30ncsaSTSI30_MT200930_MT_2009htm
For the period 2005-2009 the absolute number of fatalities for Montana
varied between a high of 277 in 2007 to a low of 229 in 2009 The fatality
rates per 100 M VMT on the other hand varied from a high of 245 for 2007
to a low of 201 for 2009 The corresponding US fatality rates varied from
136 to 114 Is the higher number for the fatality rate for Montana compared
to USA good or bad Likewise fatality rate per 100000 of population was
much higher for Montana than the US as a whole
This again highlights the pitfalls of using simple ratios to assess fatality statistics
without a full analysis of the underlying trends We will discuss this point
separately
As shown already the continuous decline in the fatality rate is a mathematical
artifact and essentially overlooks the unmistakable positive correlation
between the variables x and y of the type y = hx + c which becomes obvious
Page 29 of 45
only when we prepare the x-y scatter graph The ratio yx = h + (cx) can
decrease with increasing x (VMT) and increasing y (fatalities) since the
intercept c has a positive value when we consider only data spanning a short
period (such as 1994-2009 of more relevance to the current situation)
The debate between fatality rates and absolute number of fatalities is an
unending one A few years ago the Wall Street Journal carried an article
which was entitled (or something close) ―Unemployments rate in Ohio are
going down but why is the number of unemployed increasing The reason is
the same The graph of the number of unemployed (y) versus the number in
the labor market (x) is linear with a positive slope h and a positive intercept c
So the unemployment rate computed using the ratio yx keeps going down
year after year although the number unemployed keeps increasing Is it a
good thing that the unemployment rate is going down when more people
seem to be unable to find gainful unemployment
Or consider the situation with cancer death rates This too has been going
down in recent years but the actual number of cancer-related deaths has not
declined in any significant way Is it good that cancer death rates are going
down In all these situations the researchers or the socio-econo-politico
analysts involved in analyzing the trends in the data have failed to consider
the underlying x-y relation describing each problem
Hence it appears that the debate on the effect of increased speed limits
should not be focused on only the fatality rates (which have been decreasing
and proponents of higher speed limits cite this in their arguments) or even the
absolute number of fatalities (which has been the focus here) but on the
relationship between speed and the number of fatal crashes and the number
of fatalities within each speed segment (see Table 3 and also Figure 4)
Unfortunately details of number of fatalities and the number of fatal crashes
at each speed limit are not available even from NHTSA for detailed study
When a crash does occur (it is immaterial how many miles were driven) the
speed of the driver and vehicle design and engineering including safety
devices in place (seat belts airbags other impact absorbing technologies)
Page 30 of 45
determine if the occupants(s) will be killed One cannot argue that speed
does NOT kill That would be an absolute denial of the laws of physics
Studies show that setting the speed limit at the 85th percentile in any given
zone (this is the speed at or below which 85 of drivers are observed to
travel in traffic engineering studies) is the safest speed limit The majority of
drivers try to obey the posted speed limit while a few choose to drive at a
speed they consider is safe and prudent These are also perhaps the most
vociferous advocates of higher speed limits It is this tension caused due to
differences in speeds that leads to tailgating improper passing reckless
driving weaving from lane to lane and ultimately crashes and deaths in some
unfortunate cases
httpblogmotoristsorgspeed-limits-slower-safer
MARK TAYLOR
ANOTHER LOST A man was killed when his 4WD drive hit a tree east of Morrinsville (in New
Zealand) on Monday May 30 2011 The driver lost control of the vehicle on a bend probably tried
to correct his mistake and put the car into a ―yaw causing it to leave the road and smash sideways
into a tree Alerts to slow down had been posted since this was a high accident area but the driver
probably did not pay attention
64 Other factors
Many other factors besides speed no doubt affect highway fatalities The
vehicles of the 21st century are very different from the vehicles of the mid 20th
Page 31 of 45
century Technological innovations such as improvements in vehicle design
and engineering have greatly increased crash worthiness of vehicles even at
high speeds Environmental factors such as the weather also contribute to
accidents but not necessarily to increased fatalities Drivers actually tend to
slow down instinctively during adverse weather conditions (rain snow storms
etc) and although such weather may contribute to increased accidents the
lower speeds actually reduce fatalities
Yes technology has changed fundamentally from 1966 Drivers today are
more distracted by their cellmobile phone conversations (and also built-in
phones in luxury models) and text messaging than the drivers of the pre-1966
era High end cars now have many multimedia and internet features Again a
careful observation (even personal experience by the author) suggests that
such distracted drivers actually tend to (instinctively) drive more slowly and
hold up the traffic Perhaps such behavior leads to an increase in the number
of accidents but it does not necessarily lead to an increase in the number of
accident-related fatalities
Much talked about technological innovations such as automatic collision
avoidance systems and sensors (on the sides of vehicles) can indeed detect
vehicles in the front and neighboring lanes Furthermore vehicle-to-vehicle
communication systems vehicle-to-infrastructure communication systems
can no doubt avoid collisions and accidents Again such collision avoidance
systems work and are effective entirely because they automatically reduce
vehicle speeds - even if one of the offending vehicles is being at a super
high speed Also it must be remembered that such futuristic systems have
not yet been implemented widely nor can they be implemented widely since
the large majority of vehicles on the road are NOT luxury models Advanced
safety features come with a price and not all drivers can afford to pay that
price and ―buy that ―additional safety
Ultimately it is the laws of physics that govern what will happen when two or
more vehicles collide or even when a single vehicle collides with a stationary
infrastructural object (a bridge a wall a building or some impediment on the
road) The lower the number of crashes the lower the number of fatalities as
revealed by the 1994-2009 data graphed in Figure 5 The higher the speed of
Page 32 of 45
the object or objects that are involved in a collision the higher the kinetic
energy K that must be absorbed andor dissipated Increasing the posted
speed limit only increases the energy that must be absorbed when a crash
does occur This ultimately is the most important criterion determining the
number of fatalities
The kinetic energy increases as the square of the speed being given by the
well-known formula K = frac12 mv2 where m is the mass of the vehicle (in
laypersonlsquos language m increases directly with vehicle weight) and v is the
speed For the same vehicle mass an increase in the speed from 55 mph to
85 mph increases the kinetic energy K by a factor of 239 or roughly a 250
increase in the kinetic energy that must be absorbed in a collision
Ideally speaking the kinetic energy of the colliding object(s) is absorbed by
the vehicle infrastructure (a sturdy space frame the engine other vehicle
components etc) andor the surroundings However in the unfortunate
cases where this kinetic energy must be absorbed by the vehicle occupant(s)
the result is severe life-altering injuries andor death An unequivocal
relationship between an increase in vehicle speeds and fatal accidents can
be demonstrated by a careful examination of available traffic fatality data
This is a more involved discussion and is not the purpose of this short
communication These topics are no doubt very politically charged with many
social legal and financial implications with each interest group favoring a
different conclusion Nonetheless we cannot escape the laws of physics as
they govern the fundamental need to absorb higher and higher values of the
kinetic energy K with increasing vehicle speeds This same point is also
emphasized by Dr Friedman of the University of Illinois Chicago (see earlier
discussion)
Speed kills because of these energy transfer considerations and there can be
no doubt about it
Innovative 21st century solutions to speed management on the highways
such as strict enforcement of speed limits minimizing speed dispersion
(difference between speeds at which different drivers travel) while using
cameras to track the 15 of drivers who willfully violate the speed limit and
Page 33 of 45
create hazardous driving conditions is certainly recommended (Recall that
the optimum recommended speed limit is at or below which 85 of all drivers
travel ndash a policy also supported by NMA) Even on this score however the
results are confounding if we consider the Australian experience
httpwwwthenewspapercomnews282840asp
Up until 2007 there was no speed limit in the Northern Territory of
Australia Imposing a speed limit 130 kmph (80 mph) on some areas and
110 kmph (68 mph) in some others actually increased the number of deaths
The death toll in 2006 when there was no speed limit in this region was 44
and went up to 75 in 2009 see data table in link below
httpwwwthenewspapercomrlcdocs2009au-ntroadtollpdf
Furthermore it appears that installation of cameras to enforce speed limits
has proved to be a hazardous distraction to drivers and deaths actually
began to skyrocket between 2005 and 2007 in all Australian roadways
The main purpose here is to sound a cautionary note amid renewed attempts
in many states across the US to increase the speed limits on our highways by
calling attention to the historical facts regarding the ―epidemic levels of
highway traffic fatalities that engaged our national attention in the fateful year
of 1966 The graphical representation of the traffic fatality data in Figures 1
to 5 tells its own story
Indeed it would be tragic if highway-accident-related fatalities were to start
increasing once again and reach the historically high level that was last seen
in 1972 the year before the Arab oil embargo of 1973
Page 34 of 45
Conclusions
1 The graphical representation of the highway fatality data and the brief
summary of the historical facts of traffic safety legislation suggest that
recent attempts to increase the speed limits by various states (notably
Texas) may be misguided The distinct peak in the highway fatalities
observed in these graphs is highly alarming This appears to be related to
the enactment of the National Maximum Speed Limit (NSML) in 1974
following the 1973 Arab oil embargo Although NSML was motivated by a
desire to reduce gasoline consumption an unintended benefit might have
been a dramatic reduction in fatalities The fundamental reasons for the
peak in the fatalities-VMT curve must be examined carefully without
political posturing
2 The widely used fatality rate fatalities per 100 M vehicle miles traveled
has been declining since 1921 the first year for which a fatality rate could
be computed and has now reached a historical low The absolute number
of fatalities on the other hand was increasing in the 1950s and 1960s at
an alarming rate and the public outcry that ensued led to the highly
publicized Congressional hearing of 1966 and the subsequent traffic safety
legislations The fatality rate has been decreasing even in the most recent
15-year period (1994-2009) again with increasing fatalities although less
dramatically Thus it appears that fatality rate calculation based on vehicle
miles traveled (VMT) might not be a reliable indicator of the underlying
dynamics in the fatality trends
3 More detailed compilation of number of fatalities and the number of fatal
crashes within each speed limit segment is required to better understand
the effect of increasing speed limits on highway fatalities (and also fatality
rates) Such data is already available and is being compiled at the local
city and county levels in all jurisdictions and only needs to be reorganized
to highlight the effect of (posted) speed limits on the number of crashes
and fatalities This will require some minor rewriting and revisions to the
chapters named ―Crashes and ―States in the annual NHTSA reports
Page 35 of 45
Analysis of the fatalities-crashes data for several years with various
speed limits will be more revealing and meaningful than the current
fatality rates analysis and will be discussed separately in a follow up
report
4 One should not be lulled by the fact that vehicles of the 21st century are
now equipped with advanced safety features not available in the 1950s
and the 1960s In spite of these safety features the laws of physics dictate
that the higher the speed the higher kinetic energy of the colliding objects
and hence the greater the risk indeed near certainty of fatalities in a
higher speed collision compared to a lower speed one
5 The higher the speed at which the vehicle that is involved in a crash is
traveling the higher the kinetic energy that must be absorbed andor
dissipated without affecting the occupant(s) to avoid serious injuries andor
death This was true in the 1950s and the 1960s and will continue to be
true in the 21st century as well
Speed Kills for this just reason
6 It appears that higher fuel economies and reduced
highway fatalities were the twin societal benefits of 55
mph adopted after 1973 If so the current attempts to
increase the speed limits appear to be in conflict with
other important societal objectives
Page 36 of 45
Table 1 Annual US Street amp Highway
Fatalities from 1957
Year
Fatalities
Vehicle Miles
(millions)
Rate100M Vehicle Miles
1957 38702 646915 598
1958 36981 664915 556
1959 37910 700478 541
1960 38137 718845 531
1961 38091 737535 516
1962 40804 766852 532
1963 43564 805423 541
1964 47700 846500 563
1965 49163 887640 554
1966 51524 927915 555
1967 51559 965132 534
1968 53831 1019726 528
1969 55032 1066108 516
1970 53672 1114098 482
1971 53761 1183524 454
1972 55704 1264614 440
1973 55113 1316207 419
1974 46078 1282790 359
1975 45500 1330074 342
1976 45523 1402380 325
1977 47878 1467027 326
1978 50331 1544704 326
1979 51103 1529133 334
1980 51091 1527295 335
1981 49301 1552803 317
1982 43945 1595010 276
1983 42589 1652788 258
1984 44257 1720269 257
1985 43795 1774179 247
Page 37 of 45
1986 46056 1835000 251
1987 46385 1921000 241
1988 47093 2026000 232
1989 45555 2107040 216
1990 44529 2147501 207
1991 41162 2172214 189
1992 39235 2239828 175
1993 40115 2296585 175
1994 40676 2359984 172
1995 41798 2422696 173
1996 41907 2485848 169
1997 41967 2560373 164
Data from Federal Highway Administration
Source httpwwwpublicpurposecomhwy-fatal57+htm
Telephone +16186328507 - Facsimile +16186328538
WENDELL COX CONSULTANCY P O Box 841 - Belleville IL 62269 USA
Page 38 of 45
Fatality data for 1921-1982 compiled by NHTSA
Year
VMT
(Millions)
VMT
(Billions)
Fatalities
Fatality rate
per 100 M VMT
1921 55027 5503 13253 241 1922 67697 6770 14859 219 1923 84995 8500 17870 210 1924 104838 10484 18400 176 1925 122346 12235 20771 170 1926 140735 14074 22194 158 1927 158453 15845 24470 154 1928 172856 17286 26557 154 1929 197720 19772 29592 150 1930 206320 20632 31204 151 1931 216151 21615 31963 148 1932 200517 20052 27979 140 1933 200642 20064 29746 148 1934 215563 21556 34240 159 1935 228568 22857 34494 151 1936 252128 25213 36126 143 1937 270110 27011 37819 140 1938 271177 27118 31083 115 1939 285402 28540 30895 108 1940 302188 30219 32914 109 1941 333612 33361 38142 114 1942 268224 26822 27007 101 1943 208192 20819 22727 109 1944 212713 21271 23165 109 1945 250173 25017 26785 107 1946 340880 34088 31874 94 1947 370894 37089 31193 84 1948 397957 39796 30775 77 1949 424461 42446 30246 71 1950 458246 45825 33186 72 1951 491093 49109 35309 72
1952 513581 51358 36088 70
Page 39 of 45
1953 544433 54443 36190 66 1954 561963 56196 33890 60 1955 605646 60565 36688 61 1956 627843 62784 37965 60 1957 647004 64700 36932 57 1958 664653 66465 35331 53 1959 700480 70048 36223 52 1960 718762 71876 36399 51 1961 737421 73742 36285 49 1962 766734 76673 38980 51 1963 805249 80525 41723 52 1964 846298 84630 45645 54 1965 887812 88781 47089 53 1966 925899 92590 50894 55 1967 964005 96401 50724 53 1968 1015869 101587 52725 52 1969 1061791 106179 53543 50 1970 1109724 110972 52627 47 1971 1178811 117881 52542 45 1972 1259786 125979 54589 43 1973 1313110 131311 54052 41 1974 1280544 128054 45196 35 1975 1327664 132766 44525 34 1976 1402380 140238 45523 32 1977 1467027 146703 47878 33 1978 1544704 154470 50331 33 1979 1529133 152913 51093 33 1980 1527295 152730 51091 33 1981 1555308 155531 49301 32 1982 1595010 159501 43945 28
Source Analysis of Significant Decline in Motor Vehicle Traffic Fatalities in
2008 httpwww-nrdnhtsadotgovPubs811346pdf see Table A1 page 31
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Page 40 of 45
Acknowledgements
The author is grateful for thoughtful comments provided by friends and colleagues
with whom this document was shared via email prior to it being uploaded as a
publicly available document for wider dissemination and study The comments
offered by Prof Subra Ganesan of Oakland University Electrical and Computer
Engineering Department are reproduced with permission in their entirety
About the author
The author obtained his Masterrsquos (S M) and Doctoral (Sc D) degrees in Materials Engineering
from the Massachusetts Institute of Technology Cambridge USA He then spent his entire
professional career at leading US research institutions (MIT NASA Case Western Reserve
University and General Motors R amp D Center in Warren MI) He holds four patents in advanced
materials processing has co-authored two books and has published several scientific papers in
leading peer-reviewed international journals His expertise includes developing simple
mathematical models to explain the behavior of complex systems He can be reached by email at
vlaxmananhotmailcom
Page 41 of 45
Please Buckle Up
httpwwwlakecountypublichealthorgindexphpbuckle-up-montana
Public Awareness
Respect the Cage Exhibit
The Department of Transportation hopes that showing the reality of the crash will reduce traffic
fatalities A crushed car crash dummies and a sobering message ndash all part of the ―Respect The
Cage exhibit that is traveling across Montana The exhibit sponsored by the Montana Department
of Transportation stopped in Ronan on November 6th and is aimed at raising awareness about the
importance of wearing seat belts
The car in the exhibit was in an actual wreck many years ago
the passenger in the vehicle died because he was not wearing a
seat belt the driver who was wearing his seat belt survived
Montanarsquos likeliest crash fatality scenario
A Pickup
A Rural road
And Seat belts that
arenrsquot used
Page 42 of 45
Occupants of pickups are less likely to wear seat belts and pickups are more likely to
roll over than passenger cars
Seat belts reduce the risk of death by 60 percent in pickups and SUVs
In Montana from 2006-2008 81 of those killed in a crash while riding in a pickup were not wearing seat belts
In Montana pickups make up 401 of the vehicle population
For more information on Respect the Cage click here
Page 43 of 45
Appendix 1
Lack of seat belts leading cause of Louisiana highway deaths
1251 AM May 28 2011 |
Written by Adam Duvernay
Crashes involving unbuckled motorists were the leading cause of highway fatalities
in Louisiana last year and cost $9888 million according to recent reports The
Louisiana Highway Safety Commission reported 59 percent of vehicle occupants
killed in Louisiana crashes last year mdash about one in four mdash werent wearing seat
belts
httpwwwshreveporttimescomarticle20110528NEWS01105280354Lack-seat-
belts-leading-cause-La-highway-deathsodyssey=tab|topnews|text|FRONTPAGE
Crash bull Stats Published by NHTSAlsquos National Center for Statistics and Analysis 1200 New Jersey Avenue SE Washington DC 20590
DOT HS 811 451
Early Estimate of Motor Vehicle Traffic Fatalities in 2010
httpwww-nrdnhtsadotgovPubs811451pdf
Summary
A statistical projection of traffic fatalities in 2010 shows that an estimated 32788
people died in motor vehicle traffic crashes This represents a decline of about 3
percent as compared to the 33808 fatalities in 2009 as shown in Table 1 If these
projections are realized fatalities will be lowest on record (since 1949)
Traffic Safety Facts Overview 2009 Data
httpwww-nrdnhtsadotgovPubs811392pdf
In 2009 33808 people were killed in the estimated 5505000 police-reported
motor vehicle traffic crashes 2217000 people were injured and 3957000
crashes involved property damage only Compared to 2008 this is a 10-
percent decrease in the number of fatalities and a 5-percent decrease in the
Page 44 of 45
number of police-reported motor vehicle traffic crashes people injured and
crashes involving property damage
An average of 93 people died each day in motor vehicle crashes in 2009 mdash
an average of one every 16 minutes
Traffic Safety Facts Overview 2008 Data
httpwww-nrdnhtsadotgovPubs811162pdf
In 2008 37261 people were killed in the estimated 5811000 police-reported
motor vehicle traffic crashes 2346000 people were injured and 4146000
crashes involved property damage only
Some comments and Feedback
The following comments were received from Prof Ganesan after his review of the
first draft of this document It was subsequently revised thanks to this input to
address some of the very important issues raised here
Dear Laxman
The write up is not enough
You are emphasizing that the speed limit reduces the fatal accidents (comparing 1966
to 2000 accident numbers)
Can you also add a few sentences why the number is decreasing from 1980 to 2000
values (May be due to better design of vehicles)
Can you say anything about the fuel consumption with the speed for any typical
vehicle in 2011 or 2010 (do not consider the fatalities issue)
Probably a speed between 55 and 60 mph gives a better mileage If so this is a
compelling reason to keep the speed limit low But cars probably can be tuned to
give better mileage at any high speed also
Page 45 of 45
Weather is also a major factor in fatal accidents Speed limit may be kept low during
winter and kept higher in summer Give your comments on this too
Driver distractions can cause more accidents Now cars have many multimedia and
internet features Automatic collision avoidance systems and sensors on the sides can
detect vehicles in the front and neighboring lanes and it can automatically decrease
speed even if the driver speeds at super high speeds
Give some comments on this too There is also Vehicle to Vehicle communications
vehicle to infrastructure communications and they can avoid collisions and accidents
Technology has changed from 1966 I cannot agree with you on the speed limit
without any discussion on the above and other factors
Have a great day
Subra Ganesan
Professor Subramaniam Ganesan
Director Real Time amp DSP Lab
Electrical and Computer Engineering Department
2200 Squirrel Road Dodge Hall Room 105
Oakland University Rochester MI 48309 USA
Phone 248 370 2206 Fax 248 370 4633
wwwsecsoaklandedu~ganesan
IEEE Distinguished Visiting Speaker (2005-2009) Coordinator
IEEE SEM CS chapter Chair Region 4 and CS Society Board member
SAE ASEE ACM member
Page 8 of 45
Figure 1 Graph of the absolute number of US highway fatalities since 1957 The raw
data used to prepare this graph may be found in Table 1(relegated to the end of this
document) The absolute number of highway fatalities were quite low in the 1950s
and reached a peak in the late 1960s to early 1970s and have since decreased to
levels seen in the 1950s although the vehicle miles driven (in millions) has been
increasing from 646915 in 1957 to 2560373 in the year 2000 see also Figure 2
The fatality data from other government sources have also been studied by the author
and lead to the same conclusion of a peak in highway deaths around the late 1960s to
early 1970s
Page 9 of 45
Figure 2a Graphical representation of the absolute number of US highway fatalities
versus annual vehicle miles driven (in trillions) The number of miles driven by US
drivers has increased each year since 1957 as seen in Table 1 The absolute number
of highway fatalities has increased as well reaching a peak in the late 1960s to early
1970s The same peak is also seen here in the graph of the absolute number of
highway fatalities versus vehicle miles driven Improvements in vehicle safety devices
(notably seat belts and airbags) coupled with the institution of the national highway
speed limits (starting mid 1970s) and also improved highways are the primary
reasons for the decrease in fatalities These historical trends suggest that renewed
attempts to increase the speed limits on our highways would be counterproductive
and may eventually lead once again to an increase in fatalities with tragic
Page 10 of 45
consequences
Figure 2b Graphical representation of the US highway fatality data for the period
1921-1982 The first year for which a fatality rate yx could be computed is 1921 The
number of fatalities was 13253 and VMT was 5503 billion yielding a fatality rate of
2408 per 100 million VMT The fatality rate for any year is the slope of the ray ie
the straight line joining the (x y) data point back to the origin (00) of this graph see
dashed line for 1921 superimposed on to the graph The fatality rates (slopes of such
rays) had been declining quite consistently although the absolute number of fatalities
increased as seen here ultimately leading to the Congressional hearing in 1966 Is
VMT the single most important reason for the increasing fatalities
Page 11 of 45
Figure 3 Graphical representation of the traffic fatality data for the 15 year period
1994-2009 A sudden precipitous drop in the absolute number of fatalities (at least on
the magnified scale used here) and hence the fatality rate has been observed over
the three-year period 2007-2009 However it should be noted that the x-y scatter
graph here shows a general upward trend with fatalities actually increasing with
increasing VMT (as in the earlier era 1950s and 1960s) during the 12-year period
spanning 1994-2006 although the rate yx shows a misleading downward trend Why
is the rate yx going down
The reason is very simple and it may be just a mathematical artifact The equation of
the best-fit straight line through the most recent data points is of the form y = hx + c
= 2865 x + 34420 where h is the slope of the line and c the intercept (Note that x
here is VMT in billions The numerical value determined using this equation must be
divided by 10 to get the rate per 100 M VMT) Hence the fatality rate given by the
ratio yx = h + (cx) = 2865 + 34420x can actually decrease with increasing
values of x because of the nonzero intercept c Unlike the ray through the origin the
best-fit line does not pass through the origin (00) If we consider only the most
Page 12 of 45
recent data the intercept c is positive and fatality rates yx decrease with increasing
VMT and increasing fatalities In the earlier era both the slope h and intercept c had
very different values due to several factors being discussed here (speed limits
technology highway design etc)
Table 2 Traffic fatality data for the recent 15-year period
1994-2009 (Source NHTSA)
Year
Highway
fatalities y
Vehicle miles
traveled
VMT
(billions) x
Fatality rate
yx per 100
million VMT
Fatal crashes
1994 40716 2358 173 36254 1995 41817 2423 173 37241 1996 42065 2486 169 37494 1997 42013 2562 164 37324 1998 41501 2632 158 37107 1999 41717 2691 155 37140 2000 41945 2747 153 37526 2001 42196 2797 151 37862 2002 43005 2856 151 38491 2003 42884 2890 148 38477 2004 42836 2965 144 38444 2005 43510 2989 146 39252 2006 42708 3014 1 42 38648 2007 41259 3032 136 37435 2008 37423 2974 126 34172 2009 33808 2979 113 30797
Page 13 of 45
Figure 4 The most significant metric used by NHTSA is the fatality rate per 100
million vehicles miles traveled (VMT) This is now at a historical low of 113 for
2009 having declined year after year from 173 in 1994 The NHTSA however also
compiles other types of data on crashes There are three types of crashes fatal
injury but no death and property damage only A careful review of this crash data
for the period 1994-2009 reveals the obvious the lower the number of (fatal)
crashes x the lower the number of highway-accident-related fatalities y It is also
obvious that the number of fatalities per crash is greater than one ie more than one
person is being killed when one of more vehicles experience a crash
Clearly this is the single most important piece of information that one needs to
reduce the number of fatalities on our highways Vehicle design and engineering as
well as all other policy matters (legal political social environmental financial)
must be guided by this simple graph The best-fit line through the data derived using
simple linear regression has the equation y = hx + c = 114x ndash 10266 and is
Page 14 of 45
superimposed on to the data The design engineering goal and societal goal should
be to reduce the slope h of this statistically significant best-fit line to its ideal value of
h = 1 A fatal crash by definition is one where at least one person dies either an
occupant or a non-motorist in the path of the vehicle Hence the ideal slope h = 1
Photograph of an accident scene from the period 1955-1965
httpwwwcorinthsocialhistoryprojectorghtmlhighwaytollshtml
3 A Brief History of Traffic Safety Legislation
The following is extracted from the Wikipedia article on National Highway
Traffic Safety Administration (NHTSA)
httpenwikipediaorgwikiNational_Highway_Traffic_Safety_Administration
In 1965 and 1966 public pressure grew in the US to increase the safety of
cars The number of deaths on US highways were increasing year after year
Page 15 of 45
see Figure 1 and in 1966 Congress held a series of highly publicized
hearings on highway safety This led to the legislation for mandatory
installation of seat belts which also created the US Department of
Transportation (on Oct 15 1966)
httpwwwemsgovpdf2011EMSWeek2011_Stricklandpdf
The following is extracted from a Washington Post article on
NHTSA dated April 2 2002
httpwwwwashingtonpostcomwp-srvbusinessincludesnhtsa_primerhtm
In 1966 after decades of rising traffic fatalities (also vividly illustrated in
Figures 1 and 2 here) the publication of Ralph Naders Unsafe at Any
Speed and increasing public outcry for safer automobiles Congress held a
series of highly publicized hearings on creating a regulatory agency for traffic
safety Among the witnesses was William Haddon an epidemiologist who
introduced the idea that traffic accidents could be analyzed scientifically and
injuries reduced by changing auto design such as installing collapsible
steering columns safety glass head rests and seat belts
Congress passed the Highway Safety Act of 1966 creating the National
Highway Safety Bureau with Haddon as its first administrator The bureau
became NHTSA in 1970 under the newly established Department of
Transportation An early Nader convert Joan Claybrook headed NHTSA
under President Carter and now runs Naders organization Public Citizen
National Traffic and Motor Vehicle Safety Act
httpwwwanswerscomtopicnational-traffic-and-motor-vehicle-safety-act
Signed into law by President Lyndon Johnson on September 9 1966 this act
created the first mandatory federal safety standards for motor vehicles The
act was motivated by a variety of factors First and foremost the public was
growing increasingly concerned over the rising number of traffic fatalities on
the nations roads Such fatalities had increased by nearly 30 percent
between 1960 and 1965 and experts forecasted 100000 such deaths
Page 16 of 45
annually by 1975 unless something was done to improve traffic safety
Adding fuel to the fire Ralph Naders Unsafe at Any Speed published in
November 1965 criticized the automobile industry for neglecting safety in
favor of power and styling when designing new vehicles
4 The reason for the historical
decrease in highway fatalities
A recent news item see link given below regarding renewed attempts to
increase the speed limit by many states prompted this write up by the
present author who has studied traffic fatality data extensively and analyzed
them very carefully over the last several years
httpmoneymsncomauto-insurancewhy-speed-limits-are-
risingaspxGT1=33033
Residents of Metro Detroit area who frequently cross into Ohio from
Michigan notice that the speed limit has now increased in Ohio The speed
limit on Michigan highways was increased to 70 mph in the late 1990s but
Ohio retained its lower speed limit for many years leading Michigan drivers to
experience a ―speed trap of sorts The speed limit is also increasing in many
other states notably Texas where it is proposed to increase it to 85 mph at
least in West Texas
Historically speaking from a traffic fatality standpoint we must consider two
important dates 1966 and 1973 Only 1973 the year of the Arab oil embargo
following the Arab-Israeli war (that led to what President Obama has recently
called the pre-1967 border for Middle East peace) is mentioned in the above
article It fails to mention the significance of the year 1966
Prior to 1966 there was actually NO speed limit in many Western states and
deaths due to highway accidents were increasing year after year The
Page 17 of 45
number of highway fatalities went up from 38702 in 1957 to 51524 in 1965
a 33 increase over the 1957 level and an additional 12822 deaths in 1965
compared to 1957 It was this carnage on the US highways that forced
Congress to hold its hearings on highway traffic fatalities in 1966
Nonetheless a careful examination of the fatality data in Table 1 shows that
notwithstanding the highly publicized Congressional hearings of 1966 and
new safety legislation that was enacted the absolute number of fatalities
continued to increase after 1966 and only started decreasing after 1973
Vehicle designs especially the introduction of safety features (even the
simplest like safety belts) did not change significantly between 1966 and
1973 Nonetheless post-1973 we begin to see a dramatic turnaround
Why
After the 1973 Arab oil embargo a nationwide maximum speed limit (NMSL)
of 55 mph was imposed and accepted in the USA (effective Jan 1 1974)
during the Nixon administration primarily as an effort to conserve fuel and
reduce the US vulnerability to oil imports The unintended and indeed
fortunate consequence of this reduced speed limit was the immediate
reduction in the fatalities revealed in Figures 2 and 3 This is the real reason
for the peaks in highway fatalities observed in these two graphs
The Congressional hearings of 1966 did eventually have an impact but it was
a delayed one The impact of the 1973 nationwide speed limit of 55 mph was
however immediate as we see from the magnified plot of the same data in
Figure 5 and a closer examination of the raw fatality data in Table 1
The number of highway-accident-related fatalities decreased immediately
from a high of 55704 in 1972 to just 46078 in 1974 a 173 drop see
arrows There were 9626 fewer deaths annually even with a slight increase
in the vehicle miles driven (see Table 1) Indeed the number of highway
death reached its absolute peak value in 1972 never to be seen again
Fatalities have been decreasing every since with slight fluctuations about
each new low value
Page 18 of 45
Figure 5 Expanded view of the fatality data showing the immediate impact of the
national speed limit of 55 mph following the Arab oil embargo of 1973 Note that
fatalities continued to rise between 1966 and 1973 in spite of the highly publicized
Congressional hearings in 1966 and the traffic safety legislation enacted soon after
Each new low is probably associated with vehicle safety innovations and the
improvements in vehicle design and engineering The combined beneficial
effect of improved vehicle designs primarily the introduction of seat belts
and the laws enforcing usage of seat belts aided by the reduced speed
limits contributed to the continued decline in the absolute number of fatalities
that started since 1973 and has continued to this day The subsequent
introduction of other safety features notably air bags has contributed to a
further reduction in highway fatalities
Page 19 of 45
State police Trooper First Class Jeffrey Flowers looking at a car in which a Boswell
Pennsylvania woman was injured Tuesday (May 31 2011) The accident occurred at
an intersection when a truck (seen behind the wrecked car) entered this accident
prone intersection (part of a highway safety corridor where signs are posted to
reduce unsafe driver behavior) There have been four accidents at this intersection
since 2006 none fatal httpwwwdailyamericancomnewssomersetda-ot-woman-
injured-in-route-30-wreck-2011053104165420story
5 Numerical calculations of decline in
fatalities and the impact of NMSL post-1973
Letlsquos consider the decline in fatalities between 1972 the last year before the
adoption of the NMSL and 1974 the first year following its adoption after the
Arab oil embargo There was an immediate decrease in the number of
fatalities by 9393 ie y = -9393 with a slight increase in the VMT ie x
= 20758 millions The NHTSA data used here may be found in the table at
the end of this document The numerical value of the rate of change per
billion VMT (ie neglecting the sign) was therefore
yx = 4525 fatalitiesbillion VMT (1972-1974)
Page 20 of 45
It is instructive to compare this rate of change in fatalities with similar short
periods of a decline in fatalities in the pre-1973 era when speed limits were
much higher The absolute number of fatalities declined over a relatively
short period with both an increase and a decrease in VMT The results are
given below and are self-explanatory
yx = 454 fatalitiesbillion VMT (1953-54) decline with increase in VMT
yx = 655 fatalitiesbillion VMT (1942-43) decline with decrease in VMT
yx = 1739 fatalitiesbillion VMT (1941-42) decline with decrease in VMT
yx = 4528 fatalitiesbillion VMT (1937-39) decline with increase in VMT
yx = 2548 fatalitiesbillion VMT (1931-32) decline with decrease in VMT
The rate of decline observed between 1953 and 1954 with an increase in
VMT was just one-tenth of that observed following the adoption of the 55
mph speed limit The war years (1941-43 WWII) and the Great Depression
era (1931-32) were accompanied by big declines in fatalities with decreasing
VMT but the rate of change was still significantly lower than observed after
the adoption of the NMSL
The only apparently inexplicable decline is that between 1937 and 1939
where a nearly identical high rate of decline was observed Notice also the
big drop in the traditional fatality rate between 1937 and 1938 This large drop
appears to coincide with the creation of the National Safety Council (NSC) by
William H Cameron in June 1937 (see link below) with its far-flung campaign
of education legislation research highway engineering and traffic training
undertaken by the NSC and some two dozen other groups with the backing of the
automotive industry through its Automotive Safety Foundation Other factors
unknown to the present author probably also played a role
httpwwwtimecomtimemagazinearticle0917188379700htmlixzz1O2G
7rnUg
Page 21 of 45
These simple computations here however reveal the significant effect of
reduced speed limits on highway fatalities much more so than other factors
6 Further Considerations Pros and Cons
The singular effect of increased speeds (or speeding) on highway fatalities
has been studied and demonstrated by a number of industry sources such
as the Insurance Institute for Highway Safety (IIHS) Consumers Union and
also by government researchers
httpwwwsmartmotoristcomtraffic-and-safety-guidelineexcessive-speed-is-
a-factor-in-one-third-of-all-fatal-crasheshtml
httpwwwconsumersunionorgotherspeedlimitsspeed031500a2htm
Speed ndash defined as exceeding the posted speed limit or driving too fast for
given conditions ndash is a factor in nearly one-third of all fatal crashes Besides
fatality in 1998 nearly 40000 people were critically injured in speed-related
crashes and nearly 72000 were moderately injured
The salutary and immediate beneficial effect of the nationwide 55 mph speed
limit has been noted by other researchers (see Susan Ferguson link below)
httpwwwnhtsagovpeopleinjuryenforcespeed_forum_presentationsfergu
sonpdf
After a partial repeal of this law in 1987 which granted states the authority to
increase speed limit (especially in rural interstates) a 1989 study showed a
15 increase in fatalities in rural interstates and a 5 increase in non-rural
interstates Unfortunately such studies often tend to be discounted by
advocates of increasing the speed limits as being produced by biased
industry sources
Similar conclusions were also presented by NHTSA in February 1998 in its
report to the Congress entitled ―Report to Congress The Effect of Increased
Speed Limits in the Post-NMSL Era see link given below Among its key
Page 22 of 45
findings is the following quoted in its entirety NMSL refers to the National
Maximum Speed Limit legislated after the Arab oil embargo of 1973
httpwww-nrdnhtsadotgovPubs808-637PDF
hellip Nevertheless it is important to note that data currently available from the
National Highway Traffic Safety Administrationrsquos (NHTSA) Fatality Analysis
Reporting System (FARS) shows that states that increased speed limits in 1996
experienced approximately 350 more Interstate fatalities than would have been
expected based on historical trends -- about 9 percent above expectations
Concurrently the Interstate fatalities experienced in states that did not increase speed
limits in 1996 was consistent with pre-1996 trends The estimated increase in
Interstate fatalities found in this study while smaller in magnitude compared to the
estimated change in fatalities found in 1987 following the increase of speed limits on
rural Interstates does follow the historical pattern of increases in fatalities being
associated with increases in posted speed limits
The annual crash reports compiled by NHTSA see Table 3 indicate that the
number of fatal crashes (and hence fatalities using the regression equation
developed in Figure 4) increase as the posted speed limits increase
Page 23 of 45
Table 3 Posted speed limits and number of crashes
Speed Limit Crashes (2008) Crashes (2009)
30 mph or less 3705 3277 35 or 40 mph 6115 5516 45 or 50 mph 6461 6074
55 mph 9794 8847 60 mph or higher 6908 6124
Total 34017 30797
Source httpwww-nrdnhtsadotgovPubs811402EEpdf
61 Studies cited in favor of lower speed limits
A detailed analysis of speeding related fatalities (see link below) by NHTSA
shows that a third of all crashes involve speeding ie at least one driver was
speeding
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Furthermore the above report which covers the period 1983-2002
indicates that immediately after the NMSL was completely abolished in
December 1995 the number of speeding related fatalities at speeds
above 65 mph increased from just 15 in 1995 to a 677 in 1996 (see Table
62 on page 43 of above report) It continued to increase in the years
since climbing to 930 in 2000
More detailed studies similar to that noted above by researchers at the
University of Illinois Chicago led by Lee S Friedman again lead to the
conclusion that higher speed limits lead to an increase in the number of
fatalities (see American Journal of Public Health online July 16 2009)
httphealthusnewscomhealth-newsmanaging-your-
healthcarearticles20090716deaths-injuries-increase-with-higher-speed-
limits
Page 24 of 45
httpwwwmedpagetodaycomPublicHealthPolicyPublicHealth15122
httpwwwamericaneercomspeed-limits
httpwwwactuarialoutpostcomactuarial_discussion_forumarchiveindexph
pt-171870html
For the study period 1995-2005 these researchers found that 12545 deaths
and 36582 injuries could be attributed to the increased speed limits The
benefits of reduced speed limits are stated quite eloquently by Dr Friedman
and are reproduced below (from above news article see link)
Reduced speed limits would save lives Friedman said They would also reduce
gas consumption cut emissions of air pollutants save valuable years of productivity
(lost due to injuries)and reduce the societal cost of motor vehicle crashes (due to
both fatal crashes and due to nonfatal and severe life-changing injuries) he added
Friedman and coworkers have also shown that increasing the speed limit led
to an immediate increase in the number of fatalities on Israeli roadways (see
link below)
httpinjurypreventionbmjcomcontent133156
The effect of speeding is very significant especially in rural areas resulting
in significantly higher fatalities Fatality rates are frequently double or triple
that in urban areas (see link below)
httpsafetyfhwadotgovspeedmgtdata_factsdocsspeeding_ruralpdf
As of Jan 1 2005 five Midwestern states had increased the speed limits to
above 65 mph (Illinois Iowa Kansas Minnesota Missouri Nebraska and
South Dakota) whereas three (Illinois Iowa and Wisconsin) had not All the
five states with increased speed limits showed a 7 to 13 increase in
fatalities The NHTSA study considered an eight year period before and after
the change in Dec 1995 (see Table 1 in link below) The collective experience
of the states that did NOT increase the speed limit was a 7 decline in
fatalities (see Table 2 of link below)
httpwwwiowadotgovmvdodsstats2006speedstudypdf
Page 25 of 45
Moreover Table 5 in the above study shows the effect of imposing the NMSL
of 55 mph in Iowa and its repeal in 1995 Considering a four-year average
before 1974 when the speed limit was 75 mph there were 35 fatal crashes
with 43 fatalities In the first four years after the 55 mph there were only 23
fatal crashes and 28 fatalities In the last four years before the repeal of 55
mph in 1995 there was a further decline to 14 fatal crashes with 17 fatalities
The Iowa fatality data will be discussed in more detail separately (in a later report)
since it provides the opportunity to assess the effect of a change in the speed limit
on the relationship between number of fatalities and fatal crashes (as seen in
Figure 4 for the US as a whole)
North of the US border Canadians seem to be citing the ―shocking increase
in highway fatalities in the US states where the speed limits were raised to
curb their own speed limits
httparchivesafety-councilorginfotrafficspeed-02html
httparchivesafety-councilorginfotrafficspeedhtml
Speed kills but speed also sells notes the second of the above news items
Manufacturers are producing more high performance cars (with higher horse
power to weight ratio) and ads feature enticing cars that race and swerve in
miraculous ways on empty roads These subliminal messages encourage
drivers especially young drivers to break the speed limit leading to the
absolute increase in highway fatalities (although the rate itself is going
down) The article emphasizes the need to enforce the speed limit on
Canadian highways and in cities where street racing is becoming a problem
62 Studies cited by opponents of lower speed limits
In fairness to quote the opponents on the other side of this debate Montana
reverted back to Reasonable and Prudent speed limits when the National
Maximum Speed Limit was repealed in 1995 and appears to have
experienced no significant increase in fatalities
Page 26 of 45
httpwwwhwysafetycomhwy_montanahtm
httpwwwmotoristsorgpressmontana-no-speed-limit-safety-paradox
httpwwwsouthbayriderscomforumsshowthreadphpt=81453amppage=1
Likewise studies in the state of Maryland showed no significant increase in
highway fatalities when the speed limit was increased from 55 mph to 75
mph The reason might simply be that drivers were already speeding much
more so when the speed limit was 55 mph than after the increase to 75 mph
In other words the fatalities data already reflects the effect of higher speeds
(not speed limits) on the number of fatalities
In Utah the experimental increase in the speed limit to 80 mph was
considered to be a success in terms of safety
httpautosaolcomarticleutah-speed-limit-tests
The UDOT Director noted that there was no increase in the number of
accidents on Interstate 15 But what happens in the event of an accident
when the speed limits are higher and drivers are driving at higher speeds and
two objects collide at this higher speed However no increase in the number
of accidents is not the same as no increase in fatalities due to the higher
speeds When accidents do occur do fatalities increase
Likewise in California when the speed limit went up from 55 mph to 65
mph in 1995 (after repeal of NMSL) fewer deaths were reported in 1998
compared to the peak year of 1979 or even 1987 Again the explanation
seems to be that motorists were already speeding when the limit was 55 mph
and that increasing the speed limit did not change driver behavior in any
significant way
httparticlessfgatecom1998-11-02news17735730_1_speed-limits-mph-
limit-death-rate
The National Motorists Association (NMA) a group which advocates higher
speed limits emphasizes the importance of considering fatality rates as
opposed to the raw fatalities The argument used is that fatality rates based
on the fatality per 100 million VMT is the legitimate way to look at the data
Page 27 of 45
This is a never ending debate Historically speaking fatality rates have been
going down ever since the compilation of traffic accidents data began Table
A1 in the appendix of a recent report by NHTSA (see link below) has highway
fatality rate data going back 1921
httpwww-nrdnhtsadotgovPubs811346pdf see appendix page 31
httpwwwmotoristsorgspeed-limitstruth
httpwwwmotoristsorgothercrash-data
httpwwwraisethespeedlimitorgmythshtml
httpwwwcatoorgpubspaspa346pdf
According to Stephen Moore of the Cato Institute (see last of the links above)
―All measures of highway safety show improvement not more deaths and
injuries since 1995 Despite the fact that 33 states raised their speed limits
immediately after the repeal of the mandatory federal speed limit the NHTSA
reported last October that the traffic death rate dropped to a record low level
in 1997lsquo Moreover the average fatality rate even fell in the states that raised
their speed limits
63 The Fatality rate Is it a reliable metric
In 1921 with fewer fatalities and fewer miles driven and the first year for
which the fatality rate could be computed the rate was 2408 It was down to
1479 in 1931 but the number of deaths had climbed to 31963 more than
double the 1921 absolute fatality number of 13253 It had dropped to 550 in
1966 the year of the highly publicized Congressional hearings but the
number of fatalities had climbed to 50984 in that fateful The Highway Safety
Act of 1966 ranks as one of the major acts of Congress and President
Johnson signed it saying that ―we have been tolerating a raging epidemic of
highway deathshellip see extract pasted below
httpwwwenotescommajor-acts-congresshighway-safety-act
Page 28 of 45
The act was motivated primarily by growing public concern over the rising number
of traffic fatalities in the United States Between 1960 and 1965 the annual number
of traffic fatalities increased by nearly thirty percent As President Lyndon B
Johnson stated at the signing of the act on September 9 1966 we have tolerated
a raging epidemic of highway death which has killed more of our youth than all
other diseases combined Through the Highway Safety Act we are going to find out
more about highway diseasemdashand we aim to cure it
Nonetheless highways fatalities continued to increase until the Arab oil
embargo of 1973 led to the NMSL of 55 mph all across the USA Do we just
ignore this undeniable historical record and focus only on the declining fatality
rate as the NMA and other proponents of higher speed limits seem to argue
(see links above)
The misleading nature of using fatality rates (per 100 M VMT) alone is also
obvious if one considers fatality data for individual states Take for example
the state of Montana which seems to have experienced no increase in
fatalities after repeal of NMSL
httpwww-nrdnhtsadotgovdepartmentsnrd-
30ncsaSTSI30_MT200930_MT_2009htm
For the period 2005-2009 the absolute number of fatalities for Montana
varied between a high of 277 in 2007 to a low of 229 in 2009 The fatality
rates per 100 M VMT on the other hand varied from a high of 245 for 2007
to a low of 201 for 2009 The corresponding US fatality rates varied from
136 to 114 Is the higher number for the fatality rate for Montana compared
to USA good or bad Likewise fatality rate per 100000 of population was
much higher for Montana than the US as a whole
This again highlights the pitfalls of using simple ratios to assess fatality statistics
without a full analysis of the underlying trends We will discuss this point
separately
As shown already the continuous decline in the fatality rate is a mathematical
artifact and essentially overlooks the unmistakable positive correlation
between the variables x and y of the type y = hx + c which becomes obvious
Page 29 of 45
only when we prepare the x-y scatter graph The ratio yx = h + (cx) can
decrease with increasing x (VMT) and increasing y (fatalities) since the
intercept c has a positive value when we consider only data spanning a short
period (such as 1994-2009 of more relevance to the current situation)
The debate between fatality rates and absolute number of fatalities is an
unending one A few years ago the Wall Street Journal carried an article
which was entitled (or something close) ―Unemployments rate in Ohio are
going down but why is the number of unemployed increasing The reason is
the same The graph of the number of unemployed (y) versus the number in
the labor market (x) is linear with a positive slope h and a positive intercept c
So the unemployment rate computed using the ratio yx keeps going down
year after year although the number unemployed keeps increasing Is it a
good thing that the unemployment rate is going down when more people
seem to be unable to find gainful unemployment
Or consider the situation with cancer death rates This too has been going
down in recent years but the actual number of cancer-related deaths has not
declined in any significant way Is it good that cancer death rates are going
down In all these situations the researchers or the socio-econo-politico
analysts involved in analyzing the trends in the data have failed to consider
the underlying x-y relation describing each problem
Hence it appears that the debate on the effect of increased speed limits
should not be focused on only the fatality rates (which have been decreasing
and proponents of higher speed limits cite this in their arguments) or even the
absolute number of fatalities (which has been the focus here) but on the
relationship between speed and the number of fatal crashes and the number
of fatalities within each speed segment (see Table 3 and also Figure 4)
Unfortunately details of number of fatalities and the number of fatal crashes
at each speed limit are not available even from NHTSA for detailed study
When a crash does occur (it is immaterial how many miles were driven) the
speed of the driver and vehicle design and engineering including safety
devices in place (seat belts airbags other impact absorbing technologies)
Page 30 of 45
determine if the occupants(s) will be killed One cannot argue that speed
does NOT kill That would be an absolute denial of the laws of physics
Studies show that setting the speed limit at the 85th percentile in any given
zone (this is the speed at or below which 85 of drivers are observed to
travel in traffic engineering studies) is the safest speed limit The majority of
drivers try to obey the posted speed limit while a few choose to drive at a
speed they consider is safe and prudent These are also perhaps the most
vociferous advocates of higher speed limits It is this tension caused due to
differences in speeds that leads to tailgating improper passing reckless
driving weaving from lane to lane and ultimately crashes and deaths in some
unfortunate cases
httpblogmotoristsorgspeed-limits-slower-safer
MARK TAYLOR
ANOTHER LOST A man was killed when his 4WD drive hit a tree east of Morrinsville (in New
Zealand) on Monday May 30 2011 The driver lost control of the vehicle on a bend probably tried
to correct his mistake and put the car into a ―yaw causing it to leave the road and smash sideways
into a tree Alerts to slow down had been posted since this was a high accident area but the driver
probably did not pay attention
64 Other factors
Many other factors besides speed no doubt affect highway fatalities The
vehicles of the 21st century are very different from the vehicles of the mid 20th
Page 31 of 45
century Technological innovations such as improvements in vehicle design
and engineering have greatly increased crash worthiness of vehicles even at
high speeds Environmental factors such as the weather also contribute to
accidents but not necessarily to increased fatalities Drivers actually tend to
slow down instinctively during adverse weather conditions (rain snow storms
etc) and although such weather may contribute to increased accidents the
lower speeds actually reduce fatalities
Yes technology has changed fundamentally from 1966 Drivers today are
more distracted by their cellmobile phone conversations (and also built-in
phones in luxury models) and text messaging than the drivers of the pre-1966
era High end cars now have many multimedia and internet features Again a
careful observation (even personal experience by the author) suggests that
such distracted drivers actually tend to (instinctively) drive more slowly and
hold up the traffic Perhaps such behavior leads to an increase in the number
of accidents but it does not necessarily lead to an increase in the number of
accident-related fatalities
Much talked about technological innovations such as automatic collision
avoidance systems and sensors (on the sides of vehicles) can indeed detect
vehicles in the front and neighboring lanes Furthermore vehicle-to-vehicle
communication systems vehicle-to-infrastructure communication systems
can no doubt avoid collisions and accidents Again such collision avoidance
systems work and are effective entirely because they automatically reduce
vehicle speeds - even if one of the offending vehicles is being at a super
high speed Also it must be remembered that such futuristic systems have
not yet been implemented widely nor can they be implemented widely since
the large majority of vehicles on the road are NOT luxury models Advanced
safety features come with a price and not all drivers can afford to pay that
price and ―buy that ―additional safety
Ultimately it is the laws of physics that govern what will happen when two or
more vehicles collide or even when a single vehicle collides with a stationary
infrastructural object (a bridge a wall a building or some impediment on the
road) The lower the number of crashes the lower the number of fatalities as
revealed by the 1994-2009 data graphed in Figure 5 The higher the speed of
Page 32 of 45
the object or objects that are involved in a collision the higher the kinetic
energy K that must be absorbed andor dissipated Increasing the posted
speed limit only increases the energy that must be absorbed when a crash
does occur This ultimately is the most important criterion determining the
number of fatalities
The kinetic energy increases as the square of the speed being given by the
well-known formula K = frac12 mv2 where m is the mass of the vehicle (in
laypersonlsquos language m increases directly with vehicle weight) and v is the
speed For the same vehicle mass an increase in the speed from 55 mph to
85 mph increases the kinetic energy K by a factor of 239 or roughly a 250
increase in the kinetic energy that must be absorbed in a collision
Ideally speaking the kinetic energy of the colliding object(s) is absorbed by
the vehicle infrastructure (a sturdy space frame the engine other vehicle
components etc) andor the surroundings However in the unfortunate
cases where this kinetic energy must be absorbed by the vehicle occupant(s)
the result is severe life-altering injuries andor death An unequivocal
relationship between an increase in vehicle speeds and fatal accidents can
be demonstrated by a careful examination of available traffic fatality data
This is a more involved discussion and is not the purpose of this short
communication These topics are no doubt very politically charged with many
social legal and financial implications with each interest group favoring a
different conclusion Nonetheless we cannot escape the laws of physics as
they govern the fundamental need to absorb higher and higher values of the
kinetic energy K with increasing vehicle speeds This same point is also
emphasized by Dr Friedman of the University of Illinois Chicago (see earlier
discussion)
Speed kills because of these energy transfer considerations and there can be
no doubt about it
Innovative 21st century solutions to speed management on the highways
such as strict enforcement of speed limits minimizing speed dispersion
(difference between speeds at which different drivers travel) while using
cameras to track the 15 of drivers who willfully violate the speed limit and
Page 33 of 45
create hazardous driving conditions is certainly recommended (Recall that
the optimum recommended speed limit is at or below which 85 of all drivers
travel ndash a policy also supported by NMA) Even on this score however the
results are confounding if we consider the Australian experience
httpwwwthenewspapercomnews282840asp
Up until 2007 there was no speed limit in the Northern Territory of
Australia Imposing a speed limit 130 kmph (80 mph) on some areas and
110 kmph (68 mph) in some others actually increased the number of deaths
The death toll in 2006 when there was no speed limit in this region was 44
and went up to 75 in 2009 see data table in link below
httpwwwthenewspapercomrlcdocs2009au-ntroadtollpdf
Furthermore it appears that installation of cameras to enforce speed limits
has proved to be a hazardous distraction to drivers and deaths actually
began to skyrocket between 2005 and 2007 in all Australian roadways
The main purpose here is to sound a cautionary note amid renewed attempts
in many states across the US to increase the speed limits on our highways by
calling attention to the historical facts regarding the ―epidemic levels of
highway traffic fatalities that engaged our national attention in the fateful year
of 1966 The graphical representation of the traffic fatality data in Figures 1
to 5 tells its own story
Indeed it would be tragic if highway-accident-related fatalities were to start
increasing once again and reach the historically high level that was last seen
in 1972 the year before the Arab oil embargo of 1973
Page 34 of 45
Conclusions
1 The graphical representation of the highway fatality data and the brief
summary of the historical facts of traffic safety legislation suggest that
recent attempts to increase the speed limits by various states (notably
Texas) may be misguided The distinct peak in the highway fatalities
observed in these graphs is highly alarming This appears to be related to
the enactment of the National Maximum Speed Limit (NSML) in 1974
following the 1973 Arab oil embargo Although NSML was motivated by a
desire to reduce gasoline consumption an unintended benefit might have
been a dramatic reduction in fatalities The fundamental reasons for the
peak in the fatalities-VMT curve must be examined carefully without
political posturing
2 The widely used fatality rate fatalities per 100 M vehicle miles traveled
has been declining since 1921 the first year for which a fatality rate could
be computed and has now reached a historical low The absolute number
of fatalities on the other hand was increasing in the 1950s and 1960s at
an alarming rate and the public outcry that ensued led to the highly
publicized Congressional hearing of 1966 and the subsequent traffic safety
legislations The fatality rate has been decreasing even in the most recent
15-year period (1994-2009) again with increasing fatalities although less
dramatically Thus it appears that fatality rate calculation based on vehicle
miles traveled (VMT) might not be a reliable indicator of the underlying
dynamics in the fatality trends
3 More detailed compilation of number of fatalities and the number of fatal
crashes within each speed limit segment is required to better understand
the effect of increasing speed limits on highway fatalities (and also fatality
rates) Such data is already available and is being compiled at the local
city and county levels in all jurisdictions and only needs to be reorganized
to highlight the effect of (posted) speed limits on the number of crashes
and fatalities This will require some minor rewriting and revisions to the
chapters named ―Crashes and ―States in the annual NHTSA reports
Page 35 of 45
Analysis of the fatalities-crashes data for several years with various
speed limits will be more revealing and meaningful than the current
fatality rates analysis and will be discussed separately in a follow up
report
4 One should not be lulled by the fact that vehicles of the 21st century are
now equipped with advanced safety features not available in the 1950s
and the 1960s In spite of these safety features the laws of physics dictate
that the higher the speed the higher kinetic energy of the colliding objects
and hence the greater the risk indeed near certainty of fatalities in a
higher speed collision compared to a lower speed one
5 The higher the speed at which the vehicle that is involved in a crash is
traveling the higher the kinetic energy that must be absorbed andor
dissipated without affecting the occupant(s) to avoid serious injuries andor
death This was true in the 1950s and the 1960s and will continue to be
true in the 21st century as well
Speed Kills for this just reason
6 It appears that higher fuel economies and reduced
highway fatalities were the twin societal benefits of 55
mph adopted after 1973 If so the current attempts to
increase the speed limits appear to be in conflict with
other important societal objectives
Page 36 of 45
Table 1 Annual US Street amp Highway
Fatalities from 1957
Year
Fatalities
Vehicle Miles
(millions)
Rate100M Vehicle Miles
1957 38702 646915 598
1958 36981 664915 556
1959 37910 700478 541
1960 38137 718845 531
1961 38091 737535 516
1962 40804 766852 532
1963 43564 805423 541
1964 47700 846500 563
1965 49163 887640 554
1966 51524 927915 555
1967 51559 965132 534
1968 53831 1019726 528
1969 55032 1066108 516
1970 53672 1114098 482
1971 53761 1183524 454
1972 55704 1264614 440
1973 55113 1316207 419
1974 46078 1282790 359
1975 45500 1330074 342
1976 45523 1402380 325
1977 47878 1467027 326
1978 50331 1544704 326
1979 51103 1529133 334
1980 51091 1527295 335
1981 49301 1552803 317
1982 43945 1595010 276
1983 42589 1652788 258
1984 44257 1720269 257
1985 43795 1774179 247
Page 37 of 45
1986 46056 1835000 251
1987 46385 1921000 241
1988 47093 2026000 232
1989 45555 2107040 216
1990 44529 2147501 207
1991 41162 2172214 189
1992 39235 2239828 175
1993 40115 2296585 175
1994 40676 2359984 172
1995 41798 2422696 173
1996 41907 2485848 169
1997 41967 2560373 164
Data from Federal Highway Administration
Source httpwwwpublicpurposecomhwy-fatal57+htm
Telephone +16186328507 - Facsimile +16186328538
WENDELL COX CONSULTANCY P O Box 841 - Belleville IL 62269 USA
Page 38 of 45
Fatality data for 1921-1982 compiled by NHTSA
Year
VMT
(Millions)
VMT
(Billions)
Fatalities
Fatality rate
per 100 M VMT
1921 55027 5503 13253 241 1922 67697 6770 14859 219 1923 84995 8500 17870 210 1924 104838 10484 18400 176 1925 122346 12235 20771 170 1926 140735 14074 22194 158 1927 158453 15845 24470 154 1928 172856 17286 26557 154 1929 197720 19772 29592 150 1930 206320 20632 31204 151 1931 216151 21615 31963 148 1932 200517 20052 27979 140 1933 200642 20064 29746 148 1934 215563 21556 34240 159 1935 228568 22857 34494 151 1936 252128 25213 36126 143 1937 270110 27011 37819 140 1938 271177 27118 31083 115 1939 285402 28540 30895 108 1940 302188 30219 32914 109 1941 333612 33361 38142 114 1942 268224 26822 27007 101 1943 208192 20819 22727 109 1944 212713 21271 23165 109 1945 250173 25017 26785 107 1946 340880 34088 31874 94 1947 370894 37089 31193 84 1948 397957 39796 30775 77 1949 424461 42446 30246 71 1950 458246 45825 33186 72 1951 491093 49109 35309 72
1952 513581 51358 36088 70
Page 39 of 45
1953 544433 54443 36190 66 1954 561963 56196 33890 60 1955 605646 60565 36688 61 1956 627843 62784 37965 60 1957 647004 64700 36932 57 1958 664653 66465 35331 53 1959 700480 70048 36223 52 1960 718762 71876 36399 51 1961 737421 73742 36285 49 1962 766734 76673 38980 51 1963 805249 80525 41723 52 1964 846298 84630 45645 54 1965 887812 88781 47089 53 1966 925899 92590 50894 55 1967 964005 96401 50724 53 1968 1015869 101587 52725 52 1969 1061791 106179 53543 50 1970 1109724 110972 52627 47 1971 1178811 117881 52542 45 1972 1259786 125979 54589 43 1973 1313110 131311 54052 41 1974 1280544 128054 45196 35 1975 1327664 132766 44525 34 1976 1402380 140238 45523 32 1977 1467027 146703 47878 33 1978 1544704 154470 50331 33 1979 1529133 152913 51093 33 1980 1527295 152730 51091 33 1981 1555308 155531 49301 32 1982 1595010 159501 43945 28
Source Analysis of Significant Decline in Motor Vehicle Traffic Fatalities in
2008 httpwww-nrdnhtsadotgovPubs811346pdf see Table A1 page 31
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Page 40 of 45
Acknowledgements
The author is grateful for thoughtful comments provided by friends and colleagues
with whom this document was shared via email prior to it being uploaded as a
publicly available document for wider dissemination and study The comments
offered by Prof Subra Ganesan of Oakland University Electrical and Computer
Engineering Department are reproduced with permission in their entirety
About the author
The author obtained his Masterrsquos (S M) and Doctoral (Sc D) degrees in Materials Engineering
from the Massachusetts Institute of Technology Cambridge USA He then spent his entire
professional career at leading US research institutions (MIT NASA Case Western Reserve
University and General Motors R amp D Center in Warren MI) He holds four patents in advanced
materials processing has co-authored two books and has published several scientific papers in
leading peer-reviewed international journals His expertise includes developing simple
mathematical models to explain the behavior of complex systems He can be reached by email at
vlaxmananhotmailcom
Page 41 of 45
Please Buckle Up
httpwwwlakecountypublichealthorgindexphpbuckle-up-montana
Public Awareness
Respect the Cage Exhibit
The Department of Transportation hopes that showing the reality of the crash will reduce traffic
fatalities A crushed car crash dummies and a sobering message ndash all part of the ―Respect The
Cage exhibit that is traveling across Montana The exhibit sponsored by the Montana Department
of Transportation stopped in Ronan on November 6th and is aimed at raising awareness about the
importance of wearing seat belts
The car in the exhibit was in an actual wreck many years ago
the passenger in the vehicle died because he was not wearing a
seat belt the driver who was wearing his seat belt survived
Montanarsquos likeliest crash fatality scenario
A Pickup
A Rural road
And Seat belts that
arenrsquot used
Page 42 of 45
Occupants of pickups are less likely to wear seat belts and pickups are more likely to
roll over than passenger cars
Seat belts reduce the risk of death by 60 percent in pickups and SUVs
In Montana from 2006-2008 81 of those killed in a crash while riding in a pickup were not wearing seat belts
In Montana pickups make up 401 of the vehicle population
For more information on Respect the Cage click here
Page 43 of 45
Appendix 1
Lack of seat belts leading cause of Louisiana highway deaths
1251 AM May 28 2011 |
Written by Adam Duvernay
Crashes involving unbuckled motorists were the leading cause of highway fatalities
in Louisiana last year and cost $9888 million according to recent reports The
Louisiana Highway Safety Commission reported 59 percent of vehicle occupants
killed in Louisiana crashes last year mdash about one in four mdash werent wearing seat
belts
httpwwwshreveporttimescomarticle20110528NEWS01105280354Lack-seat-
belts-leading-cause-La-highway-deathsodyssey=tab|topnews|text|FRONTPAGE
Crash bull Stats Published by NHTSAlsquos National Center for Statistics and Analysis 1200 New Jersey Avenue SE Washington DC 20590
DOT HS 811 451
Early Estimate of Motor Vehicle Traffic Fatalities in 2010
httpwww-nrdnhtsadotgovPubs811451pdf
Summary
A statistical projection of traffic fatalities in 2010 shows that an estimated 32788
people died in motor vehicle traffic crashes This represents a decline of about 3
percent as compared to the 33808 fatalities in 2009 as shown in Table 1 If these
projections are realized fatalities will be lowest on record (since 1949)
Traffic Safety Facts Overview 2009 Data
httpwww-nrdnhtsadotgovPubs811392pdf
In 2009 33808 people were killed in the estimated 5505000 police-reported
motor vehicle traffic crashes 2217000 people were injured and 3957000
crashes involved property damage only Compared to 2008 this is a 10-
percent decrease in the number of fatalities and a 5-percent decrease in the
Page 44 of 45
number of police-reported motor vehicle traffic crashes people injured and
crashes involving property damage
An average of 93 people died each day in motor vehicle crashes in 2009 mdash
an average of one every 16 minutes
Traffic Safety Facts Overview 2008 Data
httpwww-nrdnhtsadotgovPubs811162pdf
In 2008 37261 people were killed in the estimated 5811000 police-reported
motor vehicle traffic crashes 2346000 people were injured and 4146000
crashes involved property damage only
Some comments and Feedback
The following comments were received from Prof Ganesan after his review of the
first draft of this document It was subsequently revised thanks to this input to
address some of the very important issues raised here
Dear Laxman
The write up is not enough
You are emphasizing that the speed limit reduces the fatal accidents (comparing 1966
to 2000 accident numbers)
Can you also add a few sentences why the number is decreasing from 1980 to 2000
values (May be due to better design of vehicles)
Can you say anything about the fuel consumption with the speed for any typical
vehicle in 2011 or 2010 (do not consider the fatalities issue)
Probably a speed between 55 and 60 mph gives a better mileage If so this is a
compelling reason to keep the speed limit low But cars probably can be tuned to
give better mileage at any high speed also
Page 45 of 45
Weather is also a major factor in fatal accidents Speed limit may be kept low during
winter and kept higher in summer Give your comments on this too
Driver distractions can cause more accidents Now cars have many multimedia and
internet features Automatic collision avoidance systems and sensors on the sides can
detect vehicles in the front and neighboring lanes and it can automatically decrease
speed even if the driver speeds at super high speeds
Give some comments on this too There is also Vehicle to Vehicle communications
vehicle to infrastructure communications and they can avoid collisions and accidents
Technology has changed from 1966 I cannot agree with you on the speed limit
without any discussion on the above and other factors
Have a great day
Subra Ganesan
Professor Subramaniam Ganesan
Director Real Time amp DSP Lab
Electrical and Computer Engineering Department
2200 Squirrel Road Dodge Hall Room 105
Oakland University Rochester MI 48309 USA
Phone 248 370 2206 Fax 248 370 4633
wwwsecsoaklandedu~ganesan
IEEE Distinguished Visiting Speaker (2005-2009) Coordinator
IEEE SEM CS chapter Chair Region 4 and CS Society Board member
SAE ASEE ACM member
Page 9 of 45
Figure 2a Graphical representation of the absolute number of US highway fatalities
versus annual vehicle miles driven (in trillions) The number of miles driven by US
drivers has increased each year since 1957 as seen in Table 1 The absolute number
of highway fatalities has increased as well reaching a peak in the late 1960s to early
1970s The same peak is also seen here in the graph of the absolute number of
highway fatalities versus vehicle miles driven Improvements in vehicle safety devices
(notably seat belts and airbags) coupled with the institution of the national highway
speed limits (starting mid 1970s) and also improved highways are the primary
reasons for the decrease in fatalities These historical trends suggest that renewed
attempts to increase the speed limits on our highways would be counterproductive
and may eventually lead once again to an increase in fatalities with tragic
Page 10 of 45
consequences
Figure 2b Graphical representation of the US highway fatality data for the period
1921-1982 The first year for which a fatality rate yx could be computed is 1921 The
number of fatalities was 13253 and VMT was 5503 billion yielding a fatality rate of
2408 per 100 million VMT The fatality rate for any year is the slope of the ray ie
the straight line joining the (x y) data point back to the origin (00) of this graph see
dashed line for 1921 superimposed on to the graph The fatality rates (slopes of such
rays) had been declining quite consistently although the absolute number of fatalities
increased as seen here ultimately leading to the Congressional hearing in 1966 Is
VMT the single most important reason for the increasing fatalities
Page 11 of 45
Figure 3 Graphical representation of the traffic fatality data for the 15 year period
1994-2009 A sudden precipitous drop in the absolute number of fatalities (at least on
the magnified scale used here) and hence the fatality rate has been observed over
the three-year period 2007-2009 However it should be noted that the x-y scatter
graph here shows a general upward trend with fatalities actually increasing with
increasing VMT (as in the earlier era 1950s and 1960s) during the 12-year period
spanning 1994-2006 although the rate yx shows a misleading downward trend Why
is the rate yx going down
The reason is very simple and it may be just a mathematical artifact The equation of
the best-fit straight line through the most recent data points is of the form y = hx + c
= 2865 x + 34420 where h is the slope of the line and c the intercept (Note that x
here is VMT in billions The numerical value determined using this equation must be
divided by 10 to get the rate per 100 M VMT) Hence the fatality rate given by the
ratio yx = h + (cx) = 2865 + 34420x can actually decrease with increasing
values of x because of the nonzero intercept c Unlike the ray through the origin the
best-fit line does not pass through the origin (00) If we consider only the most
Page 12 of 45
recent data the intercept c is positive and fatality rates yx decrease with increasing
VMT and increasing fatalities In the earlier era both the slope h and intercept c had
very different values due to several factors being discussed here (speed limits
technology highway design etc)
Table 2 Traffic fatality data for the recent 15-year period
1994-2009 (Source NHTSA)
Year
Highway
fatalities y
Vehicle miles
traveled
VMT
(billions) x
Fatality rate
yx per 100
million VMT
Fatal crashes
1994 40716 2358 173 36254 1995 41817 2423 173 37241 1996 42065 2486 169 37494 1997 42013 2562 164 37324 1998 41501 2632 158 37107 1999 41717 2691 155 37140 2000 41945 2747 153 37526 2001 42196 2797 151 37862 2002 43005 2856 151 38491 2003 42884 2890 148 38477 2004 42836 2965 144 38444 2005 43510 2989 146 39252 2006 42708 3014 1 42 38648 2007 41259 3032 136 37435 2008 37423 2974 126 34172 2009 33808 2979 113 30797
Page 13 of 45
Figure 4 The most significant metric used by NHTSA is the fatality rate per 100
million vehicles miles traveled (VMT) This is now at a historical low of 113 for
2009 having declined year after year from 173 in 1994 The NHTSA however also
compiles other types of data on crashes There are three types of crashes fatal
injury but no death and property damage only A careful review of this crash data
for the period 1994-2009 reveals the obvious the lower the number of (fatal)
crashes x the lower the number of highway-accident-related fatalities y It is also
obvious that the number of fatalities per crash is greater than one ie more than one
person is being killed when one of more vehicles experience a crash
Clearly this is the single most important piece of information that one needs to
reduce the number of fatalities on our highways Vehicle design and engineering as
well as all other policy matters (legal political social environmental financial)
must be guided by this simple graph The best-fit line through the data derived using
simple linear regression has the equation y = hx + c = 114x ndash 10266 and is
Page 14 of 45
superimposed on to the data The design engineering goal and societal goal should
be to reduce the slope h of this statistically significant best-fit line to its ideal value of
h = 1 A fatal crash by definition is one where at least one person dies either an
occupant or a non-motorist in the path of the vehicle Hence the ideal slope h = 1
Photograph of an accident scene from the period 1955-1965
httpwwwcorinthsocialhistoryprojectorghtmlhighwaytollshtml
3 A Brief History of Traffic Safety Legislation
The following is extracted from the Wikipedia article on National Highway
Traffic Safety Administration (NHTSA)
httpenwikipediaorgwikiNational_Highway_Traffic_Safety_Administration
In 1965 and 1966 public pressure grew in the US to increase the safety of
cars The number of deaths on US highways were increasing year after year
Page 15 of 45
see Figure 1 and in 1966 Congress held a series of highly publicized
hearings on highway safety This led to the legislation for mandatory
installation of seat belts which also created the US Department of
Transportation (on Oct 15 1966)
httpwwwemsgovpdf2011EMSWeek2011_Stricklandpdf
The following is extracted from a Washington Post article on
NHTSA dated April 2 2002
httpwwwwashingtonpostcomwp-srvbusinessincludesnhtsa_primerhtm
In 1966 after decades of rising traffic fatalities (also vividly illustrated in
Figures 1 and 2 here) the publication of Ralph Naders Unsafe at Any
Speed and increasing public outcry for safer automobiles Congress held a
series of highly publicized hearings on creating a regulatory agency for traffic
safety Among the witnesses was William Haddon an epidemiologist who
introduced the idea that traffic accidents could be analyzed scientifically and
injuries reduced by changing auto design such as installing collapsible
steering columns safety glass head rests and seat belts
Congress passed the Highway Safety Act of 1966 creating the National
Highway Safety Bureau with Haddon as its first administrator The bureau
became NHTSA in 1970 under the newly established Department of
Transportation An early Nader convert Joan Claybrook headed NHTSA
under President Carter and now runs Naders organization Public Citizen
National Traffic and Motor Vehicle Safety Act
httpwwwanswerscomtopicnational-traffic-and-motor-vehicle-safety-act
Signed into law by President Lyndon Johnson on September 9 1966 this act
created the first mandatory federal safety standards for motor vehicles The
act was motivated by a variety of factors First and foremost the public was
growing increasingly concerned over the rising number of traffic fatalities on
the nations roads Such fatalities had increased by nearly 30 percent
between 1960 and 1965 and experts forecasted 100000 such deaths
Page 16 of 45
annually by 1975 unless something was done to improve traffic safety
Adding fuel to the fire Ralph Naders Unsafe at Any Speed published in
November 1965 criticized the automobile industry for neglecting safety in
favor of power and styling when designing new vehicles
4 The reason for the historical
decrease in highway fatalities
A recent news item see link given below regarding renewed attempts to
increase the speed limit by many states prompted this write up by the
present author who has studied traffic fatality data extensively and analyzed
them very carefully over the last several years
httpmoneymsncomauto-insurancewhy-speed-limits-are-
risingaspxGT1=33033
Residents of Metro Detroit area who frequently cross into Ohio from
Michigan notice that the speed limit has now increased in Ohio The speed
limit on Michigan highways was increased to 70 mph in the late 1990s but
Ohio retained its lower speed limit for many years leading Michigan drivers to
experience a ―speed trap of sorts The speed limit is also increasing in many
other states notably Texas where it is proposed to increase it to 85 mph at
least in West Texas
Historically speaking from a traffic fatality standpoint we must consider two
important dates 1966 and 1973 Only 1973 the year of the Arab oil embargo
following the Arab-Israeli war (that led to what President Obama has recently
called the pre-1967 border for Middle East peace) is mentioned in the above
article It fails to mention the significance of the year 1966
Prior to 1966 there was actually NO speed limit in many Western states and
deaths due to highway accidents were increasing year after year The
Page 17 of 45
number of highway fatalities went up from 38702 in 1957 to 51524 in 1965
a 33 increase over the 1957 level and an additional 12822 deaths in 1965
compared to 1957 It was this carnage on the US highways that forced
Congress to hold its hearings on highway traffic fatalities in 1966
Nonetheless a careful examination of the fatality data in Table 1 shows that
notwithstanding the highly publicized Congressional hearings of 1966 and
new safety legislation that was enacted the absolute number of fatalities
continued to increase after 1966 and only started decreasing after 1973
Vehicle designs especially the introduction of safety features (even the
simplest like safety belts) did not change significantly between 1966 and
1973 Nonetheless post-1973 we begin to see a dramatic turnaround
Why
After the 1973 Arab oil embargo a nationwide maximum speed limit (NMSL)
of 55 mph was imposed and accepted in the USA (effective Jan 1 1974)
during the Nixon administration primarily as an effort to conserve fuel and
reduce the US vulnerability to oil imports The unintended and indeed
fortunate consequence of this reduced speed limit was the immediate
reduction in the fatalities revealed in Figures 2 and 3 This is the real reason
for the peaks in highway fatalities observed in these two graphs
The Congressional hearings of 1966 did eventually have an impact but it was
a delayed one The impact of the 1973 nationwide speed limit of 55 mph was
however immediate as we see from the magnified plot of the same data in
Figure 5 and a closer examination of the raw fatality data in Table 1
The number of highway-accident-related fatalities decreased immediately
from a high of 55704 in 1972 to just 46078 in 1974 a 173 drop see
arrows There were 9626 fewer deaths annually even with a slight increase
in the vehicle miles driven (see Table 1) Indeed the number of highway
death reached its absolute peak value in 1972 never to be seen again
Fatalities have been decreasing every since with slight fluctuations about
each new low value
Page 18 of 45
Figure 5 Expanded view of the fatality data showing the immediate impact of the
national speed limit of 55 mph following the Arab oil embargo of 1973 Note that
fatalities continued to rise between 1966 and 1973 in spite of the highly publicized
Congressional hearings in 1966 and the traffic safety legislation enacted soon after
Each new low is probably associated with vehicle safety innovations and the
improvements in vehicle design and engineering The combined beneficial
effect of improved vehicle designs primarily the introduction of seat belts
and the laws enforcing usage of seat belts aided by the reduced speed
limits contributed to the continued decline in the absolute number of fatalities
that started since 1973 and has continued to this day The subsequent
introduction of other safety features notably air bags has contributed to a
further reduction in highway fatalities
Page 19 of 45
State police Trooper First Class Jeffrey Flowers looking at a car in which a Boswell
Pennsylvania woman was injured Tuesday (May 31 2011) The accident occurred at
an intersection when a truck (seen behind the wrecked car) entered this accident
prone intersection (part of a highway safety corridor where signs are posted to
reduce unsafe driver behavior) There have been four accidents at this intersection
since 2006 none fatal httpwwwdailyamericancomnewssomersetda-ot-woman-
injured-in-route-30-wreck-2011053104165420story
5 Numerical calculations of decline in
fatalities and the impact of NMSL post-1973
Letlsquos consider the decline in fatalities between 1972 the last year before the
adoption of the NMSL and 1974 the first year following its adoption after the
Arab oil embargo There was an immediate decrease in the number of
fatalities by 9393 ie y = -9393 with a slight increase in the VMT ie x
= 20758 millions The NHTSA data used here may be found in the table at
the end of this document The numerical value of the rate of change per
billion VMT (ie neglecting the sign) was therefore
yx = 4525 fatalitiesbillion VMT (1972-1974)
Page 20 of 45
It is instructive to compare this rate of change in fatalities with similar short
periods of a decline in fatalities in the pre-1973 era when speed limits were
much higher The absolute number of fatalities declined over a relatively
short period with both an increase and a decrease in VMT The results are
given below and are self-explanatory
yx = 454 fatalitiesbillion VMT (1953-54) decline with increase in VMT
yx = 655 fatalitiesbillion VMT (1942-43) decline with decrease in VMT
yx = 1739 fatalitiesbillion VMT (1941-42) decline with decrease in VMT
yx = 4528 fatalitiesbillion VMT (1937-39) decline with increase in VMT
yx = 2548 fatalitiesbillion VMT (1931-32) decline with decrease in VMT
The rate of decline observed between 1953 and 1954 with an increase in
VMT was just one-tenth of that observed following the adoption of the 55
mph speed limit The war years (1941-43 WWII) and the Great Depression
era (1931-32) were accompanied by big declines in fatalities with decreasing
VMT but the rate of change was still significantly lower than observed after
the adoption of the NMSL
The only apparently inexplicable decline is that between 1937 and 1939
where a nearly identical high rate of decline was observed Notice also the
big drop in the traditional fatality rate between 1937 and 1938 This large drop
appears to coincide with the creation of the National Safety Council (NSC) by
William H Cameron in June 1937 (see link below) with its far-flung campaign
of education legislation research highway engineering and traffic training
undertaken by the NSC and some two dozen other groups with the backing of the
automotive industry through its Automotive Safety Foundation Other factors
unknown to the present author probably also played a role
httpwwwtimecomtimemagazinearticle0917188379700htmlixzz1O2G
7rnUg
Page 21 of 45
These simple computations here however reveal the significant effect of
reduced speed limits on highway fatalities much more so than other factors
6 Further Considerations Pros and Cons
The singular effect of increased speeds (or speeding) on highway fatalities
has been studied and demonstrated by a number of industry sources such
as the Insurance Institute for Highway Safety (IIHS) Consumers Union and
also by government researchers
httpwwwsmartmotoristcomtraffic-and-safety-guidelineexcessive-speed-is-
a-factor-in-one-third-of-all-fatal-crasheshtml
httpwwwconsumersunionorgotherspeedlimitsspeed031500a2htm
Speed ndash defined as exceeding the posted speed limit or driving too fast for
given conditions ndash is a factor in nearly one-third of all fatal crashes Besides
fatality in 1998 nearly 40000 people were critically injured in speed-related
crashes and nearly 72000 were moderately injured
The salutary and immediate beneficial effect of the nationwide 55 mph speed
limit has been noted by other researchers (see Susan Ferguson link below)
httpwwwnhtsagovpeopleinjuryenforcespeed_forum_presentationsfergu
sonpdf
After a partial repeal of this law in 1987 which granted states the authority to
increase speed limit (especially in rural interstates) a 1989 study showed a
15 increase in fatalities in rural interstates and a 5 increase in non-rural
interstates Unfortunately such studies often tend to be discounted by
advocates of increasing the speed limits as being produced by biased
industry sources
Similar conclusions were also presented by NHTSA in February 1998 in its
report to the Congress entitled ―Report to Congress The Effect of Increased
Speed Limits in the Post-NMSL Era see link given below Among its key
Page 22 of 45
findings is the following quoted in its entirety NMSL refers to the National
Maximum Speed Limit legislated after the Arab oil embargo of 1973
httpwww-nrdnhtsadotgovPubs808-637PDF
hellip Nevertheless it is important to note that data currently available from the
National Highway Traffic Safety Administrationrsquos (NHTSA) Fatality Analysis
Reporting System (FARS) shows that states that increased speed limits in 1996
experienced approximately 350 more Interstate fatalities than would have been
expected based on historical trends -- about 9 percent above expectations
Concurrently the Interstate fatalities experienced in states that did not increase speed
limits in 1996 was consistent with pre-1996 trends The estimated increase in
Interstate fatalities found in this study while smaller in magnitude compared to the
estimated change in fatalities found in 1987 following the increase of speed limits on
rural Interstates does follow the historical pattern of increases in fatalities being
associated with increases in posted speed limits
The annual crash reports compiled by NHTSA see Table 3 indicate that the
number of fatal crashes (and hence fatalities using the regression equation
developed in Figure 4) increase as the posted speed limits increase
Page 23 of 45
Table 3 Posted speed limits and number of crashes
Speed Limit Crashes (2008) Crashes (2009)
30 mph or less 3705 3277 35 or 40 mph 6115 5516 45 or 50 mph 6461 6074
55 mph 9794 8847 60 mph or higher 6908 6124
Total 34017 30797
Source httpwww-nrdnhtsadotgovPubs811402EEpdf
61 Studies cited in favor of lower speed limits
A detailed analysis of speeding related fatalities (see link below) by NHTSA
shows that a third of all crashes involve speeding ie at least one driver was
speeding
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Furthermore the above report which covers the period 1983-2002
indicates that immediately after the NMSL was completely abolished in
December 1995 the number of speeding related fatalities at speeds
above 65 mph increased from just 15 in 1995 to a 677 in 1996 (see Table
62 on page 43 of above report) It continued to increase in the years
since climbing to 930 in 2000
More detailed studies similar to that noted above by researchers at the
University of Illinois Chicago led by Lee S Friedman again lead to the
conclusion that higher speed limits lead to an increase in the number of
fatalities (see American Journal of Public Health online July 16 2009)
httphealthusnewscomhealth-newsmanaging-your-
healthcarearticles20090716deaths-injuries-increase-with-higher-speed-
limits
Page 24 of 45
httpwwwmedpagetodaycomPublicHealthPolicyPublicHealth15122
httpwwwamericaneercomspeed-limits
httpwwwactuarialoutpostcomactuarial_discussion_forumarchiveindexph
pt-171870html
For the study period 1995-2005 these researchers found that 12545 deaths
and 36582 injuries could be attributed to the increased speed limits The
benefits of reduced speed limits are stated quite eloquently by Dr Friedman
and are reproduced below (from above news article see link)
Reduced speed limits would save lives Friedman said They would also reduce
gas consumption cut emissions of air pollutants save valuable years of productivity
(lost due to injuries)and reduce the societal cost of motor vehicle crashes (due to
both fatal crashes and due to nonfatal and severe life-changing injuries) he added
Friedman and coworkers have also shown that increasing the speed limit led
to an immediate increase in the number of fatalities on Israeli roadways (see
link below)
httpinjurypreventionbmjcomcontent133156
The effect of speeding is very significant especially in rural areas resulting
in significantly higher fatalities Fatality rates are frequently double or triple
that in urban areas (see link below)
httpsafetyfhwadotgovspeedmgtdata_factsdocsspeeding_ruralpdf
As of Jan 1 2005 five Midwestern states had increased the speed limits to
above 65 mph (Illinois Iowa Kansas Minnesota Missouri Nebraska and
South Dakota) whereas three (Illinois Iowa and Wisconsin) had not All the
five states with increased speed limits showed a 7 to 13 increase in
fatalities The NHTSA study considered an eight year period before and after
the change in Dec 1995 (see Table 1 in link below) The collective experience
of the states that did NOT increase the speed limit was a 7 decline in
fatalities (see Table 2 of link below)
httpwwwiowadotgovmvdodsstats2006speedstudypdf
Page 25 of 45
Moreover Table 5 in the above study shows the effect of imposing the NMSL
of 55 mph in Iowa and its repeal in 1995 Considering a four-year average
before 1974 when the speed limit was 75 mph there were 35 fatal crashes
with 43 fatalities In the first four years after the 55 mph there were only 23
fatal crashes and 28 fatalities In the last four years before the repeal of 55
mph in 1995 there was a further decline to 14 fatal crashes with 17 fatalities
The Iowa fatality data will be discussed in more detail separately (in a later report)
since it provides the opportunity to assess the effect of a change in the speed limit
on the relationship between number of fatalities and fatal crashes (as seen in
Figure 4 for the US as a whole)
North of the US border Canadians seem to be citing the ―shocking increase
in highway fatalities in the US states where the speed limits were raised to
curb their own speed limits
httparchivesafety-councilorginfotrafficspeed-02html
httparchivesafety-councilorginfotrafficspeedhtml
Speed kills but speed also sells notes the second of the above news items
Manufacturers are producing more high performance cars (with higher horse
power to weight ratio) and ads feature enticing cars that race and swerve in
miraculous ways on empty roads These subliminal messages encourage
drivers especially young drivers to break the speed limit leading to the
absolute increase in highway fatalities (although the rate itself is going
down) The article emphasizes the need to enforce the speed limit on
Canadian highways and in cities where street racing is becoming a problem
62 Studies cited by opponents of lower speed limits
In fairness to quote the opponents on the other side of this debate Montana
reverted back to Reasonable and Prudent speed limits when the National
Maximum Speed Limit was repealed in 1995 and appears to have
experienced no significant increase in fatalities
Page 26 of 45
httpwwwhwysafetycomhwy_montanahtm
httpwwwmotoristsorgpressmontana-no-speed-limit-safety-paradox
httpwwwsouthbayriderscomforumsshowthreadphpt=81453amppage=1
Likewise studies in the state of Maryland showed no significant increase in
highway fatalities when the speed limit was increased from 55 mph to 75
mph The reason might simply be that drivers were already speeding much
more so when the speed limit was 55 mph than after the increase to 75 mph
In other words the fatalities data already reflects the effect of higher speeds
(not speed limits) on the number of fatalities
In Utah the experimental increase in the speed limit to 80 mph was
considered to be a success in terms of safety
httpautosaolcomarticleutah-speed-limit-tests
The UDOT Director noted that there was no increase in the number of
accidents on Interstate 15 But what happens in the event of an accident
when the speed limits are higher and drivers are driving at higher speeds and
two objects collide at this higher speed However no increase in the number
of accidents is not the same as no increase in fatalities due to the higher
speeds When accidents do occur do fatalities increase
Likewise in California when the speed limit went up from 55 mph to 65
mph in 1995 (after repeal of NMSL) fewer deaths were reported in 1998
compared to the peak year of 1979 or even 1987 Again the explanation
seems to be that motorists were already speeding when the limit was 55 mph
and that increasing the speed limit did not change driver behavior in any
significant way
httparticlessfgatecom1998-11-02news17735730_1_speed-limits-mph-
limit-death-rate
The National Motorists Association (NMA) a group which advocates higher
speed limits emphasizes the importance of considering fatality rates as
opposed to the raw fatalities The argument used is that fatality rates based
on the fatality per 100 million VMT is the legitimate way to look at the data
Page 27 of 45
This is a never ending debate Historically speaking fatality rates have been
going down ever since the compilation of traffic accidents data began Table
A1 in the appendix of a recent report by NHTSA (see link below) has highway
fatality rate data going back 1921
httpwww-nrdnhtsadotgovPubs811346pdf see appendix page 31
httpwwwmotoristsorgspeed-limitstruth
httpwwwmotoristsorgothercrash-data
httpwwwraisethespeedlimitorgmythshtml
httpwwwcatoorgpubspaspa346pdf
According to Stephen Moore of the Cato Institute (see last of the links above)
―All measures of highway safety show improvement not more deaths and
injuries since 1995 Despite the fact that 33 states raised their speed limits
immediately after the repeal of the mandatory federal speed limit the NHTSA
reported last October that the traffic death rate dropped to a record low level
in 1997lsquo Moreover the average fatality rate even fell in the states that raised
their speed limits
63 The Fatality rate Is it a reliable metric
In 1921 with fewer fatalities and fewer miles driven and the first year for
which the fatality rate could be computed the rate was 2408 It was down to
1479 in 1931 but the number of deaths had climbed to 31963 more than
double the 1921 absolute fatality number of 13253 It had dropped to 550 in
1966 the year of the highly publicized Congressional hearings but the
number of fatalities had climbed to 50984 in that fateful The Highway Safety
Act of 1966 ranks as one of the major acts of Congress and President
Johnson signed it saying that ―we have been tolerating a raging epidemic of
highway deathshellip see extract pasted below
httpwwwenotescommajor-acts-congresshighway-safety-act
Page 28 of 45
The act was motivated primarily by growing public concern over the rising number
of traffic fatalities in the United States Between 1960 and 1965 the annual number
of traffic fatalities increased by nearly thirty percent As President Lyndon B
Johnson stated at the signing of the act on September 9 1966 we have tolerated
a raging epidemic of highway death which has killed more of our youth than all
other diseases combined Through the Highway Safety Act we are going to find out
more about highway diseasemdashand we aim to cure it
Nonetheless highways fatalities continued to increase until the Arab oil
embargo of 1973 led to the NMSL of 55 mph all across the USA Do we just
ignore this undeniable historical record and focus only on the declining fatality
rate as the NMA and other proponents of higher speed limits seem to argue
(see links above)
The misleading nature of using fatality rates (per 100 M VMT) alone is also
obvious if one considers fatality data for individual states Take for example
the state of Montana which seems to have experienced no increase in
fatalities after repeal of NMSL
httpwww-nrdnhtsadotgovdepartmentsnrd-
30ncsaSTSI30_MT200930_MT_2009htm
For the period 2005-2009 the absolute number of fatalities for Montana
varied between a high of 277 in 2007 to a low of 229 in 2009 The fatality
rates per 100 M VMT on the other hand varied from a high of 245 for 2007
to a low of 201 for 2009 The corresponding US fatality rates varied from
136 to 114 Is the higher number for the fatality rate for Montana compared
to USA good or bad Likewise fatality rate per 100000 of population was
much higher for Montana than the US as a whole
This again highlights the pitfalls of using simple ratios to assess fatality statistics
without a full analysis of the underlying trends We will discuss this point
separately
As shown already the continuous decline in the fatality rate is a mathematical
artifact and essentially overlooks the unmistakable positive correlation
between the variables x and y of the type y = hx + c which becomes obvious
Page 29 of 45
only when we prepare the x-y scatter graph The ratio yx = h + (cx) can
decrease with increasing x (VMT) and increasing y (fatalities) since the
intercept c has a positive value when we consider only data spanning a short
period (such as 1994-2009 of more relevance to the current situation)
The debate between fatality rates and absolute number of fatalities is an
unending one A few years ago the Wall Street Journal carried an article
which was entitled (or something close) ―Unemployments rate in Ohio are
going down but why is the number of unemployed increasing The reason is
the same The graph of the number of unemployed (y) versus the number in
the labor market (x) is linear with a positive slope h and a positive intercept c
So the unemployment rate computed using the ratio yx keeps going down
year after year although the number unemployed keeps increasing Is it a
good thing that the unemployment rate is going down when more people
seem to be unable to find gainful unemployment
Or consider the situation with cancer death rates This too has been going
down in recent years but the actual number of cancer-related deaths has not
declined in any significant way Is it good that cancer death rates are going
down In all these situations the researchers or the socio-econo-politico
analysts involved in analyzing the trends in the data have failed to consider
the underlying x-y relation describing each problem
Hence it appears that the debate on the effect of increased speed limits
should not be focused on only the fatality rates (which have been decreasing
and proponents of higher speed limits cite this in their arguments) or even the
absolute number of fatalities (which has been the focus here) but on the
relationship between speed and the number of fatal crashes and the number
of fatalities within each speed segment (see Table 3 and also Figure 4)
Unfortunately details of number of fatalities and the number of fatal crashes
at each speed limit are not available even from NHTSA for detailed study
When a crash does occur (it is immaterial how many miles were driven) the
speed of the driver and vehicle design and engineering including safety
devices in place (seat belts airbags other impact absorbing technologies)
Page 30 of 45
determine if the occupants(s) will be killed One cannot argue that speed
does NOT kill That would be an absolute denial of the laws of physics
Studies show that setting the speed limit at the 85th percentile in any given
zone (this is the speed at or below which 85 of drivers are observed to
travel in traffic engineering studies) is the safest speed limit The majority of
drivers try to obey the posted speed limit while a few choose to drive at a
speed they consider is safe and prudent These are also perhaps the most
vociferous advocates of higher speed limits It is this tension caused due to
differences in speeds that leads to tailgating improper passing reckless
driving weaving from lane to lane and ultimately crashes and deaths in some
unfortunate cases
httpblogmotoristsorgspeed-limits-slower-safer
MARK TAYLOR
ANOTHER LOST A man was killed when his 4WD drive hit a tree east of Morrinsville (in New
Zealand) on Monday May 30 2011 The driver lost control of the vehicle on a bend probably tried
to correct his mistake and put the car into a ―yaw causing it to leave the road and smash sideways
into a tree Alerts to slow down had been posted since this was a high accident area but the driver
probably did not pay attention
64 Other factors
Many other factors besides speed no doubt affect highway fatalities The
vehicles of the 21st century are very different from the vehicles of the mid 20th
Page 31 of 45
century Technological innovations such as improvements in vehicle design
and engineering have greatly increased crash worthiness of vehicles even at
high speeds Environmental factors such as the weather also contribute to
accidents but not necessarily to increased fatalities Drivers actually tend to
slow down instinctively during adverse weather conditions (rain snow storms
etc) and although such weather may contribute to increased accidents the
lower speeds actually reduce fatalities
Yes technology has changed fundamentally from 1966 Drivers today are
more distracted by their cellmobile phone conversations (and also built-in
phones in luxury models) and text messaging than the drivers of the pre-1966
era High end cars now have many multimedia and internet features Again a
careful observation (even personal experience by the author) suggests that
such distracted drivers actually tend to (instinctively) drive more slowly and
hold up the traffic Perhaps such behavior leads to an increase in the number
of accidents but it does not necessarily lead to an increase in the number of
accident-related fatalities
Much talked about technological innovations such as automatic collision
avoidance systems and sensors (on the sides of vehicles) can indeed detect
vehicles in the front and neighboring lanes Furthermore vehicle-to-vehicle
communication systems vehicle-to-infrastructure communication systems
can no doubt avoid collisions and accidents Again such collision avoidance
systems work and are effective entirely because they automatically reduce
vehicle speeds - even if one of the offending vehicles is being at a super
high speed Also it must be remembered that such futuristic systems have
not yet been implemented widely nor can they be implemented widely since
the large majority of vehicles on the road are NOT luxury models Advanced
safety features come with a price and not all drivers can afford to pay that
price and ―buy that ―additional safety
Ultimately it is the laws of physics that govern what will happen when two or
more vehicles collide or even when a single vehicle collides with a stationary
infrastructural object (a bridge a wall a building or some impediment on the
road) The lower the number of crashes the lower the number of fatalities as
revealed by the 1994-2009 data graphed in Figure 5 The higher the speed of
Page 32 of 45
the object or objects that are involved in a collision the higher the kinetic
energy K that must be absorbed andor dissipated Increasing the posted
speed limit only increases the energy that must be absorbed when a crash
does occur This ultimately is the most important criterion determining the
number of fatalities
The kinetic energy increases as the square of the speed being given by the
well-known formula K = frac12 mv2 where m is the mass of the vehicle (in
laypersonlsquos language m increases directly with vehicle weight) and v is the
speed For the same vehicle mass an increase in the speed from 55 mph to
85 mph increases the kinetic energy K by a factor of 239 or roughly a 250
increase in the kinetic energy that must be absorbed in a collision
Ideally speaking the kinetic energy of the colliding object(s) is absorbed by
the vehicle infrastructure (a sturdy space frame the engine other vehicle
components etc) andor the surroundings However in the unfortunate
cases where this kinetic energy must be absorbed by the vehicle occupant(s)
the result is severe life-altering injuries andor death An unequivocal
relationship between an increase in vehicle speeds and fatal accidents can
be demonstrated by a careful examination of available traffic fatality data
This is a more involved discussion and is not the purpose of this short
communication These topics are no doubt very politically charged with many
social legal and financial implications with each interest group favoring a
different conclusion Nonetheless we cannot escape the laws of physics as
they govern the fundamental need to absorb higher and higher values of the
kinetic energy K with increasing vehicle speeds This same point is also
emphasized by Dr Friedman of the University of Illinois Chicago (see earlier
discussion)
Speed kills because of these energy transfer considerations and there can be
no doubt about it
Innovative 21st century solutions to speed management on the highways
such as strict enforcement of speed limits minimizing speed dispersion
(difference between speeds at which different drivers travel) while using
cameras to track the 15 of drivers who willfully violate the speed limit and
Page 33 of 45
create hazardous driving conditions is certainly recommended (Recall that
the optimum recommended speed limit is at or below which 85 of all drivers
travel ndash a policy also supported by NMA) Even on this score however the
results are confounding if we consider the Australian experience
httpwwwthenewspapercomnews282840asp
Up until 2007 there was no speed limit in the Northern Territory of
Australia Imposing a speed limit 130 kmph (80 mph) on some areas and
110 kmph (68 mph) in some others actually increased the number of deaths
The death toll in 2006 when there was no speed limit in this region was 44
and went up to 75 in 2009 see data table in link below
httpwwwthenewspapercomrlcdocs2009au-ntroadtollpdf
Furthermore it appears that installation of cameras to enforce speed limits
has proved to be a hazardous distraction to drivers and deaths actually
began to skyrocket between 2005 and 2007 in all Australian roadways
The main purpose here is to sound a cautionary note amid renewed attempts
in many states across the US to increase the speed limits on our highways by
calling attention to the historical facts regarding the ―epidemic levels of
highway traffic fatalities that engaged our national attention in the fateful year
of 1966 The graphical representation of the traffic fatality data in Figures 1
to 5 tells its own story
Indeed it would be tragic if highway-accident-related fatalities were to start
increasing once again and reach the historically high level that was last seen
in 1972 the year before the Arab oil embargo of 1973
Page 34 of 45
Conclusions
1 The graphical representation of the highway fatality data and the brief
summary of the historical facts of traffic safety legislation suggest that
recent attempts to increase the speed limits by various states (notably
Texas) may be misguided The distinct peak in the highway fatalities
observed in these graphs is highly alarming This appears to be related to
the enactment of the National Maximum Speed Limit (NSML) in 1974
following the 1973 Arab oil embargo Although NSML was motivated by a
desire to reduce gasoline consumption an unintended benefit might have
been a dramatic reduction in fatalities The fundamental reasons for the
peak in the fatalities-VMT curve must be examined carefully without
political posturing
2 The widely used fatality rate fatalities per 100 M vehicle miles traveled
has been declining since 1921 the first year for which a fatality rate could
be computed and has now reached a historical low The absolute number
of fatalities on the other hand was increasing in the 1950s and 1960s at
an alarming rate and the public outcry that ensued led to the highly
publicized Congressional hearing of 1966 and the subsequent traffic safety
legislations The fatality rate has been decreasing even in the most recent
15-year period (1994-2009) again with increasing fatalities although less
dramatically Thus it appears that fatality rate calculation based on vehicle
miles traveled (VMT) might not be a reliable indicator of the underlying
dynamics in the fatality trends
3 More detailed compilation of number of fatalities and the number of fatal
crashes within each speed limit segment is required to better understand
the effect of increasing speed limits on highway fatalities (and also fatality
rates) Such data is already available and is being compiled at the local
city and county levels in all jurisdictions and only needs to be reorganized
to highlight the effect of (posted) speed limits on the number of crashes
and fatalities This will require some minor rewriting and revisions to the
chapters named ―Crashes and ―States in the annual NHTSA reports
Page 35 of 45
Analysis of the fatalities-crashes data for several years with various
speed limits will be more revealing and meaningful than the current
fatality rates analysis and will be discussed separately in a follow up
report
4 One should not be lulled by the fact that vehicles of the 21st century are
now equipped with advanced safety features not available in the 1950s
and the 1960s In spite of these safety features the laws of physics dictate
that the higher the speed the higher kinetic energy of the colliding objects
and hence the greater the risk indeed near certainty of fatalities in a
higher speed collision compared to a lower speed one
5 The higher the speed at which the vehicle that is involved in a crash is
traveling the higher the kinetic energy that must be absorbed andor
dissipated without affecting the occupant(s) to avoid serious injuries andor
death This was true in the 1950s and the 1960s and will continue to be
true in the 21st century as well
Speed Kills for this just reason
6 It appears that higher fuel economies and reduced
highway fatalities were the twin societal benefits of 55
mph adopted after 1973 If so the current attempts to
increase the speed limits appear to be in conflict with
other important societal objectives
Page 36 of 45
Table 1 Annual US Street amp Highway
Fatalities from 1957
Year
Fatalities
Vehicle Miles
(millions)
Rate100M Vehicle Miles
1957 38702 646915 598
1958 36981 664915 556
1959 37910 700478 541
1960 38137 718845 531
1961 38091 737535 516
1962 40804 766852 532
1963 43564 805423 541
1964 47700 846500 563
1965 49163 887640 554
1966 51524 927915 555
1967 51559 965132 534
1968 53831 1019726 528
1969 55032 1066108 516
1970 53672 1114098 482
1971 53761 1183524 454
1972 55704 1264614 440
1973 55113 1316207 419
1974 46078 1282790 359
1975 45500 1330074 342
1976 45523 1402380 325
1977 47878 1467027 326
1978 50331 1544704 326
1979 51103 1529133 334
1980 51091 1527295 335
1981 49301 1552803 317
1982 43945 1595010 276
1983 42589 1652788 258
1984 44257 1720269 257
1985 43795 1774179 247
Page 37 of 45
1986 46056 1835000 251
1987 46385 1921000 241
1988 47093 2026000 232
1989 45555 2107040 216
1990 44529 2147501 207
1991 41162 2172214 189
1992 39235 2239828 175
1993 40115 2296585 175
1994 40676 2359984 172
1995 41798 2422696 173
1996 41907 2485848 169
1997 41967 2560373 164
Data from Federal Highway Administration
Source httpwwwpublicpurposecomhwy-fatal57+htm
Telephone +16186328507 - Facsimile +16186328538
WENDELL COX CONSULTANCY P O Box 841 - Belleville IL 62269 USA
Page 38 of 45
Fatality data for 1921-1982 compiled by NHTSA
Year
VMT
(Millions)
VMT
(Billions)
Fatalities
Fatality rate
per 100 M VMT
1921 55027 5503 13253 241 1922 67697 6770 14859 219 1923 84995 8500 17870 210 1924 104838 10484 18400 176 1925 122346 12235 20771 170 1926 140735 14074 22194 158 1927 158453 15845 24470 154 1928 172856 17286 26557 154 1929 197720 19772 29592 150 1930 206320 20632 31204 151 1931 216151 21615 31963 148 1932 200517 20052 27979 140 1933 200642 20064 29746 148 1934 215563 21556 34240 159 1935 228568 22857 34494 151 1936 252128 25213 36126 143 1937 270110 27011 37819 140 1938 271177 27118 31083 115 1939 285402 28540 30895 108 1940 302188 30219 32914 109 1941 333612 33361 38142 114 1942 268224 26822 27007 101 1943 208192 20819 22727 109 1944 212713 21271 23165 109 1945 250173 25017 26785 107 1946 340880 34088 31874 94 1947 370894 37089 31193 84 1948 397957 39796 30775 77 1949 424461 42446 30246 71 1950 458246 45825 33186 72 1951 491093 49109 35309 72
1952 513581 51358 36088 70
Page 39 of 45
1953 544433 54443 36190 66 1954 561963 56196 33890 60 1955 605646 60565 36688 61 1956 627843 62784 37965 60 1957 647004 64700 36932 57 1958 664653 66465 35331 53 1959 700480 70048 36223 52 1960 718762 71876 36399 51 1961 737421 73742 36285 49 1962 766734 76673 38980 51 1963 805249 80525 41723 52 1964 846298 84630 45645 54 1965 887812 88781 47089 53 1966 925899 92590 50894 55 1967 964005 96401 50724 53 1968 1015869 101587 52725 52 1969 1061791 106179 53543 50 1970 1109724 110972 52627 47 1971 1178811 117881 52542 45 1972 1259786 125979 54589 43 1973 1313110 131311 54052 41 1974 1280544 128054 45196 35 1975 1327664 132766 44525 34 1976 1402380 140238 45523 32 1977 1467027 146703 47878 33 1978 1544704 154470 50331 33 1979 1529133 152913 51093 33 1980 1527295 152730 51091 33 1981 1555308 155531 49301 32 1982 1595010 159501 43945 28
Source Analysis of Significant Decline in Motor Vehicle Traffic Fatalities in
2008 httpwww-nrdnhtsadotgovPubs811346pdf see Table A1 page 31
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Page 40 of 45
Acknowledgements
The author is grateful for thoughtful comments provided by friends and colleagues
with whom this document was shared via email prior to it being uploaded as a
publicly available document for wider dissemination and study The comments
offered by Prof Subra Ganesan of Oakland University Electrical and Computer
Engineering Department are reproduced with permission in their entirety
About the author
The author obtained his Masterrsquos (S M) and Doctoral (Sc D) degrees in Materials Engineering
from the Massachusetts Institute of Technology Cambridge USA He then spent his entire
professional career at leading US research institutions (MIT NASA Case Western Reserve
University and General Motors R amp D Center in Warren MI) He holds four patents in advanced
materials processing has co-authored two books and has published several scientific papers in
leading peer-reviewed international journals His expertise includes developing simple
mathematical models to explain the behavior of complex systems He can be reached by email at
vlaxmananhotmailcom
Page 41 of 45
Please Buckle Up
httpwwwlakecountypublichealthorgindexphpbuckle-up-montana
Public Awareness
Respect the Cage Exhibit
The Department of Transportation hopes that showing the reality of the crash will reduce traffic
fatalities A crushed car crash dummies and a sobering message ndash all part of the ―Respect The
Cage exhibit that is traveling across Montana The exhibit sponsored by the Montana Department
of Transportation stopped in Ronan on November 6th and is aimed at raising awareness about the
importance of wearing seat belts
The car in the exhibit was in an actual wreck many years ago
the passenger in the vehicle died because he was not wearing a
seat belt the driver who was wearing his seat belt survived
Montanarsquos likeliest crash fatality scenario
A Pickup
A Rural road
And Seat belts that
arenrsquot used
Page 42 of 45
Occupants of pickups are less likely to wear seat belts and pickups are more likely to
roll over than passenger cars
Seat belts reduce the risk of death by 60 percent in pickups and SUVs
In Montana from 2006-2008 81 of those killed in a crash while riding in a pickup were not wearing seat belts
In Montana pickups make up 401 of the vehicle population
For more information on Respect the Cage click here
Page 43 of 45
Appendix 1
Lack of seat belts leading cause of Louisiana highway deaths
1251 AM May 28 2011 |
Written by Adam Duvernay
Crashes involving unbuckled motorists were the leading cause of highway fatalities
in Louisiana last year and cost $9888 million according to recent reports The
Louisiana Highway Safety Commission reported 59 percent of vehicle occupants
killed in Louisiana crashes last year mdash about one in four mdash werent wearing seat
belts
httpwwwshreveporttimescomarticle20110528NEWS01105280354Lack-seat-
belts-leading-cause-La-highway-deathsodyssey=tab|topnews|text|FRONTPAGE
Crash bull Stats Published by NHTSAlsquos National Center for Statistics and Analysis 1200 New Jersey Avenue SE Washington DC 20590
DOT HS 811 451
Early Estimate of Motor Vehicle Traffic Fatalities in 2010
httpwww-nrdnhtsadotgovPubs811451pdf
Summary
A statistical projection of traffic fatalities in 2010 shows that an estimated 32788
people died in motor vehicle traffic crashes This represents a decline of about 3
percent as compared to the 33808 fatalities in 2009 as shown in Table 1 If these
projections are realized fatalities will be lowest on record (since 1949)
Traffic Safety Facts Overview 2009 Data
httpwww-nrdnhtsadotgovPubs811392pdf
In 2009 33808 people were killed in the estimated 5505000 police-reported
motor vehicle traffic crashes 2217000 people were injured and 3957000
crashes involved property damage only Compared to 2008 this is a 10-
percent decrease in the number of fatalities and a 5-percent decrease in the
Page 44 of 45
number of police-reported motor vehicle traffic crashes people injured and
crashes involving property damage
An average of 93 people died each day in motor vehicle crashes in 2009 mdash
an average of one every 16 minutes
Traffic Safety Facts Overview 2008 Data
httpwww-nrdnhtsadotgovPubs811162pdf
In 2008 37261 people were killed in the estimated 5811000 police-reported
motor vehicle traffic crashes 2346000 people were injured and 4146000
crashes involved property damage only
Some comments and Feedback
The following comments were received from Prof Ganesan after his review of the
first draft of this document It was subsequently revised thanks to this input to
address some of the very important issues raised here
Dear Laxman
The write up is not enough
You are emphasizing that the speed limit reduces the fatal accidents (comparing 1966
to 2000 accident numbers)
Can you also add a few sentences why the number is decreasing from 1980 to 2000
values (May be due to better design of vehicles)
Can you say anything about the fuel consumption with the speed for any typical
vehicle in 2011 or 2010 (do not consider the fatalities issue)
Probably a speed between 55 and 60 mph gives a better mileage If so this is a
compelling reason to keep the speed limit low But cars probably can be tuned to
give better mileage at any high speed also
Page 45 of 45
Weather is also a major factor in fatal accidents Speed limit may be kept low during
winter and kept higher in summer Give your comments on this too
Driver distractions can cause more accidents Now cars have many multimedia and
internet features Automatic collision avoidance systems and sensors on the sides can
detect vehicles in the front and neighboring lanes and it can automatically decrease
speed even if the driver speeds at super high speeds
Give some comments on this too There is also Vehicle to Vehicle communications
vehicle to infrastructure communications and they can avoid collisions and accidents
Technology has changed from 1966 I cannot agree with you on the speed limit
without any discussion on the above and other factors
Have a great day
Subra Ganesan
Professor Subramaniam Ganesan
Director Real Time amp DSP Lab
Electrical and Computer Engineering Department
2200 Squirrel Road Dodge Hall Room 105
Oakland University Rochester MI 48309 USA
Phone 248 370 2206 Fax 248 370 4633
wwwsecsoaklandedu~ganesan
IEEE Distinguished Visiting Speaker (2005-2009) Coordinator
IEEE SEM CS chapter Chair Region 4 and CS Society Board member
SAE ASEE ACM member
Page 10 of 45
consequences
Figure 2b Graphical representation of the US highway fatality data for the period
1921-1982 The first year for which a fatality rate yx could be computed is 1921 The
number of fatalities was 13253 and VMT was 5503 billion yielding a fatality rate of
2408 per 100 million VMT The fatality rate for any year is the slope of the ray ie
the straight line joining the (x y) data point back to the origin (00) of this graph see
dashed line for 1921 superimposed on to the graph The fatality rates (slopes of such
rays) had been declining quite consistently although the absolute number of fatalities
increased as seen here ultimately leading to the Congressional hearing in 1966 Is
VMT the single most important reason for the increasing fatalities
Page 11 of 45
Figure 3 Graphical representation of the traffic fatality data for the 15 year period
1994-2009 A sudden precipitous drop in the absolute number of fatalities (at least on
the magnified scale used here) and hence the fatality rate has been observed over
the three-year period 2007-2009 However it should be noted that the x-y scatter
graph here shows a general upward trend with fatalities actually increasing with
increasing VMT (as in the earlier era 1950s and 1960s) during the 12-year period
spanning 1994-2006 although the rate yx shows a misleading downward trend Why
is the rate yx going down
The reason is very simple and it may be just a mathematical artifact The equation of
the best-fit straight line through the most recent data points is of the form y = hx + c
= 2865 x + 34420 where h is the slope of the line and c the intercept (Note that x
here is VMT in billions The numerical value determined using this equation must be
divided by 10 to get the rate per 100 M VMT) Hence the fatality rate given by the
ratio yx = h + (cx) = 2865 + 34420x can actually decrease with increasing
values of x because of the nonzero intercept c Unlike the ray through the origin the
best-fit line does not pass through the origin (00) If we consider only the most
Page 12 of 45
recent data the intercept c is positive and fatality rates yx decrease with increasing
VMT and increasing fatalities In the earlier era both the slope h and intercept c had
very different values due to several factors being discussed here (speed limits
technology highway design etc)
Table 2 Traffic fatality data for the recent 15-year period
1994-2009 (Source NHTSA)
Year
Highway
fatalities y
Vehicle miles
traveled
VMT
(billions) x
Fatality rate
yx per 100
million VMT
Fatal crashes
1994 40716 2358 173 36254 1995 41817 2423 173 37241 1996 42065 2486 169 37494 1997 42013 2562 164 37324 1998 41501 2632 158 37107 1999 41717 2691 155 37140 2000 41945 2747 153 37526 2001 42196 2797 151 37862 2002 43005 2856 151 38491 2003 42884 2890 148 38477 2004 42836 2965 144 38444 2005 43510 2989 146 39252 2006 42708 3014 1 42 38648 2007 41259 3032 136 37435 2008 37423 2974 126 34172 2009 33808 2979 113 30797
Page 13 of 45
Figure 4 The most significant metric used by NHTSA is the fatality rate per 100
million vehicles miles traveled (VMT) This is now at a historical low of 113 for
2009 having declined year after year from 173 in 1994 The NHTSA however also
compiles other types of data on crashes There are three types of crashes fatal
injury but no death and property damage only A careful review of this crash data
for the period 1994-2009 reveals the obvious the lower the number of (fatal)
crashes x the lower the number of highway-accident-related fatalities y It is also
obvious that the number of fatalities per crash is greater than one ie more than one
person is being killed when one of more vehicles experience a crash
Clearly this is the single most important piece of information that one needs to
reduce the number of fatalities on our highways Vehicle design and engineering as
well as all other policy matters (legal political social environmental financial)
must be guided by this simple graph The best-fit line through the data derived using
simple linear regression has the equation y = hx + c = 114x ndash 10266 and is
Page 14 of 45
superimposed on to the data The design engineering goal and societal goal should
be to reduce the slope h of this statistically significant best-fit line to its ideal value of
h = 1 A fatal crash by definition is one where at least one person dies either an
occupant or a non-motorist in the path of the vehicle Hence the ideal slope h = 1
Photograph of an accident scene from the period 1955-1965
httpwwwcorinthsocialhistoryprojectorghtmlhighwaytollshtml
3 A Brief History of Traffic Safety Legislation
The following is extracted from the Wikipedia article on National Highway
Traffic Safety Administration (NHTSA)
httpenwikipediaorgwikiNational_Highway_Traffic_Safety_Administration
In 1965 and 1966 public pressure grew in the US to increase the safety of
cars The number of deaths on US highways were increasing year after year
Page 15 of 45
see Figure 1 and in 1966 Congress held a series of highly publicized
hearings on highway safety This led to the legislation for mandatory
installation of seat belts which also created the US Department of
Transportation (on Oct 15 1966)
httpwwwemsgovpdf2011EMSWeek2011_Stricklandpdf
The following is extracted from a Washington Post article on
NHTSA dated April 2 2002
httpwwwwashingtonpostcomwp-srvbusinessincludesnhtsa_primerhtm
In 1966 after decades of rising traffic fatalities (also vividly illustrated in
Figures 1 and 2 here) the publication of Ralph Naders Unsafe at Any
Speed and increasing public outcry for safer automobiles Congress held a
series of highly publicized hearings on creating a regulatory agency for traffic
safety Among the witnesses was William Haddon an epidemiologist who
introduced the idea that traffic accidents could be analyzed scientifically and
injuries reduced by changing auto design such as installing collapsible
steering columns safety glass head rests and seat belts
Congress passed the Highway Safety Act of 1966 creating the National
Highway Safety Bureau with Haddon as its first administrator The bureau
became NHTSA in 1970 under the newly established Department of
Transportation An early Nader convert Joan Claybrook headed NHTSA
under President Carter and now runs Naders organization Public Citizen
National Traffic and Motor Vehicle Safety Act
httpwwwanswerscomtopicnational-traffic-and-motor-vehicle-safety-act
Signed into law by President Lyndon Johnson on September 9 1966 this act
created the first mandatory federal safety standards for motor vehicles The
act was motivated by a variety of factors First and foremost the public was
growing increasingly concerned over the rising number of traffic fatalities on
the nations roads Such fatalities had increased by nearly 30 percent
between 1960 and 1965 and experts forecasted 100000 such deaths
Page 16 of 45
annually by 1975 unless something was done to improve traffic safety
Adding fuel to the fire Ralph Naders Unsafe at Any Speed published in
November 1965 criticized the automobile industry for neglecting safety in
favor of power and styling when designing new vehicles
4 The reason for the historical
decrease in highway fatalities
A recent news item see link given below regarding renewed attempts to
increase the speed limit by many states prompted this write up by the
present author who has studied traffic fatality data extensively and analyzed
them very carefully over the last several years
httpmoneymsncomauto-insurancewhy-speed-limits-are-
risingaspxGT1=33033
Residents of Metro Detroit area who frequently cross into Ohio from
Michigan notice that the speed limit has now increased in Ohio The speed
limit on Michigan highways was increased to 70 mph in the late 1990s but
Ohio retained its lower speed limit for many years leading Michigan drivers to
experience a ―speed trap of sorts The speed limit is also increasing in many
other states notably Texas where it is proposed to increase it to 85 mph at
least in West Texas
Historically speaking from a traffic fatality standpoint we must consider two
important dates 1966 and 1973 Only 1973 the year of the Arab oil embargo
following the Arab-Israeli war (that led to what President Obama has recently
called the pre-1967 border for Middle East peace) is mentioned in the above
article It fails to mention the significance of the year 1966
Prior to 1966 there was actually NO speed limit in many Western states and
deaths due to highway accidents were increasing year after year The
Page 17 of 45
number of highway fatalities went up from 38702 in 1957 to 51524 in 1965
a 33 increase over the 1957 level and an additional 12822 deaths in 1965
compared to 1957 It was this carnage on the US highways that forced
Congress to hold its hearings on highway traffic fatalities in 1966
Nonetheless a careful examination of the fatality data in Table 1 shows that
notwithstanding the highly publicized Congressional hearings of 1966 and
new safety legislation that was enacted the absolute number of fatalities
continued to increase after 1966 and only started decreasing after 1973
Vehicle designs especially the introduction of safety features (even the
simplest like safety belts) did not change significantly between 1966 and
1973 Nonetheless post-1973 we begin to see a dramatic turnaround
Why
After the 1973 Arab oil embargo a nationwide maximum speed limit (NMSL)
of 55 mph was imposed and accepted in the USA (effective Jan 1 1974)
during the Nixon administration primarily as an effort to conserve fuel and
reduce the US vulnerability to oil imports The unintended and indeed
fortunate consequence of this reduced speed limit was the immediate
reduction in the fatalities revealed in Figures 2 and 3 This is the real reason
for the peaks in highway fatalities observed in these two graphs
The Congressional hearings of 1966 did eventually have an impact but it was
a delayed one The impact of the 1973 nationwide speed limit of 55 mph was
however immediate as we see from the magnified plot of the same data in
Figure 5 and a closer examination of the raw fatality data in Table 1
The number of highway-accident-related fatalities decreased immediately
from a high of 55704 in 1972 to just 46078 in 1974 a 173 drop see
arrows There were 9626 fewer deaths annually even with a slight increase
in the vehicle miles driven (see Table 1) Indeed the number of highway
death reached its absolute peak value in 1972 never to be seen again
Fatalities have been decreasing every since with slight fluctuations about
each new low value
Page 18 of 45
Figure 5 Expanded view of the fatality data showing the immediate impact of the
national speed limit of 55 mph following the Arab oil embargo of 1973 Note that
fatalities continued to rise between 1966 and 1973 in spite of the highly publicized
Congressional hearings in 1966 and the traffic safety legislation enacted soon after
Each new low is probably associated with vehicle safety innovations and the
improvements in vehicle design and engineering The combined beneficial
effect of improved vehicle designs primarily the introduction of seat belts
and the laws enforcing usage of seat belts aided by the reduced speed
limits contributed to the continued decline in the absolute number of fatalities
that started since 1973 and has continued to this day The subsequent
introduction of other safety features notably air bags has contributed to a
further reduction in highway fatalities
Page 19 of 45
State police Trooper First Class Jeffrey Flowers looking at a car in which a Boswell
Pennsylvania woman was injured Tuesday (May 31 2011) The accident occurred at
an intersection when a truck (seen behind the wrecked car) entered this accident
prone intersection (part of a highway safety corridor where signs are posted to
reduce unsafe driver behavior) There have been four accidents at this intersection
since 2006 none fatal httpwwwdailyamericancomnewssomersetda-ot-woman-
injured-in-route-30-wreck-2011053104165420story
5 Numerical calculations of decline in
fatalities and the impact of NMSL post-1973
Letlsquos consider the decline in fatalities between 1972 the last year before the
adoption of the NMSL and 1974 the first year following its adoption after the
Arab oil embargo There was an immediate decrease in the number of
fatalities by 9393 ie y = -9393 with a slight increase in the VMT ie x
= 20758 millions The NHTSA data used here may be found in the table at
the end of this document The numerical value of the rate of change per
billion VMT (ie neglecting the sign) was therefore
yx = 4525 fatalitiesbillion VMT (1972-1974)
Page 20 of 45
It is instructive to compare this rate of change in fatalities with similar short
periods of a decline in fatalities in the pre-1973 era when speed limits were
much higher The absolute number of fatalities declined over a relatively
short period with both an increase and a decrease in VMT The results are
given below and are self-explanatory
yx = 454 fatalitiesbillion VMT (1953-54) decline with increase in VMT
yx = 655 fatalitiesbillion VMT (1942-43) decline with decrease in VMT
yx = 1739 fatalitiesbillion VMT (1941-42) decline with decrease in VMT
yx = 4528 fatalitiesbillion VMT (1937-39) decline with increase in VMT
yx = 2548 fatalitiesbillion VMT (1931-32) decline with decrease in VMT
The rate of decline observed between 1953 and 1954 with an increase in
VMT was just one-tenth of that observed following the adoption of the 55
mph speed limit The war years (1941-43 WWII) and the Great Depression
era (1931-32) were accompanied by big declines in fatalities with decreasing
VMT but the rate of change was still significantly lower than observed after
the adoption of the NMSL
The only apparently inexplicable decline is that between 1937 and 1939
where a nearly identical high rate of decline was observed Notice also the
big drop in the traditional fatality rate between 1937 and 1938 This large drop
appears to coincide with the creation of the National Safety Council (NSC) by
William H Cameron in June 1937 (see link below) with its far-flung campaign
of education legislation research highway engineering and traffic training
undertaken by the NSC and some two dozen other groups with the backing of the
automotive industry through its Automotive Safety Foundation Other factors
unknown to the present author probably also played a role
httpwwwtimecomtimemagazinearticle0917188379700htmlixzz1O2G
7rnUg
Page 21 of 45
These simple computations here however reveal the significant effect of
reduced speed limits on highway fatalities much more so than other factors
6 Further Considerations Pros and Cons
The singular effect of increased speeds (or speeding) on highway fatalities
has been studied and demonstrated by a number of industry sources such
as the Insurance Institute for Highway Safety (IIHS) Consumers Union and
also by government researchers
httpwwwsmartmotoristcomtraffic-and-safety-guidelineexcessive-speed-is-
a-factor-in-one-third-of-all-fatal-crasheshtml
httpwwwconsumersunionorgotherspeedlimitsspeed031500a2htm
Speed ndash defined as exceeding the posted speed limit or driving too fast for
given conditions ndash is a factor in nearly one-third of all fatal crashes Besides
fatality in 1998 nearly 40000 people were critically injured in speed-related
crashes and nearly 72000 were moderately injured
The salutary and immediate beneficial effect of the nationwide 55 mph speed
limit has been noted by other researchers (see Susan Ferguson link below)
httpwwwnhtsagovpeopleinjuryenforcespeed_forum_presentationsfergu
sonpdf
After a partial repeal of this law in 1987 which granted states the authority to
increase speed limit (especially in rural interstates) a 1989 study showed a
15 increase in fatalities in rural interstates and a 5 increase in non-rural
interstates Unfortunately such studies often tend to be discounted by
advocates of increasing the speed limits as being produced by biased
industry sources
Similar conclusions were also presented by NHTSA in February 1998 in its
report to the Congress entitled ―Report to Congress The Effect of Increased
Speed Limits in the Post-NMSL Era see link given below Among its key
Page 22 of 45
findings is the following quoted in its entirety NMSL refers to the National
Maximum Speed Limit legislated after the Arab oil embargo of 1973
httpwww-nrdnhtsadotgovPubs808-637PDF
hellip Nevertheless it is important to note that data currently available from the
National Highway Traffic Safety Administrationrsquos (NHTSA) Fatality Analysis
Reporting System (FARS) shows that states that increased speed limits in 1996
experienced approximately 350 more Interstate fatalities than would have been
expected based on historical trends -- about 9 percent above expectations
Concurrently the Interstate fatalities experienced in states that did not increase speed
limits in 1996 was consistent with pre-1996 trends The estimated increase in
Interstate fatalities found in this study while smaller in magnitude compared to the
estimated change in fatalities found in 1987 following the increase of speed limits on
rural Interstates does follow the historical pattern of increases in fatalities being
associated with increases in posted speed limits
The annual crash reports compiled by NHTSA see Table 3 indicate that the
number of fatal crashes (and hence fatalities using the regression equation
developed in Figure 4) increase as the posted speed limits increase
Page 23 of 45
Table 3 Posted speed limits and number of crashes
Speed Limit Crashes (2008) Crashes (2009)
30 mph or less 3705 3277 35 or 40 mph 6115 5516 45 or 50 mph 6461 6074
55 mph 9794 8847 60 mph or higher 6908 6124
Total 34017 30797
Source httpwww-nrdnhtsadotgovPubs811402EEpdf
61 Studies cited in favor of lower speed limits
A detailed analysis of speeding related fatalities (see link below) by NHTSA
shows that a third of all crashes involve speeding ie at least one driver was
speeding
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Furthermore the above report which covers the period 1983-2002
indicates that immediately after the NMSL was completely abolished in
December 1995 the number of speeding related fatalities at speeds
above 65 mph increased from just 15 in 1995 to a 677 in 1996 (see Table
62 on page 43 of above report) It continued to increase in the years
since climbing to 930 in 2000
More detailed studies similar to that noted above by researchers at the
University of Illinois Chicago led by Lee S Friedman again lead to the
conclusion that higher speed limits lead to an increase in the number of
fatalities (see American Journal of Public Health online July 16 2009)
httphealthusnewscomhealth-newsmanaging-your-
healthcarearticles20090716deaths-injuries-increase-with-higher-speed-
limits
Page 24 of 45
httpwwwmedpagetodaycomPublicHealthPolicyPublicHealth15122
httpwwwamericaneercomspeed-limits
httpwwwactuarialoutpostcomactuarial_discussion_forumarchiveindexph
pt-171870html
For the study period 1995-2005 these researchers found that 12545 deaths
and 36582 injuries could be attributed to the increased speed limits The
benefits of reduced speed limits are stated quite eloquently by Dr Friedman
and are reproduced below (from above news article see link)
Reduced speed limits would save lives Friedman said They would also reduce
gas consumption cut emissions of air pollutants save valuable years of productivity
(lost due to injuries)and reduce the societal cost of motor vehicle crashes (due to
both fatal crashes and due to nonfatal and severe life-changing injuries) he added
Friedman and coworkers have also shown that increasing the speed limit led
to an immediate increase in the number of fatalities on Israeli roadways (see
link below)
httpinjurypreventionbmjcomcontent133156
The effect of speeding is very significant especially in rural areas resulting
in significantly higher fatalities Fatality rates are frequently double or triple
that in urban areas (see link below)
httpsafetyfhwadotgovspeedmgtdata_factsdocsspeeding_ruralpdf
As of Jan 1 2005 five Midwestern states had increased the speed limits to
above 65 mph (Illinois Iowa Kansas Minnesota Missouri Nebraska and
South Dakota) whereas three (Illinois Iowa and Wisconsin) had not All the
five states with increased speed limits showed a 7 to 13 increase in
fatalities The NHTSA study considered an eight year period before and after
the change in Dec 1995 (see Table 1 in link below) The collective experience
of the states that did NOT increase the speed limit was a 7 decline in
fatalities (see Table 2 of link below)
httpwwwiowadotgovmvdodsstats2006speedstudypdf
Page 25 of 45
Moreover Table 5 in the above study shows the effect of imposing the NMSL
of 55 mph in Iowa and its repeal in 1995 Considering a four-year average
before 1974 when the speed limit was 75 mph there were 35 fatal crashes
with 43 fatalities In the first four years after the 55 mph there were only 23
fatal crashes and 28 fatalities In the last four years before the repeal of 55
mph in 1995 there was a further decline to 14 fatal crashes with 17 fatalities
The Iowa fatality data will be discussed in more detail separately (in a later report)
since it provides the opportunity to assess the effect of a change in the speed limit
on the relationship between number of fatalities and fatal crashes (as seen in
Figure 4 for the US as a whole)
North of the US border Canadians seem to be citing the ―shocking increase
in highway fatalities in the US states where the speed limits were raised to
curb their own speed limits
httparchivesafety-councilorginfotrafficspeed-02html
httparchivesafety-councilorginfotrafficspeedhtml
Speed kills but speed also sells notes the second of the above news items
Manufacturers are producing more high performance cars (with higher horse
power to weight ratio) and ads feature enticing cars that race and swerve in
miraculous ways on empty roads These subliminal messages encourage
drivers especially young drivers to break the speed limit leading to the
absolute increase in highway fatalities (although the rate itself is going
down) The article emphasizes the need to enforce the speed limit on
Canadian highways and in cities where street racing is becoming a problem
62 Studies cited by opponents of lower speed limits
In fairness to quote the opponents on the other side of this debate Montana
reverted back to Reasonable and Prudent speed limits when the National
Maximum Speed Limit was repealed in 1995 and appears to have
experienced no significant increase in fatalities
Page 26 of 45
httpwwwhwysafetycomhwy_montanahtm
httpwwwmotoristsorgpressmontana-no-speed-limit-safety-paradox
httpwwwsouthbayriderscomforumsshowthreadphpt=81453amppage=1
Likewise studies in the state of Maryland showed no significant increase in
highway fatalities when the speed limit was increased from 55 mph to 75
mph The reason might simply be that drivers were already speeding much
more so when the speed limit was 55 mph than after the increase to 75 mph
In other words the fatalities data already reflects the effect of higher speeds
(not speed limits) on the number of fatalities
In Utah the experimental increase in the speed limit to 80 mph was
considered to be a success in terms of safety
httpautosaolcomarticleutah-speed-limit-tests
The UDOT Director noted that there was no increase in the number of
accidents on Interstate 15 But what happens in the event of an accident
when the speed limits are higher and drivers are driving at higher speeds and
two objects collide at this higher speed However no increase in the number
of accidents is not the same as no increase in fatalities due to the higher
speeds When accidents do occur do fatalities increase
Likewise in California when the speed limit went up from 55 mph to 65
mph in 1995 (after repeal of NMSL) fewer deaths were reported in 1998
compared to the peak year of 1979 or even 1987 Again the explanation
seems to be that motorists were already speeding when the limit was 55 mph
and that increasing the speed limit did not change driver behavior in any
significant way
httparticlessfgatecom1998-11-02news17735730_1_speed-limits-mph-
limit-death-rate
The National Motorists Association (NMA) a group which advocates higher
speed limits emphasizes the importance of considering fatality rates as
opposed to the raw fatalities The argument used is that fatality rates based
on the fatality per 100 million VMT is the legitimate way to look at the data
Page 27 of 45
This is a never ending debate Historically speaking fatality rates have been
going down ever since the compilation of traffic accidents data began Table
A1 in the appendix of a recent report by NHTSA (see link below) has highway
fatality rate data going back 1921
httpwww-nrdnhtsadotgovPubs811346pdf see appendix page 31
httpwwwmotoristsorgspeed-limitstruth
httpwwwmotoristsorgothercrash-data
httpwwwraisethespeedlimitorgmythshtml
httpwwwcatoorgpubspaspa346pdf
According to Stephen Moore of the Cato Institute (see last of the links above)
―All measures of highway safety show improvement not more deaths and
injuries since 1995 Despite the fact that 33 states raised their speed limits
immediately after the repeal of the mandatory federal speed limit the NHTSA
reported last October that the traffic death rate dropped to a record low level
in 1997lsquo Moreover the average fatality rate even fell in the states that raised
their speed limits
63 The Fatality rate Is it a reliable metric
In 1921 with fewer fatalities and fewer miles driven and the first year for
which the fatality rate could be computed the rate was 2408 It was down to
1479 in 1931 but the number of deaths had climbed to 31963 more than
double the 1921 absolute fatality number of 13253 It had dropped to 550 in
1966 the year of the highly publicized Congressional hearings but the
number of fatalities had climbed to 50984 in that fateful The Highway Safety
Act of 1966 ranks as one of the major acts of Congress and President
Johnson signed it saying that ―we have been tolerating a raging epidemic of
highway deathshellip see extract pasted below
httpwwwenotescommajor-acts-congresshighway-safety-act
Page 28 of 45
The act was motivated primarily by growing public concern over the rising number
of traffic fatalities in the United States Between 1960 and 1965 the annual number
of traffic fatalities increased by nearly thirty percent As President Lyndon B
Johnson stated at the signing of the act on September 9 1966 we have tolerated
a raging epidemic of highway death which has killed more of our youth than all
other diseases combined Through the Highway Safety Act we are going to find out
more about highway diseasemdashand we aim to cure it
Nonetheless highways fatalities continued to increase until the Arab oil
embargo of 1973 led to the NMSL of 55 mph all across the USA Do we just
ignore this undeniable historical record and focus only on the declining fatality
rate as the NMA and other proponents of higher speed limits seem to argue
(see links above)
The misleading nature of using fatality rates (per 100 M VMT) alone is also
obvious if one considers fatality data for individual states Take for example
the state of Montana which seems to have experienced no increase in
fatalities after repeal of NMSL
httpwww-nrdnhtsadotgovdepartmentsnrd-
30ncsaSTSI30_MT200930_MT_2009htm
For the period 2005-2009 the absolute number of fatalities for Montana
varied between a high of 277 in 2007 to a low of 229 in 2009 The fatality
rates per 100 M VMT on the other hand varied from a high of 245 for 2007
to a low of 201 for 2009 The corresponding US fatality rates varied from
136 to 114 Is the higher number for the fatality rate for Montana compared
to USA good or bad Likewise fatality rate per 100000 of population was
much higher for Montana than the US as a whole
This again highlights the pitfalls of using simple ratios to assess fatality statistics
without a full analysis of the underlying trends We will discuss this point
separately
As shown already the continuous decline in the fatality rate is a mathematical
artifact and essentially overlooks the unmistakable positive correlation
between the variables x and y of the type y = hx + c which becomes obvious
Page 29 of 45
only when we prepare the x-y scatter graph The ratio yx = h + (cx) can
decrease with increasing x (VMT) and increasing y (fatalities) since the
intercept c has a positive value when we consider only data spanning a short
period (such as 1994-2009 of more relevance to the current situation)
The debate between fatality rates and absolute number of fatalities is an
unending one A few years ago the Wall Street Journal carried an article
which was entitled (or something close) ―Unemployments rate in Ohio are
going down but why is the number of unemployed increasing The reason is
the same The graph of the number of unemployed (y) versus the number in
the labor market (x) is linear with a positive slope h and a positive intercept c
So the unemployment rate computed using the ratio yx keeps going down
year after year although the number unemployed keeps increasing Is it a
good thing that the unemployment rate is going down when more people
seem to be unable to find gainful unemployment
Or consider the situation with cancer death rates This too has been going
down in recent years but the actual number of cancer-related deaths has not
declined in any significant way Is it good that cancer death rates are going
down In all these situations the researchers or the socio-econo-politico
analysts involved in analyzing the trends in the data have failed to consider
the underlying x-y relation describing each problem
Hence it appears that the debate on the effect of increased speed limits
should not be focused on only the fatality rates (which have been decreasing
and proponents of higher speed limits cite this in their arguments) or even the
absolute number of fatalities (which has been the focus here) but on the
relationship between speed and the number of fatal crashes and the number
of fatalities within each speed segment (see Table 3 and also Figure 4)
Unfortunately details of number of fatalities and the number of fatal crashes
at each speed limit are not available even from NHTSA for detailed study
When a crash does occur (it is immaterial how many miles were driven) the
speed of the driver and vehicle design and engineering including safety
devices in place (seat belts airbags other impact absorbing technologies)
Page 30 of 45
determine if the occupants(s) will be killed One cannot argue that speed
does NOT kill That would be an absolute denial of the laws of physics
Studies show that setting the speed limit at the 85th percentile in any given
zone (this is the speed at or below which 85 of drivers are observed to
travel in traffic engineering studies) is the safest speed limit The majority of
drivers try to obey the posted speed limit while a few choose to drive at a
speed they consider is safe and prudent These are also perhaps the most
vociferous advocates of higher speed limits It is this tension caused due to
differences in speeds that leads to tailgating improper passing reckless
driving weaving from lane to lane and ultimately crashes and deaths in some
unfortunate cases
httpblogmotoristsorgspeed-limits-slower-safer
MARK TAYLOR
ANOTHER LOST A man was killed when his 4WD drive hit a tree east of Morrinsville (in New
Zealand) on Monday May 30 2011 The driver lost control of the vehicle on a bend probably tried
to correct his mistake and put the car into a ―yaw causing it to leave the road and smash sideways
into a tree Alerts to slow down had been posted since this was a high accident area but the driver
probably did not pay attention
64 Other factors
Many other factors besides speed no doubt affect highway fatalities The
vehicles of the 21st century are very different from the vehicles of the mid 20th
Page 31 of 45
century Technological innovations such as improvements in vehicle design
and engineering have greatly increased crash worthiness of vehicles even at
high speeds Environmental factors such as the weather also contribute to
accidents but not necessarily to increased fatalities Drivers actually tend to
slow down instinctively during adverse weather conditions (rain snow storms
etc) and although such weather may contribute to increased accidents the
lower speeds actually reduce fatalities
Yes technology has changed fundamentally from 1966 Drivers today are
more distracted by their cellmobile phone conversations (and also built-in
phones in luxury models) and text messaging than the drivers of the pre-1966
era High end cars now have many multimedia and internet features Again a
careful observation (even personal experience by the author) suggests that
such distracted drivers actually tend to (instinctively) drive more slowly and
hold up the traffic Perhaps such behavior leads to an increase in the number
of accidents but it does not necessarily lead to an increase in the number of
accident-related fatalities
Much talked about technological innovations such as automatic collision
avoidance systems and sensors (on the sides of vehicles) can indeed detect
vehicles in the front and neighboring lanes Furthermore vehicle-to-vehicle
communication systems vehicle-to-infrastructure communication systems
can no doubt avoid collisions and accidents Again such collision avoidance
systems work and are effective entirely because they automatically reduce
vehicle speeds - even if one of the offending vehicles is being at a super
high speed Also it must be remembered that such futuristic systems have
not yet been implemented widely nor can they be implemented widely since
the large majority of vehicles on the road are NOT luxury models Advanced
safety features come with a price and not all drivers can afford to pay that
price and ―buy that ―additional safety
Ultimately it is the laws of physics that govern what will happen when two or
more vehicles collide or even when a single vehicle collides with a stationary
infrastructural object (a bridge a wall a building or some impediment on the
road) The lower the number of crashes the lower the number of fatalities as
revealed by the 1994-2009 data graphed in Figure 5 The higher the speed of
Page 32 of 45
the object or objects that are involved in a collision the higher the kinetic
energy K that must be absorbed andor dissipated Increasing the posted
speed limit only increases the energy that must be absorbed when a crash
does occur This ultimately is the most important criterion determining the
number of fatalities
The kinetic energy increases as the square of the speed being given by the
well-known formula K = frac12 mv2 where m is the mass of the vehicle (in
laypersonlsquos language m increases directly with vehicle weight) and v is the
speed For the same vehicle mass an increase in the speed from 55 mph to
85 mph increases the kinetic energy K by a factor of 239 or roughly a 250
increase in the kinetic energy that must be absorbed in a collision
Ideally speaking the kinetic energy of the colliding object(s) is absorbed by
the vehicle infrastructure (a sturdy space frame the engine other vehicle
components etc) andor the surroundings However in the unfortunate
cases where this kinetic energy must be absorbed by the vehicle occupant(s)
the result is severe life-altering injuries andor death An unequivocal
relationship between an increase in vehicle speeds and fatal accidents can
be demonstrated by a careful examination of available traffic fatality data
This is a more involved discussion and is not the purpose of this short
communication These topics are no doubt very politically charged with many
social legal and financial implications with each interest group favoring a
different conclusion Nonetheless we cannot escape the laws of physics as
they govern the fundamental need to absorb higher and higher values of the
kinetic energy K with increasing vehicle speeds This same point is also
emphasized by Dr Friedman of the University of Illinois Chicago (see earlier
discussion)
Speed kills because of these energy transfer considerations and there can be
no doubt about it
Innovative 21st century solutions to speed management on the highways
such as strict enforcement of speed limits minimizing speed dispersion
(difference between speeds at which different drivers travel) while using
cameras to track the 15 of drivers who willfully violate the speed limit and
Page 33 of 45
create hazardous driving conditions is certainly recommended (Recall that
the optimum recommended speed limit is at or below which 85 of all drivers
travel ndash a policy also supported by NMA) Even on this score however the
results are confounding if we consider the Australian experience
httpwwwthenewspapercomnews282840asp
Up until 2007 there was no speed limit in the Northern Territory of
Australia Imposing a speed limit 130 kmph (80 mph) on some areas and
110 kmph (68 mph) in some others actually increased the number of deaths
The death toll in 2006 when there was no speed limit in this region was 44
and went up to 75 in 2009 see data table in link below
httpwwwthenewspapercomrlcdocs2009au-ntroadtollpdf
Furthermore it appears that installation of cameras to enforce speed limits
has proved to be a hazardous distraction to drivers and deaths actually
began to skyrocket between 2005 and 2007 in all Australian roadways
The main purpose here is to sound a cautionary note amid renewed attempts
in many states across the US to increase the speed limits on our highways by
calling attention to the historical facts regarding the ―epidemic levels of
highway traffic fatalities that engaged our national attention in the fateful year
of 1966 The graphical representation of the traffic fatality data in Figures 1
to 5 tells its own story
Indeed it would be tragic if highway-accident-related fatalities were to start
increasing once again and reach the historically high level that was last seen
in 1972 the year before the Arab oil embargo of 1973
Page 34 of 45
Conclusions
1 The graphical representation of the highway fatality data and the brief
summary of the historical facts of traffic safety legislation suggest that
recent attempts to increase the speed limits by various states (notably
Texas) may be misguided The distinct peak in the highway fatalities
observed in these graphs is highly alarming This appears to be related to
the enactment of the National Maximum Speed Limit (NSML) in 1974
following the 1973 Arab oil embargo Although NSML was motivated by a
desire to reduce gasoline consumption an unintended benefit might have
been a dramatic reduction in fatalities The fundamental reasons for the
peak in the fatalities-VMT curve must be examined carefully without
political posturing
2 The widely used fatality rate fatalities per 100 M vehicle miles traveled
has been declining since 1921 the first year for which a fatality rate could
be computed and has now reached a historical low The absolute number
of fatalities on the other hand was increasing in the 1950s and 1960s at
an alarming rate and the public outcry that ensued led to the highly
publicized Congressional hearing of 1966 and the subsequent traffic safety
legislations The fatality rate has been decreasing even in the most recent
15-year period (1994-2009) again with increasing fatalities although less
dramatically Thus it appears that fatality rate calculation based on vehicle
miles traveled (VMT) might not be a reliable indicator of the underlying
dynamics in the fatality trends
3 More detailed compilation of number of fatalities and the number of fatal
crashes within each speed limit segment is required to better understand
the effect of increasing speed limits on highway fatalities (and also fatality
rates) Such data is already available and is being compiled at the local
city and county levels in all jurisdictions and only needs to be reorganized
to highlight the effect of (posted) speed limits on the number of crashes
and fatalities This will require some minor rewriting and revisions to the
chapters named ―Crashes and ―States in the annual NHTSA reports
Page 35 of 45
Analysis of the fatalities-crashes data for several years with various
speed limits will be more revealing and meaningful than the current
fatality rates analysis and will be discussed separately in a follow up
report
4 One should not be lulled by the fact that vehicles of the 21st century are
now equipped with advanced safety features not available in the 1950s
and the 1960s In spite of these safety features the laws of physics dictate
that the higher the speed the higher kinetic energy of the colliding objects
and hence the greater the risk indeed near certainty of fatalities in a
higher speed collision compared to a lower speed one
5 The higher the speed at which the vehicle that is involved in a crash is
traveling the higher the kinetic energy that must be absorbed andor
dissipated without affecting the occupant(s) to avoid serious injuries andor
death This was true in the 1950s and the 1960s and will continue to be
true in the 21st century as well
Speed Kills for this just reason
6 It appears that higher fuel economies and reduced
highway fatalities were the twin societal benefits of 55
mph adopted after 1973 If so the current attempts to
increase the speed limits appear to be in conflict with
other important societal objectives
Page 36 of 45
Table 1 Annual US Street amp Highway
Fatalities from 1957
Year
Fatalities
Vehicle Miles
(millions)
Rate100M Vehicle Miles
1957 38702 646915 598
1958 36981 664915 556
1959 37910 700478 541
1960 38137 718845 531
1961 38091 737535 516
1962 40804 766852 532
1963 43564 805423 541
1964 47700 846500 563
1965 49163 887640 554
1966 51524 927915 555
1967 51559 965132 534
1968 53831 1019726 528
1969 55032 1066108 516
1970 53672 1114098 482
1971 53761 1183524 454
1972 55704 1264614 440
1973 55113 1316207 419
1974 46078 1282790 359
1975 45500 1330074 342
1976 45523 1402380 325
1977 47878 1467027 326
1978 50331 1544704 326
1979 51103 1529133 334
1980 51091 1527295 335
1981 49301 1552803 317
1982 43945 1595010 276
1983 42589 1652788 258
1984 44257 1720269 257
1985 43795 1774179 247
Page 37 of 45
1986 46056 1835000 251
1987 46385 1921000 241
1988 47093 2026000 232
1989 45555 2107040 216
1990 44529 2147501 207
1991 41162 2172214 189
1992 39235 2239828 175
1993 40115 2296585 175
1994 40676 2359984 172
1995 41798 2422696 173
1996 41907 2485848 169
1997 41967 2560373 164
Data from Federal Highway Administration
Source httpwwwpublicpurposecomhwy-fatal57+htm
Telephone +16186328507 - Facsimile +16186328538
WENDELL COX CONSULTANCY P O Box 841 - Belleville IL 62269 USA
Page 38 of 45
Fatality data for 1921-1982 compiled by NHTSA
Year
VMT
(Millions)
VMT
(Billions)
Fatalities
Fatality rate
per 100 M VMT
1921 55027 5503 13253 241 1922 67697 6770 14859 219 1923 84995 8500 17870 210 1924 104838 10484 18400 176 1925 122346 12235 20771 170 1926 140735 14074 22194 158 1927 158453 15845 24470 154 1928 172856 17286 26557 154 1929 197720 19772 29592 150 1930 206320 20632 31204 151 1931 216151 21615 31963 148 1932 200517 20052 27979 140 1933 200642 20064 29746 148 1934 215563 21556 34240 159 1935 228568 22857 34494 151 1936 252128 25213 36126 143 1937 270110 27011 37819 140 1938 271177 27118 31083 115 1939 285402 28540 30895 108 1940 302188 30219 32914 109 1941 333612 33361 38142 114 1942 268224 26822 27007 101 1943 208192 20819 22727 109 1944 212713 21271 23165 109 1945 250173 25017 26785 107 1946 340880 34088 31874 94 1947 370894 37089 31193 84 1948 397957 39796 30775 77 1949 424461 42446 30246 71 1950 458246 45825 33186 72 1951 491093 49109 35309 72
1952 513581 51358 36088 70
Page 39 of 45
1953 544433 54443 36190 66 1954 561963 56196 33890 60 1955 605646 60565 36688 61 1956 627843 62784 37965 60 1957 647004 64700 36932 57 1958 664653 66465 35331 53 1959 700480 70048 36223 52 1960 718762 71876 36399 51 1961 737421 73742 36285 49 1962 766734 76673 38980 51 1963 805249 80525 41723 52 1964 846298 84630 45645 54 1965 887812 88781 47089 53 1966 925899 92590 50894 55 1967 964005 96401 50724 53 1968 1015869 101587 52725 52 1969 1061791 106179 53543 50 1970 1109724 110972 52627 47 1971 1178811 117881 52542 45 1972 1259786 125979 54589 43 1973 1313110 131311 54052 41 1974 1280544 128054 45196 35 1975 1327664 132766 44525 34 1976 1402380 140238 45523 32 1977 1467027 146703 47878 33 1978 1544704 154470 50331 33 1979 1529133 152913 51093 33 1980 1527295 152730 51091 33 1981 1555308 155531 49301 32 1982 1595010 159501 43945 28
Source Analysis of Significant Decline in Motor Vehicle Traffic Fatalities in
2008 httpwww-nrdnhtsadotgovPubs811346pdf see Table A1 page 31
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Page 40 of 45
Acknowledgements
The author is grateful for thoughtful comments provided by friends and colleagues
with whom this document was shared via email prior to it being uploaded as a
publicly available document for wider dissemination and study The comments
offered by Prof Subra Ganesan of Oakland University Electrical and Computer
Engineering Department are reproduced with permission in their entirety
About the author
The author obtained his Masterrsquos (S M) and Doctoral (Sc D) degrees in Materials Engineering
from the Massachusetts Institute of Technology Cambridge USA He then spent his entire
professional career at leading US research institutions (MIT NASA Case Western Reserve
University and General Motors R amp D Center in Warren MI) He holds four patents in advanced
materials processing has co-authored two books and has published several scientific papers in
leading peer-reviewed international journals His expertise includes developing simple
mathematical models to explain the behavior of complex systems He can be reached by email at
vlaxmananhotmailcom
Page 41 of 45
Please Buckle Up
httpwwwlakecountypublichealthorgindexphpbuckle-up-montana
Public Awareness
Respect the Cage Exhibit
The Department of Transportation hopes that showing the reality of the crash will reduce traffic
fatalities A crushed car crash dummies and a sobering message ndash all part of the ―Respect The
Cage exhibit that is traveling across Montana The exhibit sponsored by the Montana Department
of Transportation stopped in Ronan on November 6th and is aimed at raising awareness about the
importance of wearing seat belts
The car in the exhibit was in an actual wreck many years ago
the passenger in the vehicle died because he was not wearing a
seat belt the driver who was wearing his seat belt survived
Montanarsquos likeliest crash fatality scenario
A Pickup
A Rural road
And Seat belts that
arenrsquot used
Page 42 of 45
Occupants of pickups are less likely to wear seat belts and pickups are more likely to
roll over than passenger cars
Seat belts reduce the risk of death by 60 percent in pickups and SUVs
In Montana from 2006-2008 81 of those killed in a crash while riding in a pickup were not wearing seat belts
In Montana pickups make up 401 of the vehicle population
For more information on Respect the Cage click here
Page 43 of 45
Appendix 1
Lack of seat belts leading cause of Louisiana highway deaths
1251 AM May 28 2011 |
Written by Adam Duvernay
Crashes involving unbuckled motorists were the leading cause of highway fatalities
in Louisiana last year and cost $9888 million according to recent reports The
Louisiana Highway Safety Commission reported 59 percent of vehicle occupants
killed in Louisiana crashes last year mdash about one in four mdash werent wearing seat
belts
httpwwwshreveporttimescomarticle20110528NEWS01105280354Lack-seat-
belts-leading-cause-La-highway-deathsodyssey=tab|topnews|text|FRONTPAGE
Crash bull Stats Published by NHTSAlsquos National Center for Statistics and Analysis 1200 New Jersey Avenue SE Washington DC 20590
DOT HS 811 451
Early Estimate of Motor Vehicle Traffic Fatalities in 2010
httpwww-nrdnhtsadotgovPubs811451pdf
Summary
A statistical projection of traffic fatalities in 2010 shows that an estimated 32788
people died in motor vehicle traffic crashes This represents a decline of about 3
percent as compared to the 33808 fatalities in 2009 as shown in Table 1 If these
projections are realized fatalities will be lowest on record (since 1949)
Traffic Safety Facts Overview 2009 Data
httpwww-nrdnhtsadotgovPubs811392pdf
In 2009 33808 people were killed in the estimated 5505000 police-reported
motor vehicle traffic crashes 2217000 people were injured and 3957000
crashes involved property damage only Compared to 2008 this is a 10-
percent decrease in the number of fatalities and a 5-percent decrease in the
Page 44 of 45
number of police-reported motor vehicle traffic crashes people injured and
crashes involving property damage
An average of 93 people died each day in motor vehicle crashes in 2009 mdash
an average of one every 16 minutes
Traffic Safety Facts Overview 2008 Data
httpwww-nrdnhtsadotgovPubs811162pdf
In 2008 37261 people were killed in the estimated 5811000 police-reported
motor vehicle traffic crashes 2346000 people were injured and 4146000
crashes involved property damage only
Some comments and Feedback
The following comments were received from Prof Ganesan after his review of the
first draft of this document It was subsequently revised thanks to this input to
address some of the very important issues raised here
Dear Laxman
The write up is not enough
You are emphasizing that the speed limit reduces the fatal accidents (comparing 1966
to 2000 accident numbers)
Can you also add a few sentences why the number is decreasing from 1980 to 2000
values (May be due to better design of vehicles)
Can you say anything about the fuel consumption with the speed for any typical
vehicle in 2011 or 2010 (do not consider the fatalities issue)
Probably a speed between 55 and 60 mph gives a better mileage If so this is a
compelling reason to keep the speed limit low But cars probably can be tuned to
give better mileage at any high speed also
Page 45 of 45
Weather is also a major factor in fatal accidents Speed limit may be kept low during
winter and kept higher in summer Give your comments on this too
Driver distractions can cause more accidents Now cars have many multimedia and
internet features Automatic collision avoidance systems and sensors on the sides can
detect vehicles in the front and neighboring lanes and it can automatically decrease
speed even if the driver speeds at super high speeds
Give some comments on this too There is also Vehicle to Vehicle communications
vehicle to infrastructure communications and they can avoid collisions and accidents
Technology has changed from 1966 I cannot agree with you on the speed limit
without any discussion on the above and other factors
Have a great day
Subra Ganesan
Professor Subramaniam Ganesan
Director Real Time amp DSP Lab
Electrical and Computer Engineering Department
2200 Squirrel Road Dodge Hall Room 105
Oakland University Rochester MI 48309 USA
Phone 248 370 2206 Fax 248 370 4633
wwwsecsoaklandedu~ganesan
IEEE Distinguished Visiting Speaker (2005-2009) Coordinator
IEEE SEM CS chapter Chair Region 4 and CS Society Board member
SAE ASEE ACM member
Page 11 of 45
Figure 3 Graphical representation of the traffic fatality data for the 15 year period
1994-2009 A sudden precipitous drop in the absolute number of fatalities (at least on
the magnified scale used here) and hence the fatality rate has been observed over
the three-year period 2007-2009 However it should be noted that the x-y scatter
graph here shows a general upward trend with fatalities actually increasing with
increasing VMT (as in the earlier era 1950s and 1960s) during the 12-year period
spanning 1994-2006 although the rate yx shows a misleading downward trend Why
is the rate yx going down
The reason is very simple and it may be just a mathematical artifact The equation of
the best-fit straight line through the most recent data points is of the form y = hx + c
= 2865 x + 34420 where h is the slope of the line and c the intercept (Note that x
here is VMT in billions The numerical value determined using this equation must be
divided by 10 to get the rate per 100 M VMT) Hence the fatality rate given by the
ratio yx = h + (cx) = 2865 + 34420x can actually decrease with increasing
values of x because of the nonzero intercept c Unlike the ray through the origin the
best-fit line does not pass through the origin (00) If we consider only the most
Page 12 of 45
recent data the intercept c is positive and fatality rates yx decrease with increasing
VMT and increasing fatalities In the earlier era both the slope h and intercept c had
very different values due to several factors being discussed here (speed limits
technology highway design etc)
Table 2 Traffic fatality data for the recent 15-year period
1994-2009 (Source NHTSA)
Year
Highway
fatalities y
Vehicle miles
traveled
VMT
(billions) x
Fatality rate
yx per 100
million VMT
Fatal crashes
1994 40716 2358 173 36254 1995 41817 2423 173 37241 1996 42065 2486 169 37494 1997 42013 2562 164 37324 1998 41501 2632 158 37107 1999 41717 2691 155 37140 2000 41945 2747 153 37526 2001 42196 2797 151 37862 2002 43005 2856 151 38491 2003 42884 2890 148 38477 2004 42836 2965 144 38444 2005 43510 2989 146 39252 2006 42708 3014 1 42 38648 2007 41259 3032 136 37435 2008 37423 2974 126 34172 2009 33808 2979 113 30797
Page 13 of 45
Figure 4 The most significant metric used by NHTSA is the fatality rate per 100
million vehicles miles traveled (VMT) This is now at a historical low of 113 for
2009 having declined year after year from 173 in 1994 The NHTSA however also
compiles other types of data on crashes There are three types of crashes fatal
injury but no death and property damage only A careful review of this crash data
for the period 1994-2009 reveals the obvious the lower the number of (fatal)
crashes x the lower the number of highway-accident-related fatalities y It is also
obvious that the number of fatalities per crash is greater than one ie more than one
person is being killed when one of more vehicles experience a crash
Clearly this is the single most important piece of information that one needs to
reduce the number of fatalities on our highways Vehicle design and engineering as
well as all other policy matters (legal political social environmental financial)
must be guided by this simple graph The best-fit line through the data derived using
simple linear regression has the equation y = hx + c = 114x ndash 10266 and is
Page 14 of 45
superimposed on to the data The design engineering goal and societal goal should
be to reduce the slope h of this statistically significant best-fit line to its ideal value of
h = 1 A fatal crash by definition is one where at least one person dies either an
occupant or a non-motorist in the path of the vehicle Hence the ideal slope h = 1
Photograph of an accident scene from the period 1955-1965
httpwwwcorinthsocialhistoryprojectorghtmlhighwaytollshtml
3 A Brief History of Traffic Safety Legislation
The following is extracted from the Wikipedia article on National Highway
Traffic Safety Administration (NHTSA)
httpenwikipediaorgwikiNational_Highway_Traffic_Safety_Administration
In 1965 and 1966 public pressure grew in the US to increase the safety of
cars The number of deaths on US highways were increasing year after year
Page 15 of 45
see Figure 1 and in 1966 Congress held a series of highly publicized
hearings on highway safety This led to the legislation for mandatory
installation of seat belts which also created the US Department of
Transportation (on Oct 15 1966)
httpwwwemsgovpdf2011EMSWeek2011_Stricklandpdf
The following is extracted from a Washington Post article on
NHTSA dated April 2 2002
httpwwwwashingtonpostcomwp-srvbusinessincludesnhtsa_primerhtm
In 1966 after decades of rising traffic fatalities (also vividly illustrated in
Figures 1 and 2 here) the publication of Ralph Naders Unsafe at Any
Speed and increasing public outcry for safer automobiles Congress held a
series of highly publicized hearings on creating a regulatory agency for traffic
safety Among the witnesses was William Haddon an epidemiologist who
introduced the idea that traffic accidents could be analyzed scientifically and
injuries reduced by changing auto design such as installing collapsible
steering columns safety glass head rests and seat belts
Congress passed the Highway Safety Act of 1966 creating the National
Highway Safety Bureau with Haddon as its first administrator The bureau
became NHTSA in 1970 under the newly established Department of
Transportation An early Nader convert Joan Claybrook headed NHTSA
under President Carter and now runs Naders organization Public Citizen
National Traffic and Motor Vehicle Safety Act
httpwwwanswerscomtopicnational-traffic-and-motor-vehicle-safety-act
Signed into law by President Lyndon Johnson on September 9 1966 this act
created the first mandatory federal safety standards for motor vehicles The
act was motivated by a variety of factors First and foremost the public was
growing increasingly concerned over the rising number of traffic fatalities on
the nations roads Such fatalities had increased by nearly 30 percent
between 1960 and 1965 and experts forecasted 100000 such deaths
Page 16 of 45
annually by 1975 unless something was done to improve traffic safety
Adding fuel to the fire Ralph Naders Unsafe at Any Speed published in
November 1965 criticized the automobile industry for neglecting safety in
favor of power and styling when designing new vehicles
4 The reason for the historical
decrease in highway fatalities
A recent news item see link given below regarding renewed attempts to
increase the speed limit by many states prompted this write up by the
present author who has studied traffic fatality data extensively and analyzed
them very carefully over the last several years
httpmoneymsncomauto-insurancewhy-speed-limits-are-
risingaspxGT1=33033
Residents of Metro Detroit area who frequently cross into Ohio from
Michigan notice that the speed limit has now increased in Ohio The speed
limit on Michigan highways was increased to 70 mph in the late 1990s but
Ohio retained its lower speed limit for many years leading Michigan drivers to
experience a ―speed trap of sorts The speed limit is also increasing in many
other states notably Texas where it is proposed to increase it to 85 mph at
least in West Texas
Historically speaking from a traffic fatality standpoint we must consider two
important dates 1966 and 1973 Only 1973 the year of the Arab oil embargo
following the Arab-Israeli war (that led to what President Obama has recently
called the pre-1967 border for Middle East peace) is mentioned in the above
article It fails to mention the significance of the year 1966
Prior to 1966 there was actually NO speed limit in many Western states and
deaths due to highway accidents were increasing year after year The
Page 17 of 45
number of highway fatalities went up from 38702 in 1957 to 51524 in 1965
a 33 increase over the 1957 level and an additional 12822 deaths in 1965
compared to 1957 It was this carnage on the US highways that forced
Congress to hold its hearings on highway traffic fatalities in 1966
Nonetheless a careful examination of the fatality data in Table 1 shows that
notwithstanding the highly publicized Congressional hearings of 1966 and
new safety legislation that was enacted the absolute number of fatalities
continued to increase after 1966 and only started decreasing after 1973
Vehicle designs especially the introduction of safety features (even the
simplest like safety belts) did not change significantly between 1966 and
1973 Nonetheless post-1973 we begin to see a dramatic turnaround
Why
After the 1973 Arab oil embargo a nationwide maximum speed limit (NMSL)
of 55 mph was imposed and accepted in the USA (effective Jan 1 1974)
during the Nixon administration primarily as an effort to conserve fuel and
reduce the US vulnerability to oil imports The unintended and indeed
fortunate consequence of this reduced speed limit was the immediate
reduction in the fatalities revealed in Figures 2 and 3 This is the real reason
for the peaks in highway fatalities observed in these two graphs
The Congressional hearings of 1966 did eventually have an impact but it was
a delayed one The impact of the 1973 nationwide speed limit of 55 mph was
however immediate as we see from the magnified plot of the same data in
Figure 5 and a closer examination of the raw fatality data in Table 1
The number of highway-accident-related fatalities decreased immediately
from a high of 55704 in 1972 to just 46078 in 1974 a 173 drop see
arrows There were 9626 fewer deaths annually even with a slight increase
in the vehicle miles driven (see Table 1) Indeed the number of highway
death reached its absolute peak value in 1972 never to be seen again
Fatalities have been decreasing every since with slight fluctuations about
each new low value
Page 18 of 45
Figure 5 Expanded view of the fatality data showing the immediate impact of the
national speed limit of 55 mph following the Arab oil embargo of 1973 Note that
fatalities continued to rise between 1966 and 1973 in spite of the highly publicized
Congressional hearings in 1966 and the traffic safety legislation enacted soon after
Each new low is probably associated with vehicle safety innovations and the
improvements in vehicle design and engineering The combined beneficial
effect of improved vehicle designs primarily the introduction of seat belts
and the laws enforcing usage of seat belts aided by the reduced speed
limits contributed to the continued decline in the absolute number of fatalities
that started since 1973 and has continued to this day The subsequent
introduction of other safety features notably air bags has contributed to a
further reduction in highway fatalities
Page 19 of 45
State police Trooper First Class Jeffrey Flowers looking at a car in which a Boswell
Pennsylvania woman was injured Tuesday (May 31 2011) The accident occurred at
an intersection when a truck (seen behind the wrecked car) entered this accident
prone intersection (part of a highway safety corridor where signs are posted to
reduce unsafe driver behavior) There have been four accidents at this intersection
since 2006 none fatal httpwwwdailyamericancomnewssomersetda-ot-woman-
injured-in-route-30-wreck-2011053104165420story
5 Numerical calculations of decline in
fatalities and the impact of NMSL post-1973
Letlsquos consider the decline in fatalities between 1972 the last year before the
adoption of the NMSL and 1974 the first year following its adoption after the
Arab oil embargo There was an immediate decrease in the number of
fatalities by 9393 ie y = -9393 with a slight increase in the VMT ie x
= 20758 millions The NHTSA data used here may be found in the table at
the end of this document The numerical value of the rate of change per
billion VMT (ie neglecting the sign) was therefore
yx = 4525 fatalitiesbillion VMT (1972-1974)
Page 20 of 45
It is instructive to compare this rate of change in fatalities with similar short
periods of a decline in fatalities in the pre-1973 era when speed limits were
much higher The absolute number of fatalities declined over a relatively
short period with both an increase and a decrease in VMT The results are
given below and are self-explanatory
yx = 454 fatalitiesbillion VMT (1953-54) decline with increase in VMT
yx = 655 fatalitiesbillion VMT (1942-43) decline with decrease in VMT
yx = 1739 fatalitiesbillion VMT (1941-42) decline with decrease in VMT
yx = 4528 fatalitiesbillion VMT (1937-39) decline with increase in VMT
yx = 2548 fatalitiesbillion VMT (1931-32) decline with decrease in VMT
The rate of decline observed between 1953 and 1954 with an increase in
VMT was just one-tenth of that observed following the adoption of the 55
mph speed limit The war years (1941-43 WWII) and the Great Depression
era (1931-32) were accompanied by big declines in fatalities with decreasing
VMT but the rate of change was still significantly lower than observed after
the adoption of the NMSL
The only apparently inexplicable decline is that between 1937 and 1939
where a nearly identical high rate of decline was observed Notice also the
big drop in the traditional fatality rate between 1937 and 1938 This large drop
appears to coincide with the creation of the National Safety Council (NSC) by
William H Cameron in June 1937 (see link below) with its far-flung campaign
of education legislation research highway engineering and traffic training
undertaken by the NSC and some two dozen other groups with the backing of the
automotive industry through its Automotive Safety Foundation Other factors
unknown to the present author probably also played a role
httpwwwtimecomtimemagazinearticle0917188379700htmlixzz1O2G
7rnUg
Page 21 of 45
These simple computations here however reveal the significant effect of
reduced speed limits on highway fatalities much more so than other factors
6 Further Considerations Pros and Cons
The singular effect of increased speeds (or speeding) on highway fatalities
has been studied and demonstrated by a number of industry sources such
as the Insurance Institute for Highway Safety (IIHS) Consumers Union and
also by government researchers
httpwwwsmartmotoristcomtraffic-and-safety-guidelineexcessive-speed-is-
a-factor-in-one-third-of-all-fatal-crasheshtml
httpwwwconsumersunionorgotherspeedlimitsspeed031500a2htm
Speed ndash defined as exceeding the posted speed limit or driving too fast for
given conditions ndash is a factor in nearly one-third of all fatal crashes Besides
fatality in 1998 nearly 40000 people were critically injured in speed-related
crashes and nearly 72000 were moderately injured
The salutary and immediate beneficial effect of the nationwide 55 mph speed
limit has been noted by other researchers (see Susan Ferguson link below)
httpwwwnhtsagovpeopleinjuryenforcespeed_forum_presentationsfergu
sonpdf
After a partial repeal of this law in 1987 which granted states the authority to
increase speed limit (especially in rural interstates) a 1989 study showed a
15 increase in fatalities in rural interstates and a 5 increase in non-rural
interstates Unfortunately such studies often tend to be discounted by
advocates of increasing the speed limits as being produced by biased
industry sources
Similar conclusions were also presented by NHTSA in February 1998 in its
report to the Congress entitled ―Report to Congress The Effect of Increased
Speed Limits in the Post-NMSL Era see link given below Among its key
Page 22 of 45
findings is the following quoted in its entirety NMSL refers to the National
Maximum Speed Limit legislated after the Arab oil embargo of 1973
httpwww-nrdnhtsadotgovPubs808-637PDF
hellip Nevertheless it is important to note that data currently available from the
National Highway Traffic Safety Administrationrsquos (NHTSA) Fatality Analysis
Reporting System (FARS) shows that states that increased speed limits in 1996
experienced approximately 350 more Interstate fatalities than would have been
expected based on historical trends -- about 9 percent above expectations
Concurrently the Interstate fatalities experienced in states that did not increase speed
limits in 1996 was consistent with pre-1996 trends The estimated increase in
Interstate fatalities found in this study while smaller in magnitude compared to the
estimated change in fatalities found in 1987 following the increase of speed limits on
rural Interstates does follow the historical pattern of increases in fatalities being
associated with increases in posted speed limits
The annual crash reports compiled by NHTSA see Table 3 indicate that the
number of fatal crashes (and hence fatalities using the regression equation
developed in Figure 4) increase as the posted speed limits increase
Page 23 of 45
Table 3 Posted speed limits and number of crashes
Speed Limit Crashes (2008) Crashes (2009)
30 mph or less 3705 3277 35 or 40 mph 6115 5516 45 or 50 mph 6461 6074
55 mph 9794 8847 60 mph or higher 6908 6124
Total 34017 30797
Source httpwww-nrdnhtsadotgovPubs811402EEpdf
61 Studies cited in favor of lower speed limits
A detailed analysis of speeding related fatalities (see link below) by NHTSA
shows that a third of all crashes involve speeding ie at least one driver was
speeding
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Furthermore the above report which covers the period 1983-2002
indicates that immediately after the NMSL was completely abolished in
December 1995 the number of speeding related fatalities at speeds
above 65 mph increased from just 15 in 1995 to a 677 in 1996 (see Table
62 on page 43 of above report) It continued to increase in the years
since climbing to 930 in 2000
More detailed studies similar to that noted above by researchers at the
University of Illinois Chicago led by Lee S Friedman again lead to the
conclusion that higher speed limits lead to an increase in the number of
fatalities (see American Journal of Public Health online July 16 2009)
httphealthusnewscomhealth-newsmanaging-your-
healthcarearticles20090716deaths-injuries-increase-with-higher-speed-
limits
Page 24 of 45
httpwwwmedpagetodaycomPublicHealthPolicyPublicHealth15122
httpwwwamericaneercomspeed-limits
httpwwwactuarialoutpostcomactuarial_discussion_forumarchiveindexph
pt-171870html
For the study period 1995-2005 these researchers found that 12545 deaths
and 36582 injuries could be attributed to the increased speed limits The
benefits of reduced speed limits are stated quite eloquently by Dr Friedman
and are reproduced below (from above news article see link)
Reduced speed limits would save lives Friedman said They would also reduce
gas consumption cut emissions of air pollutants save valuable years of productivity
(lost due to injuries)and reduce the societal cost of motor vehicle crashes (due to
both fatal crashes and due to nonfatal and severe life-changing injuries) he added
Friedman and coworkers have also shown that increasing the speed limit led
to an immediate increase in the number of fatalities on Israeli roadways (see
link below)
httpinjurypreventionbmjcomcontent133156
The effect of speeding is very significant especially in rural areas resulting
in significantly higher fatalities Fatality rates are frequently double or triple
that in urban areas (see link below)
httpsafetyfhwadotgovspeedmgtdata_factsdocsspeeding_ruralpdf
As of Jan 1 2005 five Midwestern states had increased the speed limits to
above 65 mph (Illinois Iowa Kansas Minnesota Missouri Nebraska and
South Dakota) whereas three (Illinois Iowa and Wisconsin) had not All the
five states with increased speed limits showed a 7 to 13 increase in
fatalities The NHTSA study considered an eight year period before and after
the change in Dec 1995 (see Table 1 in link below) The collective experience
of the states that did NOT increase the speed limit was a 7 decline in
fatalities (see Table 2 of link below)
httpwwwiowadotgovmvdodsstats2006speedstudypdf
Page 25 of 45
Moreover Table 5 in the above study shows the effect of imposing the NMSL
of 55 mph in Iowa and its repeal in 1995 Considering a four-year average
before 1974 when the speed limit was 75 mph there were 35 fatal crashes
with 43 fatalities In the first four years after the 55 mph there were only 23
fatal crashes and 28 fatalities In the last four years before the repeal of 55
mph in 1995 there was a further decline to 14 fatal crashes with 17 fatalities
The Iowa fatality data will be discussed in more detail separately (in a later report)
since it provides the opportunity to assess the effect of a change in the speed limit
on the relationship between number of fatalities and fatal crashes (as seen in
Figure 4 for the US as a whole)
North of the US border Canadians seem to be citing the ―shocking increase
in highway fatalities in the US states where the speed limits were raised to
curb their own speed limits
httparchivesafety-councilorginfotrafficspeed-02html
httparchivesafety-councilorginfotrafficspeedhtml
Speed kills but speed also sells notes the second of the above news items
Manufacturers are producing more high performance cars (with higher horse
power to weight ratio) and ads feature enticing cars that race and swerve in
miraculous ways on empty roads These subliminal messages encourage
drivers especially young drivers to break the speed limit leading to the
absolute increase in highway fatalities (although the rate itself is going
down) The article emphasizes the need to enforce the speed limit on
Canadian highways and in cities where street racing is becoming a problem
62 Studies cited by opponents of lower speed limits
In fairness to quote the opponents on the other side of this debate Montana
reverted back to Reasonable and Prudent speed limits when the National
Maximum Speed Limit was repealed in 1995 and appears to have
experienced no significant increase in fatalities
Page 26 of 45
httpwwwhwysafetycomhwy_montanahtm
httpwwwmotoristsorgpressmontana-no-speed-limit-safety-paradox
httpwwwsouthbayriderscomforumsshowthreadphpt=81453amppage=1
Likewise studies in the state of Maryland showed no significant increase in
highway fatalities when the speed limit was increased from 55 mph to 75
mph The reason might simply be that drivers were already speeding much
more so when the speed limit was 55 mph than after the increase to 75 mph
In other words the fatalities data already reflects the effect of higher speeds
(not speed limits) on the number of fatalities
In Utah the experimental increase in the speed limit to 80 mph was
considered to be a success in terms of safety
httpautosaolcomarticleutah-speed-limit-tests
The UDOT Director noted that there was no increase in the number of
accidents on Interstate 15 But what happens in the event of an accident
when the speed limits are higher and drivers are driving at higher speeds and
two objects collide at this higher speed However no increase in the number
of accidents is not the same as no increase in fatalities due to the higher
speeds When accidents do occur do fatalities increase
Likewise in California when the speed limit went up from 55 mph to 65
mph in 1995 (after repeal of NMSL) fewer deaths were reported in 1998
compared to the peak year of 1979 or even 1987 Again the explanation
seems to be that motorists were already speeding when the limit was 55 mph
and that increasing the speed limit did not change driver behavior in any
significant way
httparticlessfgatecom1998-11-02news17735730_1_speed-limits-mph-
limit-death-rate
The National Motorists Association (NMA) a group which advocates higher
speed limits emphasizes the importance of considering fatality rates as
opposed to the raw fatalities The argument used is that fatality rates based
on the fatality per 100 million VMT is the legitimate way to look at the data
Page 27 of 45
This is a never ending debate Historically speaking fatality rates have been
going down ever since the compilation of traffic accidents data began Table
A1 in the appendix of a recent report by NHTSA (see link below) has highway
fatality rate data going back 1921
httpwww-nrdnhtsadotgovPubs811346pdf see appendix page 31
httpwwwmotoristsorgspeed-limitstruth
httpwwwmotoristsorgothercrash-data
httpwwwraisethespeedlimitorgmythshtml
httpwwwcatoorgpubspaspa346pdf
According to Stephen Moore of the Cato Institute (see last of the links above)
―All measures of highway safety show improvement not more deaths and
injuries since 1995 Despite the fact that 33 states raised their speed limits
immediately after the repeal of the mandatory federal speed limit the NHTSA
reported last October that the traffic death rate dropped to a record low level
in 1997lsquo Moreover the average fatality rate even fell in the states that raised
their speed limits
63 The Fatality rate Is it a reliable metric
In 1921 with fewer fatalities and fewer miles driven and the first year for
which the fatality rate could be computed the rate was 2408 It was down to
1479 in 1931 but the number of deaths had climbed to 31963 more than
double the 1921 absolute fatality number of 13253 It had dropped to 550 in
1966 the year of the highly publicized Congressional hearings but the
number of fatalities had climbed to 50984 in that fateful The Highway Safety
Act of 1966 ranks as one of the major acts of Congress and President
Johnson signed it saying that ―we have been tolerating a raging epidemic of
highway deathshellip see extract pasted below
httpwwwenotescommajor-acts-congresshighway-safety-act
Page 28 of 45
The act was motivated primarily by growing public concern over the rising number
of traffic fatalities in the United States Between 1960 and 1965 the annual number
of traffic fatalities increased by nearly thirty percent As President Lyndon B
Johnson stated at the signing of the act on September 9 1966 we have tolerated
a raging epidemic of highway death which has killed more of our youth than all
other diseases combined Through the Highway Safety Act we are going to find out
more about highway diseasemdashand we aim to cure it
Nonetheless highways fatalities continued to increase until the Arab oil
embargo of 1973 led to the NMSL of 55 mph all across the USA Do we just
ignore this undeniable historical record and focus only on the declining fatality
rate as the NMA and other proponents of higher speed limits seem to argue
(see links above)
The misleading nature of using fatality rates (per 100 M VMT) alone is also
obvious if one considers fatality data for individual states Take for example
the state of Montana which seems to have experienced no increase in
fatalities after repeal of NMSL
httpwww-nrdnhtsadotgovdepartmentsnrd-
30ncsaSTSI30_MT200930_MT_2009htm
For the period 2005-2009 the absolute number of fatalities for Montana
varied between a high of 277 in 2007 to a low of 229 in 2009 The fatality
rates per 100 M VMT on the other hand varied from a high of 245 for 2007
to a low of 201 for 2009 The corresponding US fatality rates varied from
136 to 114 Is the higher number for the fatality rate for Montana compared
to USA good or bad Likewise fatality rate per 100000 of population was
much higher for Montana than the US as a whole
This again highlights the pitfalls of using simple ratios to assess fatality statistics
without a full analysis of the underlying trends We will discuss this point
separately
As shown already the continuous decline in the fatality rate is a mathematical
artifact and essentially overlooks the unmistakable positive correlation
between the variables x and y of the type y = hx + c which becomes obvious
Page 29 of 45
only when we prepare the x-y scatter graph The ratio yx = h + (cx) can
decrease with increasing x (VMT) and increasing y (fatalities) since the
intercept c has a positive value when we consider only data spanning a short
period (such as 1994-2009 of more relevance to the current situation)
The debate between fatality rates and absolute number of fatalities is an
unending one A few years ago the Wall Street Journal carried an article
which was entitled (or something close) ―Unemployments rate in Ohio are
going down but why is the number of unemployed increasing The reason is
the same The graph of the number of unemployed (y) versus the number in
the labor market (x) is linear with a positive slope h and a positive intercept c
So the unemployment rate computed using the ratio yx keeps going down
year after year although the number unemployed keeps increasing Is it a
good thing that the unemployment rate is going down when more people
seem to be unable to find gainful unemployment
Or consider the situation with cancer death rates This too has been going
down in recent years but the actual number of cancer-related deaths has not
declined in any significant way Is it good that cancer death rates are going
down In all these situations the researchers or the socio-econo-politico
analysts involved in analyzing the trends in the data have failed to consider
the underlying x-y relation describing each problem
Hence it appears that the debate on the effect of increased speed limits
should not be focused on only the fatality rates (which have been decreasing
and proponents of higher speed limits cite this in their arguments) or even the
absolute number of fatalities (which has been the focus here) but on the
relationship between speed and the number of fatal crashes and the number
of fatalities within each speed segment (see Table 3 and also Figure 4)
Unfortunately details of number of fatalities and the number of fatal crashes
at each speed limit are not available even from NHTSA for detailed study
When a crash does occur (it is immaterial how many miles were driven) the
speed of the driver and vehicle design and engineering including safety
devices in place (seat belts airbags other impact absorbing technologies)
Page 30 of 45
determine if the occupants(s) will be killed One cannot argue that speed
does NOT kill That would be an absolute denial of the laws of physics
Studies show that setting the speed limit at the 85th percentile in any given
zone (this is the speed at or below which 85 of drivers are observed to
travel in traffic engineering studies) is the safest speed limit The majority of
drivers try to obey the posted speed limit while a few choose to drive at a
speed they consider is safe and prudent These are also perhaps the most
vociferous advocates of higher speed limits It is this tension caused due to
differences in speeds that leads to tailgating improper passing reckless
driving weaving from lane to lane and ultimately crashes and deaths in some
unfortunate cases
httpblogmotoristsorgspeed-limits-slower-safer
MARK TAYLOR
ANOTHER LOST A man was killed when his 4WD drive hit a tree east of Morrinsville (in New
Zealand) on Monday May 30 2011 The driver lost control of the vehicle on a bend probably tried
to correct his mistake and put the car into a ―yaw causing it to leave the road and smash sideways
into a tree Alerts to slow down had been posted since this was a high accident area but the driver
probably did not pay attention
64 Other factors
Many other factors besides speed no doubt affect highway fatalities The
vehicles of the 21st century are very different from the vehicles of the mid 20th
Page 31 of 45
century Technological innovations such as improvements in vehicle design
and engineering have greatly increased crash worthiness of vehicles even at
high speeds Environmental factors such as the weather also contribute to
accidents but not necessarily to increased fatalities Drivers actually tend to
slow down instinctively during adverse weather conditions (rain snow storms
etc) and although such weather may contribute to increased accidents the
lower speeds actually reduce fatalities
Yes technology has changed fundamentally from 1966 Drivers today are
more distracted by their cellmobile phone conversations (and also built-in
phones in luxury models) and text messaging than the drivers of the pre-1966
era High end cars now have many multimedia and internet features Again a
careful observation (even personal experience by the author) suggests that
such distracted drivers actually tend to (instinctively) drive more slowly and
hold up the traffic Perhaps such behavior leads to an increase in the number
of accidents but it does not necessarily lead to an increase in the number of
accident-related fatalities
Much talked about technological innovations such as automatic collision
avoidance systems and sensors (on the sides of vehicles) can indeed detect
vehicles in the front and neighboring lanes Furthermore vehicle-to-vehicle
communication systems vehicle-to-infrastructure communication systems
can no doubt avoid collisions and accidents Again such collision avoidance
systems work and are effective entirely because they automatically reduce
vehicle speeds - even if one of the offending vehicles is being at a super
high speed Also it must be remembered that such futuristic systems have
not yet been implemented widely nor can they be implemented widely since
the large majority of vehicles on the road are NOT luxury models Advanced
safety features come with a price and not all drivers can afford to pay that
price and ―buy that ―additional safety
Ultimately it is the laws of physics that govern what will happen when two or
more vehicles collide or even when a single vehicle collides with a stationary
infrastructural object (a bridge a wall a building or some impediment on the
road) The lower the number of crashes the lower the number of fatalities as
revealed by the 1994-2009 data graphed in Figure 5 The higher the speed of
Page 32 of 45
the object or objects that are involved in a collision the higher the kinetic
energy K that must be absorbed andor dissipated Increasing the posted
speed limit only increases the energy that must be absorbed when a crash
does occur This ultimately is the most important criterion determining the
number of fatalities
The kinetic energy increases as the square of the speed being given by the
well-known formula K = frac12 mv2 where m is the mass of the vehicle (in
laypersonlsquos language m increases directly with vehicle weight) and v is the
speed For the same vehicle mass an increase in the speed from 55 mph to
85 mph increases the kinetic energy K by a factor of 239 or roughly a 250
increase in the kinetic energy that must be absorbed in a collision
Ideally speaking the kinetic energy of the colliding object(s) is absorbed by
the vehicle infrastructure (a sturdy space frame the engine other vehicle
components etc) andor the surroundings However in the unfortunate
cases where this kinetic energy must be absorbed by the vehicle occupant(s)
the result is severe life-altering injuries andor death An unequivocal
relationship between an increase in vehicle speeds and fatal accidents can
be demonstrated by a careful examination of available traffic fatality data
This is a more involved discussion and is not the purpose of this short
communication These topics are no doubt very politically charged with many
social legal and financial implications with each interest group favoring a
different conclusion Nonetheless we cannot escape the laws of physics as
they govern the fundamental need to absorb higher and higher values of the
kinetic energy K with increasing vehicle speeds This same point is also
emphasized by Dr Friedman of the University of Illinois Chicago (see earlier
discussion)
Speed kills because of these energy transfer considerations and there can be
no doubt about it
Innovative 21st century solutions to speed management on the highways
such as strict enforcement of speed limits minimizing speed dispersion
(difference between speeds at which different drivers travel) while using
cameras to track the 15 of drivers who willfully violate the speed limit and
Page 33 of 45
create hazardous driving conditions is certainly recommended (Recall that
the optimum recommended speed limit is at or below which 85 of all drivers
travel ndash a policy also supported by NMA) Even on this score however the
results are confounding if we consider the Australian experience
httpwwwthenewspapercomnews282840asp
Up until 2007 there was no speed limit in the Northern Territory of
Australia Imposing a speed limit 130 kmph (80 mph) on some areas and
110 kmph (68 mph) in some others actually increased the number of deaths
The death toll in 2006 when there was no speed limit in this region was 44
and went up to 75 in 2009 see data table in link below
httpwwwthenewspapercomrlcdocs2009au-ntroadtollpdf
Furthermore it appears that installation of cameras to enforce speed limits
has proved to be a hazardous distraction to drivers and deaths actually
began to skyrocket between 2005 and 2007 in all Australian roadways
The main purpose here is to sound a cautionary note amid renewed attempts
in many states across the US to increase the speed limits on our highways by
calling attention to the historical facts regarding the ―epidemic levels of
highway traffic fatalities that engaged our national attention in the fateful year
of 1966 The graphical representation of the traffic fatality data in Figures 1
to 5 tells its own story
Indeed it would be tragic if highway-accident-related fatalities were to start
increasing once again and reach the historically high level that was last seen
in 1972 the year before the Arab oil embargo of 1973
Page 34 of 45
Conclusions
1 The graphical representation of the highway fatality data and the brief
summary of the historical facts of traffic safety legislation suggest that
recent attempts to increase the speed limits by various states (notably
Texas) may be misguided The distinct peak in the highway fatalities
observed in these graphs is highly alarming This appears to be related to
the enactment of the National Maximum Speed Limit (NSML) in 1974
following the 1973 Arab oil embargo Although NSML was motivated by a
desire to reduce gasoline consumption an unintended benefit might have
been a dramatic reduction in fatalities The fundamental reasons for the
peak in the fatalities-VMT curve must be examined carefully without
political posturing
2 The widely used fatality rate fatalities per 100 M vehicle miles traveled
has been declining since 1921 the first year for which a fatality rate could
be computed and has now reached a historical low The absolute number
of fatalities on the other hand was increasing in the 1950s and 1960s at
an alarming rate and the public outcry that ensued led to the highly
publicized Congressional hearing of 1966 and the subsequent traffic safety
legislations The fatality rate has been decreasing even in the most recent
15-year period (1994-2009) again with increasing fatalities although less
dramatically Thus it appears that fatality rate calculation based on vehicle
miles traveled (VMT) might not be a reliable indicator of the underlying
dynamics in the fatality trends
3 More detailed compilation of number of fatalities and the number of fatal
crashes within each speed limit segment is required to better understand
the effect of increasing speed limits on highway fatalities (and also fatality
rates) Such data is already available and is being compiled at the local
city and county levels in all jurisdictions and only needs to be reorganized
to highlight the effect of (posted) speed limits on the number of crashes
and fatalities This will require some minor rewriting and revisions to the
chapters named ―Crashes and ―States in the annual NHTSA reports
Page 35 of 45
Analysis of the fatalities-crashes data for several years with various
speed limits will be more revealing and meaningful than the current
fatality rates analysis and will be discussed separately in a follow up
report
4 One should not be lulled by the fact that vehicles of the 21st century are
now equipped with advanced safety features not available in the 1950s
and the 1960s In spite of these safety features the laws of physics dictate
that the higher the speed the higher kinetic energy of the colliding objects
and hence the greater the risk indeed near certainty of fatalities in a
higher speed collision compared to a lower speed one
5 The higher the speed at which the vehicle that is involved in a crash is
traveling the higher the kinetic energy that must be absorbed andor
dissipated without affecting the occupant(s) to avoid serious injuries andor
death This was true in the 1950s and the 1960s and will continue to be
true in the 21st century as well
Speed Kills for this just reason
6 It appears that higher fuel economies and reduced
highway fatalities were the twin societal benefits of 55
mph adopted after 1973 If so the current attempts to
increase the speed limits appear to be in conflict with
other important societal objectives
Page 36 of 45
Table 1 Annual US Street amp Highway
Fatalities from 1957
Year
Fatalities
Vehicle Miles
(millions)
Rate100M Vehicle Miles
1957 38702 646915 598
1958 36981 664915 556
1959 37910 700478 541
1960 38137 718845 531
1961 38091 737535 516
1962 40804 766852 532
1963 43564 805423 541
1964 47700 846500 563
1965 49163 887640 554
1966 51524 927915 555
1967 51559 965132 534
1968 53831 1019726 528
1969 55032 1066108 516
1970 53672 1114098 482
1971 53761 1183524 454
1972 55704 1264614 440
1973 55113 1316207 419
1974 46078 1282790 359
1975 45500 1330074 342
1976 45523 1402380 325
1977 47878 1467027 326
1978 50331 1544704 326
1979 51103 1529133 334
1980 51091 1527295 335
1981 49301 1552803 317
1982 43945 1595010 276
1983 42589 1652788 258
1984 44257 1720269 257
1985 43795 1774179 247
Page 37 of 45
1986 46056 1835000 251
1987 46385 1921000 241
1988 47093 2026000 232
1989 45555 2107040 216
1990 44529 2147501 207
1991 41162 2172214 189
1992 39235 2239828 175
1993 40115 2296585 175
1994 40676 2359984 172
1995 41798 2422696 173
1996 41907 2485848 169
1997 41967 2560373 164
Data from Federal Highway Administration
Source httpwwwpublicpurposecomhwy-fatal57+htm
Telephone +16186328507 - Facsimile +16186328538
WENDELL COX CONSULTANCY P O Box 841 - Belleville IL 62269 USA
Page 38 of 45
Fatality data for 1921-1982 compiled by NHTSA
Year
VMT
(Millions)
VMT
(Billions)
Fatalities
Fatality rate
per 100 M VMT
1921 55027 5503 13253 241 1922 67697 6770 14859 219 1923 84995 8500 17870 210 1924 104838 10484 18400 176 1925 122346 12235 20771 170 1926 140735 14074 22194 158 1927 158453 15845 24470 154 1928 172856 17286 26557 154 1929 197720 19772 29592 150 1930 206320 20632 31204 151 1931 216151 21615 31963 148 1932 200517 20052 27979 140 1933 200642 20064 29746 148 1934 215563 21556 34240 159 1935 228568 22857 34494 151 1936 252128 25213 36126 143 1937 270110 27011 37819 140 1938 271177 27118 31083 115 1939 285402 28540 30895 108 1940 302188 30219 32914 109 1941 333612 33361 38142 114 1942 268224 26822 27007 101 1943 208192 20819 22727 109 1944 212713 21271 23165 109 1945 250173 25017 26785 107 1946 340880 34088 31874 94 1947 370894 37089 31193 84 1948 397957 39796 30775 77 1949 424461 42446 30246 71 1950 458246 45825 33186 72 1951 491093 49109 35309 72
1952 513581 51358 36088 70
Page 39 of 45
1953 544433 54443 36190 66 1954 561963 56196 33890 60 1955 605646 60565 36688 61 1956 627843 62784 37965 60 1957 647004 64700 36932 57 1958 664653 66465 35331 53 1959 700480 70048 36223 52 1960 718762 71876 36399 51 1961 737421 73742 36285 49 1962 766734 76673 38980 51 1963 805249 80525 41723 52 1964 846298 84630 45645 54 1965 887812 88781 47089 53 1966 925899 92590 50894 55 1967 964005 96401 50724 53 1968 1015869 101587 52725 52 1969 1061791 106179 53543 50 1970 1109724 110972 52627 47 1971 1178811 117881 52542 45 1972 1259786 125979 54589 43 1973 1313110 131311 54052 41 1974 1280544 128054 45196 35 1975 1327664 132766 44525 34 1976 1402380 140238 45523 32 1977 1467027 146703 47878 33 1978 1544704 154470 50331 33 1979 1529133 152913 51093 33 1980 1527295 152730 51091 33 1981 1555308 155531 49301 32 1982 1595010 159501 43945 28
Source Analysis of Significant Decline in Motor Vehicle Traffic Fatalities in
2008 httpwww-nrdnhtsadotgovPubs811346pdf see Table A1 page 31
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Page 40 of 45
Acknowledgements
The author is grateful for thoughtful comments provided by friends and colleagues
with whom this document was shared via email prior to it being uploaded as a
publicly available document for wider dissemination and study The comments
offered by Prof Subra Ganesan of Oakland University Electrical and Computer
Engineering Department are reproduced with permission in their entirety
About the author
The author obtained his Masterrsquos (S M) and Doctoral (Sc D) degrees in Materials Engineering
from the Massachusetts Institute of Technology Cambridge USA He then spent his entire
professional career at leading US research institutions (MIT NASA Case Western Reserve
University and General Motors R amp D Center in Warren MI) He holds four patents in advanced
materials processing has co-authored two books and has published several scientific papers in
leading peer-reviewed international journals His expertise includes developing simple
mathematical models to explain the behavior of complex systems He can be reached by email at
vlaxmananhotmailcom
Page 41 of 45
Please Buckle Up
httpwwwlakecountypublichealthorgindexphpbuckle-up-montana
Public Awareness
Respect the Cage Exhibit
The Department of Transportation hopes that showing the reality of the crash will reduce traffic
fatalities A crushed car crash dummies and a sobering message ndash all part of the ―Respect The
Cage exhibit that is traveling across Montana The exhibit sponsored by the Montana Department
of Transportation stopped in Ronan on November 6th and is aimed at raising awareness about the
importance of wearing seat belts
The car in the exhibit was in an actual wreck many years ago
the passenger in the vehicle died because he was not wearing a
seat belt the driver who was wearing his seat belt survived
Montanarsquos likeliest crash fatality scenario
A Pickup
A Rural road
And Seat belts that
arenrsquot used
Page 42 of 45
Occupants of pickups are less likely to wear seat belts and pickups are more likely to
roll over than passenger cars
Seat belts reduce the risk of death by 60 percent in pickups and SUVs
In Montana from 2006-2008 81 of those killed in a crash while riding in a pickup were not wearing seat belts
In Montana pickups make up 401 of the vehicle population
For more information on Respect the Cage click here
Page 43 of 45
Appendix 1
Lack of seat belts leading cause of Louisiana highway deaths
1251 AM May 28 2011 |
Written by Adam Duvernay
Crashes involving unbuckled motorists were the leading cause of highway fatalities
in Louisiana last year and cost $9888 million according to recent reports The
Louisiana Highway Safety Commission reported 59 percent of vehicle occupants
killed in Louisiana crashes last year mdash about one in four mdash werent wearing seat
belts
httpwwwshreveporttimescomarticle20110528NEWS01105280354Lack-seat-
belts-leading-cause-La-highway-deathsodyssey=tab|topnews|text|FRONTPAGE
Crash bull Stats Published by NHTSAlsquos National Center for Statistics and Analysis 1200 New Jersey Avenue SE Washington DC 20590
DOT HS 811 451
Early Estimate of Motor Vehicle Traffic Fatalities in 2010
httpwww-nrdnhtsadotgovPubs811451pdf
Summary
A statistical projection of traffic fatalities in 2010 shows that an estimated 32788
people died in motor vehicle traffic crashes This represents a decline of about 3
percent as compared to the 33808 fatalities in 2009 as shown in Table 1 If these
projections are realized fatalities will be lowest on record (since 1949)
Traffic Safety Facts Overview 2009 Data
httpwww-nrdnhtsadotgovPubs811392pdf
In 2009 33808 people were killed in the estimated 5505000 police-reported
motor vehicle traffic crashes 2217000 people were injured and 3957000
crashes involved property damage only Compared to 2008 this is a 10-
percent decrease in the number of fatalities and a 5-percent decrease in the
Page 44 of 45
number of police-reported motor vehicle traffic crashes people injured and
crashes involving property damage
An average of 93 people died each day in motor vehicle crashes in 2009 mdash
an average of one every 16 minutes
Traffic Safety Facts Overview 2008 Data
httpwww-nrdnhtsadotgovPubs811162pdf
In 2008 37261 people were killed in the estimated 5811000 police-reported
motor vehicle traffic crashes 2346000 people were injured and 4146000
crashes involved property damage only
Some comments and Feedback
The following comments were received from Prof Ganesan after his review of the
first draft of this document It was subsequently revised thanks to this input to
address some of the very important issues raised here
Dear Laxman
The write up is not enough
You are emphasizing that the speed limit reduces the fatal accidents (comparing 1966
to 2000 accident numbers)
Can you also add a few sentences why the number is decreasing from 1980 to 2000
values (May be due to better design of vehicles)
Can you say anything about the fuel consumption with the speed for any typical
vehicle in 2011 or 2010 (do not consider the fatalities issue)
Probably a speed between 55 and 60 mph gives a better mileage If so this is a
compelling reason to keep the speed limit low But cars probably can be tuned to
give better mileage at any high speed also
Page 45 of 45
Weather is also a major factor in fatal accidents Speed limit may be kept low during
winter and kept higher in summer Give your comments on this too
Driver distractions can cause more accidents Now cars have many multimedia and
internet features Automatic collision avoidance systems and sensors on the sides can
detect vehicles in the front and neighboring lanes and it can automatically decrease
speed even if the driver speeds at super high speeds
Give some comments on this too There is also Vehicle to Vehicle communications
vehicle to infrastructure communications and they can avoid collisions and accidents
Technology has changed from 1966 I cannot agree with you on the speed limit
without any discussion on the above and other factors
Have a great day
Subra Ganesan
Professor Subramaniam Ganesan
Director Real Time amp DSP Lab
Electrical and Computer Engineering Department
2200 Squirrel Road Dodge Hall Room 105
Oakland University Rochester MI 48309 USA
Phone 248 370 2206 Fax 248 370 4633
wwwsecsoaklandedu~ganesan
IEEE Distinguished Visiting Speaker (2005-2009) Coordinator
IEEE SEM CS chapter Chair Region 4 and CS Society Board member
SAE ASEE ACM member
Page 12 of 45
recent data the intercept c is positive and fatality rates yx decrease with increasing
VMT and increasing fatalities In the earlier era both the slope h and intercept c had
very different values due to several factors being discussed here (speed limits
technology highway design etc)
Table 2 Traffic fatality data for the recent 15-year period
1994-2009 (Source NHTSA)
Year
Highway
fatalities y
Vehicle miles
traveled
VMT
(billions) x
Fatality rate
yx per 100
million VMT
Fatal crashes
1994 40716 2358 173 36254 1995 41817 2423 173 37241 1996 42065 2486 169 37494 1997 42013 2562 164 37324 1998 41501 2632 158 37107 1999 41717 2691 155 37140 2000 41945 2747 153 37526 2001 42196 2797 151 37862 2002 43005 2856 151 38491 2003 42884 2890 148 38477 2004 42836 2965 144 38444 2005 43510 2989 146 39252 2006 42708 3014 1 42 38648 2007 41259 3032 136 37435 2008 37423 2974 126 34172 2009 33808 2979 113 30797
Page 13 of 45
Figure 4 The most significant metric used by NHTSA is the fatality rate per 100
million vehicles miles traveled (VMT) This is now at a historical low of 113 for
2009 having declined year after year from 173 in 1994 The NHTSA however also
compiles other types of data on crashes There are three types of crashes fatal
injury but no death and property damage only A careful review of this crash data
for the period 1994-2009 reveals the obvious the lower the number of (fatal)
crashes x the lower the number of highway-accident-related fatalities y It is also
obvious that the number of fatalities per crash is greater than one ie more than one
person is being killed when one of more vehicles experience a crash
Clearly this is the single most important piece of information that one needs to
reduce the number of fatalities on our highways Vehicle design and engineering as
well as all other policy matters (legal political social environmental financial)
must be guided by this simple graph The best-fit line through the data derived using
simple linear regression has the equation y = hx + c = 114x ndash 10266 and is
Page 14 of 45
superimposed on to the data The design engineering goal and societal goal should
be to reduce the slope h of this statistically significant best-fit line to its ideal value of
h = 1 A fatal crash by definition is one where at least one person dies either an
occupant or a non-motorist in the path of the vehicle Hence the ideal slope h = 1
Photograph of an accident scene from the period 1955-1965
httpwwwcorinthsocialhistoryprojectorghtmlhighwaytollshtml
3 A Brief History of Traffic Safety Legislation
The following is extracted from the Wikipedia article on National Highway
Traffic Safety Administration (NHTSA)
httpenwikipediaorgwikiNational_Highway_Traffic_Safety_Administration
In 1965 and 1966 public pressure grew in the US to increase the safety of
cars The number of deaths on US highways were increasing year after year
Page 15 of 45
see Figure 1 and in 1966 Congress held a series of highly publicized
hearings on highway safety This led to the legislation for mandatory
installation of seat belts which also created the US Department of
Transportation (on Oct 15 1966)
httpwwwemsgovpdf2011EMSWeek2011_Stricklandpdf
The following is extracted from a Washington Post article on
NHTSA dated April 2 2002
httpwwwwashingtonpostcomwp-srvbusinessincludesnhtsa_primerhtm
In 1966 after decades of rising traffic fatalities (also vividly illustrated in
Figures 1 and 2 here) the publication of Ralph Naders Unsafe at Any
Speed and increasing public outcry for safer automobiles Congress held a
series of highly publicized hearings on creating a regulatory agency for traffic
safety Among the witnesses was William Haddon an epidemiologist who
introduced the idea that traffic accidents could be analyzed scientifically and
injuries reduced by changing auto design such as installing collapsible
steering columns safety glass head rests and seat belts
Congress passed the Highway Safety Act of 1966 creating the National
Highway Safety Bureau with Haddon as its first administrator The bureau
became NHTSA in 1970 under the newly established Department of
Transportation An early Nader convert Joan Claybrook headed NHTSA
under President Carter and now runs Naders organization Public Citizen
National Traffic and Motor Vehicle Safety Act
httpwwwanswerscomtopicnational-traffic-and-motor-vehicle-safety-act
Signed into law by President Lyndon Johnson on September 9 1966 this act
created the first mandatory federal safety standards for motor vehicles The
act was motivated by a variety of factors First and foremost the public was
growing increasingly concerned over the rising number of traffic fatalities on
the nations roads Such fatalities had increased by nearly 30 percent
between 1960 and 1965 and experts forecasted 100000 such deaths
Page 16 of 45
annually by 1975 unless something was done to improve traffic safety
Adding fuel to the fire Ralph Naders Unsafe at Any Speed published in
November 1965 criticized the automobile industry for neglecting safety in
favor of power and styling when designing new vehicles
4 The reason for the historical
decrease in highway fatalities
A recent news item see link given below regarding renewed attempts to
increase the speed limit by many states prompted this write up by the
present author who has studied traffic fatality data extensively and analyzed
them very carefully over the last several years
httpmoneymsncomauto-insurancewhy-speed-limits-are-
risingaspxGT1=33033
Residents of Metro Detroit area who frequently cross into Ohio from
Michigan notice that the speed limit has now increased in Ohio The speed
limit on Michigan highways was increased to 70 mph in the late 1990s but
Ohio retained its lower speed limit for many years leading Michigan drivers to
experience a ―speed trap of sorts The speed limit is also increasing in many
other states notably Texas where it is proposed to increase it to 85 mph at
least in West Texas
Historically speaking from a traffic fatality standpoint we must consider two
important dates 1966 and 1973 Only 1973 the year of the Arab oil embargo
following the Arab-Israeli war (that led to what President Obama has recently
called the pre-1967 border for Middle East peace) is mentioned in the above
article It fails to mention the significance of the year 1966
Prior to 1966 there was actually NO speed limit in many Western states and
deaths due to highway accidents were increasing year after year The
Page 17 of 45
number of highway fatalities went up from 38702 in 1957 to 51524 in 1965
a 33 increase over the 1957 level and an additional 12822 deaths in 1965
compared to 1957 It was this carnage on the US highways that forced
Congress to hold its hearings on highway traffic fatalities in 1966
Nonetheless a careful examination of the fatality data in Table 1 shows that
notwithstanding the highly publicized Congressional hearings of 1966 and
new safety legislation that was enacted the absolute number of fatalities
continued to increase after 1966 and only started decreasing after 1973
Vehicle designs especially the introduction of safety features (even the
simplest like safety belts) did not change significantly between 1966 and
1973 Nonetheless post-1973 we begin to see a dramatic turnaround
Why
After the 1973 Arab oil embargo a nationwide maximum speed limit (NMSL)
of 55 mph was imposed and accepted in the USA (effective Jan 1 1974)
during the Nixon administration primarily as an effort to conserve fuel and
reduce the US vulnerability to oil imports The unintended and indeed
fortunate consequence of this reduced speed limit was the immediate
reduction in the fatalities revealed in Figures 2 and 3 This is the real reason
for the peaks in highway fatalities observed in these two graphs
The Congressional hearings of 1966 did eventually have an impact but it was
a delayed one The impact of the 1973 nationwide speed limit of 55 mph was
however immediate as we see from the magnified plot of the same data in
Figure 5 and a closer examination of the raw fatality data in Table 1
The number of highway-accident-related fatalities decreased immediately
from a high of 55704 in 1972 to just 46078 in 1974 a 173 drop see
arrows There were 9626 fewer deaths annually even with a slight increase
in the vehicle miles driven (see Table 1) Indeed the number of highway
death reached its absolute peak value in 1972 never to be seen again
Fatalities have been decreasing every since with slight fluctuations about
each new low value
Page 18 of 45
Figure 5 Expanded view of the fatality data showing the immediate impact of the
national speed limit of 55 mph following the Arab oil embargo of 1973 Note that
fatalities continued to rise between 1966 and 1973 in spite of the highly publicized
Congressional hearings in 1966 and the traffic safety legislation enacted soon after
Each new low is probably associated with vehicle safety innovations and the
improvements in vehicle design and engineering The combined beneficial
effect of improved vehicle designs primarily the introduction of seat belts
and the laws enforcing usage of seat belts aided by the reduced speed
limits contributed to the continued decline in the absolute number of fatalities
that started since 1973 and has continued to this day The subsequent
introduction of other safety features notably air bags has contributed to a
further reduction in highway fatalities
Page 19 of 45
State police Trooper First Class Jeffrey Flowers looking at a car in which a Boswell
Pennsylvania woman was injured Tuesday (May 31 2011) The accident occurred at
an intersection when a truck (seen behind the wrecked car) entered this accident
prone intersection (part of a highway safety corridor where signs are posted to
reduce unsafe driver behavior) There have been four accidents at this intersection
since 2006 none fatal httpwwwdailyamericancomnewssomersetda-ot-woman-
injured-in-route-30-wreck-2011053104165420story
5 Numerical calculations of decline in
fatalities and the impact of NMSL post-1973
Letlsquos consider the decline in fatalities between 1972 the last year before the
adoption of the NMSL and 1974 the first year following its adoption after the
Arab oil embargo There was an immediate decrease in the number of
fatalities by 9393 ie y = -9393 with a slight increase in the VMT ie x
= 20758 millions The NHTSA data used here may be found in the table at
the end of this document The numerical value of the rate of change per
billion VMT (ie neglecting the sign) was therefore
yx = 4525 fatalitiesbillion VMT (1972-1974)
Page 20 of 45
It is instructive to compare this rate of change in fatalities with similar short
periods of a decline in fatalities in the pre-1973 era when speed limits were
much higher The absolute number of fatalities declined over a relatively
short period with both an increase and a decrease in VMT The results are
given below and are self-explanatory
yx = 454 fatalitiesbillion VMT (1953-54) decline with increase in VMT
yx = 655 fatalitiesbillion VMT (1942-43) decline with decrease in VMT
yx = 1739 fatalitiesbillion VMT (1941-42) decline with decrease in VMT
yx = 4528 fatalitiesbillion VMT (1937-39) decline with increase in VMT
yx = 2548 fatalitiesbillion VMT (1931-32) decline with decrease in VMT
The rate of decline observed between 1953 and 1954 with an increase in
VMT was just one-tenth of that observed following the adoption of the 55
mph speed limit The war years (1941-43 WWII) and the Great Depression
era (1931-32) were accompanied by big declines in fatalities with decreasing
VMT but the rate of change was still significantly lower than observed after
the adoption of the NMSL
The only apparently inexplicable decline is that between 1937 and 1939
where a nearly identical high rate of decline was observed Notice also the
big drop in the traditional fatality rate between 1937 and 1938 This large drop
appears to coincide with the creation of the National Safety Council (NSC) by
William H Cameron in June 1937 (see link below) with its far-flung campaign
of education legislation research highway engineering and traffic training
undertaken by the NSC and some two dozen other groups with the backing of the
automotive industry through its Automotive Safety Foundation Other factors
unknown to the present author probably also played a role
httpwwwtimecomtimemagazinearticle0917188379700htmlixzz1O2G
7rnUg
Page 21 of 45
These simple computations here however reveal the significant effect of
reduced speed limits on highway fatalities much more so than other factors
6 Further Considerations Pros and Cons
The singular effect of increased speeds (or speeding) on highway fatalities
has been studied and demonstrated by a number of industry sources such
as the Insurance Institute for Highway Safety (IIHS) Consumers Union and
also by government researchers
httpwwwsmartmotoristcomtraffic-and-safety-guidelineexcessive-speed-is-
a-factor-in-one-third-of-all-fatal-crasheshtml
httpwwwconsumersunionorgotherspeedlimitsspeed031500a2htm
Speed ndash defined as exceeding the posted speed limit or driving too fast for
given conditions ndash is a factor in nearly one-third of all fatal crashes Besides
fatality in 1998 nearly 40000 people were critically injured in speed-related
crashes and nearly 72000 were moderately injured
The salutary and immediate beneficial effect of the nationwide 55 mph speed
limit has been noted by other researchers (see Susan Ferguson link below)
httpwwwnhtsagovpeopleinjuryenforcespeed_forum_presentationsfergu
sonpdf
After a partial repeal of this law in 1987 which granted states the authority to
increase speed limit (especially in rural interstates) a 1989 study showed a
15 increase in fatalities in rural interstates and a 5 increase in non-rural
interstates Unfortunately such studies often tend to be discounted by
advocates of increasing the speed limits as being produced by biased
industry sources
Similar conclusions were also presented by NHTSA in February 1998 in its
report to the Congress entitled ―Report to Congress The Effect of Increased
Speed Limits in the Post-NMSL Era see link given below Among its key
Page 22 of 45
findings is the following quoted in its entirety NMSL refers to the National
Maximum Speed Limit legislated after the Arab oil embargo of 1973
httpwww-nrdnhtsadotgovPubs808-637PDF
hellip Nevertheless it is important to note that data currently available from the
National Highway Traffic Safety Administrationrsquos (NHTSA) Fatality Analysis
Reporting System (FARS) shows that states that increased speed limits in 1996
experienced approximately 350 more Interstate fatalities than would have been
expected based on historical trends -- about 9 percent above expectations
Concurrently the Interstate fatalities experienced in states that did not increase speed
limits in 1996 was consistent with pre-1996 trends The estimated increase in
Interstate fatalities found in this study while smaller in magnitude compared to the
estimated change in fatalities found in 1987 following the increase of speed limits on
rural Interstates does follow the historical pattern of increases in fatalities being
associated with increases in posted speed limits
The annual crash reports compiled by NHTSA see Table 3 indicate that the
number of fatal crashes (and hence fatalities using the regression equation
developed in Figure 4) increase as the posted speed limits increase
Page 23 of 45
Table 3 Posted speed limits and number of crashes
Speed Limit Crashes (2008) Crashes (2009)
30 mph or less 3705 3277 35 or 40 mph 6115 5516 45 or 50 mph 6461 6074
55 mph 9794 8847 60 mph or higher 6908 6124
Total 34017 30797
Source httpwww-nrdnhtsadotgovPubs811402EEpdf
61 Studies cited in favor of lower speed limits
A detailed analysis of speeding related fatalities (see link below) by NHTSA
shows that a third of all crashes involve speeding ie at least one driver was
speeding
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Furthermore the above report which covers the period 1983-2002
indicates that immediately after the NMSL was completely abolished in
December 1995 the number of speeding related fatalities at speeds
above 65 mph increased from just 15 in 1995 to a 677 in 1996 (see Table
62 on page 43 of above report) It continued to increase in the years
since climbing to 930 in 2000
More detailed studies similar to that noted above by researchers at the
University of Illinois Chicago led by Lee S Friedman again lead to the
conclusion that higher speed limits lead to an increase in the number of
fatalities (see American Journal of Public Health online July 16 2009)
httphealthusnewscomhealth-newsmanaging-your-
healthcarearticles20090716deaths-injuries-increase-with-higher-speed-
limits
Page 24 of 45
httpwwwmedpagetodaycomPublicHealthPolicyPublicHealth15122
httpwwwamericaneercomspeed-limits
httpwwwactuarialoutpostcomactuarial_discussion_forumarchiveindexph
pt-171870html
For the study period 1995-2005 these researchers found that 12545 deaths
and 36582 injuries could be attributed to the increased speed limits The
benefits of reduced speed limits are stated quite eloquently by Dr Friedman
and are reproduced below (from above news article see link)
Reduced speed limits would save lives Friedman said They would also reduce
gas consumption cut emissions of air pollutants save valuable years of productivity
(lost due to injuries)and reduce the societal cost of motor vehicle crashes (due to
both fatal crashes and due to nonfatal and severe life-changing injuries) he added
Friedman and coworkers have also shown that increasing the speed limit led
to an immediate increase in the number of fatalities on Israeli roadways (see
link below)
httpinjurypreventionbmjcomcontent133156
The effect of speeding is very significant especially in rural areas resulting
in significantly higher fatalities Fatality rates are frequently double or triple
that in urban areas (see link below)
httpsafetyfhwadotgovspeedmgtdata_factsdocsspeeding_ruralpdf
As of Jan 1 2005 five Midwestern states had increased the speed limits to
above 65 mph (Illinois Iowa Kansas Minnesota Missouri Nebraska and
South Dakota) whereas three (Illinois Iowa and Wisconsin) had not All the
five states with increased speed limits showed a 7 to 13 increase in
fatalities The NHTSA study considered an eight year period before and after
the change in Dec 1995 (see Table 1 in link below) The collective experience
of the states that did NOT increase the speed limit was a 7 decline in
fatalities (see Table 2 of link below)
httpwwwiowadotgovmvdodsstats2006speedstudypdf
Page 25 of 45
Moreover Table 5 in the above study shows the effect of imposing the NMSL
of 55 mph in Iowa and its repeal in 1995 Considering a four-year average
before 1974 when the speed limit was 75 mph there were 35 fatal crashes
with 43 fatalities In the first four years after the 55 mph there were only 23
fatal crashes and 28 fatalities In the last four years before the repeal of 55
mph in 1995 there was a further decline to 14 fatal crashes with 17 fatalities
The Iowa fatality data will be discussed in more detail separately (in a later report)
since it provides the opportunity to assess the effect of a change in the speed limit
on the relationship between number of fatalities and fatal crashes (as seen in
Figure 4 for the US as a whole)
North of the US border Canadians seem to be citing the ―shocking increase
in highway fatalities in the US states where the speed limits were raised to
curb their own speed limits
httparchivesafety-councilorginfotrafficspeed-02html
httparchivesafety-councilorginfotrafficspeedhtml
Speed kills but speed also sells notes the second of the above news items
Manufacturers are producing more high performance cars (with higher horse
power to weight ratio) and ads feature enticing cars that race and swerve in
miraculous ways on empty roads These subliminal messages encourage
drivers especially young drivers to break the speed limit leading to the
absolute increase in highway fatalities (although the rate itself is going
down) The article emphasizes the need to enforce the speed limit on
Canadian highways and in cities where street racing is becoming a problem
62 Studies cited by opponents of lower speed limits
In fairness to quote the opponents on the other side of this debate Montana
reverted back to Reasonable and Prudent speed limits when the National
Maximum Speed Limit was repealed in 1995 and appears to have
experienced no significant increase in fatalities
Page 26 of 45
httpwwwhwysafetycomhwy_montanahtm
httpwwwmotoristsorgpressmontana-no-speed-limit-safety-paradox
httpwwwsouthbayriderscomforumsshowthreadphpt=81453amppage=1
Likewise studies in the state of Maryland showed no significant increase in
highway fatalities when the speed limit was increased from 55 mph to 75
mph The reason might simply be that drivers were already speeding much
more so when the speed limit was 55 mph than after the increase to 75 mph
In other words the fatalities data already reflects the effect of higher speeds
(not speed limits) on the number of fatalities
In Utah the experimental increase in the speed limit to 80 mph was
considered to be a success in terms of safety
httpautosaolcomarticleutah-speed-limit-tests
The UDOT Director noted that there was no increase in the number of
accidents on Interstate 15 But what happens in the event of an accident
when the speed limits are higher and drivers are driving at higher speeds and
two objects collide at this higher speed However no increase in the number
of accidents is not the same as no increase in fatalities due to the higher
speeds When accidents do occur do fatalities increase
Likewise in California when the speed limit went up from 55 mph to 65
mph in 1995 (after repeal of NMSL) fewer deaths were reported in 1998
compared to the peak year of 1979 or even 1987 Again the explanation
seems to be that motorists were already speeding when the limit was 55 mph
and that increasing the speed limit did not change driver behavior in any
significant way
httparticlessfgatecom1998-11-02news17735730_1_speed-limits-mph-
limit-death-rate
The National Motorists Association (NMA) a group which advocates higher
speed limits emphasizes the importance of considering fatality rates as
opposed to the raw fatalities The argument used is that fatality rates based
on the fatality per 100 million VMT is the legitimate way to look at the data
Page 27 of 45
This is a never ending debate Historically speaking fatality rates have been
going down ever since the compilation of traffic accidents data began Table
A1 in the appendix of a recent report by NHTSA (see link below) has highway
fatality rate data going back 1921
httpwww-nrdnhtsadotgovPubs811346pdf see appendix page 31
httpwwwmotoristsorgspeed-limitstruth
httpwwwmotoristsorgothercrash-data
httpwwwraisethespeedlimitorgmythshtml
httpwwwcatoorgpubspaspa346pdf
According to Stephen Moore of the Cato Institute (see last of the links above)
―All measures of highway safety show improvement not more deaths and
injuries since 1995 Despite the fact that 33 states raised their speed limits
immediately after the repeal of the mandatory federal speed limit the NHTSA
reported last October that the traffic death rate dropped to a record low level
in 1997lsquo Moreover the average fatality rate even fell in the states that raised
their speed limits
63 The Fatality rate Is it a reliable metric
In 1921 with fewer fatalities and fewer miles driven and the first year for
which the fatality rate could be computed the rate was 2408 It was down to
1479 in 1931 but the number of deaths had climbed to 31963 more than
double the 1921 absolute fatality number of 13253 It had dropped to 550 in
1966 the year of the highly publicized Congressional hearings but the
number of fatalities had climbed to 50984 in that fateful The Highway Safety
Act of 1966 ranks as one of the major acts of Congress and President
Johnson signed it saying that ―we have been tolerating a raging epidemic of
highway deathshellip see extract pasted below
httpwwwenotescommajor-acts-congresshighway-safety-act
Page 28 of 45
The act was motivated primarily by growing public concern over the rising number
of traffic fatalities in the United States Between 1960 and 1965 the annual number
of traffic fatalities increased by nearly thirty percent As President Lyndon B
Johnson stated at the signing of the act on September 9 1966 we have tolerated
a raging epidemic of highway death which has killed more of our youth than all
other diseases combined Through the Highway Safety Act we are going to find out
more about highway diseasemdashand we aim to cure it
Nonetheless highways fatalities continued to increase until the Arab oil
embargo of 1973 led to the NMSL of 55 mph all across the USA Do we just
ignore this undeniable historical record and focus only on the declining fatality
rate as the NMA and other proponents of higher speed limits seem to argue
(see links above)
The misleading nature of using fatality rates (per 100 M VMT) alone is also
obvious if one considers fatality data for individual states Take for example
the state of Montana which seems to have experienced no increase in
fatalities after repeal of NMSL
httpwww-nrdnhtsadotgovdepartmentsnrd-
30ncsaSTSI30_MT200930_MT_2009htm
For the period 2005-2009 the absolute number of fatalities for Montana
varied between a high of 277 in 2007 to a low of 229 in 2009 The fatality
rates per 100 M VMT on the other hand varied from a high of 245 for 2007
to a low of 201 for 2009 The corresponding US fatality rates varied from
136 to 114 Is the higher number for the fatality rate for Montana compared
to USA good or bad Likewise fatality rate per 100000 of population was
much higher for Montana than the US as a whole
This again highlights the pitfalls of using simple ratios to assess fatality statistics
without a full analysis of the underlying trends We will discuss this point
separately
As shown already the continuous decline in the fatality rate is a mathematical
artifact and essentially overlooks the unmistakable positive correlation
between the variables x and y of the type y = hx + c which becomes obvious
Page 29 of 45
only when we prepare the x-y scatter graph The ratio yx = h + (cx) can
decrease with increasing x (VMT) and increasing y (fatalities) since the
intercept c has a positive value when we consider only data spanning a short
period (such as 1994-2009 of more relevance to the current situation)
The debate between fatality rates and absolute number of fatalities is an
unending one A few years ago the Wall Street Journal carried an article
which was entitled (or something close) ―Unemployments rate in Ohio are
going down but why is the number of unemployed increasing The reason is
the same The graph of the number of unemployed (y) versus the number in
the labor market (x) is linear with a positive slope h and a positive intercept c
So the unemployment rate computed using the ratio yx keeps going down
year after year although the number unemployed keeps increasing Is it a
good thing that the unemployment rate is going down when more people
seem to be unable to find gainful unemployment
Or consider the situation with cancer death rates This too has been going
down in recent years but the actual number of cancer-related deaths has not
declined in any significant way Is it good that cancer death rates are going
down In all these situations the researchers or the socio-econo-politico
analysts involved in analyzing the trends in the data have failed to consider
the underlying x-y relation describing each problem
Hence it appears that the debate on the effect of increased speed limits
should not be focused on only the fatality rates (which have been decreasing
and proponents of higher speed limits cite this in their arguments) or even the
absolute number of fatalities (which has been the focus here) but on the
relationship between speed and the number of fatal crashes and the number
of fatalities within each speed segment (see Table 3 and also Figure 4)
Unfortunately details of number of fatalities and the number of fatal crashes
at each speed limit are not available even from NHTSA for detailed study
When a crash does occur (it is immaterial how many miles were driven) the
speed of the driver and vehicle design and engineering including safety
devices in place (seat belts airbags other impact absorbing technologies)
Page 30 of 45
determine if the occupants(s) will be killed One cannot argue that speed
does NOT kill That would be an absolute denial of the laws of physics
Studies show that setting the speed limit at the 85th percentile in any given
zone (this is the speed at or below which 85 of drivers are observed to
travel in traffic engineering studies) is the safest speed limit The majority of
drivers try to obey the posted speed limit while a few choose to drive at a
speed they consider is safe and prudent These are also perhaps the most
vociferous advocates of higher speed limits It is this tension caused due to
differences in speeds that leads to tailgating improper passing reckless
driving weaving from lane to lane and ultimately crashes and deaths in some
unfortunate cases
httpblogmotoristsorgspeed-limits-slower-safer
MARK TAYLOR
ANOTHER LOST A man was killed when his 4WD drive hit a tree east of Morrinsville (in New
Zealand) on Monday May 30 2011 The driver lost control of the vehicle on a bend probably tried
to correct his mistake and put the car into a ―yaw causing it to leave the road and smash sideways
into a tree Alerts to slow down had been posted since this was a high accident area but the driver
probably did not pay attention
64 Other factors
Many other factors besides speed no doubt affect highway fatalities The
vehicles of the 21st century are very different from the vehicles of the mid 20th
Page 31 of 45
century Technological innovations such as improvements in vehicle design
and engineering have greatly increased crash worthiness of vehicles even at
high speeds Environmental factors such as the weather also contribute to
accidents but not necessarily to increased fatalities Drivers actually tend to
slow down instinctively during adverse weather conditions (rain snow storms
etc) and although such weather may contribute to increased accidents the
lower speeds actually reduce fatalities
Yes technology has changed fundamentally from 1966 Drivers today are
more distracted by their cellmobile phone conversations (and also built-in
phones in luxury models) and text messaging than the drivers of the pre-1966
era High end cars now have many multimedia and internet features Again a
careful observation (even personal experience by the author) suggests that
such distracted drivers actually tend to (instinctively) drive more slowly and
hold up the traffic Perhaps such behavior leads to an increase in the number
of accidents but it does not necessarily lead to an increase in the number of
accident-related fatalities
Much talked about technological innovations such as automatic collision
avoidance systems and sensors (on the sides of vehicles) can indeed detect
vehicles in the front and neighboring lanes Furthermore vehicle-to-vehicle
communication systems vehicle-to-infrastructure communication systems
can no doubt avoid collisions and accidents Again such collision avoidance
systems work and are effective entirely because they automatically reduce
vehicle speeds - even if one of the offending vehicles is being at a super
high speed Also it must be remembered that such futuristic systems have
not yet been implemented widely nor can they be implemented widely since
the large majority of vehicles on the road are NOT luxury models Advanced
safety features come with a price and not all drivers can afford to pay that
price and ―buy that ―additional safety
Ultimately it is the laws of physics that govern what will happen when two or
more vehicles collide or even when a single vehicle collides with a stationary
infrastructural object (a bridge a wall a building or some impediment on the
road) The lower the number of crashes the lower the number of fatalities as
revealed by the 1994-2009 data graphed in Figure 5 The higher the speed of
Page 32 of 45
the object or objects that are involved in a collision the higher the kinetic
energy K that must be absorbed andor dissipated Increasing the posted
speed limit only increases the energy that must be absorbed when a crash
does occur This ultimately is the most important criterion determining the
number of fatalities
The kinetic energy increases as the square of the speed being given by the
well-known formula K = frac12 mv2 where m is the mass of the vehicle (in
laypersonlsquos language m increases directly with vehicle weight) and v is the
speed For the same vehicle mass an increase in the speed from 55 mph to
85 mph increases the kinetic energy K by a factor of 239 or roughly a 250
increase in the kinetic energy that must be absorbed in a collision
Ideally speaking the kinetic energy of the colliding object(s) is absorbed by
the vehicle infrastructure (a sturdy space frame the engine other vehicle
components etc) andor the surroundings However in the unfortunate
cases where this kinetic energy must be absorbed by the vehicle occupant(s)
the result is severe life-altering injuries andor death An unequivocal
relationship between an increase in vehicle speeds and fatal accidents can
be demonstrated by a careful examination of available traffic fatality data
This is a more involved discussion and is not the purpose of this short
communication These topics are no doubt very politically charged with many
social legal and financial implications with each interest group favoring a
different conclusion Nonetheless we cannot escape the laws of physics as
they govern the fundamental need to absorb higher and higher values of the
kinetic energy K with increasing vehicle speeds This same point is also
emphasized by Dr Friedman of the University of Illinois Chicago (see earlier
discussion)
Speed kills because of these energy transfer considerations and there can be
no doubt about it
Innovative 21st century solutions to speed management on the highways
such as strict enforcement of speed limits minimizing speed dispersion
(difference between speeds at which different drivers travel) while using
cameras to track the 15 of drivers who willfully violate the speed limit and
Page 33 of 45
create hazardous driving conditions is certainly recommended (Recall that
the optimum recommended speed limit is at or below which 85 of all drivers
travel ndash a policy also supported by NMA) Even on this score however the
results are confounding if we consider the Australian experience
httpwwwthenewspapercomnews282840asp
Up until 2007 there was no speed limit in the Northern Territory of
Australia Imposing a speed limit 130 kmph (80 mph) on some areas and
110 kmph (68 mph) in some others actually increased the number of deaths
The death toll in 2006 when there was no speed limit in this region was 44
and went up to 75 in 2009 see data table in link below
httpwwwthenewspapercomrlcdocs2009au-ntroadtollpdf
Furthermore it appears that installation of cameras to enforce speed limits
has proved to be a hazardous distraction to drivers and deaths actually
began to skyrocket between 2005 and 2007 in all Australian roadways
The main purpose here is to sound a cautionary note amid renewed attempts
in many states across the US to increase the speed limits on our highways by
calling attention to the historical facts regarding the ―epidemic levels of
highway traffic fatalities that engaged our national attention in the fateful year
of 1966 The graphical representation of the traffic fatality data in Figures 1
to 5 tells its own story
Indeed it would be tragic if highway-accident-related fatalities were to start
increasing once again and reach the historically high level that was last seen
in 1972 the year before the Arab oil embargo of 1973
Page 34 of 45
Conclusions
1 The graphical representation of the highway fatality data and the brief
summary of the historical facts of traffic safety legislation suggest that
recent attempts to increase the speed limits by various states (notably
Texas) may be misguided The distinct peak in the highway fatalities
observed in these graphs is highly alarming This appears to be related to
the enactment of the National Maximum Speed Limit (NSML) in 1974
following the 1973 Arab oil embargo Although NSML was motivated by a
desire to reduce gasoline consumption an unintended benefit might have
been a dramatic reduction in fatalities The fundamental reasons for the
peak in the fatalities-VMT curve must be examined carefully without
political posturing
2 The widely used fatality rate fatalities per 100 M vehicle miles traveled
has been declining since 1921 the first year for which a fatality rate could
be computed and has now reached a historical low The absolute number
of fatalities on the other hand was increasing in the 1950s and 1960s at
an alarming rate and the public outcry that ensued led to the highly
publicized Congressional hearing of 1966 and the subsequent traffic safety
legislations The fatality rate has been decreasing even in the most recent
15-year period (1994-2009) again with increasing fatalities although less
dramatically Thus it appears that fatality rate calculation based on vehicle
miles traveled (VMT) might not be a reliable indicator of the underlying
dynamics in the fatality trends
3 More detailed compilation of number of fatalities and the number of fatal
crashes within each speed limit segment is required to better understand
the effect of increasing speed limits on highway fatalities (and also fatality
rates) Such data is already available and is being compiled at the local
city and county levels in all jurisdictions and only needs to be reorganized
to highlight the effect of (posted) speed limits on the number of crashes
and fatalities This will require some minor rewriting and revisions to the
chapters named ―Crashes and ―States in the annual NHTSA reports
Page 35 of 45
Analysis of the fatalities-crashes data for several years with various
speed limits will be more revealing and meaningful than the current
fatality rates analysis and will be discussed separately in a follow up
report
4 One should not be lulled by the fact that vehicles of the 21st century are
now equipped with advanced safety features not available in the 1950s
and the 1960s In spite of these safety features the laws of physics dictate
that the higher the speed the higher kinetic energy of the colliding objects
and hence the greater the risk indeed near certainty of fatalities in a
higher speed collision compared to a lower speed one
5 The higher the speed at which the vehicle that is involved in a crash is
traveling the higher the kinetic energy that must be absorbed andor
dissipated without affecting the occupant(s) to avoid serious injuries andor
death This was true in the 1950s and the 1960s and will continue to be
true in the 21st century as well
Speed Kills for this just reason
6 It appears that higher fuel economies and reduced
highway fatalities were the twin societal benefits of 55
mph adopted after 1973 If so the current attempts to
increase the speed limits appear to be in conflict with
other important societal objectives
Page 36 of 45
Table 1 Annual US Street amp Highway
Fatalities from 1957
Year
Fatalities
Vehicle Miles
(millions)
Rate100M Vehicle Miles
1957 38702 646915 598
1958 36981 664915 556
1959 37910 700478 541
1960 38137 718845 531
1961 38091 737535 516
1962 40804 766852 532
1963 43564 805423 541
1964 47700 846500 563
1965 49163 887640 554
1966 51524 927915 555
1967 51559 965132 534
1968 53831 1019726 528
1969 55032 1066108 516
1970 53672 1114098 482
1971 53761 1183524 454
1972 55704 1264614 440
1973 55113 1316207 419
1974 46078 1282790 359
1975 45500 1330074 342
1976 45523 1402380 325
1977 47878 1467027 326
1978 50331 1544704 326
1979 51103 1529133 334
1980 51091 1527295 335
1981 49301 1552803 317
1982 43945 1595010 276
1983 42589 1652788 258
1984 44257 1720269 257
1985 43795 1774179 247
Page 37 of 45
1986 46056 1835000 251
1987 46385 1921000 241
1988 47093 2026000 232
1989 45555 2107040 216
1990 44529 2147501 207
1991 41162 2172214 189
1992 39235 2239828 175
1993 40115 2296585 175
1994 40676 2359984 172
1995 41798 2422696 173
1996 41907 2485848 169
1997 41967 2560373 164
Data from Federal Highway Administration
Source httpwwwpublicpurposecomhwy-fatal57+htm
Telephone +16186328507 - Facsimile +16186328538
WENDELL COX CONSULTANCY P O Box 841 - Belleville IL 62269 USA
Page 38 of 45
Fatality data for 1921-1982 compiled by NHTSA
Year
VMT
(Millions)
VMT
(Billions)
Fatalities
Fatality rate
per 100 M VMT
1921 55027 5503 13253 241 1922 67697 6770 14859 219 1923 84995 8500 17870 210 1924 104838 10484 18400 176 1925 122346 12235 20771 170 1926 140735 14074 22194 158 1927 158453 15845 24470 154 1928 172856 17286 26557 154 1929 197720 19772 29592 150 1930 206320 20632 31204 151 1931 216151 21615 31963 148 1932 200517 20052 27979 140 1933 200642 20064 29746 148 1934 215563 21556 34240 159 1935 228568 22857 34494 151 1936 252128 25213 36126 143 1937 270110 27011 37819 140 1938 271177 27118 31083 115 1939 285402 28540 30895 108 1940 302188 30219 32914 109 1941 333612 33361 38142 114 1942 268224 26822 27007 101 1943 208192 20819 22727 109 1944 212713 21271 23165 109 1945 250173 25017 26785 107 1946 340880 34088 31874 94 1947 370894 37089 31193 84 1948 397957 39796 30775 77 1949 424461 42446 30246 71 1950 458246 45825 33186 72 1951 491093 49109 35309 72
1952 513581 51358 36088 70
Page 39 of 45
1953 544433 54443 36190 66 1954 561963 56196 33890 60 1955 605646 60565 36688 61 1956 627843 62784 37965 60 1957 647004 64700 36932 57 1958 664653 66465 35331 53 1959 700480 70048 36223 52 1960 718762 71876 36399 51 1961 737421 73742 36285 49 1962 766734 76673 38980 51 1963 805249 80525 41723 52 1964 846298 84630 45645 54 1965 887812 88781 47089 53 1966 925899 92590 50894 55 1967 964005 96401 50724 53 1968 1015869 101587 52725 52 1969 1061791 106179 53543 50 1970 1109724 110972 52627 47 1971 1178811 117881 52542 45 1972 1259786 125979 54589 43 1973 1313110 131311 54052 41 1974 1280544 128054 45196 35 1975 1327664 132766 44525 34 1976 1402380 140238 45523 32 1977 1467027 146703 47878 33 1978 1544704 154470 50331 33 1979 1529133 152913 51093 33 1980 1527295 152730 51091 33 1981 1555308 155531 49301 32 1982 1595010 159501 43945 28
Source Analysis of Significant Decline in Motor Vehicle Traffic Fatalities in
2008 httpwww-nrdnhtsadotgovPubs811346pdf see Table A1 page 31
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Page 40 of 45
Acknowledgements
The author is grateful for thoughtful comments provided by friends and colleagues
with whom this document was shared via email prior to it being uploaded as a
publicly available document for wider dissemination and study The comments
offered by Prof Subra Ganesan of Oakland University Electrical and Computer
Engineering Department are reproduced with permission in their entirety
About the author
The author obtained his Masterrsquos (S M) and Doctoral (Sc D) degrees in Materials Engineering
from the Massachusetts Institute of Technology Cambridge USA He then spent his entire
professional career at leading US research institutions (MIT NASA Case Western Reserve
University and General Motors R amp D Center in Warren MI) He holds four patents in advanced
materials processing has co-authored two books and has published several scientific papers in
leading peer-reviewed international journals His expertise includes developing simple
mathematical models to explain the behavior of complex systems He can be reached by email at
vlaxmananhotmailcom
Page 41 of 45
Please Buckle Up
httpwwwlakecountypublichealthorgindexphpbuckle-up-montana
Public Awareness
Respect the Cage Exhibit
The Department of Transportation hopes that showing the reality of the crash will reduce traffic
fatalities A crushed car crash dummies and a sobering message ndash all part of the ―Respect The
Cage exhibit that is traveling across Montana The exhibit sponsored by the Montana Department
of Transportation stopped in Ronan on November 6th and is aimed at raising awareness about the
importance of wearing seat belts
The car in the exhibit was in an actual wreck many years ago
the passenger in the vehicle died because he was not wearing a
seat belt the driver who was wearing his seat belt survived
Montanarsquos likeliest crash fatality scenario
A Pickup
A Rural road
And Seat belts that
arenrsquot used
Page 42 of 45
Occupants of pickups are less likely to wear seat belts and pickups are more likely to
roll over than passenger cars
Seat belts reduce the risk of death by 60 percent in pickups and SUVs
In Montana from 2006-2008 81 of those killed in a crash while riding in a pickup were not wearing seat belts
In Montana pickups make up 401 of the vehicle population
For more information on Respect the Cage click here
Page 43 of 45
Appendix 1
Lack of seat belts leading cause of Louisiana highway deaths
1251 AM May 28 2011 |
Written by Adam Duvernay
Crashes involving unbuckled motorists were the leading cause of highway fatalities
in Louisiana last year and cost $9888 million according to recent reports The
Louisiana Highway Safety Commission reported 59 percent of vehicle occupants
killed in Louisiana crashes last year mdash about one in four mdash werent wearing seat
belts
httpwwwshreveporttimescomarticle20110528NEWS01105280354Lack-seat-
belts-leading-cause-La-highway-deathsodyssey=tab|topnews|text|FRONTPAGE
Crash bull Stats Published by NHTSAlsquos National Center for Statistics and Analysis 1200 New Jersey Avenue SE Washington DC 20590
DOT HS 811 451
Early Estimate of Motor Vehicle Traffic Fatalities in 2010
httpwww-nrdnhtsadotgovPubs811451pdf
Summary
A statistical projection of traffic fatalities in 2010 shows that an estimated 32788
people died in motor vehicle traffic crashes This represents a decline of about 3
percent as compared to the 33808 fatalities in 2009 as shown in Table 1 If these
projections are realized fatalities will be lowest on record (since 1949)
Traffic Safety Facts Overview 2009 Data
httpwww-nrdnhtsadotgovPubs811392pdf
In 2009 33808 people were killed in the estimated 5505000 police-reported
motor vehicle traffic crashes 2217000 people were injured and 3957000
crashes involved property damage only Compared to 2008 this is a 10-
percent decrease in the number of fatalities and a 5-percent decrease in the
Page 44 of 45
number of police-reported motor vehicle traffic crashes people injured and
crashes involving property damage
An average of 93 people died each day in motor vehicle crashes in 2009 mdash
an average of one every 16 minutes
Traffic Safety Facts Overview 2008 Data
httpwww-nrdnhtsadotgovPubs811162pdf
In 2008 37261 people were killed in the estimated 5811000 police-reported
motor vehicle traffic crashes 2346000 people were injured and 4146000
crashes involved property damage only
Some comments and Feedback
The following comments were received from Prof Ganesan after his review of the
first draft of this document It was subsequently revised thanks to this input to
address some of the very important issues raised here
Dear Laxman
The write up is not enough
You are emphasizing that the speed limit reduces the fatal accidents (comparing 1966
to 2000 accident numbers)
Can you also add a few sentences why the number is decreasing from 1980 to 2000
values (May be due to better design of vehicles)
Can you say anything about the fuel consumption with the speed for any typical
vehicle in 2011 or 2010 (do not consider the fatalities issue)
Probably a speed between 55 and 60 mph gives a better mileage If so this is a
compelling reason to keep the speed limit low But cars probably can be tuned to
give better mileage at any high speed also
Page 45 of 45
Weather is also a major factor in fatal accidents Speed limit may be kept low during
winter and kept higher in summer Give your comments on this too
Driver distractions can cause more accidents Now cars have many multimedia and
internet features Automatic collision avoidance systems and sensors on the sides can
detect vehicles in the front and neighboring lanes and it can automatically decrease
speed even if the driver speeds at super high speeds
Give some comments on this too There is also Vehicle to Vehicle communications
vehicle to infrastructure communications and they can avoid collisions and accidents
Technology has changed from 1966 I cannot agree with you on the speed limit
without any discussion on the above and other factors
Have a great day
Subra Ganesan
Professor Subramaniam Ganesan
Director Real Time amp DSP Lab
Electrical and Computer Engineering Department
2200 Squirrel Road Dodge Hall Room 105
Oakland University Rochester MI 48309 USA
Phone 248 370 2206 Fax 248 370 4633
wwwsecsoaklandedu~ganesan
IEEE Distinguished Visiting Speaker (2005-2009) Coordinator
IEEE SEM CS chapter Chair Region 4 and CS Society Board member
SAE ASEE ACM member
Page 13 of 45
Figure 4 The most significant metric used by NHTSA is the fatality rate per 100
million vehicles miles traveled (VMT) This is now at a historical low of 113 for
2009 having declined year after year from 173 in 1994 The NHTSA however also
compiles other types of data on crashes There are three types of crashes fatal
injury but no death and property damage only A careful review of this crash data
for the period 1994-2009 reveals the obvious the lower the number of (fatal)
crashes x the lower the number of highway-accident-related fatalities y It is also
obvious that the number of fatalities per crash is greater than one ie more than one
person is being killed when one of more vehicles experience a crash
Clearly this is the single most important piece of information that one needs to
reduce the number of fatalities on our highways Vehicle design and engineering as
well as all other policy matters (legal political social environmental financial)
must be guided by this simple graph The best-fit line through the data derived using
simple linear regression has the equation y = hx + c = 114x ndash 10266 and is
Page 14 of 45
superimposed on to the data The design engineering goal and societal goal should
be to reduce the slope h of this statistically significant best-fit line to its ideal value of
h = 1 A fatal crash by definition is one where at least one person dies either an
occupant or a non-motorist in the path of the vehicle Hence the ideal slope h = 1
Photograph of an accident scene from the period 1955-1965
httpwwwcorinthsocialhistoryprojectorghtmlhighwaytollshtml
3 A Brief History of Traffic Safety Legislation
The following is extracted from the Wikipedia article on National Highway
Traffic Safety Administration (NHTSA)
httpenwikipediaorgwikiNational_Highway_Traffic_Safety_Administration
In 1965 and 1966 public pressure grew in the US to increase the safety of
cars The number of deaths on US highways were increasing year after year
Page 15 of 45
see Figure 1 and in 1966 Congress held a series of highly publicized
hearings on highway safety This led to the legislation for mandatory
installation of seat belts which also created the US Department of
Transportation (on Oct 15 1966)
httpwwwemsgovpdf2011EMSWeek2011_Stricklandpdf
The following is extracted from a Washington Post article on
NHTSA dated April 2 2002
httpwwwwashingtonpostcomwp-srvbusinessincludesnhtsa_primerhtm
In 1966 after decades of rising traffic fatalities (also vividly illustrated in
Figures 1 and 2 here) the publication of Ralph Naders Unsafe at Any
Speed and increasing public outcry for safer automobiles Congress held a
series of highly publicized hearings on creating a regulatory agency for traffic
safety Among the witnesses was William Haddon an epidemiologist who
introduced the idea that traffic accidents could be analyzed scientifically and
injuries reduced by changing auto design such as installing collapsible
steering columns safety glass head rests and seat belts
Congress passed the Highway Safety Act of 1966 creating the National
Highway Safety Bureau with Haddon as its first administrator The bureau
became NHTSA in 1970 under the newly established Department of
Transportation An early Nader convert Joan Claybrook headed NHTSA
under President Carter and now runs Naders organization Public Citizen
National Traffic and Motor Vehicle Safety Act
httpwwwanswerscomtopicnational-traffic-and-motor-vehicle-safety-act
Signed into law by President Lyndon Johnson on September 9 1966 this act
created the first mandatory federal safety standards for motor vehicles The
act was motivated by a variety of factors First and foremost the public was
growing increasingly concerned over the rising number of traffic fatalities on
the nations roads Such fatalities had increased by nearly 30 percent
between 1960 and 1965 and experts forecasted 100000 such deaths
Page 16 of 45
annually by 1975 unless something was done to improve traffic safety
Adding fuel to the fire Ralph Naders Unsafe at Any Speed published in
November 1965 criticized the automobile industry for neglecting safety in
favor of power and styling when designing new vehicles
4 The reason for the historical
decrease in highway fatalities
A recent news item see link given below regarding renewed attempts to
increase the speed limit by many states prompted this write up by the
present author who has studied traffic fatality data extensively and analyzed
them very carefully over the last several years
httpmoneymsncomauto-insurancewhy-speed-limits-are-
risingaspxGT1=33033
Residents of Metro Detroit area who frequently cross into Ohio from
Michigan notice that the speed limit has now increased in Ohio The speed
limit on Michigan highways was increased to 70 mph in the late 1990s but
Ohio retained its lower speed limit for many years leading Michigan drivers to
experience a ―speed trap of sorts The speed limit is also increasing in many
other states notably Texas where it is proposed to increase it to 85 mph at
least in West Texas
Historically speaking from a traffic fatality standpoint we must consider two
important dates 1966 and 1973 Only 1973 the year of the Arab oil embargo
following the Arab-Israeli war (that led to what President Obama has recently
called the pre-1967 border for Middle East peace) is mentioned in the above
article It fails to mention the significance of the year 1966
Prior to 1966 there was actually NO speed limit in many Western states and
deaths due to highway accidents were increasing year after year The
Page 17 of 45
number of highway fatalities went up from 38702 in 1957 to 51524 in 1965
a 33 increase over the 1957 level and an additional 12822 deaths in 1965
compared to 1957 It was this carnage on the US highways that forced
Congress to hold its hearings on highway traffic fatalities in 1966
Nonetheless a careful examination of the fatality data in Table 1 shows that
notwithstanding the highly publicized Congressional hearings of 1966 and
new safety legislation that was enacted the absolute number of fatalities
continued to increase after 1966 and only started decreasing after 1973
Vehicle designs especially the introduction of safety features (even the
simplest like safety belts) did not change significantly between 1966 and
1973 Nonetheless post-1973 we begin to see a dramatic turnaround
Why
After the 1973 Arab oil embargo a nationwide maximum speed limit (NMSL)
of 55 mph was imposed and accepted in the USA (effective Jan 1 1974)
during the Nixon administration primarily as an effort to conserve fuel and
reduce the US vulnerability to oil imports The unintended and indeed
fortunate consequence of this reduced speed limit was the immediate
reduction in the fatalities revealed in Figures 2 and 3 This is the real reason
for the peaks in highway fatalities observed in these two graphs
The Congressional hearings of 1966 did eventually have an impact but it was
a delayed one The impact of the 1973 nationwide speed limit of 55 mph was
however immediate as we see from the magnified plot of the same data in
Figure 5 and a closer examination of the raw fatality data in Table 1
The number of highway-accident-related fatalities decreased immediately
from a high of 55704 in 1972 to just 46078 in 1974 a 173 drop see
arrows There were 9626 fewer deaths annually even with a slight increase
in the vehicle miles driven (see Table 1) Indeed the number of highway
death reached its absolute peak value in 1972 never to be seen again
Fatalities have been decreasing every since with slight fluctuations about
each new low value
Page 18 of 45
Figure 5 Expanded view of the fatality data showing the immediate impact of the
national speed limit of 55 mph following the Arab oil embargo of 1973 Note that
fatalities continued to rise between 1966 and 1973 in spite of the highly publicized
Congressional hearings in 1966 and the traffic safety legislation enacted soon after
Each new low is probably associated with vehicle safety innovations and the
improvements in vehicle design and engineering The combined beneficial
effect of improved vehicle designs primarily the introduction of seat belts
and the laws enforcing usage of seat belts aided by the reduced speed
limits contributed to the continued decline in the absolute number of fatalities
that started since 1973 and has continued to this day The subsequent
introduction of other safety features notably air bags has contributed to a
further reduction in highway fatalities
Page 19 of 45
State police Trooper First Class Jeffrey Flowers looking at a car in which a Boswell
Pennsylvania woman was injured Tuesday (May 31 2011) The accident occurred at
an intersection when a truck (seen behind the wrecked car) entered this accident
prone intersection (part of a highway safety corridor where signs are posted to
reduce unsafe driver behavior) There have been four accidents at this intersection
since 2006 none fatal httpwwwdailyamericancomnewssomersetda-ot-woman-
injured-in-route-30-wreck-2011053104165420story
5 Numerical calculations of decline in
fatalities and the impact of NMSL post-1973
Letlsquos consider the decline in fatalities between 1972 the last year before the
adoption of the NMSL and 1974 the first year following its adoption after the
Arab oil embargo There was an immediate decrease in the number of
fatalities by 9393 ie y = -9393 with a slight increase in the VMT ie x
= 20758 millions The NHTSA data used here may be found in the table at
the end of this document The numerical value of the rate of change per
billion VMT (ie neglecting the sign) was therefore
yx = 4525 fatalitiesbillion VMT (1972-1974)
Page 20 of 45
It is instructive to compare this rate of change in fatalities with similar short
periods of a decline in fatalities in the pre-1973 era when speed limits were
much higher The absolute number of fatalities declined over a relatively
short period with both an increase and a decrease in VMT The results are
given below and are self-explanatory
yx = 454 fatalitiesbillion VMT (1953-54) decline with increase in VMT
yx = 655 fatalitiesbillion VMT (1942-43) decline with decrease in VMT
yx = 1739 fatalitiesbillion VMT (1941-42) decline with decrease in VMT
yx = 4528 fatalitiesbillion VMT (1937-39) decline with increase in VMT
yx = 2548 fatalitiesbillion VMT (1931-32) decline with decrease in VMT
The rate of decline observed between 1953 and 1954 with an increase in
VMT was just one-tenth of that observed following the adoption of the 55
mph speed limit The war years (1941-43 WWII) and the Great Depression
era (1931-32) were accompanied by big declines in fatalities with decreasing
VMT but the rate of change was still significantly lower than observed after
the adoption of the NMSL
The only apparently inexplicable decline is that between 1937 and 1939
where a nearly identical high rate of decline was observed Notice also the
big drop in the traditional fatality rate between 1937 and 1938 This large drop
appears to coincide with the creation of the National Safety Council (NSC) by
William H Cameron in June 1937 (see link below) with its far-flung campaign
of education legislation research highway engineering and traffic training
undertaken by the NSC and some two dozen other groups with the backing of the
automotive industry through its Automotive Safety Foundation Other factors
unknown to the present author probably also played a role
httpwwwtimecomtimemagazinearticle0917188379700htmlixzz1O2G
7rnUg
Page 21 of 45
These simple computations here however reveal the significant effect of
reduced speed limits on highway fatalities much more so than other factors
6 Further Considerations Pros and Cons
The singular effect of increased speeds (or speeding) on highway fatalities
has been studied and demonstrated by a number of industry sources such
as the Insurance Institute for Highway Safety (IIHS) Consumers Union and
also by government researchers
httpwwwsmartmotoristcomtraffic-and-safety-guidelineexcessive-speed-is-
a-factor-in-one-third-of-all-fatal-crasheshtml
httpwwwconsumersunionorgotherspeedlimitsspeed031500a2htm
Speed ndash defined as exceeding the posted speed limit or driving too fast for
given conditions ndash is a factor in nearly one-third of all fatal crashes Besides
fatality in 1998 nearly 40000 people were critically injured in speed-related
crashes and nearly 72000 were moderately injured
The salutary and immediate beneficial effect of the nationwide 55 mph speed
limit has been noted by other researchers (see Susan Ferguson link below)
httpwwwnhtsagovpeopleinjuryenforcespeed_forum_presentationsfergu
sonpdf
After a partial repeal of this law in 1987 which granted states the authority to
increase speed limit (especially in rural interstates) a 1989 study showed a
15 increase in fatalities in rural interstates and a 5 increase in non-rural
interstates Unfortunately such studies often tend to be discounted by
advocates of increasing the speed limits as being produced by biased
industry sources
Similar conclusions were also presented by NHTSA in February 1998 in its
report to the Congress entitled ―Report to Congress The Effect of Increased
Speed Limits in the Post-NMSL Era see link given below Among its key
Page 22 of 45
findings is the following quoted in its entirety NMSL refers to the National
Maximum Speed Limit legislated after the Arab oil embargo of 1973
httpwww-nrdnhtsadotgovPubs808-637PDF
hellip Nevertheless it is important to note that data currently available from the
National Highway Traffic Safety Administrationrsquos (NHTSA) Fatality Analysis
Reporting System (FARS) shows that states that increased speed limits in 1996
experienced approximately 350 more Interstate fatalities than would have been
expected based on historical trends -- about 9 percent above expectations
Concurrently the Interstate fatalities experienced in states that did not increase speed
limits in 1996 was consistent with pre-1996 trends The estimated increase in
Interstate fatalities found in this study while smaller in magnitude compared to the
estimated change in fatalities found in 1987 following the increase of speed limits on
rural Interstates does follow the historical pattern of increases in fatalities being
associated with increases in posted speed limits
The annual crash reports compiled by NHTSA see Table 3 indicate that the
number of fatal crashes (and hence fatalities using the regression equation
developed in Figure 4) increase as the posted speed limits increase
Page 23 of 45
Table 3 Posted speed limits and number of crashes
Speed Limit Crashes (2008) Crashes (2009)
30 mph or less 3705 3277 35 or 40 mph 6115 5516 45 or 50 mph 6461 6074
55 mph 9794 8847 60 mph or higher 6908 6124
Total 34017 30797
Source httpwww-nrdnhtsadotgovPubs811402EEpdf
61 Studies cited in favor of lower speed limits
A detailed analysis of speeding related fatalities (see link below) by NHTSA
shows that a third of all crashes involve speeding ie at least one driver was
speeding
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Furthermore the above report which covers the period 1983-2002
indicates that immediately after the NMSL was completely abolished in
December 1995 the number of speeding related fatalities at speeds
above 65 mph increased from just 15 in 1995 to a 677 in 1996 (see Table
62 on page 43 of above report) It continued to increase in the years
since climbing to 930 in 2000
More detailed studies similar to that noted above by researchers at the
University of Illinois Chicago led by Lee S Friedman again lead to the
conclusion that higher speed limits lead to an increase in the number of
fatalities (see American Journal of Public Health online July 16 2009)
httphealthusnewscomhealth-newsmanaging-your-
healthcarearticles20090716deaths-injuries-increase-with-higher-speed-
limits
Page 24 of 45
httpwwwmedpagetodaycomPublicHealthPolicyPublicHealth15122
httpwwwamericaneercomspeed-limits
httpwwwactuarialoutpostcomactuarial_discussion_forumarchiveindexph
pt-171870html
For the study period 1995-2005 these researchers found that 12545 deaths
and 36582 injuries could be attributed to the increased speed limits The
benefits of reduced speed limits are stated quite eloquently by Dr Friedman
and are reproduced below (from above news article see link)
Reduced speed limits would save lives Friedman said They would also reduce
gas consumption cut emissions of air pollutants save valuable years of productivity
(lost due to injuries)and reduce the societal cost of motor vehicle crashes (due to
both fatal crashes and due to nonfatal and severe life-changing injuries) he added
Friedman and coworkers have also shown that increasing the speed limit led
to an immediate increase in the number of fatalities on Israeli roadways (see
link below)
httpinjurypreventionbmjcomcontent133156
The effect of speeding is very significant especially in rural areas resulting
in significantly higher fatalities Fatality rates are frequently double or triple
that in urban areas (see link below)
httpsafetyfhwadotgovspeedmgtdata_factsdocsspeeding_ruralpdf
As of Jan 1 2005 five Midwestern states had increased the speed limits to
above 65 mph (Illinois Iowa Kansas Minnesota Missouri Nebraska and
South Dakota) whereas three (Illinois Iowa and Wisconsin) had not All the
five states with increased speed limits showed a 7 to 13 increase in
fatalities The NHTSA study considered an eight year period before and after
the change in Dec 1995 (see Table 1 in link below) The collective experience
of the states that did NOT increase the speed limit was a 7 decline in
fatalities (see Table 2 of link below)
httpwwwiowadotgovmvdodsstats2006speedstudypdf
Page 25 of 45
Moreover Table 5 in the above study shows the effect of imposing the NMSL
of 55 mph in Iowa and its repeal in 1995 Considering a four-year average
before 1974 when the speed limit was 75 mph there were 35 fatal crashes
with 43 fatalities In the first four years after the 55 mph there were only 23
fatal crashes and 28 fatalities In the last four years before the repeal of 55
mph in 1995 there was a further decline to 14 fatal crashes with 17 fatalities
The Iowa fatality data will be discussed in more detail separately (in a later report)
since it provides the opportunity to assess the effect of a change in the speed limit
on the relationship between number of fatalities and fatal crashes (as seen in
Figure 4 for the US as a whole)
North of the US border Canadians seem to be citing the ―shocking increase
in highway fatalities in the US states where the speed limits were raised to
curb their own speed limits
httparchivesafety-councilorginfotrafficspeed-02html
httparchivesafety-councilorginfotrafficspeedhtml
Speed kills but speed also sells notes the second of the above news items
Manufacturers are producing more high performance cars (with higher horse
power to weight ratio) and ads feature enticing cars that race and swerve in
miraculous ways on empty roads These subliminal messages encourage
drivers especially young drivers to break the speed limit leading to the
absolute increase in highway fatalities (although the rate itself is going
down) The article emphasizes the need to enforce the speed limit on
Canadian highways and in cities where street racing is becoming a problem
62 Studies cited by opponents of lower speed limits
In fairness to quote the opponents on the other side of this debate Montana
reverted back to Reasonable and Prudent speed limits when the National
Maximum Speed Limit was repealed in 1995 and appears to have
experienced no significant increase in fatalities
Page 26 of 45
httpwwwhwysafetycomhwy_montanahtm
httpwwwmotoristsorgpressmontana-no-speed-limit-safety-paradox
httpwwwsouthbayriderscomforumsshowthreadphpt=81453amppage=1
Likewise studies in the state of Maryland showed no significant increase in
highway fatalities when the speed limit was increased from 55 mph to 75
mph The reason might simply be that drivers were already speeding much
more so when the speed limit was 55 mph than after the increase to 75 mph
In other words the fatalities data already reflects the effect of higher speeds
(not speed limits) on the number of fatalities
In Utah the experimental increase in the speed limit to 80 mph was
considered to be a success in terms of safety
httpautosaolcomarticleutah-speed-limit-tests
The UDOT Director noted that there was no increase in the number of
accidents on Interstate 15 But what happens in the event of an accident
when the speed limits are higher and drivers are driving at higher speeds and
two objects collide at this higher speed However no increase in the number
of accidents is not the same as no increase in fatalities due to the higher
speeds When accidents do occur do fatalities increase
Likewise in California when the speed limit went up from 55 mph to 65
mph in 1995 (after repeal of NMSL) fewer deaths were reported in 1998
compared to the peak year of 1979 or even 1987 Again the explanation
seems to be that motorists were already speeding when the limit was 55 mph
and that increasing the speed limit did not change driver behavior in any
significant way
httparticlessfgatecom1998-11-02news17735730_1_speed-limits-mph-
limit-death-rate
The National Motorists Association (NMA) a group which advocates higher
speed limits emphasizes the importance of considering fatality rates as
opposed to the raw fatalities The argument used is that fatality rates based
on the fatality per 100 million VMT is the legitimate way to look at the data
Page 27 of 45
This is a never ending debate Historically speaking fatality rates have been
going down ever since the compilation of traffic accidents data began Table
A1 in the appendix of a recent report by NHTSA (see link below) has highway
fatality rate data going back 1921
httpwww-nrdnhtsadotgovPubs811346pdf see appendix page 31
httpwwwmotoristsorgspeed-limitstruth
httpwwwmotoristsorgothercrash-data
httpwwwraisethespeedlimitorgmythshtml
httpwwwcatoorgpubspaspa346pdf
According to Stephen Moore of the Cato Institute (see last of the links above)
―All measures of highway safety show improvement not more deaths and
injuries since 1995 Despite the fact that 33 states raised their speed limits
immediately after the repeal of the mandatory federal speed limit the NHTSA
reported last October that the traffic death rate dropped to a record low level
in 1997lsquo Moreover the average fatality rate even fell in the states that raised
their speed limits
63 The Fatality rate Is it a reliable metric
In 1921 with fewer fatalities and fewer miles driven and the first year for
which the fatality rate could be computed the rate was 2408 It was down to
1479 in 1931 but the number of deaths had climbed to 31963 more than
double the 1921 absolute fatality number of 13253 It had dropped to 550 in
1966 the year of the highly publicized Congressional hearings but the
number of fatalities had climbed to 50984 in that fateful The Highway Safety
Act of 1966 ranks as one of the major acts of Congress and President
Johnson signed it saying that ―we have been tolerating a raging epidemic of
highway deathshellip see extract pasted below
httpwwwenotescommajor-acts-congresshighway-safety-act
Page 28 of 45
The act was motivated primarily by growing public concern over the rising number
of traffic fatalities in the United States Between 1960 and 1965 the annual number
of traffic fatalities increased by nearly thirty percent As President Lyndon B
Johnson stated at the signing of the act on September 9 1966 we have tolerated
a raging epidemic of highway death which has killed more of our youth than all
other diseases combined Through the Highway Safety Act we are going to find out
more about highway diseasemdashand we aim to cure it
Nonetheless highways fatalities continued to increase until the Arab oil
embargo of 1973 led to the NMSL of 55 mph all across the USA Do we just
ignore this undeniable historical record and focus only on the declining fatality
rate as the NMA and other proponents of higher speed limits seem to argue
(see links above)
The misleading nature of using fatality rates (per 100 M VMT) alone is also
obvious if one considers fatality data for individual states Take for example
the state of Montana which seems to have experienced no increase in
fatalities after repeal of NMSL
httpwww-nrdnhtsadotgovdepartmentsnrd-
30ncsaSTSI30_MT200930_MT_2009htm
For the period 2005-2009 the absolute number of fatalities for Montana
varied between a high of 277 in 2007 to a low of 229 in 2009 The fatality
rates per 100 M VMT on the other hand varied from a high of 245 for 2007
to a low of 201 for 2009 The corresponding US fatality rates varied from
136 to 114 Is the higher number for the fatality rate for Montana compared
to USA good or bad Likewise fatality rate per 100000 of population was
much higher for Montana than the US as a whole
This again highlights the pitfalls of using simple ratios to assess fatality statistics
without a full analysis of the underlying trends We will discuss this point
separately
As shown already the continuous decline in the fatality rate is a mathematical
artifact and essentially overlooks the unmistakable positive correlation
between the variables x and y of the type y = hx + c which becomes obvious
Page 29 of 45
only when we prepare the x-y scatter graph The ratio yx = h + (cx) can
decrease with increasing x (VMT) and increasing y (fatalities) since the
intercept c has a positive value when we consider only data spanning a short
period (such as 1994-2009 of more relevance to the current situation)
The debate between fatality rates and absolute number of fatalities is an
unending one A few years ago the Wall Street Journal carried an article
which was entitled (or something close) ―Unemployments rate in Ohio are
going down but why is the number of unemployed increasing The reason is
the same The graph of the number of unemployed (y) versus the number in
the labor market (x) is linear with a positive slope h and a positive intercept c
So the unemployment rate computed using the ratio yx keeps going down
year after year although the number unemployed keeps increasing Is it a
good thing that the unemployment rate is going down when more people
seem to be unable to find gainful unemployment
Or consider the situation with cancer death rates This too has been going
down in recent years but the actual number of cancer-related deaths has not
declined in any significant way Is it good that cancer death rates are going
down In all these situations the researchers or the socio-econo-politico
analysts involved in analyzing the trends in the data have failed to consider
the underlying x-y relation describing each problem
Hence it appears that the debate on the effect of increased speed limits
should not be focused on only the fatality rates (which have been decreasing
and proponents of higher speed limits cite this in their arguments) or even the
absolute number of fatalities (which has been the focus here) but on the
relationship between speed and the number of fatal crashes and the number
of fatalities within each speed segment (see Table 3 and also Figure 4)
Unfortunately details of number of fatalities and the number of fatal crashes
at each speed limit are not available even from NHTSA for detailed study
When a crash does occur (it is immaterial how many miles were driven) the
speed of the driver and vehicle design and engineering including safety
devices in place (seat belts airbags other impact absorbing technologies)
Page 30 of 45
determine if the occupants(s) will be killed One cannot argue that speed
does NOT kill That would be an absolute denial of the laws of physics
Studies show that setting the speed limit at the 85th percentile in any given
zone (this is the speed at or below which 85 of drivers are observed to
travel in traffic engineering studies) is the safest speed limit The majority of
drivers try to obey the posted speed limit while a few choose to drive at a
speed they consider is safe and prudent These are also perhaps the most
vociferous advocates of higher speed limits It is this tension caused due to
differences in speeds that leads to tailgating improper passing reckless
driving weaving from lane to lane and ultimately crashes and deaths in some
unfortunate cases
httpblogmotoristsorgspeed-limits-slower-safer
MARK TAYLOR
ANOTHER LOST A man was killed when his 4WD drive hit a tree east of Morrinsville (in New
Zealand) on Monday May 30 2011 The driver lost control of the vehicle on a bend probably tried
to correct his mistake and put the car into a ―yaw causing it to leave the road and smash sideways
into a tree Alerts to slow down had been posted since this was a high accident area but the driver
probably did not pay attention
64 Other factors
Many other factors besides speed no doubt affect highway fatalities The
vehicles of the 21st century are very different from the vehicles of the mid 20th
Page 31 of 45
century Technological innovations such as improvements in vehicle design
and engineering have greatly increased crash worthiness of vehicles even at
high speeds Environmental factors such as the weather also contribute to
accidents but not necessarily to increased fatalities Drivers actually tend to
slow down instinctively during adverse weather conditions (rain snow storms
etc) and although such weather may contribute to increased accidents the
lower speeds actually reduce fatalities
Yes technology has changed fundamentally from 1966 Drivers today are
more distracted by their cellmobile phone conversations (and also built-in
phones in luxury models) and text messaging than the drivers of the pre-1966
era High end cars now have many multimedia and internet features Again a
careful observation (even personal experience by the author) suggests that
such distracted drivers actually tend to (instinctively) drive more slowly and
hold up the traffic Perhaps such behavior leads to an increase in the number
of accidents but it does not necessarily lead to an increase in the number of
accident-related fatalities
Much talked about technological innovations such as automatic collision
avoidance systems and sensors (on the sides of vehicles) can indeed detect
vehicles in the front and neighboring lanes Furthermore vehicle-to-vehicle
communication systems vehicle-to-infrastructure communication systems
can no doubt avoid collisions and accidents Again such collision avoidance
systems work and are effective entirely because they automatically reduce
vehicle speeds - even if one of the offending vehicles is being at a super
high speed Also it must be remembered that such futuristic systems have
not yet been implemented widely nor can they be implemented widely since
the large majority of vehicles on the road are NOT luxury models Advanced
safety features come with a price and not all drivers can afford to pay that
price and ―buy that ―additional safety
Ultimately it is the laws of physics that govern what will happen when two or
more vehicles collide or even when a single vehicle collides with a stationary
infrastructural object (a bridge a wall a building or some impediment on the
road) The lower the number of crashes the lower the number of fatalities as
revealed by the 1994-2009 data graphed in Figure 5 The higher the speed of
Page 32 of 45
the object or objects that are involved in a collision the higher the kinetic
energy K that must be absorbed andor dissipated Increasing the posted
speed limit only increases the energy that must be absorbed when a crash
does occur This ultimately is the most important criterion determining the
number of fatalities
The kinetic energy increases as the square of the speed being given by the
well-known formula K = frac12 mv2 where m is the mass of the vehicle (in
laypersonlsquos language m increases directly with vehicle weight) and v is the
speed For the same vehicle mass an increase in the speed from 55 mph to
85 mph increases the kinetic energy K by a factor of 239 or roughly a 250
increase in the kinetic energy that must be absorbed in a collision
Ideally speaking the kinetic energy of the colliding object(s) is absorbed by
the vehicle infrastructure (a sturdy space frame the engine other vehicle
components etc) andor the surroundings However in the unfortunate
cases where this kinetic energy must be absorbed by the vehicle occupant(s)
the result is severe life-altering injuries andor death An unequivocal
relationship between an increase in vehicle speeds and fatal accidents can
be demonstrated by a careful examination of available traffic fatality data
This is a more involved discussion and is not the purpose of this short
communication These topics are no doubt very politically charged with many
social legal and financial implications with each interest group favoring a
different conclusion Nonetheless we cannot escape the laws of physics as
they govern the fundamental need to absorb higher and higher values of the
kinetic energy K with increasing vehicle speeds This same point is also
emphasized by Dr Friedman of the University of Illinois Chicago (see earlier
discussion)
Speed kills because of these energy transfer considerations and there can be
no doubt about it
Innovative 21st century solutions to speed management on the highways
such as strict enforcement of speed limits minimizing speed dispersion
(difference between speeds at which different drivers travel) while using
cameras to track the 15 of drivers who willfully violate the speed limit and
Page 33 of 45
create hazardous driving conditions is certainly recommended (Recall that
the optimum recommended speed limit is at or below which 85 of all drivers
travel ndash a policy also supported by NMA) Even on this score however the
results are confounding if we consider the Australian experience
httpwwwthenewspapercomnews282840asp
Up until 2007 there was no speed limit in the Northern Territory of
Australia Imposing a speed limit 130 kmph (80 mph) on some areas and
110 kmph (68 mph) in some others actually increased the number of deaths
The death toll in 2006 when there was no speed limit in this region was 44
and went up to 75 in 2009 see data table in link below
httpwwwthenewspapercomrlcdocs2009au-ntroadtollpdf
Furthermore it appears that installation of cameras to enforce speed limits
has proved to be a hazardous distraction to drivers and deaths actually
began to skyrocket between 2005 and 2007 in all Australian roadways
The main purpose here is to sound a cautionary note amid renewed attempts
in many states across the US to increase the speed limits on our highways by
calling attention to the historical facts regarding the ―epidemic levels of
highway traffic fatalities that engaged our national attention in the fateful year
of 1966 The graphical representation of the traffic fatality data in Figures 1
to 5 tells its own story
Indeed it would be tragic if highway-accident-related fatalities were to start
increasing once again and reach the historically high level that was last seen
in 1972 the year before the Arab oil embargo of 1973
Page 34 of 45
Conclusions
1 The graphical representation of the highway fatality data and the brief
summary of the historical facts of traffic safety legislation suggest that
recent attempts to increase the speed limits by various states (notably
Texas) may be misguided The distinct peak in the highway fatalities
observed in these graphs is highly alarming This appears to be related to
the enactment of the National Maximum Speed Limit (NSML) in 1974
following the 1973 Arab oil embargo Although NSML was motivated by a
desire to reduce gasoline consumption an unintended benefit might have
been a dramatic reduction in fatalities The fundamental reasons for the
peak in the fatalities-VMT curve must be examined carefully without
political posturing
2 The widely used fatality rate fatalities per 100 M vehicle miles traveled
has been declining since 1921 the first year for which a fatality rate could
be computed and has now reached a historical low The absolute number
of fatalities on the other hand was increasing in the 1950s and 1960s at
an alarming rate and the public outcry that ensued led to the highly
publicized Congressional hearing of 1966 and the subsequent traffic safety
legislations The fatality rate has been decreasing even in the most recent
15-year period (1994-2009) again with increasing fatalities although less
dramatically Thus it appears that fatality rate calculation based on vehicle
miles traveled (VMT) might not be a reliable indicator of the underlying
dynamics in the fatality trends
3 More detailed compilation of number of fatalities and the number of fatal
crashes within each speed limit segment is required to better understand
the effect of increasing speed limits on highway fatalities (and also fatality
rates) Such data is already available and is being compiled at the local
city and county levels in all jurisdictions and only needs to be reorganized
to highlight the effect of (posted) speed limits on the number of crashes
and fatalities This will require some minor rewriting and revisions to the
chapters named ―Crashes and ―States in the annual NHTSA reports
Page 35 of 45
Analysis of the fatalities-crashes data for several years with various
speed limits will be more revealing and meaningful than the current
fatality rates analysis and will be discussed separately in a follow up
report
4 One should not be lulled by the fact that vehicles of the 21st century are
now equipped with advanced safety features not available in the 1950s
and the 1960s In spite of these safety features the laws of physics dictate
that the higher the speed the higher kinetic energy of the colliding objects
and hence the greater the risk indeed near certainty of fatalities in a
higher speed collision compared to a lower speed one
5 The higher the speed at which the vehicle that is involved in a crash is
traveling the higher the kinetic energy that must be absorbed andor
dissipated without affecting the occupant(s) to avoid serious injuries andor
death This was true in the 1950s and the 1960s and will continue to be
true in the 21st century as well
Speed Kills for this just reason
6 It appears that higher fuel economies and reduced
highway fatalities were the twin societal benefits of 55
mph adopted after 1973 If so the current attempts to
increase the speed limits appear to be in conflict with
other important societal objectives
Page 36 of 45
Table 1 Annual US Street amp Highway
Fatalities from 1957
Year
Fatalities
Vehicle Miles
(millions)
Rate100M Vehicle Miles
1957 38702 646915 598
1958 36981 664915 556
1959 37910 700478 541
1960 38137 718845 531
1961 38091 737535 516
1962 40804 766852 532
1963 43564 805423 541
1964 47700 846500 563
1965 49163 887640 554
1966 51524 927915 555
1967 51559 965132 534
1968 53831 1019726 528
1969 55032 1066108 516
1970 53672 1114098 482
1971 53761 1183524 454
1972 55704 1264614 440
1973 55113 1316207 419
1974 46078 1282790 359
1975 45500 1330074 342
1976 45523 1402380 325
1977 47878 1467027 326
1978 50331 1544704 326
1979 51103 1529133 334
1980 51091 1527295 335
1981 49301 1552803 317
1982 43945 1595010 276
1983 42589 1652788 258
1984 44257 1720269 257
1985 43795 1774179 247
Page 37 of 45
1986 46056 1835000 251
1987 46385 1921000 241
1988 47093 2026000 232
1989 45555 2107040 216
1990 44529 2147501 207
1991 41162 2172214 189
1992 39235 2239828 175
1993 40115 2296585 175
1994 40676 2359984 172
1995 41798 2422696 173
1996 41907 2485848 169
1997 41967 2560373 164
Data from Federal Highway Administration
Source httpwwwpublicpurposecomhwy-fatal57+htm
Telephone +16186328507 - Facsimile +16186328538
WENDELL COX CONSULTANCY P O Box 841 - Belleville IL 62269 USA
Page 38 of 45
Fatality data for 1921-1982 compiled by NHTSA
Year
VMT
(Millions)
VMT
(Billions)
Fatalities
Fatality rate
per 100 M VMT
1921 55027 5503 13253 241 1922 67697 6770 14859 219 1923 84995 8500 17870 210 1924 104838 10484 18400 176 1925 122346 12235 20771 170 1926 140735 14074 22194 158 1927 158453 15845 24470 154 1928 172856 17286 26557 154 1929 197720 19772 29592 150 1930 206320 20632 31204 151 1931 216151 21615 31963 148 1932 200517 20052 27979 140 1933 200642 20064 29746 148 1934 215563 21556 34240 159 1935 228568 22857 34494 151 1936 252128 25213 36126 143 1937 270110 27011 37819 140 1938 271177 27118 31083 115 1939 285402 28540 30895 108 1940 302188 30219 32914 109 1941 333612 33361 38142 114 1942 268224 26822 27007 101 1943 208192 20819 22727 109 1944 212713 21271 23165 109 1945 250173 25017 26785 107 1946 340880 34088 31874 94 1947 370894 37089 31193 84 1948 397957 39796 30775 77 1949 424461 42446 30246 71 1950 458246 45825 33186 72 1951 491093 49109 35309 72
1952 513581 51358 36088 70
Page 39 of 45
1953 544433 54443 36190 66 1954 561963 56196 33890 60 1955 605646 60565 36688 61 1956 627843 62784 37965 60 1957 647004 64700 36932 57 1958 664653 66465 35331 53 1959 700480 70048 36223 52 1960 718762 71876 36399 51 1961 737421 73742 36285 49 1962 766734 76673 38980 51 1963 805249 80525 41723 52 1964 846298 84630 45645 54 1965 887812 88781 47089 53 1966 925899 92590 50894 55 1967 964005 96401 50724 53 1968 1015869 101587 52725 52 1969 1061791 106179 53543 50 1970 1109724 110972 52627 47 1971 1178811 117881 52542 45 1972 1259786 125979 54589 43 1973 1313110 131311 54052 41 1974 1280544 128054 45196 35 1975 1327664 132766 44525 34 1976 1402380 140238 45523 32 1977 1467027 146703 47878 33 1978 1544704 154470 50331 33 1979 1529133 152913 51093 33 1980 1527295 152730 51091 33 1981 1555308 155531 49301 32 1982 1595010 159501 43945 28
Source Analysis of Significant Decline in Motor Vehicle Traffic Fatalities in
2008 httpwww-nrdnhtsadotgovPubs811346pdf see Table A1 page 31
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Page 40 of 45
Acknowledgements
The author is grateful for thoughtful comments provided by friends and colleagues
with whom this document was shared via email prior to it being uploaded as a
publicly available document for wider dissemination and study The comments
offered by Prof Subra Ganesan of Oakland University Electrical and Computer
Engineering Department are reproduced with permission in their entirety
About the author
The author obtained his Masterrsquos (S M) and Doctoral (Sc D) degrees in Materials Engineering
from the Massachusetts Institute of Technology Cambridge USA He then spent his entire
professional career at leading US research institutions (MIT NASA Case Western Reserve
University and General Motors R amp D Center in Warren MI) He holds four patents in advanced
materials processing has co-authored two books and has published several scientific papers in
leading peer-reviewed international journals His expertise includes developing simple
mathematical models to explain the behavior of complex systems He can be reached by email at
vlaxmananhotmailcom
Page 41 of 45
Please Buckle Up
httpwwwlakecountypublichealthorgindexphpbuckle-up-montana
Public Awareness
Respect the Cage Exhibit
The Department of Transportation hopes that showing the reality of the crash will reduce traffic
fatalities A crushed car crash dummies and a sobering message ndash all part of the ―Respect The
Cage exhibit that is traveling across Montana The exhibit sponsored by the Montana Department
of Transportation stopped in Ronan on November 6th and is aimed at raising awareness about the
importance of wearing seat belts
The car in the exhibit was in an actual wreck many years ago
the passenger in the vehicle died because he was not wearing a
seat belt the driver who was wearing his seat belt survived
Montanarsquos likeliest crash fatality scenario
A Pickup
A Rural road
And Seat belts that
arenrsquot used
Page 42 of 45
Occupants of pickups are less likely to wear seat belts and pickups are more likely to
roll over than passenger cars
Seat belts reduce the risk of death by 60 percent in pickups and SUVs
In Montana from 2006-2008 81 of those killed in a crash while riding in a pickup were not wearing seat belts
In Montana pickups make up 401 of the vehicle population
For more information on Respect the Cage click here
Page 43 of 45
Appendix 1
Lack of seat belts leading cause of Louisiana highway deaths
1251 AM May 28 2011 |
Written by Adam Duvernay
Crashes involving unbuckled motorists were the leading cause of highway fatalities
in Louisiana last year and cost $9888 million according to recent reports The
Louisiana Highway Safety Commission reported 59 percent of vehicle occupants
killed in Louisiana crashes last year mdash about one in four mdash werent wearing seat
belts
httpwwwshreveporttimescomarticle20110528NEWS01105280354Lack-seat-
belts-leading-cause-La-highway-deathsodyssey=tab|topnews|text|FRONTPAGE
Crash bull Stats Published by NHTSAlsquos National Center for Statistics and Analysis 1200 New Jersey Avenue SE Washington DC 20590
DOT HS 811 451
Early Estimate of Motor Vehicle Traffic Fatalities in 2010
httpwww-nrdnhtsadotgovPubs811451pdf
Summary
A statistical projection of traffic fatalities in 2010 shows that an estimated 32788
people died in motor vehicle traffic crashes This represents a decline of about 3
percent as compared to the 33808 fatalities in 2009 as shown in Table 1 If these
projections are realized fatalities will be lowest on record (since 1949)
Traffic Safety Facts Overview 2009 Data
httpwww-nrdnhtsadotgovPubs811392pdf
In 2009 33808 people were killed in the estimated 5505000 police-reported
motor vehicle traffic crashes 2217000 people were injured and 3957000
crashes involved property damage only Compared to 2008 this is a 10-
percent decrease in the number of fatalities and a 5-percent decrease in the
Page 44 of 45
number of police-reported motor vehicle traffic crashes people injured and
crashes involving property damage
An average of 93 people died each day in motor vehicle crashes in 2009 mdash
an average of one every 16 minutes
Traffic Safety Facts Overview 2008 Data
httpwww-nrdnhtsadotgovPubs811162pdf
In 2008 37261 people were killed in the estimated 5811000 police-reported
motor vehicle traffic crashes 2346000 people were injured and 4146000
crashes involved property damage only
Some comments and Feedback
The following comments were received from Prof Ganesan after his review of the
first draft of this document It was subsequently revised thanks to this input to
address some of the very important issues raised here
Dear Laxman
The write up is not enough
You are emphasizing that the speed limit reduces the fatal accidents (comparing 1966
to 2000 accident numbers)
Can you also add a few sentences why the number is decreasing from 1980 to 2000
values (May be due to better design of vehicles)
Can you say anything about the fuel consumption with the speed for any typical
vehicle in 2011 or 2010 (do not consider the fatalities issue)
Probably a speed between 55 and 60 mph gives a better mileage If so this is a
compelling reason to keep the speed limit low But cars probably can be tuned to
give better mileage at any high speed also
Page 45 of 45
Weather is also a major factor in fatal accidents Speed limit may be kept low during
winter and kept higher in summer Give your comments on this too
Driver distractions can cause more accidents Now cars have many multimedia and
internet features Automatic collision avoidance systems and sensors on the sides can
detect vehicles in the front and neighboring lanes and it can automatically decrease
speed even if the driver speeds at super high speeds
Give some comments on this too There is also Vehicle to Vehicle communications
vehicle to infrastructure communications and they can avoid collisions and accidents
Technology has changed from 1966 I cannot agree with you on the speed limit
without any discussion on the above and other factors
Have a great day
Subra Ganesan
Professor Subramaniam Ganesan
Director Real Time amp DSP Lab
Electrical and Computer Engineering Department
2200 Squirrel Road Dodge Hall Room 105
Oakland University Rochester MI 48309 USA
Phone 248 370 2206 Fax 248 370 4633
wwwsecsoaklandedu~ganesan
IEEE Distinguished Visiting Speaker (2005-2009) Coordinator
IEEE SEM CS chapter Chair Region 4 and CS Society Board member
SAE ASEE ACM member
Page 14 of 45
superimposed on to the data The design engineering goal and societal goal should
be to reduce the slope h of this statistically significant best-fit line to its ideal value of
h = 1 A fatal crash by definition is one where at least one person dies either an
occupant or a non-motorist in the path of the vehicle Hence the ideal slope h = 1
Photograph of an accident scene from the period 1955-1965
httpwwwcorinthsocialhistoryprojectorghtmlhighwaytollshtml
3 A Brief History of Traffic Safety Legislation
The following is extracted from the Wikipedia article on National Highway
Traffic Safety Administration (NHTSA)
httpenwikipediaorgwikiNational_Highway_Traffic_Safety_Administration
In 1965 and 1966 public pressure grew in the US to increase the safety of
cars The number of deaths on US highways were increasing year after year
Page 15 of 45
see Figure 1 and in 1966 Congress held a series of highly publicized
hearings on highway safety This led to the legislation for mandatory
installation of seat belts which also created the US Department of
Transportation (on Oct 15 1966)
httpwwwemsgovpdf2011EMSWeek2011_Stricklandpdf
The following is extracted from a Washington Post article on
NHTSA dated April 2 2002
httpwwwwashingtonpostcomwp-srvbusinessincludesnhtsa_primerhtm
In 1966 after decades of rising traffic fatalities (also vividly illustrated in
Figures 1 and 2 here) the publication of Ralph Naders Unsafe at Any
Speed and increasing public outcry for safer automobiles Congress held a
series of highly publicized hearings on creating a regulatory agency for traffic
safety Among the witnesses was William Haddon an epidemiologist who
introduced the idea that traffic accidents could be analyzed scientifically and
injuries reduced by changing auto design such as installing collapsible
steering columns safety glass head rests and seat belts
Congress passed the Highway Safety Act of 1966 creating the National
Highway Safety Bureau with Haddon as its first administrator The bureau
became NHTSA in 1970 under the newly established Department of
Transportation An early Nader convert Joan Claybrook headed NHTSA
under President Carter and now runs Naders organization Public Citizen
National Traffic and Motor Vehicle Safety Act
httpwwwanswerscomtopicnational-traffic-and-motor-vehicle-safety-act
Signed into law by President Lyndon Johnson on September 9 1966 this act
created the first mandatory federal safety standards for motor vehicles The
act was motivated by a variety of factors First and foremost the public was
growing increasingly concerned over the rising number of traffic fatalities on
the nations roads Such fatalities had increased by nearly 30 percent
between 1960 and 1965 and experts forecasted 100000 such deaths
Page 16 of 45
annually by 1975 unless something was done to improve traffic safety
Adding fuel to the fire Ralph Naders Unsafe at Any Speed published in
November 1965 criticized the automobile industry for neglecting safety in
favor of power and styling when designing new vehicles
4 The reason for the historical
decrease in highway fatalities
A recent news item see link given below regarding renewed attempts to
increase the speed limit by many states prompted this write up by the
present author who has studied traffic fatality data extensively and analyzed
them very carefully over the last several years
httpmoneymsncomauto-insurancewhy-speed-limits-are-
risingaspxGT1=33033
Residents of Metro Detroit area who frequently cross into Ohio from
Michigan notice that the speed limit has now increased in Ohio The speed
limit on Michigan highways was increased to 70 mph in the late 1990s but
Ohio retained its lower speed limit for many years leading Michigan drivers to
experience a ―speed trap of sorts The speed limit is also increasing in many
other states notably Texas where it is proposed to increase it to 85 mph at
least in West Texas
Historically speaking from a traffic fatality standpoint we must consider two
important dates 1966 and 1973 Only 1973 the year of the Arab oil embargo
following the Arab-Israeli war (that led to what President Obama has recently
called the pre-1967 border for Middle East peace) is mentioned in the above
article It fails to mention the significance of the year 1966
Prior to 1966 there was actually NO speed limit in many Western states and
deaths due to highway accidents were increasing year after year The
Page 17 of 45
number of highway fatalities went up from 38702 in 1957 to 51524 in 1965
a 33 increase over the 1957 level and an additional 12822 deaths in 1965
compared to 1957 It was this carnage on the US highways that forced
Congress to hold its hearings on highway traffic fatalities in 1966
Nonetheless a careful examination of the fatality data in Table 1 shows that
notwithstanding the highly publicized Congressional hearings of 1966 and
new safety legislation that was enacted the absolute number of fatalities
continued to increase after 1966 and only started decreasing after 1973
Vehicle designs especially the introduction of safety features (even the
simplest like safety belts) did not change significantly between 1966 and
1973 Nonetheless post-1973 we begin to see a dramatic turnaround
Why
After the 1973 Arab oil embargo a nationwide maximum speed limit (NMSL)
of 55 mph was imposed and accepted in the USA (effective Jan 1 1974)
during the Nixon administration primarily as an effort to conserve fuel and
reduce the US vulnerability to oil imports The unintended and indeed
fortunate consequence of this reduced speed limit was the immediate
reduction in the fatalities revealed in Figures 2 and 3 This is the real reason
for the peaks in highway fatalities observed in these two graphs
The Congressional hearings of 1966 did eventually have an impact but it was
a delayed one The impact of the 1973 nationwide speed limit of 55 mph was
however immediate as we see from the magnified plot of the same data in
Figure 5 and a closer examination of the raw fatality data in Table 1
The number of highway-accident-related fatalities decreased immediately
from a high of 55704 in 1972 to just 46078 in 1974 a 173 drop see
arrows There were 9626 fewer deaths annually even with a slight increase
in the vehicle miles driven (see Table 1) Indeed the number of highway
death reached its absolute peak value in 1972 never to be seen again
Fatalities have been decreasing every since with slight fluctuations about
each new low value
Page 18 of 45
Figure 5 Expanded view of the fatality data showing the immediate impact of the
national speed limit of 55 mph following the Arab oil embargo of 1973 Note that
fatalities continued to rise between 1966 and 1973 in spite of the highly publicized
Congressional hearings in 1966 and the traffic safety legislation enacted soon after
Each new low is probably associated with vehicle safety innovations and the
improvements in vehicle design and engineering The combined beneficial
effect of improved vehicle designs primarily the introduction of seat belts
and the laws enforcing usage of seat belts aided by the reduced speed
limits contributed to the continued decline in the absolute number of fatalities
that started since 1973 and has continued to this day The subsequent
introduction of other safety features notably air bags has contributed to a
further reduction in highway fatalities
Page 19 of 45
State police Trooper First Class Jeffrey Flowers looking at a car in which a Boswell
Pennsylvania woman was injured Tuesday (May 31 2011) The accident occurred at
an intersection when a truck (seen behind the wrecked car) entered this accident
prone intersection (part of a highway safety corridor where signs are posted to
reduce unsafe driver behavior) There have been four accidents at this intersection
since 2006 none fatal httpwwwdailyamericancomnewssomersetda-ot-woman-
injured-in-route-30-wreck-2011053104165420story
5 Numerical calculations of decline in
fatalities and the impact of NMSL post-1973
Letlsquos consider the decline in fatalities between 1972 the last year before the
adoption of the NMSL and 1974 the first year following its adoption after the
Arab oil embargo There was an immediate decrease in the number of
fatalities by 9393 ie y = -9393 with a slight increase in the VMT ie x
= 20758 millions The NHTSA data used here may be found in the table at
the end of this document The numerical value of the rate of change per
billion VMT (ie neglecting the sign) was therefore
yx = 4525 fatalitiesbillion VMT (1972-1974)
Page 20 of 45
It is instructive to compare this rate of change in fatalities with similar short
periods of a decline in fatalities in the pre-1973 era when speed limits were
much higher The absolute number of fatalities declined over a relatively
short period with both an increase and a decrease in VMT The results are
given below and are self-explanatory
yx = 454 fatalitiesbillion VMT (1953-54) decline with increase in VMT
yx = 655 fatalitiesbillion VMT (1942-43) decline with decrease in VMT
yx = 1739 fatalitiesbillion VMT (1941-42) decline with decrease in VMT
yx = 4528 fatalitiesbillion VMT (1937-39) decline with increase in VMT
yx = 2548 fatalitiesbillion VMT (1931-32) decline with decrease in VMT
The rate of decline observed between 1953 and 1954 with an increase in
VMT was just one-tenth of that observed following the adoption of the 55
mph speed limit The war years (1941-43 WWII) and the Great Depression
era (1931-32) were accompanied by big declines in fatalities with decreasing
VMT but the rate of change was still significantly lower than observed after
the adoption of the NMSL
The only apparently inexplicable decline is that between 1937 and 1939
where a nearly identical high rate of decline was observed Notice also the
big drop in the traditional fatality rate between 1937 and 1938 This large drop
appears to coincide with the creation of the National Safety Council (NSC) by
William H Cameron in June 1937 (see link below) with its far-flung campaign
of education legislation research highway engineering and traffic training
undertaken by the NSC and some two dozen other groups with the backing of the
automotive industry through its Automotive Safety Foundation Other factors
unknown to the present author probably also played a role
httpwwwtimecomtimemagazinearticle0917188379700htmlixzz1O2G
7rnUg
Page 21 of 45
These simple computations here however reveal the significant effect of
reduced speed limits on highway fatalities much more so than other factors
6 Further Considerations Pros and Cons
The singular effect of increased speeds (or speeding) on highway fatalities
has been studied and demonstrated by a number of industry sources such
as the Insurance Institute for Highway Safety (IIHS) Consumers Union and
also by government researchers
httpwwwsmartmotoristcomtraffic-and-safety-guidelineexcessive-speed-is-
a-factor-in-one-third-of-all-fatal-crasheshtml
httpwwwconsumersunionorgotherspeedlimitsspeed031500a2htm
Speed ndash defined as exceeding the posted speed limit or driving too fast for
given conditions ndash is a factor in nearly one-third of all fatal crashes Besides
fatality in 1998 nearly 40000 people were critically injured in speed-related
crashes and nearly 72000 were moderately injured
The salutary and immediate beneficial effect of the nationwide 55 mph speed
limit has been noted by other researchers (see Susan Ferguson link below)
httpwwwnhtsagovpeopleinjuryenforcespeed_forum_presentationsfergu
sonpdf
After a partial repeal of this law in 1987 which granted states the authority to
increase speed limit (especially in rural interstates) a 1989 study showed a
15 increase in fatalities in rural interstates and a 5 increase in non-rural
interstates Unfortunately such studies often tend to be discounted by
advocates of increasing the speed limits as being produced by biased
industry sources
Similar conclusions were also presented by NHTSA in February 1998 in its
report to the Congress entitled ―Report to Congress The Effect of Increased
Speed Limits in the Post-NMSL Era see link given below Among its key
Page 22 of 45
findings is the following quoted in its entirety NMSL refers to the National
Maximum Speed Limit legislated after the Arab oil embargo of 1973
httpwww-nrdnhtsadotgovPubs808-637PDF
hellip Nevertheless it is important to note that data currently available from the
National Highway Traffic Safety Administrationrsquos (NHTSA) Fatality Analysis
Reporting System (FARS) shows that states that increased speed limits in 1996
experienced approximately 350 more Interstate fatalities than would have been
expected based on historical trends -- about 9 percent above expectations
Concurrently the Interstate fatalities experienced in states that did not increase speed
limits in 1996 was consistent with pre-1996 trends The estimated increase in
Interstate fatalities found in this study while smaller in magnitude compared to the
estimated change in fatalities found in 1987 following the increase of speed limits on
rural Interstates does follow the historical pattern of increases in fatalities being
associated with increases in posted speed limits
The annual crash reports compiled by NHTSA see Table 3 indicate that the
number of fatal crashes (and hence fatalities using the regression equation
developed in Figure 4) increase as the posted speed limits increase
Page 23 of 45
Table 3 Posted speed limits and number of crashes
Speed Limit Crashes (2008) Crashes (2009)
30 mph or less 3705 3277 35 or 40 mph 6115 5516 45 or 50 mph 6461 6074
55 mph 9794 8847 60 mph or higher 6908 6124
Total 34017 30797
Source httpwww-nrdnhtsadotgovPubs811402EEpdf
61 Studies cited in favor of lower speed limits
A detailed analysis of speeding related fatalities (see link below) by NHTSA
shows that a third of all crashes involve speeding ie at least one driver was
speeding
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Furthermore the above report which covers the period 1983-2002
indicates that immediately after the NMSL was completely abolished in
December 1995 the number of speeding related fatalities at speeds
above 65 mph increased from just 15 in 1995 to a 677 in 1996 (see Table
62 on page 43 of above report) It continued to increase in the years
since climbing to 930 in 2000
More detailed studies similar to that noted above by researchers at the
University of Illinois Chicago led by Lee S Friedman again lead to the
conclusion that higher speed limits lead to an increase in the number of
fatalities (see American Journal of Public Health online July 16 2009)
httphealthusnewscomhealth-newsmanaging-your-
healthcarearticles20090716deaths-injuries-increase-with-higher-speed-
limits
Page 24 of 45
httpwwwmedpagetodaycomPublicHealthPolicyPublicHealth15122
httpwwwamericaneercomspeed-limits
httpwwwactuarialoutpostcomactuarial_discussion_forumarchiveindexph
pt-171870html
For the study period 1995-2005 these researchers found that 12545 deaths
and 36582 injuries could be attributed to the increased speed limits The
benefits of reduced speed limits are stated quite eloquently by Dr Friedman
and are reproduced below (from above news article see link)
Reduced speed limits would save lives Friedman said They would also reduce
gas consumption cut emissions of air pollutants save valuable years of productivity
(lost due to injuries)and reduce the societal cost of motor vehicle crashes (due to
both fatal crashes and due to nonfatal and severe life-changing injuries) he added
Friedman and coworkers have also shown that increasing the speed limit led
to an immediate increase in the number of fatalities on Israeli roadways (see
link below)
httpinjurypreventionbmjcomcontent133156
The effect of speeding is very significant especially in rural areas resulting
in significantly higher fatalities Fatality rates are frequently double or triple
that in urban areas (see link below)
httpsafetyfhwadotgovspeedmgtdata_factsdocsspeeding_ruralpdf
As of Jan 1 2005 five Midwestern states had increased the speed limits to
above 65 mph (Illinois Iowa Kansas Minnesota Missouri Nebraska and
South Dakota) whereas three (Illinois Iowa and Wisconsin) had not All the
five states with increased speed limits showed a 7 to 13 increase in
fatalities The NHTSA study considered an eight year period before and after
the change in Dec 1995 (see Table 1 in link below) The collective experience
of the states that did NOT increase the speed limit was a 7 decline in
fatalities (see Table 2 of link below)
httpwwwiowadotgovmvdodsstats2006speedstudypdf
Page 25 of 45
Moreover Table 5 in the above study shows the effect of imposing the NMSL
of 55 mph in Iowa and its repeal in 1995 Considering a four-year average
before 1974 when the speed limit was 75 mph there were 35 fatal crashes
with 43 fatalities In the first four years after the 55 mph there were only 23
fatal crashes and 28 fatalities In the last four years before the repeal of 55
mph in 1995 there was a further decline to 14 fatal crashes with 17 fatalities
The Iowa fatality data will be discussed in more detail separately (in a later report)
since it provides the opportunity to assess the effect of a change in the speed limit
on the relationship between number of fatalities and fatal crashes (as seen in
Figure 4 for the US as a whole)
North of the US border Canadians seem to be citing the ―shocking increase
in highway fatalities in the US states where the speed limits were raised to
curb their own speed limits
httparchivesafety-councilorginfotrafficspeed-02html
httparchivesafety-councilorginfotrafficspeedhtml
Speed kills but speed also sells notes the second of the above news items
Manufacturers are producing more high performance cars (with higher horse
power to weight ratio) and ads feature enticing cars that race and swerve in
miraculous ways on empty roads These subliminal messages encourage
drivers especially young drivers to break the speed limit leading to the
absolute increase in highway fatalities (although the rate itself is going
down) The article emphasizes the need to enforce the speed limit on
Canadian highways and in cities where street racing is becoming a problem
62 Studies cited by opponents of lower speed limits
In fairness to quote the opponents on the other side of this debate Montana
reverted back to Reasonable and Prudent speed limits when the National
Maximum Speed Limit was repealed in 1995 and appears to have
experienced no significant increase in fatalities
Page 26 of 45
httpwwwhwysafetycomhwy_montanahtm
httpwwwmotoristsorgpressmontana-no-speed-limit-safety-paradox
httpwwwsouthbayriderscomforumsshowthreadphpt=81453amppage=1
Likewise studies in the state of Maryland showed no significant increase in
highway fatalities when the speed limit was increased from 55 mph to 75
mph The reason might simply be that drivers were already speeding much
more so when the speed limit was 55 mph than after the increase to 75 mph
In other words the fatalities data already reflects the effect of higher speeds
(not speed limits) on the number of fatalities
In Utah the experimental increase in the speed limit to 80 mph was
considered to be a success in terms of safety
httpautosaolcomarticleutah-speed-limit-tests
The UDOT Director noted that there was no increase in the number of
accidents on Interstate 15 But what happens in the event of an accident
when the speed limits are higher and drivers are driving at higher speeds and
two objects collide at this higher speed However no increase in the number
of accidents is not the same as no increase in fatalities due to the higher
speeds When accidents do occur do fatalities increase
Likewise in California when the speed limit went up from 55 mph to 65
mph in 1995 (after repeal of NMSL) fewer deaths were reported in 1998
compared to the peak year of 1979 or even 1987 Again the explanation
seems to be that motorists were already speeding when the limit was 55 mph
and that increasing the speed limit did not change driver behavior in any
significant way
httparticlessfgatecom1998-11-02news17735730_1_speed-limits-mph-
limit-death-rate
The National Motorists Association (NMA) a group which advocates higher
speed limits emphasizes the importance of considering fatality rates as
opposed to the raw fatalities The argument used is that fatality rates based
on the fatality per 100 million VMT is the legitimate way to look at the data
Page 27 of 45
This is a never ending debate Historically speaking fatality rates have been
going down ever since the compilation of traffic accidents data began Table
A1 in the appendix of a recent report by NHTSA (see link below) has highway
fatality rate data going back 1921
httpwww-nrdnhtsadotgovPubs811346pdf see appendix page 31
httpwwwmotoristsorgspeed-limitstruth
httpwwwmotoristsorgothercrash-data
httpwwwraisethespeedlimitorgmythshtml
httpwwwcatoorgpubspaspa346pdf
According to Stephen Moore of the Cato Institute (see last of the links above)
―All measures of highway safety show improvement not more deaths and
injuries since 1995 Despite the fact that 33 states raised their speed limits
immediately after the repeal of the mandatory federal speed limit the NHTSA
reported last October that the traffic death rate dropped to a record low level
in 1997lsquo Moreover the average fatality rate even fell in the states that raised
their speed limits
63 The Fatality rate Is it a reliable metric
In 1921 with fewer fatalities and fewer miles driven and the first year for
which the fatality rate could be computed the rate was 2408 It was down to
1479 in 1931 but the number of deaths had climbed to 31963 more than
double the 1921 absolute fatality number of 13253 It had dropped to 550 in
1966 the year of the highly publicized Congressional hearings but the
number of fatalities had climbed to 50984 in that fateful The Highway Safety
Act of 1966 ranks as one of the major acts of Congress and President
Johnson signed it saying that ―we have been tolerating a raging epidemic of
highway deathshellip see extract pasted below
httpwwwenotescommajor-acts-congresshighway-safety-act
Page 28 of 45
The act was motivated primarily by growing public concern over the rising number
of traffic fatalities in the United States Between 1960 and 1965 the annual number
of traffic fatalities increased by nearly thirty percent As President Lyndon B
Johnson stated at the signing of the act on September 9 1966 we have tolerated
a raging epidemic of highway death which has killed more of our youth than all
other diseases combined Through the Highway Safety Act we are going to find out
more about highway diseasemdashand we aim to cure it
Nonetheless highways fatalities continued to increase until the Arab oil
embargo of 1973 led to the NMSL of 55 mph all across the USA Do we just
ignore this undeniable historical record and focus only on the declining fatality
rate as the NMA and other proponents of higher speed limits seem to argue
(see links above)
The misleading nature of using fatality rates (per 100 M VMT) alone is also
obvious if one considers fatality data for individual states Take for example
the state of Montana which seems to have experienced no increase in
fatalities after repeal of NMSL
httpwww-nrdnhtsadotgovdepartmentsnrd-
30ncsaSTSI30_MT200930_MT_2009htm
For the period 2005-2009 the absolute number of fatalities for Montana
varied between a high of 277 in 2007 to a low of 229 in 2009 The fatality
rates per 100 M VMT on the other hand varied from a high of 245 for 2007
to a low of 201 for 2009 The corresponding US fatality rates varied from
136 to 114 Is the higher number for the fatality rate for Montana compared
to USA good or bad Likewise fatality rate per 100000 of population was
much higher for Montana than the US as a whole
This again highlights the pitfalls of using simple ratios to assess fatality statistics
without a full analysis of the underlying trends We will discuss this point
separately
As shown already the continuous decline in the fatality rate is a mathematical
artifact and essentially overlooks the unmistakable positive correlation
between the variables x and y of the type y = hx + c which becomes obvious
Page 29 of 45
only when we prepare the x-y scatter graph The ratio yx = h + (cx) can
decrease with increasing x (VMT) and increasing y (fatalities) since the
intercept c has a positive value when we consider only data spanning a short
period (such as 1994-2009 of more relevance to the current situation)
The debate between fatality rates and absolute number of fatalities is an
unending one A few years ago the Wall Street Journal carried an article
which was entitled (or something close) ―Unemployments rate in Ohio are
going down but why is the number of unemployed increasing The reason is
the same The graph of the number of unemployed (y) versus the number in
the labor market (x) is linear with a positive slope h and a positive intercept c
So the unemployment rate computed using the ratio yx keeps going down
year after year although the number unemployed keeps increasing Is it a
good thing that the unemployment rate is going down when more people
seem to be unable to find gainful unemployment
Or consider the situation with cancer death rates This too has been going
down in recent years but the actual number of cancer-related deaths has not
declined in any significant way Is it good that cancer death rates are going
down In all these situations the researchers or the socio-econo-politico
analysts involved in analyzing the trends in the data have failed to consider
the underlying x-y relation describing each problem
Hence it appears that the debate on the effect of increased speed limits
should not be focused on only the fatality rates (which have been decreasing
and proponents of higher speed limits cite this in their arguments) or even the
absolute number of fatalities (which has been the focus here) but on the
relationship between speed and the number of fatal crashes and the number
of fatalities within each speed segment (see Table 3 and also Figure 4)
Unfortunately details of number of fatalities and the number of fatal crashes
at each speed limit are not available even from NHTSA for detailed study
When a crash does occur (it is immaterial how many miles were driven) the
speed of the driver and vehicle design and engineering including safety
devices in place (seat belts airbags other impact absorbing technologies)
Page 30 of 45
determine if the occupants(s) will be killed One cannot argue that speed
does NOT kill That would be an absolute denial of the laws of physics
Studies show that setting the speed limit at the 85th percentile in any given
zone (this is the speed at or below which 85 of drivers are observed to
travel in traffic engineering studies) is the safest speed limit The majority of
drivers try to obey the posted speed limit while a few choose to drive at a
speed they consider is safe and prudent These are also perhaps the most
vociferous advocates of higher speed limits It is this tension caused due to
differences in speeds that leads to tailgating improper passing reckless
driving weaving from lane to lane and ultimately crashes and deaths in some
unfortunate cases
httpblogmotoristsorgspeed-limits-slower-safer
MARK TAYLOR
ANOTHER LOST A man was killed when his 4WD drive hit a tree east of Morrinsville (in New
Zealand) on Monday May 30 2011 The driver lost control of the vehicle on a bend probably tried
to correct his mistake and put the car into a ―yaw causing it to leave the road and smash sideways
into a tree Alerts to slow down had been posted since this was a high accident area but the driver
probably did not pay attention
64 Other factors
Many other factors besides speed no doubt affect highway fatalities The
vehicles of the 21st century are very different from the vehicles of the mid 20th
Page 31 of 45
century Technological innovations such as improvements in vehicle design
and engineering have greatly increased crash worthiness of vehicles even at
high speeds Environmental factors such as the weather also contribute to
accidents but not necessarily to increased fatalities Drivers actually tend to
slow down instinctively during adverse weather conditions (rain snow storms
etc) and although such weather may contribute to increased accidents the
lower speeds actually reduce fatalities
Yes technology has changed fundamentally from 1966 Drivers today are
more distracted by their cellmobile phone conversations (and also built-in
phones in luxury models) and text messaging than the drivers of the pre-1966
era High end cars now have many multimedia and internet features Again a
careful observation (even personal experience by the author) suggests that
such distracted drivers actually tend to (instinctively) drive more slowly and
hold up the traffic Perhaps such behavior leads to an increase in the number
of accidents but it does not necessarily lead to an increase in the number of
accident-related fatalities
Much talked about technological innovations such as automatic collision
avoidance systems and sensors (on the sides of vehicles) can indeed detect
vehicles in the front and neighboring lanes Furthermore vehicle-to-vehicle
communication systems vehicle-to-infrastructure communication systems
can no doubt avoid collisions and accidents Again such collision avoidance
systems work and are effective entirely because they automatically reduce
vehicle speeds - even if one of the offending vehicles is being at a super
high speed Also it must be remembered that such futuristic systems have
not yet been implemented widely nor can they be implemented widely since
the large majority of vehicles on the road are NOT luxury models Advanced
safety features come with a price and not all drivers can afford to pay that
price and ―buy that ―additional safety
Ultimately it is the laws of physics that govern what will happen when two or
more vehicles collide or even when a single vehicle collides with a stationary
infrastructural object (a bridge a wall a building or some impediment on the
road) The lower the number of crashes the lower the number of fatalities as
revealed by the 1994-2009 data graphed in Figure 5 The higher the speed of
Page 32 of 45
the object or objects that are involved in a collision the higher the kinetic
energy K that must be absorbed andor dissipated Increasing the posted
speed limit only increases the energy that must be absorbed when a crash
does occur This ultimately is the most important criterion determining the
number of fatalities
The kinetic energy increases as the square of the speed being given by the
well-known formula K = frac12 mv2 where m is the mass of the vehicle (in
laypersonlsquos language m increases directly with vehicle weight) and v is the
speed For the same vehicle mass an increase in the speed from 55 mph to
85 mph increases the kinetic energy K by a factor of 239 or roughly a 250
increase in the kinetic energy that must be absorbed in a collision
Ideally speaking the kinetic energy of the colliding object(s) is absorbed by
the vehicle infrastructure (a sturdy space frame the engine other vehicle
components etc) andor the surroundings However in the unfortunate
cases where this kinetic energy must be absorbed by the vehicle occupant(s)
the result is severe life-altering injuries andor death An unequivocal
relationship between an increase in vehicle speeds and fatal accidents can
be demonstrated by a careful examination of available traffic fatality data
This is a more involved discussion and is not the purpose of this short
communication These topics are no doubt very politically charged with many
social legal and financial implications with each interest group favoring a
different conclusion Nonetheless we cannot escape the laws of physics as
they govern the fundamental need to absorb higher and higher values of the
kinetic energy K with increasing vehicle speeds This same point is also
emphasized by Dr Friedman of the University of Illinois Chicago (see earlier
discussion)
Speed kills because of these energy transfer considerations and there can be
no doubt about it
Innovative 21st century solutions to speed management on the highways
such as strict enforcement of speed limits minimizing speed dispersion
(difference between speeds at which different drivers travel) while using
cameras to track the 15 of drivers who willfully violate the speed limit and
Page 33 of 45
create hazardous driving conditions is certainly recommended (Recall that
the optimum recommended speed limit is at or below which 85 of all drivers
travel ndash a policy also supported by NMA) Even on this score however the
results are confounding if we consider the Australian experience
httpwwwthenewspapercomnews282840asp
Up until 2007 there was no speed limit in the Northern Territory of
Australia Imposing a speed limit 130 kmph (80 mph) on some areas and
110 kmph (68 mph) in some others actually increased the number of deaths
The death toll in 2006 when there was no speed limit in this region was 44
and went up to 75 in 2009 see data table in link below
httpwwwthenewspapercomrlcdocs2009au-ntroadtollpdf
Furthermore it appears that installation of cameras to enforce speed limits
has proved to be a hazardous distraction to drivers and deaths actually
began to skyrocket between 2005 and 2007 in all Australian roadways
The main purpose here is to sound a cautionary note amid renewed attempts
in many states across the US to increase the speed limits on our highways by
calling attention to the historical facts regarding the ―epidemic levels of
highway traffic fatalities that engaged our national attention in the fateful year
of 1966 The graphical representation of the traffic fatality data in Figures 1
to 5 tells its own story
Indeed it would be tragic if highway-accident-related fatalities were to start
increasing once again and reach the historically high level that was last seen
in 1972 the year before the Arab oil embargo of 1973
Page 34 of 45
Conclusions
1 The graphical representation of the highway fatality data and the brief
summary of the historical facts of traffic safety legislation suggest that
recent attempts to increase the speed limits by various states (notably
Texas) may be misguided The distinct peak in the highway fatalities
observed in these graphs is highly alarming This appears to be related to
the enactment of the National Maximum Speed Limit (NSML) in 1974
following the 1973 Arab oil embargo Although NSML was motivated by a
desire to reduce gasoline consumption an unintended benefit might have
been a dramatic reduction in fatalities The fundamental reasons for the
peak in the fatalities-VMT curve must be examined carefully without
political posturing
2 The widely used fatality rate fatalities per 100 M vehicle miles traveled
has been declining since 1921 the first year for which a fatality rate could
be computed and has now reached a historical low The absolute number
of fatalities on the other hand was increasing in the 1950s and 1960s at
an alarming rate and the public outcry that ensued led to the highly
publicized Congressional hearing of 1966 and the subsequent traffic safety
legislations The fatality rate has been decreasing even in the most recent
15-year period (1994-2009) again with increasing fatalities although less
dramatically Thus it appears that fatality rate calculation based on vehicle
miles traveled (VMT) might not be a reliable indicator of the underlying
dynamics in the fatality trends
3 More detailed compilation of number of fatalities and the number of fatal
crashes within each speed limit segment is required to better understand
the effect of increasing speed limits on highway fatalities (and also fatality
rates) Such data is already available and is being compiled at the local
city and county levels in all jurisdictions and only needs to be reorganized
to highlight the effect of (posted) speed limits on the number of crashes
and fatalities This will require some minor rewriting and revisions to the
chapters named ―Crashes and ―States in the annual NHTSA reports
Page 35 of 45
Analysis of the fatalities-crashes data for several years with various
speed limits will be more revealing and meaningful than the current
fatality rates analysis and will be discussed separately in a follow up
report
4 One should not be lulled by the fact that vehicles of the 21st century are
now equipped with advanced safety features not available in the 1950s
and the 1960s In spite of these safety features the laws of physics dictate
that the higher the speed the higher kinetic energy of the colliding objects
and hence the greater the risk indeed near certainty of fatalities in a
higher speed collision compared to a lower speed one
5 The higher the speed at which the vehicle that is involved in a crash is
traveling the higher the kinetic energy that must be absorbed andor
dissipated without affecting the occupant(s) to avoid serious injuries andor
death This was true in the 1950s and the 1960s and will continue to be
true in the 21st century as well
Speed Kills for this just reason
6 It appears that higher fuel economies and reduced
highway fatalities were the twin societal benefits of 55
mph adopted after 1973 If so the current attempts to
increase the speed limits appear to be in conflict with
other important societal objectives
Page 36 of 45
Table 1 Annual US Street amp Highway
Fatalities from 1957
Year
Fatalities
Vehicle Miles
(millions)
Rate100M Vehicle Miles
1957 38702 646915 598
1958 36981 664915 556
1959 37910 700478 541
1960 38137 718845 531
1961 38091 737535 516
1962 40804 766852 532
1963 43564 805423 541
1964 47700 846500 563
1965 49163 887640 554
1966 51524 927915 555
1967 51559 965132 534
1968 53831 1019726 528
1969 55032 1066108 516
1970 53672 1114098 482
1971 53761 1183524 454
1972 55704 1264614 440
1973 55113 1316207 419
1974 46078 1282790 359
1975 45500 1330074 342
1976 45523 1402380 325
1977 47878 1467027 326
1978 50331 1544704 326
1979 51103 1529133 334
1980 51091 1527295 335
1981 49301 1552803 317
1982 43945 1595010 276
1983 42589 1652788 258
1984 44257 1720269 257
1985 43795 1774179 247
Page 37 of 45
1986 46056 1835000 251
1987 46385 1921000 241
1988 47093 2026000 232
1989 45555 2107040 216
1990 44529 2147501 207
1991 41162 2172214 189
1992 39235 2239828 175
1993 40115 2296585 175
1994 40676 2359984 172
1995 41798 2422696 173
1996 41907 2485848 169
1997 41967 2560373 164
Data from Federal Highway Administration
Source httpwwwpublicpurposecomhwy-fatal57+htm
Telephone +16186328507 - Facsimile +16186328538
WENDELL COX CONSULTANCY P O Box 841 - Belleville IL 62269 USA
Page 38 of 45
Fatality data for 1921-1982 compiled by NHTSA
Year
VMT
(Millions)
VMT
(Billions)
Fatalities
Fatality rate
per 100 M VMT
1921 55027 5503 13253 241 1922 67697 6770 14859 219 1923 84995 8500 17870 210 1924 104838 10484 18400 176 1925 122346 12235 20771 170 1926 140735 14074 22194 158 1927 158453 15845 24470 154 1928 172856 17286 26557 154 1929 197720 19772 29592 150 1930 206320 20632 31204 151 1931 216151 21615 31963 148 1932 200517 20052 27979 140 1933 200642 20064 29746 148 1934 215563 21556 34240 159 1935 228568 22857 34494 151 1936 252128 25213 36126 143 1937 270110 27011 37819 140 1938 271177 27118 31083 115 1939 285402 28540 30895 108 1940 302188 30219 32914 109 1941 333612 33361 38142 114 1942 268224 26822 27007 101 1943 208192 20819 22727 109 1944 212713 21271 23165 109 1945 250173 25017 26785 107 1946 340880 34088 31874 94 1947 370894 37089 31193 84 1948 397957 39796 30775 77 1949 424461 42446 30246 71 1950 458246 45825 33186 72 1951 491093 49109 35309 72
1952 513581 51358 36088 70
Page 39 of 45
1953 544433 54443 36190 66 1954 561963 56196 33890 60 1955 605646 60565 36688 61 1956 627843 62784 37965 60 1957 647004 64700 36932 57 1958 664653 66465 35331 53 1959 700480 70048 36223 52 1960 718762 71876 36399 51 1961 737421 73742 36285 49 1962 766734 76673 38980 51 1963 805249 80525 41723 52 1964 846298 84630 45645 54 1965 887812 88781 47089 53 1966 925899 92590 50894 55 1967 964005 96401 50724 53 1968 1015869 101587 52725 52 1969 1061791 106179 53543 50 1970 1109724 110972 52627 47 1971 1178811 117881 52542 45 1972 1259786 125979 54589 43 1973 1313110 131311 54052 41 1974 1280544 128054 45196 35 1975 1327664 132766 44525 34 1976 1402380 140238 45523 32 1977 1467027 146703 47878 33 1978 1544704 154470 50331 33 1979 1529133 152913 51093 33 1980 1527295 152730 51091 33 1981 1555308 155531 49301 32 1982 1595010 159501 43945 28
Source Analysis of Significant Decline in Motor Vehicle Traffic Fatalities in
2008 httpwww-nrdnhtsadotgovPubs811346pdf see Table A1 page 31
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Page 40 of 45
Acknowledgements
The author is grateful for thoughtful comments provided by friends and colleagues
with whom this document was shared via email prior to it being uploaded as a
publicly available document for wider dissemination and study The comments
offered by Prof Subra Ganesan of Oakland University Electrical and Computer
Engineering Department are reproduced with permission in their entirety
About the author
The author obtained his Masterrsquos (S M) and Doctoral (Sc D) degrees in Materials Engineering
from the Massachusetts Institute of Technology Cambridge USA He then spent his entire
professional career at leading US research institutions (MIT NASA Case Western Reserve
University and General Motors R amp D Center in Warren MI) He holds four patents in advanced
materials processing has co-authored two books and has published several scientific papers in
leading peer-reviewed international journals His expertise includes developing simple
mathematical models to explain the behavior of complex systems He can be reached by email at
vlaxmananhotmailcom
Page 41 of 45
Please Buckle Up
httpwwwlakecountypublichealthorgindexphpbuckle-up-montana
Public Awareness
Respect the Cage Exhibit
The Department of Transportation hopes that showing the reality of the crash will reduce traffic
fatalities A crushed car crash dummies and a sobering message ndash all part of the ―Respect The
Cage exhibit that is traveling across Montana The exhibit sponsored by the Montana Department
of Transportation stopped in Ronan on November 6th and is aimed at raising awareness about the
importance of wearing seat belts
The car in the exhibit was in an actual wreck many years ago
the passenger in the vehicle died because he was not wearing a
seat belt the driver who was wearing his seat belt survived
Montanarsquos likeliest crash fatality scenario
A Pickup
A Rural road
And Seat belts that
arenrsquot used
Page 42 of 45
Occupants of pickups are less likely to wear seat belts and pickups are more likely to
roll over than passenger cars
Seat belts reduce the risk of death by 60 percent in pickups and SUVs
In Montana from 2006-2008 81 of those killed in a crash while riding in a pickup were not wearing seat belts
In Montana pickups make up 401 of the vehicle population
For more information on Respect the Cage click here
Page 43 of 45
Appendix 1
Lack of seat belts leading cause of Louisiana highway deaths
1251 AM May 28 2011 |
Written by Adam Duvernay
Crashes involving unbuckled motorists were the leading cause of highway fatalities
in Louisiana last year and cost $9888 million according to recent reports The
Louisiana Highway Safety Commission reported 59 percent of vehicle occupants
killed in Louisiana crashes last year mdash about one in four mdash werent wearing seat
belts
httpwwwshreveporttimescomarticle20110528NEWS01105280354Lack-seat-
belts-leading-cause-La-highway-deathsodyssey=tab|topnews|text|FRONTPAGE
Crash bull Stats Published by NHTSAlsquos National Center for Statistics and Analysis 1200 New Jersey Avenue SE Washington DC 20590
DOT HS 811 451
Early Estimate of Motor Vehicle Traffic Fatalities in 2010
httpwww-nrdnhtsadotgovPubs811451pdf
Summary
A statistical projection of traffic fatalities in 2010 shows that an estimated 32788
people died in motor vehicle traffic crashes This represents a decline of about 3
percent as compared to the 33808 fatalities in 2009 as shown in Table 1 If these
projections are realized fatalities will be lowest on record (since 1949)
Traffic Safety Facts Overview 2009 Data
httpwww-nrdnhtsadotgovPubs811392pdf
In 2009 33808 people were killed in the estimated 5505000 police-reported
motor vehicle traffic crashes 2217000 people were injured and 3957000
crashes involved property damage only Compared to 2008 this is a 10-
percent decrease in the number of fatalities and a 5-percent decrease in the
Page 44 of 45
number of police-reported motor vehicle traffic crashes people injured and
crashes involving property damage
An average of 93 people died each day in motor vehicle crashes in 2009 mdash
an average of one every 16 minutes
Traffic Safety Facts Overview 2008 Data
httpwww-nrdnhtsadotgovPubs811162pdf
In 2008 37261 people were killed in the estimated 5811000 police-reported
motor vehicle traffic crashes 2346000 people were injured and 4146000
crashes involved property damage only
Some comments and Feedback
The following comments were received from Prof Ganesan after his review of the
first draft of this document It was subsequently revised thanks to this input to
address some of the very important issues raised here
Dear Laxman
The write up is not enough
You are emphasizing that the speed limit reduces the fatal accidents (comparing 1966
to 2000 accident numbers)
Can you also add a few sentences why the number is decreasing from 1980 to 2000
values (May be due to better design of vehicles)
Can you say anything about the fuel consumption with the speed for any typical
vehicle in 2011 or 2010 (do not consider the fatalities issue)
Probably a speed between 55 and 60 mph gives a better mileage If so this is a
compelling reason to keep the speed limit low But cars probably can be tuned to
give better mileage at any high speed also
Page 45 of 45
Weather is also a major factor in fatal accidents Speed limit may be kept low during
winter and kept higher in summer Give your comments on this too
Driver distractions can cause more accidents Now cars have many multimedia and
internet features Automatic collision avoidance systems and sensors on the sides can
detect vehicles in the front and neighboring lanes and it can automatically decrease
speed even if the driver speeds at super high speeds
Give some comments on this too There is also Vehicle to Vehicle communications
vehicle to infrastructure communications and they can avoid collisions and accidents
Technology has changed from 1966 I cannot agree with you on the speed limit
without any discussion on the above and other factors
Have a great day
Subra Ganesan
Professor Subramaniam Ganesan
Director Real Time amp DSP Lab
Electrical and Computer Engineering Department
2200 Squirrel Road Dodge Hall Room 105
Oakland University Rochester MI 48309 USA
Phone 248 370 2206 Fax 248 370 4633
wwwsecsoaklandedu~ganesan
IEEE Distinguished Visiting Speaker (2005-2009) Coordinator
IEEE SEM CS chapter Chair Region 4 and CS Society Board member
SAE ASEE ACM member
Page 15 of 45
see Figure 1 and in 1966 Congress held a series of highly publicized
hearings on highway safety This led to the legislation for mandatory
installation of seat belts which also created the US Department of
Transportation (on Oct 15 1966)
httpwwwemsgovpdf2011EMSWeek2011_Stricklandpdf
The following is extracted from a Washington Post article on
NHTSA dated April 2 2002
httpwwwwashingtonpostcomwp-srvbusinessincludesnhtsa_primerhtm
In 1966 after decades of rising traffic fatalities (also vividly illustrated in
Figures 1 and 2 here) the publication of Ralph Naders Unsafe at Any
Speed and increasing public outcry for safer automobiles Congress held a
series of highly publicized hearings on creating a regulatory agency for traffic
safety Among the witnesses was William Haddon an epidemiologist who
introduced the idea that traffic accidents could be analyzed scientifically and
injuries reduced by changing auto design such as installing collapsible
steering columns safety glass head rests and seat belts
Congress passed the Highway Safety Act of 1966 creating the National
Highway Safety Bureau with Haddon as its first administrator The bureau
became NHTSA in 1970 under the newly established Department of
Transportation An early Nader convert Joan Claybrook headed NHTSA
under President Carter and now runs Naders organization Public Citizen
National Traffic and Motor Vehicle Safety Act
httpwwwanswerscomtopicnational-traffic-and-motor-vehicle-safety-act
Signed into law by President Lyndon Johnson on September 9 1966 this act
created the first mandatory federal safety standards for motor vehicles The
act was motivated by a variety of factors First and foremost the public was
growing increasingly concerned over the rising number of traffic fatalities on
the nations roads Such fatalities had increased by nearly 30 percent
between 1960 and 1965 and experts forecasted 100000 such deaths
Page 16 of 45
annually by 1975 unless something was done to improve traffic safety
Adding fuel to the fire Ralph Naders Unsafe at Any Speed published in
November 1965 criticized the automobile industry for neglecting safety in
favor of power and styling when designing new vehicles
4 The reason for the historical
decrease in highway fatalities
A recent news item see link given below regarding renewed attempts to
increase the speed limit by many states prompted this write up by the
present author who has studied traffic fatality data extensively and analyzed
them very carefully over the last several years
httpmoneymsncomauto-insurancewhy-speed-limits-are-
risingaspxGT1=33033
Residents of Metro Detroit area who frequently cross into Ohio from
Michigan notice that the speed limit has now increased in Ohio The speed
limit on Michigan highways was increased to 70 mph in the late 1990s but
Ohio retained its lower speed limit for many years leading Michigan drivers to
experience a ―speed trap of sorts The speed limit is also increasing in many
other states notably Texas where it is proposed to increase it to 85 mph at
least in West Texas
Historically speaking from a traffic fatality standpoint we must consider two
important dates 1966 and 1973 Only 1973 the year of the Arab oil embargo
following the Arab-Israeli war (that led to what President Obama has recently
called the pre-1967 border for Middle East peace) is mentioned in the above
article It fails to mention the significance of the year 1966
Prior to 1966 there was actually NO speed limit in many Western states and
deaths due to highway accidents were increasing year after year The
Page 17 of 45
number of highway fatalities went up from 38702 in 1957 to 51524 in 1965
a 33 increase over the 1957 level and an additional 12822 deaths in 1965
compared to 1957 It was this carnage on the US highways that forced
Congress to hold its hearings on highway traffic fatalities in 1966
Nonetheless a careful examination of the fatality data in Table 1 shows that
notwithstanding the highly publicized Congressional hearings of 1966 and
new safety legislation that was enacted the absolute number of fatalities
continued to increase after 1966 and only started decreasing after 1973
Vehicle designs especially the introduction of safety features (even the
simplest like safety belts) did not change significantly between 1966 and
1973 Nonetheless post-1973 we begin to see a dramatic turnaround
Why
After the 1973 Arab oil embargo a nationwide maximum speed limit (NMSL)
of 55 mph was imposed and accepted in the USA (effective Jan 1 1974)
during the Nixon administration primarily as an effort to conserve fuel and
reduce the US vulnerability to oil imports The unintended and indeed
fortunate consequence of this reduced speed limit was the immediate
reduction in the fatalities revealed in Figures 2 and 3 This is the real reason
for the peaks in highway fatalities observed in these two graphs
The Congressional hearings of 1966 did eventually have an impact but it was
a delayed one The impact of the 1973 nationwide speed limit of 55 mph was
however immediate as we see from the magnified plot of the same data in
Figure 5 and a closer examination of the raw fatality data in Table 1
The number of highway-accident-related fatalities decreased immediately
from a high of 55704 in 1972 to just 46078 in 1974 a 173 drop see
arrows There were 9626 fewer deaths annually even with a slight increase
in the vehicle miles driven (see Table 1) Indeed the number of highway
death reached its absolute peak value in 1972 never to be seen again
Fatalities have been decreasing every since with slight fluctuations about
each new low value
Page 18 of 45
Figure 5 Expanded view of the fatality data showing the immediate impact of the
national speed limit of 55 mph following the Arab oil embargo of 1973 Note that
fatalities continued to rise between 1966 and 1973 in spite of the highly publicized
Congressional hearings in 1966 and the traffic safety legislation enacted soon after
Each new low is probably associated with vehicle safety innovations and the
improvements in vehicle design and engineering The combined beneficial
effect of improved vehicle designs primarily the introduction of seat belts
and the laws enforcing usage of seat belts aided by the reduced speed
limits contributed to the continued decline in the absolute number of fatalities
that started since 1973 and has continued to this day The subsequent
introduction of other safety features notably air bags has contributed to a
further reduction in highway fatalities
Page 19 of 45
State police Trooper First Class Jeffrey Flowers looking at a car in which a Boswell
Pennsylvania woman was injured Tuesday (May 31 2011) The accident occurred at
an intersection when a truck (seen behind the wrecked car) entered this accident
prone intersection (part of a highway safety corridor where signs are posted to
reduce unsafe driver behavior) There have been four accidents at this intersection
since 2006 none fatal httpwwwdailyamericancomnewssomersetda-ot-woman-
injured-in-route-30-wreck-2011053104165420story
5 Numerical calculations of decline in
fatalities and the impact of NMSL post-1973
Letlsquos consider the decline in fatalities between 1972 the last year before the
adoption of the NMSL and 1974 the first year following its adoption after the
Arab oil embargo There was an immediate decrease in the number of
fatalities by 9393 ie y = -9393 with a slight increase in the VMT ie x
= 20758 millions The NHTSA data used here may be found in the table at
the end of this document The numerical value of the rate of change per
billion VMT (ie neglecting the sign) was therefore
yx = 4525 fatalitiesbillion VMT (1972-1974)
Page 20 of 45
It is instructive to compare this rate of change in fatalities with similar short
periods of a decline in fatalities in the pre-1973 era when speed limits were
much higher The absolute number of fatalities declined over a relatively
short period with both an increase and a decrease in VMT The results are
given below and are self-explanatory
yx = 454 fatalitiesbillion VMT (1953-54) decline with increase in VMT
yx = 655 fatalitiesbillion VMT (1942-43) decline with decrease in VMT
yx = 1739 fatalitiesbillion VMT (1941-42) decline with decrease in VMT
yx = 4528 fatalitiesbillion VMT (1937-39) decline with increase in VMT
yx = 2548 fatalitiesbillion VMT (1931-32) decline with decrease in VMT
The rate of decline observed between 1953 and 1954 with an increase in
VMT was just one-tenth of that observed following the adoption of the 55
mph speed limit The war years (1941-43 WWII) and the Great Depression
era (1931-32) were accompanied by big declines in fatalities with decreasing
VMT but the rate of change was still significantly lower than observed after
the adoption of the NMSL
The only apparently inexplicable decline is that between 1937 and 1939
where a nearly identical high rate of decline was observed Notice also the
big drop in the traditional fatality rate between 1937 and 1938 This large drop
appears to coincide with the creation of the National Safety Council (NSC) by
William H Cameron in June 1937 (see link below) with its far-flung campaign
of education legislation research highway engineering and traffic training
undertaken by the NSC and some two dozen other groups with the backing of the
automotive industry through its Automotive Safety Foundation Other factors
unknown to the present author probably also played a role
httpwwwtimecomtimemagazinearticle0917188379700htmlixzz1O2G
7rnUg
Page 21 of 45
These simple computations here however reveal the significant effect of
reduced speed limits on highway fatalities much more so than other factors
6 Further Considerations Pros and Cons
The singular effect of increased speeds (or speeding) on highway fatalities
has been studied and demonstrated by a number of industry sources such
as the Insurance Institute for Highway Safety (IIHS) Consumers Union and
also by government researchers
httpwwwsmartmotoristcomtraffic-and-safety-guidelineexcessive-speed-is-
a-factor-in-one-third-of-all-fatal-crasheshtml
httpwwwconsumersunionorgotherspeedlimitsspeed031500a2htm
Speed ndash defined as exceeding the posted speed limit or driving too fast for
given conditions ndash is a factor in nearly one-third of all fatal crashes Besides
fatality in 1998 nearly 40000 people were critically injured in speed-related
crashes and nearly 72000 were moderately injured
The salutary and immediate beneficial effect of the nationwide 55 mph speed
limit has been noted by other researchers (see Susan Ferguson link below)
httpwwwnhtsagovpeopleinjuryenforcespeed_forum_presentationsfergu
sonpdf
After a partial repeal of this law in 1987 which granted states the authority to
increase speed limit (especially in rural interstates) a 1989 study showed a
15 increase in fatalities in rural interstates and a 5 increase in non-rural
interstates Unfortunately such studies often tend to be discounted by
advocates of increasing the speed limits as being produced by biased
industry sources
Similar conclusions were also presented by NHTSA in February 1998 in its
report to the Congress entitled ―Report to Congress The Effect of Increased
Speed Limits in the Post-NMSL Era see link given below Among its key
Page 22 of 45
findings is the following quoted in its entirety NMSL refers to the National
Maximum Speed Limit legislated after the Arab oil embargo of 1973
httpwww-nrdnhtsadotgovPubs808-637PDF
hellip Nevertheless it is important to note that data currently available from the
National Highway Traffic Safety Administrationrsquos (NHTSA) Fatality Analysis
Reporting System (FARS) shows that states that increased speed limits in 1996
experienced approximately 350 more Interstate fatalities than would have been
expected based on historical trends -- about 9 percent above expectations
Concurrently the Interstate fatalities experienced in states that did not increase speed
limits in 1996 was consistent with pre-1996 trends The estimated increase in
Interstate fatalities found in this study while smaller in magnitude compared to the
estimated change in fatalities found in 1987 following the increase of speed limits on
rural Interstates does follow the historical pattern of increases in fatalities being
associated with increases in posted speed limits
The annual crash reports compiled by NHTSA see Table 3 indicate that the
number of fatal crashes (and hence fatalities using the regression equation
developed in Figure 4) increase as the posted speed limits increase
Page 23 of 45
Table 3 Posted speed limits and number of crashes
Speed Limit Crashes (2008) Crashes (2009)
30 mph or less 3705 3277 35 or 40 mph 6115 5516 45 or 50 mph 6461 6074
55 mph 9794 8847 60 mph or higher 6908 6124
Total 34017 30797
Source httpwww-nrdnhtsadotgovPubs811402EEpdf
61 Studies cited in favor of lower speed limits
A detailed analysis of speeding related fatalities (see link below) by NHTSA
shows that a third of all crashes involve speeding ie at least one driver was
speeding
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Furthermore the above report which covers the period 1983-2002
indicates that immediately after the NMSL was completely abolished in
December 1995 the number of speeding related fatalities at speeds
above 65 mph increased from just 15 in 1995 to a 677 in 1996 (see Table
62 on page 43 of above report) It continued to increase in the years
since climbing to 930 in 2000
More detailed studies similar to that noted above by researchers at the
University of Illinois Chicago led by Lee S Friedman again lead to the
conclusion that higher speed limits lead to an increase in the number of
fatalities (see American Journal of Public Health online July 16 2009)
httphealthusnewscomhealth-newsmanaging-your-
healthcarearticles20090716deaths-injuries-increase-with-higher-speed-
limits
Page 24 of 45
httpwwwmedpagetodaycomPublicHealthPolicyPublicHealth15122
httpwwwamericaneercomspeed-limits
httpwwwactuarialoutpostcomactuarial_discussion_forumarchiveindexph
pt-171870html
For the study period 1995-2005 these researchers found that 12545 deaths
and 36582 injuries could be attributed to the increased speed limits The
benefits of reduced speed limits are stated quite eloquently by Dr Friedman
and are reproduced below (from above news article see link)
Reduced speed limits would save lives Friedman said They would also reduce
gas consumption cut emissions of air pollutants save valuable years of productivity
(lost due to injuries)and reduce the societal cost of motor vehicle crashes (due to
both fatal crashes and due to nonfatal and severe life-changing injuries) he added
Friedman and coworkers have also shown that increasing the speed limit led
to an immediate increase in the number of fatalities on Israeli roadways (see
link below)
httpinjurypreventionbmjcomcontent133156
The effect of speeding is very significant especially in rural areas resulting
in significantly higher fatalities Fatality rates are frequently double or triple
that in urban areas (see link below)
httpsafetyfhwadotgovspeedmgtdata_factsdocsspeeding_ruralpdf
As of Jan 1 2005 five Midwestern states had increased the speed limits to
above 65 mph (Illinois Iowa Kansas Minnesota Missouri Nebraska and
South Dakota) whereas three (Illinois Iowa and Wisconsin) had not All the
five states with increased speed limits showed a 7 to 13 increase in
fatalities The NHTSA study considered an eight year period before and after
the change in Dec 1995 (see Table 1 in link below) The collective experience
of the states that did NOT increase the speed limit was a 7 decline in
fatalities (see Table 2 of link below)
httpwwwiowadotgovmvdodsstats2006speedstudypdf
Page 25 of 45
Moreover Table 5 in the above study shows the effect of imposing the NMSL
of 55 mph in Iowa and its repeal in 1995 Considering a four-year average
before 1974 when the speed limit was 75 mph there were 35 fatal crashes
with 43 fatalities In the first four years after the 55 mph there were only 23
fatal crashes and 28 fatalities In the last four years before the repeal of 55
mph in 1995 there was a further decline to 14 fatal crashes with 17 fatalities
The Iowa fatality data will be discussed in more detail separately (in a later report)
since it provides the opportunity to assess the effect of a change in the speed limit
on the relationship between number of fatalities and fatal crashes (as seen in
Figure 4 for the US as a whole)
North of the US border Canadians seem to be citing the ―shocking increase
in highway fatalities in the US states where the speed limits were raised to
curb their own speed limits
httparchivesafety-councilorginfotrafficspeed-02html
httparchivesafety-councilorginfotrafficspeedhtml
Speed kills but speed also sells notes the second of the above news items
Manufacturers are producing more high performance cars (with higher horse
power to weight ratio) and ads feature enticing cars that race and swerve in
miraculous ways on empty roads These subliminal messages encourage
drivers especially young drivers to break the speed limit leading to the
absolute increase in highway fatalities (although the rate itself is going
down) The article emphasizes the need to enforce the speed limit on
Canadian highways and in cities where street racing is becoming a problem
62 Studies cited by opponents of lower speed limits
In fairness to quote the opponents on the other side of this debate Montana
reverted back to Reasonable and Prudent speed limits when the National
Maximum Speed Limit was repealed in 1995 and appears to have
experienced no significant increase in fatalities
Page 26 of 45
httpwwwhwysafetycomhwy_montanahtm
httpwwwmotoristsorgpressmontana-no-speed-limit-safety-paradox
httpwwwsouthbayriderscomforumsshowthreadphpt=81453amppage=1
Likewise studies in the state of Maryland showed no significant increase in
highway fatalities when the speed limit was increased from 55 mph to 75
mph The reason might simply be that drivers were already speeding much
more so when the speed limit was 55 mph than after the increase to 75 mph
In other words the fatalities data already reflects the effect of higher speeds
(not speed limits) on the number of fatalities
In Utah the experimental increase in the speed limit to 80 mph was
considered to be a success in terms of safety
httpautosaolcomarticleutah-speed-limit-tests
The UDOT Director noted that there was no increase in the number of
accidents on Interstate 15 But what happens in the event of an accident
when the speed limits are higher and drivers are driving at higher speeds and
two objects collide at this higher speed However no increase in the number
of accidents is not the same as no increase in fatalities due to the higher
speeds When accidents do occur do fatalities increase
Likewise in California when the speed limit went up from 55 mph to 65
mph in 1995 (after repeal of NMSL) fewer deaths were reported in 1998
compared to the peak year of 1979 or even 1987 Again the explanation
seems to be that motorists were already speeding when the limit was 55 mph
and that increasing the speed limit did not change driver behavior in any
significant way
httparticlessfgatecom1998-11-02news17735730_1_speed-limits-mph-
limit-death-rate
The National Motorists Association (NMA) a group which advocates higher
speed limits emphasizes the importance of considering fatality rates as
opposed to the raw fatalities The argument used is that fatality rates based
on the fatality per 100 million VMT is the legitimate way to look at the data
Page 27 of 45
This is a never ending debate Historically speaking fatality rates have been
going down ever since the compilation of traffic accidents data began Table
A1 in the appendix of a recent report by NHTSA (see link below) has highway
fatality rate data going back 1921
httpwww-nrdnhtsadotgovPubs811346pdf see appendix page 31
httpwwwmotoristsorgspeed-limitstruth
httpwwwmotoristsorgothercrash-data
httpwwwraisethespeedlimitorgmythshtml
httpwwwcatoorgpubspaspa346pdf
According to Stephen Moore of the Cato Institute (see last of the links above)
―All measures of highway safety show improvement not more deaths and
injuries since 1995 Despite the fact that 33 states raised their speed limits
immediately after the repeal of the mandatory federal speed limit the NHTSA
reported last October that the traffic death rate dropped to a record low level
in 1997lsquo Moreover the average fatality rate even fell in the states that raised
their speed limits
63 The Fatality rate Is it a reliable metric
In 1921 with fewer fatalities and fewer miles driven and the first year for
which the fatality rate could be computed the rate was 2408 It was down to
1479 in 1931 but the number of deaths had climbed to 31963 more than
double the 1921 absolute fatality number of 13253 It had dropped to 550 in
1966 the year of the highly publicized Congressional hearings but the
number of fatalities had climbed to 50984 in that fateful The Highway Safety
Act of 1966 ranks as one of the major acts of Congress and President
Johnson signed it saying that ―we have been tolerating a raging epidemic of
highway deathshellip see extract pasted below
httpwwwenotescommajor-acts-congresshighway-safety-act
Page 28 of 45
The act was motivated primarily by growing public concern over the rising number
of traffic fatalities in the United States Between 1960 and 1965 the annual number
of traffic fatalities increased by nearly thirty percent As President Lyndon B
Johnson stated at the signing of the act on September 9 1966 we have tolerated
a raging epidemic of highway death which has killed more of our youth than all
other diseases combined Through the Highway Safety Act we are going to find out
more about highway diseasemdashand we aim to cure it
Nonetheless highways fatalities continued to increase until the Arab oil
embargo of 1973 led to the NMSL of 55 mph all across the USA Do we just
ignore this undeniable historical record and focus only on the declining fatality
rate as the NMA and other proponents of higher speed limits seem to argue
(see links above)
The misleading nature of using fatality rates (per 100 M VMT) alone is also
obvious if one considers fatality data for individual states Take for example
the state of Montana which seems to have experienced no increase in
fatalities after repeal of NMSL
httpwww-nrdnhtsadotgovdepartmentsnrd-
30ncsaSTSI30_MT200930_MT_2009htm
For the period 2005-2009 the absolute number of fatalities for Montana
varied between a high of 277 in 2007 to a low of 229 in 2009 The fatality
rates per 100 M VMT on the other hand varied from a high of 245 for 2007
to a low of 201 for 2009 The corresponding US fatality rates varied from
136 to 114 Is the higher number for the fatality rate for Montana compared
to USA good or bad Likewise fatality rate per 100000 of population was
much higher for Montana than the US as a whole
This again highlights the pitfalls of using simple ratios to assess fatality statistics
without a full analysis of the underlying trends We will discuss this point
separately
As shown already the continuous decline in the fatality rate is a mathematical
artifact and essentially overlooks the unmistakable positive correlation
between the variables x and y of the type y = hx + c which becomes obvious
Page 29 of 45
only when we prepare the x-y scatter graph The ratio yx = h + (cx) can
decrease with increasing x (VMT) and increasing y (fatalities) since the
intercept c has a positive value when we consider only data spanning a short
period (such as 1994-2009 of more relevance to the current situation)
The debate between fatality rates and absolute number of fatalities is an
unending one A few years ago the Wall Street Journal carried an article
which was entitled (or something close) ―Unemployments rate in Ohio are
going down but why is the number of unemployed increasing The reason is
the same The graph of the number of unemployed (y) versus the number in
the labor market (x) is linear with a positive slope h and a positive intercept c
So the unemployment rate computed using the ratio yx keeps going down
year after year although the number unemployed keeps increasing Is it a
good thing that the unemployment rate is going down when more people
seem to be unable to find gainful unemployment
Or consider the situation with cancer death rates This too has been going
down in recent years but the actual number of cancer-related deaths has not
declined in any significant way Is it good that cancer death rates are going
down In all these situations the researchers or the socio-econo-politico
analysts involved in analyzing the trends in the data have failed to consider
the underlying x-y relation describing each problem
Hence it appears that the debate on the effect of increased speed limits
should not be focused on only the fatality rates (which have been decreasing
and proponents of higher speed limits cite this in their arguments) or even the
absolute number of fatalities (which has been the focus here) but on the
relationship between speed and the number of fatal crashes and the number
of fatalities within each speed segment (see Table 3 and also Figure 4)
Unfortunately details of number of fatalities and the number of fatal crashes
at each speed limit are not available even from NHTSA for detailed study
When a crash does occur (it is immaterial how many miles were driven) the
speed of the driver and vehicle design and engineering including safety
devices in place (seat belts airbags other impact absorbing technologies)
Page 30 of 45
determine if the occupants(s) will be killed One cannot argue that speed
does NOT kill That would be an absolute denial of the laws of physics
Studies show that setting the speed limit at the 85th percentile in any given
zone (this is the speed at or below which 85 of drivers are observed to
travel in traffic engineering studies) is the safest speed limit The majority of
drivers try to obey the posted speed limit while a few choose to drive at a
speed they consider is safe and prudent These are also perhaps the most
vociferous advocates of higher speed limits It is this tension caused due to
differences in speeds that leads to tailgating improper passing reckless
driving weaving from lane to lane and ultimately crashes and deaths in some
unfortunate cases
httpblogmotoristsorgspeed-limits-slower-safer
MARK TAYLOR
ANOTHER LOST A man was killed when his 4WD drive hit a tree east of Morrinsville (in New
Zealand) on Monday May 30 2011 The driver lost control of the vehicle on a bend probably tried
to correct his mistake and put the car into a ―yaw causing it to leave the road and smash sideways
into a tree Alerts to slow down had been posted since this was a high accident area but the driver
probably did not pay attention
64 Other factors
Many other factors besides speed no doubt affect highway fatalities The
vehicles of the 21st century are very different from the vehicles of the mid 20th
Page 31 of 45
century Technological innovations such as improvements in vehicle design
and engineering have greatly increased crash worthiness of vehicles even at
high speeds Environmental factors such as the weather also contribute to
accidents but not necessarily to increased fatalities Drivers actually tend to
slow down instinctively during adverse weather conditions (rain snow storms
etc) and although such weather may contribute to increased accidents the
lower speeds actually reduce fatalities
Yes technology has changed fundamentally from 1966 Drivers today are
more distracted by their cellmobile phone conversations (and also built-in
phones in luxury models) and text messaging than the drivers of the pre-1966
era High end cars now have many multimedia and internet features Again a
careful observation (even personal experience by the author) suggests that
such distracted drivers actually tend to (instinctively) drive more slowly and
hold up the traffic Perhaps such behavior leads to an increase in the number
of accidents but it does not necessarily lead to an increase in the number of
accident-related fatalities
Much talked about technological innovations such as automatic collision
avoidance systems and sensors (on the sides of vehicles) can indeed detect
vehicles in the front and neighboring lanes Furthermore vehicle-to-vehicle
communication systems vehicle-to-infrastructure communication systems
can no doubt avoid collisions and accidents Again such collision avoidance
systems work and are effective entirely because they automatically reduce
vehicle speeds - even if one of the offending vehicles is being at a super
high speed Also it must be remembered that such futuristic systems have
not yet been implemented widely nor can they be implemented widely since
the large majority of vehicles on the road are NOT luxury models Advanced
safety features come with a price and not all drivers can afford to pay that
price and ―buy that ―additional safety
Ultimately it is the laws of physics that govern what will happen when two or
more vehicles collide or even when a single vehicle collides with a stationary
infrastructural object (a bridge a wall a building or some impediment on the
road) The lower the number of crashes the lower the number of fatalities as
revealed by the 1994-2009 data graphed in Figure 5 The higher the speed of
Page 32 of 45
the object or objects that are involved in a collision the higher the kinetic
energy K that must be absorbed andor dissipated Increasing the posted
speed limit only increases the energy that must be absorbed when a crash
does occur This ultimately is the most important criterion determining the
number of fatalities
The kinetic energy increases as the square of the speed being given by the
well-known formula K = frac12 mv2 where m is the mass of the vehicle (in
laypersonlsquos language m increases directly with vehicle weight) and v is the
speed For the same vehicle mass an increase in the speed from 55 mph to
85 mph increases the kinetic energy K by a factor of 239 or roughly a 250
increase in the kinetic energy that must be absorbed in a collision
Ideally speaking the kinetic energy of the colliding object(s) is absorbed by
the vehicle infrastructure (a sturdy space frame the engine other vehicle
components etc) andor the surroundings However in the unfortunate
cases where this kinetic energy must be absorbed by the vehicle occupant(s)
the result is severe life-altering injuries andor death An unequivocal
relationship between an increase in vehicle speeds and fatal accidents can
be demonstrated by a careful examination of available traffic fatality data
This is a more involved discussion and is not the purpose of this short
communication These topics are no doubt very politically charged with many
social legal and financial implications with each interest group favoring a
different conclusion Nonetheless we cannot escape the laws of physics as
they govern the fundamental need to absorb higher and higher values of the
kinetic energy K with increasing vehicle speeds This same point is also
emphasized by Dr Friedman of the University of Illinois Chicago (see earlier
discussion)
Speed kills because of these energy transfer considerations and there can be
no doubt about it
Innovative 21st century solutions to speed management on the highways
such as strict enforcement of speed limits minimizing speed dispersion
(difference between speeds at which different drivers travel) while using
cameras to track the 15 of drivers who willfully violate the speed limit and
Page 33 of 45
create hazardous driving conditions is certainly recommended (Recall that
the optimum recommended speed limit is at or below which 85 of all drivers
travel ndash a policy also supported by NMA) Even on this score however the
results are confounding if we consider the Australian experience
httpwwwthenewspapercomnews282840asp
Up until 2007 there was no speed limit in the Northern Territory of
Australia Imposing a speed limit 130 kmph (80 mph) on some areas and
110 kmph (68 mph) in some others actually increased the number of deaths
The death toll in 2006 when there was no speed limit in this region was 44
and went up to 75 in 2009 see data table in link below
httpwwwthenewspapercomrlcdocs2009au-ntroadtollpdf
Furthermore it appears that installation of cameras to enforce speed limits
has proved to be a hazardous distraction to drivers and deaths actually
began to skyrocket between 2005 and 2007 in all Australian roadways
The main purpose here is to sound a cautionary note amid renewed attempts
in many states across the US to increase the speed limits on our highways by
calling attention to the historical facts regarding the ―epidemic levels of
highway traffic fatalities that engaged our national attention in the fateful year
of 1966 The graphical representation of the traffic fatality data in Figures 1
to 5 tells its own story
Indeed it would be tragic if highway-accident-related fatalities were to start
increasing once again and reach the historically high level that was last seen
in 1972 the year before the Arab oil embargo of 1973
Page 34 of 45
Conclusions
1 The graphical representation of the highway fatality data and the brief
summary of the historical facts of traffic safety legislation suggest that
recent attempts to increase the speed limits by various states (notably
Texas) may be misguided The distinct peak in the highway fatalities
observed in these graphs is highly alarming This appears to be related to
the enactment of the National Maximum Speed Limit (NSML) in 1974
following the 1973 Arab oil embargo Although NSML was motivated by a
desire to reduce gasoline consumption an unintended benefit might have
been a dramatic reduction in fatalities The fundamental reasons for the
peak in the fatalities-VMT curve must be examined carefully without
political posturing
2 The widely used fatality rate fatalities per 100 M vehicle miles traveled
has been declining since 1921 the first year for which a fatality rate could
be computed and has now reached a historical low The absolute number
of fatalities on the other hand was increasing in the 1950s and 1960s at
an alarming rate and the public outcry that ensued led to the highly
publicized Congressional hearing of 1966 and the subsequent traffic safety
legislations The fatality rate has been decreasing even in the most recent
15-year period (1994-2009) again with increasing fatalities although less
dramatically Thus it appears that fatality rate calculation based on vehicle
miles traveled (VMT) might not be a reliable indicator of the underlying
dynamics in the fatality trends
3 More detailed compilation of number of fatalities and the number of fatal
crashes within each speed limit segment is required to better understand
the effect of increasing speed limits on highway fatalities (and also fatality
rates) Such data is already available and is being compiled at the local
city and county levels in all jurisdictions and only needs to be reorganized
to highlight the effect of (posted) speed limits on the number of crashes
and fatalities This will require some minor rewriting and revisions to the
chapters named ―Crashes and ―States in the annual NHTSA reports
Page 35 of 45
Analysis of the fatalities-crashes data for several years with various
speed limits will be more revealing and meaningful than the current
fatality rates analysis and will be discussed separately in a follow up
report
4 One should not be lulled by the fact that vehicles of the 21st century are
now equipped with advanced safety features not available in the 1950s
and the 1960s In spite of these safety features the laws of physics dictate
that the higher the speed the higher kinetic energy of the colliding objects
and hence the greater the risk indeed near certainty of fatalities in a
higher speed collision compared to a lower speed one
5 The higher the speed at which the vehicle that is involved in a crash is
traveling the higher the kinetic energy that must be absorbed andor
dissipated without affecting the occupant(s) to avoid serious injuries andor
death This was true in the 1950s and the 1960s and will continue to be
true in the 21st century as well
Speed Kills for this just reason
6 It appears that higher fuel economies and reduced
highway fatalities were the twin societal benefits of 55
mph adopted after 1973 If so the current attempts to
increase the speed limits appear to be in conflict with
other important societal objectives
Page 36 of 45
Table 1 Annual US Street amp Highway
Fatalities from 1957
Year
Fatalities
Vehicle Miles
(millions)
Rate100M Vehicle Miles
1957 38702 646915 598
1958 36981 664915 556
1959 37910 700478 541
1960 38137 718845 531
1961 38091 737535 516
1962 40804 766852 532
1963 43564 805423 541
1964 47700 846500 563
1965 49163 887640 554
1966 51524 927915 555
1967 51559 965132 534
1968 53831 1019726 528
1969 55032 1066108 516
1970 53672 1114098 482
1971 53761 1183524 454
1972 55704 1264614 440
1973 55113 1316207 419
1974 46078 1282790 359
1975 45500 1330074 342
1976 45523 1402380 325
1977 47878 1467027 326
1978 50331 1544704 326
1979 51103 1529133 334
1980 51091 1527295 335
1981 49301 1552803 317
1982 43945 1595010 276
1983 42589 1652788 258
1984 44257 1720269 257
1985 43795 1774179 247
Page 37 of 45
1986 46056 1835000 251
1987 46385 1921000 241
1988 47093 2026000 232
1989 45555 2107040 216
1990 44529 2147501 207
1991 41162 2172214 189
1992 39235 2239828 175
1993 40115 2296585 175
1994 40676 2359984 172
1995 41798 2422696 173
1996 41907 2485848 169
1997 41967 2560373 164
Data from Federal Highway Administration
Source httpwwwpublicpurposecomhwy-fatal57+htm
Telephone +16186328507 - Facsimile +16186328538
WENDELL COX CONSULTANCY P O Box 841 - Belleville IL 62269 USA
Page 38 of 45
Fatality data for 1921-1982 compiled by NHTSA
Year
VMT
(Millions)
VMT
(Billions)
Fatalities
Fatality rate
per 100 M VMT
1921 55027 5503 13253 241 1922 67697 6770 14859 219 1923 84995 8500 17870 210 1924 104838 10484 18400 176 1925 122346 12235 20771 170 1926 140735 14074 22194 158 1927 158453 15845 24470 154 1928 172856 17286 26557 154 1929 197720 19772 29592 150 1930 206320 20632 31204 151 1931 216151 21615 31963 148 1932 200517 20052 27979 140 1933 200642 20064 29746 148 1934 215563 21556 34240 159 1935 228568 22857 34494 151 1936 252128 25213 36126 143 1937 270110 27011 37819 140 1938 271177 27118 31083 115 1939 285402 28540 30895 108 1940 302188 30219 32914 109 1941 333612 33361 38142 114 1942 268224 26822 27007 101 1943 208192 20819 22727 109 1944 212713 21271 23165 109 1945 250173 25017 26785 107 1946 340880 34088 31874 94 1947 370894 37089 31193 84 1948 397957 39796 30775 77 1949 424461 42446 30246 71 1950 458246 45825 33186 72 1951 491093 49109 35309 72
1952 513581 51358 36088 70
Page 39 of 45
1953 544433 54443 36190 66 1954 561963 56196 33890 60 1955 605646 60565 36688 61 1956 627843 62784 37965 60 1957 647004 64700 36932 57 1958 664653 66465 35331 53 1959 700480 70048 36223 52 1960 718762 71876 36399 51 1961 737421 73742 36285 49 1962 766734 76673 38980 51 1963 805249 80525 41723 52 1964 846298 84630 45645 54 1965 887812 88781 47089 53 1966 925899 92590 50894 55 1967 964005 96401 50724 53 1968 1015869 101587 52725 52 1969 1061791 106179 53543 50 1970 1109724 110972 52627 47 1971 1178811 117881 52542 45 1972 1259786 125979 54589 43 1973 1313110 131311 54052 41 1974 1280544 128054 45196 35 1975 1327664 132766 44525 34 1976 1402380 140238 45523 32 1977 1467027 146703 47878 33 1978 1544704 154470 50331 33 1979 1529133 152913 51093 33 1980 1527295 152730 51091 33 1981 1555308 155531 49301 32 1982 1595010 159501 43945 28
Source Analysis of Significant Decline in Motor Vehicle Traffic Fatalities in
2008 httpwww-nrdnhtsadotgovPubs811346pdf see Table A1 page 31
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Page 40 of 45
Acknowledgements
The author is grateful for thoughtful comments provided by friends and colleagues
with whom this document was shared via email prior to it being uploaded as a
publicly available document for wider dissemination and study The comments
offered by Prof Subra Ganesan of Oakland University Electrical and Computer
Engineering Department are reproduced with permission in their entirety
About the author
The author obtained his Masterrsquos (S M) and Doctoral (Sc D) degrees in Materials Engineering
from the Massachusetts Institute of Technology Cambridge USA He then spent his entire
professional career at leading US research institutions (MIT NASA Case Western Reserve
University and General Motors R amp D Center in Warren MI) He holds four patents in advanced
materials processing has co-authored two books and has published several scientific papers in
leading peer-reviewed international journals His expertise includes developing simple
mathematical models to explain the behavior of complex systems He can be reached by email at
vlaxmananhotmailcom
Page 41 of 45
Please Buckle Up
httpwwwlakecountypublichealthorgindexphpbuckle-up-montana
Public Awareness
Respect the Cage Exhibit
The Department of Transportation hopes that showing the reality of the crash will reduce traffic
fatalities A crushed car crash dummies and a sobering message ndash all part of the ―Respect The
Cage exhibit that is traveling across Montana The exhibit sponsored by the Montana Department
of Transportation stopped in Ronan on November 6th and is aimed at raising awareness about the
importance of wearing seat belts
The car in the exhibit was in an actual wreck many years ago
the passenger in the vehicle died because he was not wearing a
seat belt the driver who was wearing his seat belt survived
Montanarsquos likeliest crash fatality scenario
A Pickup
A Rural road
And Seat belts that
arenrsquot used
Page 42 of 45
Occupants of pickups are less likely to wear seat belts and pickups are more likely to
roll over than passenger cars
Seat belts reduce the risk of death by 60 percent in pickups and SUVs
In Montana from 2006-2008 81 of those killed in a crash while riding in a pickup were not wearing seat belts
In Montana pickups make up 401 of the vehicle population
For more information on Respect the Cage click here
Page 43 of 45
Appendix 1
Lack of seat belts leading cause of Louisiana highway deaths
1251 AM May 28 2011 |
Written by Adam Duvernay
Crashes involving unbuckled motorists were the leading cause of highway fatalities
in Louisiana last year and cost $9888 million according to recent reports The
Louisiana Highway Safety Commission reported 59 percent of vehicle occupants
killed in Louisiana crashes last year mdash about one in four mdash werent wearing seat
belts
httpwwwshreveporttimescomarticle20110528NEWS01105280354Lack-seat-
belts-leading-cause-La-highway-deathsodyssey=tab|topnews|text|FRONTPAGE
Crash bull Stats Published by NHTSAlsquos National Center for Statistics and Analysis 1200 New Jersey Avenue SE Washington DC 20590
DOT HS 811 451
Early Estimate of Motor Vehicle Traffic Fatalities in 2010
httpwww-nrdnhtsadotgovPubs811451pdf
Summary
A statistical projection of traffic fatalities in 2010 shows that an estimated 32788
people died in motor vehicle traffic crashes This represents a decline of about 3
percent as compared to the 33808 fatalities in 2009 as shown in Table 1 If these
projections are realized fatalities will be lowest on record (since 1949)
Traffic Safety Facts Overview 2009 Data
httpwww-nrdnhtsadotgovPubs811392pdf
In 2009 33808 people were killed in the estimated 5505000 police-reported
motor vehicle traffic crashes 2217000 people were injured and 3957000
crashes involved property damage only Compared to 2008 this is a 10-
percent decrease in the number of fatalities and a 5-percent decrease in the
Page 44 of 45
number of police-reported motor vehicle traffic crashes people injured and
crashes involving property damage
An average of 93 people died each day in motor vehicle crashes in 2009 mdash
an average of one every 16 minutes
Traffic Safety Facts Overview 2008 Data
httpwww-nrdnhtsadotgovPubs811162pdf
In 2008 37261 people were killed in the estimated 5811000 police-reported
motor vehicle traffic crashes 2346000 people were injured and 4146000
crashes involved property damage only
Some comments and Feedback
The following comments were received from Prof Ganesan after his review of the
first draft of this document It was subsequently revised thanks to this input to
address some of the very important issues raised here
Dear Laxman
The write up is not enough
You are emphasizing that the speed limit reduces the fatal accidents (comparing 1966
to 2000 accident numbers)
Can you also add a few sentences why the number is decreasing from 1980 to 2000
values (May be due to better design of vehicles)
Can you say anything about the fuel consumption with the speed for any typical
vehicle in 2011 or 2010 (do not consider the fatalities issue)
Probably a speed between 55 and 60 mph gives a better mileage If so this is a
compelling reason to keep the speed limit low But cars probably can be tuned to
give better mileage at any high speed also
Page 45 of 45
Weather is also a major factor in fatal accidents Speed limit may be kept low during
winter and kept higher in summer Give your comments on this too
Driver distractions can cause more accidents Now cars have many multimedia and
internet features Automatic collision avoidance systems and sensors on the sides can
detect vehicles in the front and neighboring lanes and it can automatically decrease
speed even if the driver speeds at super high speeds
Give some comments on this too There is also Vehicle to Vehicle communications
vehicle to infrastructure communications and they can avoid collisions and accidents
Technology has changed from 1966 I cannot agree with you on the speed limit
without any discussion on the above and other factors
Have a great day
Subra Ganesan
Professor Subramaniam Ganesan
Director Real Time amp DSP Lab
Electrical and Computer Engineering Department
2200 Squirrel Road Dodge Hall Room 105
Oakland University Rochester MI 48309 USA
Phone 248 370 2206 Fax 248 370 4633
wwwsecsoaklandedu~ganesan
IEEE Distinguished Visiting Speaker (2005-2009) Coordinator
IEEE SEM CS chapter Chair Region 4 and CS Society Board member
SAE ASEE ACM member
Page 16 of 45
annually by 1975 unless something was done to improve traffic safety
Adding fuel to the fire Ralph Naders Unsafe at Any Speed published in
November 1965 criticized the automobile industry for neglecting safety in
favor of power and styling when designing new vehicles
4 The reason for the historical
decrease in highway fatalities
A recent news item see link given below regarding renewed attempts to
increase the speed limit by many states prompted this write up by the
present author who has studied traffic fatality data extensively and analyzed
them very carefully over the last several years
httpmoneymsncomauto-insurancewhy-speed-limits-are-
risingaspxGT1=33033
Residents of Metro Detroit area who frequently cross into Ohio from
Michigan notice that the speed limit has now increased in Ohio The speed
limit on Michigan highways was increased to 70 mph in the late 1990s but
Ohio retained its lower speed limit for many years leading Michigan drivers to
experience a ―speed trap of sorts The speed limit is also increasing in many
other states notably Texas where it is proposed to increase it to 85 mph at
least in West Texas
Historically speaking from a traffic fatality standpoint we must consider two
important dates 1966 and 1973 Only 1973 the year of the Arab oil embargo
following the Arab-Israeli war (that led to what President Obama has recently
called the pre-1967 border for Middle East peace) is mentioned in the above
article It fails to mention the significance of the year 1966
Prior to 1966 there was actually NO speed limit in many Western states and
deaths due to highway accidents were increasing year after year The
Page 17 of 45
number of highway fatalities went up from 38702 in 1957 to 51524 in 1965
a 33 increase over the 1957 level and an additional 12822 deaths in 1965
compared to 1957 It was this carnage on the US highways that forced
Congress to hold its hearings on highway traffic fatalities in 1966
Nonetheless a careful examination of the fatality data in Table 1 shows that
notwithstanding the highly publicized Congressional hearings of 1966 and
new safety legislation that was enacted the absolute number of fatalities
continued to increase after 1966 and only started decreasing after 1973
Vehicle designs especially the introduction of safety features (even the
simplest like safety belts) did not change significantly between 1966 and
1973 Nonetheless post-1973 we begin to see a dramatic turnaround
Why
After the 1973 Arab oil embargo a nationwide maximum speed limit (NMSL)
of 55 mph was imposed and accepted in the USA (effective Jan 1 1974)
during the Nixon administration primarily as an effort to conserve fuel and
reduce the US vulnerability to oil imports The unintended and indeed
fortunate consequence of this reduced speed limit was the immediate
reduction in the fatalities revealed in Figures 2 and 3 This is the real reason
for the peaks in highway fatalities observed in these two graphs
The Congressional hearings of 1966 did eventually have an impact but it was
a delayed one The impact of the 1973 nationwide speed limit of 55 mph was
however immediate as we see from the magnified plot of the same data in
Figure 5 and a closer examination of the raw fatality data in Table 1
The number of highway-accident-related fatalities decreased immediately
from a high of 55704 in 1972 to just 46078 in 1974 a 173 drop see
arrows There were 9626 fewer deaths annually even with a slight increase
in the vehicle miles driven (see Table 1) Indeed the number of highway
death reached its absolute peak value in 1972 never to be seen again
Fatalities have been decreasing every since with slight fluctuations about
each new low value
Page 18 of 45
Figure 5 Expanded view of the fatality data showing the immediate impact of the
national speed limit of 55 mph following the Arab oil embargo of 1973 Note that
fatalities continued to rise between 1966 and 1973 in spite of the highly publicized
Congressional hearings in 1966 and the traffic safety legislation enacted soon after
Each new low is probably associated with vehicle safety innovations and the
improvements in vehicle design and engineering The combined beneficial
effect of improved vehicle designs primarily the introduction of seat belts
and the laws enforcing usage of seat belts aided by the reduced speed
limits contributed to the continued decline in the absolute number of fatalities
that started since 1973 and has continued to this day The subsequent
introduction of other safety features notably air bags has contributed to a
further reduction in highway fatalities
Page 19 of 45
State police Trooper First Class Jeffrey Flowers looking at a car in which a Boswell
Pennsylvania woman was injured Tuesday (May 31 2011) The accident occurred at
an intersection when a truck (seen behind the wrecked car) entered this accident
prone intersection (part of a highway safety corridor where signs are posted to
reduce unsafe driver behavior) There have been four accidents at this intersection
since 2006 none fatal httpwwwdailyamericancomnewssomersetda-ot-woman-
injured-in-route-30-wreck-2011053104165420story
5 Numerical calculations of decline in
fatalities and the impact of NMSL post-1973
Letlsquos consider the decline in fatalities between 1972 the last year before the
adoption of the NMSL and 1974 the first year following its adoption after the
Arab oil embargo There was an immediate decrease in the number of
fatalities by 9393 ie y = -9393 with a slight increase in the VMT ie x
= 20758 millions The NHTSA data used here may be found in the table at
the end of this document The numerical value of the rate of change per
billion VMT (ie neglecting the sign) was therefore
yx = 4525 fatalitiesbillion VMT (1972-1974)
Page 20 of 45
It is instructive to compare this rate of change in fatalities with similar short
periods of a decline in fatalities in the pre-1973 era when speed limits were
much higher The absolute number of fatalities declined over a relatively
short period with both an increase and a decrease in VMT The results are
given below and are self-explanatory
yx = 454 fatalitiesbillion VMT (1953-54) decline with increase in VMT
yx = 655 fatalitiesbillion VMT (1942-43) decline with decrease in VMT
yx = 1739 fatalitiesbillion VMT (1941-42) decline with decrease in VMT
yx = 4528 fatalitiesbillion VMT (1937-39) decline with increase in VMT
yx = 2548 fatalitiesbillion VMT (1931-32) decline with decrease in VMT
The rate of decline observed between 1953 and 1954 with an increase in
VMT was just one-tenth of that observed following the adoption of the 55
mph speed limit The war years (1941-43 WWII) and the Great Depression
era (1931-32) were accompanied by big declines in fatalities with decreasing
VMT but the rate of change was still significantly lower than observed after
the adoption of the NMSL
The only apparently inexplicable decline is that between 1937 and 1939
where a nearly identical high rate of decline was observed Notice also the
big drop in the traditional fatality rate between 1937 and 1938 This large drop
appears to coincide with the creation of the National Safety Council (NSC) by
William H Cameron in June 1937 (see link below) with its far-flung campaign
of education legislation research highway engineering and traffic training
undertaken by the NSC and some two dozen other groups with the backing of the
automotive industry through its Automotive Safety Foundation Other factors
unknown to the present author probably also played a role
httpwwwtimecomtimemagazinearticle0917188379700htmlixzz1O2G
7rnUg
Page 21 of 45
These simple computations here however reveal the significant effect of
reduced speed limits on highway fatalities much more so than other factors
6 Further Considerations Pros and Cons
The singular effect of increased speeds (or speeding) on highway fatalities
has been studied and demonstrated by a number of industry sources such
as the Insurance Institute for Highway Safety (IIHS) Consumers Union and
also by government researchers
httpwwwsmartmotoristcomtraffic-and-safety-guidelineexcessive-speed-is-
a-factor-in-one-third-of-all-fatal-crasheshtml
httpwwwconsumersunionorgotherspeedlimitsspeed031500a2htm
Speed ndash defined as exceeding the posted speed limit or driving too fast for
given conditions ndash is a factor in nearly one-third of all fatal crashes Besides
fatality in 1998 nearly 40000 people were critically injured in speed-related
crashes and nearly 72000 were moderately injured
The salutary and immediate beneficial effect of the nationwide 55 mph speed
limit has been noted by other researchers (see Susan Ferguson link below)
httpwwwnhtsagovpeopleinjuryenforcespeed_forum_presentationsfergu
sonpdf
After a partial repeal of this law in 1987 which granted states the authority to
increase speed limit (especially in rural interstates) a 1989 study showed a
15 increase in fatalities in rural interstates and a 5 increase in non-rural
interstates Unfortunately such studies often tend to be discounted by
advocates of increasing the speed limits as being produced by biased
industry sources
Similar conclusions were also presented by NHTSA in February 1998 in its
report to the Congress entitled ―Report to Congress The Effect of Increased
Speed Limits in the Post-NMSL Era see link given below Among its key
Page 22 of 45
findings is the following quoted in its entirety NMSL refers to the National
Maximum Speed Limit legislated after the Arab oil embargo of 1973
httpwww-nrdnhtsadotgovPubs808-637PDF
hellip Nevertheless it is important to note that data currently available from the
National Highway Traffic Safety Administrationrsquos (NHTSA) Fatality Analysis
Reporting System (FARS) shows that states that increased speed limits in 1996
experienced approximately 350 more Interstate fatalities than would have been
expected based on historical trends -- about 9 percent above expectations
Concurrently the Interstate fatalities experienced in states that did not increase speed
limits in 1996 was consistent with pre-1996 trends The estimated increase in
Interstate fatalities found in this study while smaller in magnitude compared to the
estimated change in fatalities found in 1987 following the increase of speed limits on
rural Interstates does follow the historical pattern of increases in fatalities being
associated with increases in posted speed limits
The annual crash reports compiled by NHTSA see Table 3 indicate that the
number of fatal crashes (and hence fatalities using the regression equation
developed in Figure 4) increase as the posted speed limits increase
Page 23 of 45
Table 3 Posted speed limits and number of crashes
Speed Limit Crashes (2008) Crashes (2009)
30 mph or less 3705 3277 35 or 40 mph 6115 5516 45 or 50 mph 6461 6074
55 mph 9794 8847 60 mph or higher 6908 6124
Total 34017 30797
Source httpwww-nrdnhtsadotgovPubs811402EEpdf
61 Studies cited in favor of lower speed limits
A detailed analysis of speeding related fatalities (see link below) by NHTSA
shows that a third of all crashes involve speeding ie at least one driver was
speeding
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Furthermore the above report which covers the period 1983-2002
indicates that immediately after the NMSL was completely abolished in
December 1995 the number of speeding related fatalities at speeds
above 65 mph increased from just 15 in 1995 to a 677 in 1996 (see Table
62 on page 43 of above report) It continued to increase in the years
since climbing to 930 in 2000
More detailed studies similar to that noted above by researchers at the
University of Illinois Chicago led by Lee S Friedman again lead to the
conclusion that higher speed limits lead to an increase in the number of
fatalities (see American Journal of Public Health online July 16 2009)
httphealthusnewscomhealth-newsmanaging-your-
healthcarearticles20090716deaths-injuries-increase-with-higher-speed-
limits
Page 24 of 45
httpwwwmedpagetodaycomPublicHealthPolicyPublicHealth15122
httpwwwamericaneercomspeed-limits
httpwwwactuarialoutpostcomactuarial_discussion_forumarchiveindexph
pt-171870html
For the study period 1995-2005 these researchers found that 12545 deaths
and 36582 injuries could be attributed to the increased speed limits The
benefits of reduced speed limits are stated quite eloquently by Dr Friedman
and are reproduced below (from above news article see link)
Reduced speed limits would save lives Friedman said They would also reduce
gas consumption cut emissions of air pollutants save valuable years of productivity
(lost due to injuries)and reduce the societal cost of motor vehicle crashes (due to
both fatal crashes and due to nonfatal and severe life-changing injuries) he added
Friedman and coworkers have also shown that increasing the speed limit led
to an immediate increase in the number of fatalities on Israeli roadways (see
link below)
httpinjurypreventionbmjcomcontent133156
The effect of speeding is very significant especially in rural areas resulting
in significantly higher fatalities Fatality rates are frequently double or triple
that in urban areas (see link below)
httpsafetyfhwadotgovspeedmgtdata_factsdocsspeeding_ruralpdf
As of Jan 1 2005 five Midwestern states had increased the speed limits to
above 65 mph (Illinois Iowa Kansas Minnesota Missouri Nebraska and
South Dakota) whereas three (Illinois Iowa and Wisconsin) had not All the
five states with increased speed limits showed a 7 to 13 increase in
fatalities The NHTSA study considered an eight year period before and after
the change in Dec 1995 (see Table 1 in link below) The collective experience
of the states that did NOT increase the speed limit was a 7 decline in
fatalities (see Table 2 of link below)
httpwwwiowadotgovmvdodsstats2006speedstudypdf
Page 25 of 45
Moreover Table 5 in the above study shows the effect of imposing the NMSL
of 55 mph in Iowa and its repeal in 1995 Considering a four-year average
before 1974 when the speed limit was 75 mph there were 35 fatal crashes
with 43 fatalities In the first four years after the 55 mph there were only 23
fatal crashes and 28 fatalities In the last four years before the repeal of 55
mph in 1995 there was a further decline to 14 fatal crashes with 17 fatalities
The Iowa fatality data will be discussed in more detail separately (in a later report)
since it provides the opportunity to assess the effect of a change in the speed limit
on the relationship between number of fatalities and fatal crashes (as seen in
Figure 4 for the US as a whole)
North of the US border Canadians seem to be citing the ―shocking increase
in highway fatalities in the US states where the speed limits were raised to
curb their own speed limits
httparchivesafety-councilorginfotrafficspeed-02html
httparchivesafety-councilorginfotrafficspeedhtml
Speed kills but speed also sells notes the second of the above news items
Manufacturers are producing more high performance cars (with higher horse
power to weight ratio) and ads feature enticing cars that race and swerve in
miraculous ways on empty roads These subliminal messages encourage
drivers especially young drivers to break the speed limit leading to the
absolute increase in highway fatalities (although the rate itself is going
down) The article emphasizes the need to enforce the speed limit on
Canadian highways and in cities where street racing is becoming a problem
62 Studies cited by opponents of lower speed limits
In fairness to quote the opponents on the other side of this debate Montana
reverted back to Reasonable and Prudent speed limits when the National
Maximum Speed Limit was repealed in 1995 and appears to have
experienced no significant increase in fatalities
Page 26 of 45
httpwwwhwysafetycomhwy_montanahtm
httpwwwmotoristsorgpressmontana-no-speed-limit-safety-paradox
httpwwwsouthbayriderscomforumsshowthreadphpt=81453amppage=1
Likewise studies in the state of Maryland showed no significant increase in
highway fatalities when the speed limit was increased from 55 mph to 75
mph The reason might simply be that drivers were already speeding much
more so when the speed limit was 55 mph than after the increase to 75 mph
In other words the fatalities data already reflects the effect of higher speeds
(not speed limits) on the number of fatalities
In Utah the experimental increase in the speed limit to 80 mph was
considered to be a success in terms of safety
httpautosaolcomarticleutah-speed-limit-tests
The UDOT Director noted that there was no increase in the number of
accidents on Interstate 15 But what happens in the event of an accident
when the speed limits are higher and drivers are driving at higher speeds and
two objects collide at this higher speed However no increase in the number
of accidents is not the same as no increase in fatalities due to the higher
speeds When accidents do occur do fatalities increase
Likewise in California when the speed limit went up from 55 mph to 65
mph in 1995 (after repeal of NMSL) fewer deaths were reported in 1998
compared to the peak year of 1979 or even 1987 Again the explanation
seems to be that motorists were already speeding when the limit was 55 mph
and that increasing the speed limit did not change driver behavior in any
significant way
httparticlessfgatecom1998-11-02news17735730_1_speed-limits-mph-
limit-death-rate
The National Motorists Association (NMA) a group which advocates higher
speed limits emphasizes the importance of considering fatality rates as
opposed to the raw fatalities The argument used is that fatality rates based
on the fatality per 100 million VMT is the legitimate way to look at the data
Page 27 of 45
This is a never ending debate Historically speaking fatality rates have been
going down ever since the compilation of traffic accidents data began Table
A1 in the appendix of a recent report by NHTSA (see link below) has highway
fatality rate data going back 1921
httpwww-nrdnhtsadotgovPubs811346pdf see appendix page 31
httpwwwmotoristsorgspeed-limitstruth
httpwwwmotoristsorgothercrash-data
httpwwwraisethespeedlimitorgmythshtml
httpwwwcatoorgpubspaspa346pdf
According to Stephen Moore of the Cato Institute (see last of the links above)
―All measures of highway safety show improvement not more deaths and
injuries since 1995 Despite the fact that 33 states raised their speed limits
immediately after the repeal of the mandatory federal speed limit the NHTSA
reported last October that the traffic death rate dropped to a record low level
in 1997lsquo Moreover the average fatality rate even fell in the states that raised
their speed limits
63 The Fatality rate Is it a reliable metric
In 1921 with fewer fatalities and fewer miles driven and the first year for
which the fatality rate could be computed the rate was 2408 It was down to
1479 in 1931 but the number of deaths had climbed to 31963 more than
double the 1921 absolute fatality number of 13253 It had dropped to 550 in
1966 the year of the highly publicized Congressional hearings but the
number of fatalities had climbed to 50984 in that fateful The Highway Safety
Act of 1966 ranks as one of the major acts of Congress and President
Johnson signed it saying that ―we have been tolerating a raging epidemic of
highway deathshellip see extract pasted below
httpwwwenotescommajor-acts-congresshighway-safety-act
Page 28 of 45
The act was motivated primarily by growing public concern over the rising number
of traffic fatalities in the United States Between 1960 and 1965 the annual number
of traffic fatalities increased by nearly thirty percent As President Lyndon B
Johnson stated at the signing of the act on September 9 1966 we have tolerated
a raging epidemic of highway death which has killed more of our youth than all
other diseases combined Through the Highway Safety Act we are going to find out
more about highway diseasemdashand we aim to cure it
Nonetheless highways fatalities continued to increase until the Arab oil
embargo of 1973 led to the NMSL of 55 mph all across the USA Do we just
ignore this undeniable historical record and focus only on the declining fatality
rate as the NMA and other proponents of higher speed limits seem to argue
(see links above)
The misleading nature of using fatality rates (per 100 M VMT) alone is also
obvious if one considers fatality data for individual states Take for example
the state of Montana which seems to have experienced no increase in
fatalities after repeal of NMSL
httpwww-nrdnhtsadotgovdepartmentsnrd-
30ncsaSTSI30_MT200930_MT_2009htm
For the period 2005-2009 the absolute number of fatalities for Montana
varied between a high of 277 in 2007 to a low of 229 in 2009 The fatality
rates per 100 M VMT on the other hand varied from a high of 245 for 2007
to a low of 201 for 2009 The corresponding US fatality rates varied from
136 to 114 Is the higher number for the fatality rate for Montana compared
to USA good or bad Likewise fatality rate per 100000 of population was
much higher for Montana than the US as a whole
This again highlights the pitfalls of using simple ratios to assess fatality statistics
without a full analysis of the underlying trends We will discuss this point
separately
As shown already the continuous decline in the fatality rate is a mathematical
artifact and essentially overlooks the unmistakable positive correlation
between the variables x and y of the type y = hx + c which becomes obvious
Page 29 of 45
only when we prepare the x-y scatter graph The ratio yx = h + (cx) can
decrease with increasing x (VMT) and increasing y (fatalities) since the
intercept c has a positive value when we consider only data spanning a short
period (such as 1994-2009 of more relevance to the current situation)
The debate between fatality rates and absolute number of fatalities is an
unending one A few years ago the Wall Street Journal carried an article
which was entitled (or something close) ―Unemployments rate in Ohio are
going down but why is the number of unemployed increasing The reason is
the same The graph of the number of unemployed (y) versus the number in
the labor market (x) is linear with a positive slope h and a positive intercept c
So the unemployment rate computed using the ratio yx keeps going down
year after year although the number unemployed keeps increasing Is it a
good thing that the unemployment rate is going down when more people
seem to be unable to find gainful unemployment
Or consider the situation with cancer death rates This too has been going
down in recent years but the actual number of cancer-related deaths has not
declined in any significant way Is it good that cancer death rates are going
down In all these situations the researchers or the socio-econo-politico
analysts involved in analyzing the trends in the data have failed to consider
the underlying x-y relation describing each problem
Hence it appears that the debate on the effect of increased speed limits
should not be focused on only the fatality rates (which have been decreasing
and proponents of higher speed limits cite this in their arguments) or even the
absolute number of fatalities (which has been the focus here) but on the
relationship between speed and the number of fatal crashes and the number
of fatalities within each speed segment (see Table 3 and also Figure 4)
Unfortunately details of number of fatalities and the number of fatal crashes
at each speed limit are not available even from NHTSA for detailed study
When a crash does occur (it is immaterial how many miles were driven) the
speed of the driver and vehicle design and engineering including safety
devices in place (seat belts airbags other impact absorbing technologies)
Page 30 of 45
determine if the occupants(s) will be killed One cannot argue that speed
does NOT kill That would be an absolute denial of the laws of physics
Studies show that setting the speed limit at the 85th percentile in any given
zone (this is the speed at or below which 85 of drivers are observed to
travel in traffic engineering studies) is the safest speed limit The majority of
drivers try to obey the posted speed limit while a few choose to drive at a
speed they consider is safe and prudent These are also perhaps the most
vociferous advocates of higher speed limits It is this tension caused due to
differences in speeds that leads to tailgating improper passing reckless
driving weaving from lane to lane and ultimately crashes and deaths in some
unfortunate cases
httpblogmotoristsorgspeed-limits-slower-safer
MARK TAYLOR
ANOTHER LOST A man was killed when his 4WD drive hit a tree east of Morrinsville (in New
Zealand) on Monday May 30 2011 The driver lost control of the vehicle on a bend probably tried
to correct his mistake and put the car into a ―yaw causing it to leave the road and smash sideways
into a tree Alerts to slow down had been posted since this was a high accident area but the driver
probably did not pay attention
64 Other factors
Many other factors besides speed no doubt affect highway fatalities The
vehicles of the 21st century are very different from the vehicles of the mid 20th
Page 31 of 45
century Technological innovations such as improvements in vehicle design
and engineering have greatly increased crash worthiness of vehicles even at
high speeds Environmental factors such as the weather also contribute to
accidents but not necessarily to increased fatalities Drivers actually tend to
slow down instinctively during adverse weather conditions (rain snow storms
etc) and although such weather may contribute to increased accidents the
lower speeds actually reduce fatalities
Yes technology has changed fundamentally from 1966 Drivers today are
more distracted by their cellmobile phone conversations (and also built-in
phones in luxury models) and text messaging than the drivers of the pre-1966
era High end cars now have many multimedia and internet features Again a
careful observation (even personal experience by the author) suggests that
such distracted drivers actually tend to (instinctively) drive more slowly and
hold up the traffic Perhaps such behavior leads to an increase in the number
of accidents but it does not necessarily lead to an increase in the number of
accident-related fatalities
Much talked about technological innovations such as automatic collision
avoidance systems and sensors (on the sides of vehicles) can indeed detect
vehicles in the front and neighboring lanes Furthermore vehicle-to-vehicle
communication systems vehicle-to-infrastructure communication systems
can no doubt avoid collisions and accidents Again such collision avoidance
systems work and are effective entirely because they automatically reduce
vehicle speeds - even if one of the offending vehicles is being at a super
high speed Also it must be remembered that such futuristic systems have
not yet been implemented widely nor can they be implemented widely since
the large majority of vehicles on the road are NOT luxury models Advanced
safety features come with a price and not all drivers can afford to pay that
price and ―buy that ―additional safety
Ultimately it is the laws of physics that govern what will happen when two or
more vehicles collide or even when a single vehicle collides with a stationary
infrastructural object (a bridge a wall a building or some impediment on the
road) The lower the number of crashes the lower the number of fatalities as
revealed by the 1994-2009 data graphed in Figure 5 The higher the speed of
Page 32 of 45
the object or objects that are involved in a collision the higher the kinetic
energy K that must be absorbed andor dissipated Increasing the posted
speed limit only increases the energy that must be absorbed when a crash
does occur This ultimately is the most important criterion determining the
number of fatalities
The kinetic energy increases as the square of the speed being given by the
well-known formula K = frac12 mv2 where m is the mass of the vehicle (in
laypersonlsquos language m increases directly with vehicle weight) and v is the
speed For the same vehicle mass an increase in the speed from 55 mph to
85 mph increases the kinetic energy K by a factor of 239 or roughly a 250
increase in the kinetic energy that must be absorbed in a collision
Ideally speaking the kinetic energy of the colliding object(s) is absorbed by
the vehicle infrastructure (a sturdy space frame the engine other vehicle
components etc) andor the surroundings However in the unfortunate
cases where this kinetic energy must be absorbed by the vehicle occupant(s)
the result is severe life-altering injuries andor death An unequivocal
relationship between an increase in vehicle speeds and fatal accidents can
be demonstrated by a careful examination of available traffic fatality data
This is a more involved discussion and is not the purpose of this short
communication These topics are no doubt very politically charged with many
social legal and financial implications with each interest group favoring a
different conclusion Nonetheless we cannot escape the laws of physics as
they govern the fundamental need to absorb higher and higher values of the
kinetic energy K with increasing vehicle speeds This same point is also
emphasized by Dr Friedman of the University of Illinois Chicago (see earlier
discussion)
Speed kills because of these energy transfer considerations and there can be
no doubt about it
Innovative 21st century solutions to speed management on the highways
such as strict enforcement of speed limits minimizing speed dispersion
(difference between speeds at which different drivers travel) while using
cameras to track the 15 of drivers who willfully violate the speed limit and
Page 33 of 45
create hazardous driving conditions is certainly recommended (Recall that
the optimum recommended speed limit is at or below which 85 of all drivers
travel ndash a policy also supported by NMA) Even on this score however the
results are confounding if we consider the Australian experience
httpwwwthenewspapercomnews282840asp
Up until 2007 there was no speed limit in the Northern Territory of
Australia Imposing a speed limit 130 kmph (80 mph) on some areas and
110 kmph (68 mph) in some others actually increased the number of deaths
The death toll in 2006 when there was no speed limit in this region was 44
and went up to 75 in 2009 see data table in link below
httpwwwthenewspapercomrlcdocs2009au-ntroadtollpdf
Furthermore it appears that installation of cameras to enforce speed limits
has proved to be a hazardous distraction to drivers and deaths actually
began to skyrocket between 2005 and 2007 in all Australian roadways
The main purpose here is to sound a cautionary note amid renewed attempts
in many states across the US to increase the speed limits on our highways by
calling attention to the historical facts regarding the ―epidemic levels of
highway traffic fatalities that engaged our national attention in the fateful year
of 1966 The graphical representation of the traffic fatality data in Figures 1
to 5 tells its own story
Indeed it would be tragic if highway-accident-related fatalities were to start
increasing once again and reach the historically high level that was last seen
in 1972 the year before the Arab oil embargo of 1973
Page 34 of 45
Conclusions
1 The graphical representation of the highway fatality data and the brief
summary of the historical facts of traffic safety legislation suggest that
recent attempts to increase the speed limits by various states (notably
Texas) may be misguided The distinct peak in the highway fatalities
observed in these graphs is highly alarming This appears to be related to
the enactment of the National Maximum Speed Limit (NSML) in 1974
following the 1973 Arab oil embargo Although NSML was motivated by a
desire to reduce gasoline consumption an unintended benefit might have
been a dramatic reduction in fatalities The fundamental reasons for the
peak in the fatalities-VMT curve must be examined carefully without
political posturing
2 The widely used fatality rate fatalities per 100 M vehicle miles traveled
has been declining since 1921 the first year for which a fatality rate could
be computed and has now reached a historical low The absolute number
of fatalities on the other hand was increasing in the 1950s and 1960s at
an alarming rate and the public outcry that ensued led to the highly
publicized Congressional hearing of 1966 and the subsequent traffic safety
legislations The fatality rate has been decreasing even in the most recent
15-year period (1994-2009) again with increasing fatalities although less
dramatically Thus it appears that fatality rate calculation based on vehicle
miles traveled (VMT) might not be a reliable indicator of the underlying
dynamics in the fatality trends
3 More detailed compilation of number of fatalities and the number of fatal
crashes within each speed limit segment is required to better understand
the effect of increasing speed limits on highway fatalities (and also fatality
rates) Such data is already available and is being compiled at the local
city and county levels in all jurisdictions and only needs to be reorganized
to highlight the effect of (posted) speed limits on the number of crashes
and fatalities This will require some minor rewriting and revisions to the
chapters named ―Crashes and ―States in the annual NHTSA reports
Page 35 of 45
Analysis of the fatalities-crashes data for several years with various
speed limits will be more revealing and meaningful than the current
fatality rates analysis and will be discussed separately in a follow up
report
4 One should not be lulled by the fact that vehicles of the 21st century are
now equipped with advanced safety features not available in the 1950s
and the 1960s In spite of these safety features the laws of physics dictate
that the higher the speed the higher kinetic energy of the colliding objects
and hence the greater the risk indeed near certainty of fatalities in a
higher speed collision compared to a lower speed one
5 The higher the speed at which the vehicle that is involved in a crash is
traveling the higher the kinetic energy that must be absorbed andor
dissipated without affecting the occupant(s) to avoid serious injuries andor
death This was true in the 1950s and the 1960s and will continue to be
true in the 21st century as well
Speed Kills for this just reason
6 It appears that higher fuel economies and reduced
highway fatalities were the twin societal benefits of 55
mph adopted after 1973 If so the current attempts to
increase the speed limits appear to be in conflict with
other important societal objectives
Page 36 of 45
Table 1 Annual US Street amp Highway
Fatalities from 1957
Year
Fatalities
Vehicle Miles
(millions)
Rate100M Vehicle Miles
1957 38702 646915 598
1958 36981 664915 556
1959 37910 700478 541
1960 38137 718845 531
1961 38091 737535 516
1962 40804 766852 532
1963 43564 805423 541
1964 47700 846500 563
1965 49163 887640 554
1966 51524 927915 555
1967 51559 965132 534
1968 53831 1019726 528
1969 55032 1066108 516
1970 53672 1114098 482
1971 53761 1183524 454
1972 55704 1264614 440
1973 55113 1316207 419
1974 46078 1282790 359
1975 45500 1330074 342
1976 45523 1402380 325
1977 47878 1467027 326
1978 50331 1544704 326
1979 51103 1529133 334
1980 51091 1527295 335
1981 49301 1552803 317
1982 43945 1595010 276
1983 42589 1652788 258
1984 44257 1720269 257
1985 43795 1774179 247
Page 37 of 45
1986 46056 1835000 251
1987 46385 1921000 241
1988 47093 2026000 232
1989 45555 2107040 216
1990 44529 2147501 207
1991 41162 2172214 189
1992 39235 2239828 175
1993 40115 2296585 175
1994 40676 2359984 172
1995 41798 2422696 173
1996 41907 2485848 169
1997 41967 2560373 164
Data from Federal Highway Administration
Source httpwwwpublicpurposecomhwy-fatal57+htm
Telephone +16186328507 - Facsimile +16186328538
WENDELL COX CONSULTANCY P O Box 841 - Belleville IL 62269 USA
Page 38 of 45
Fatality data for 1921-1982 compiled by NHTSA
Year
VMT
(Millions)
VMT
(Billions)
Fatalities
Fatality rate
per 100 M VMT
1921 55027 5503 13253 241 1922 67697 6770 14859 219 1923 84995 8500 17870 210 1924 104838 10484 18400 176 1925 122346 12235 20771 170 1926 140735 14074 22194 158 1927 158453 15845 24470 154 1928 172856 17286 26557 154 1929 197720 19772 29592 150 1930 206320 20632 31204 151 1931 216151 21615 31963 148 1932 200517 20052 27979 140 1933 200642 20064 29746 148 1934 215563 21556 34240 159 1935 228568 22857 34494 151 1936 252128 25213 36126 143 1937 270110 27011 37819 140 1938 271177 27118 31083 115 1939 285402 28540 30895 108 1940 302188 30219 32914 109 1941 333612 33361 38142 114 1942 268224 26822 27007 101 1943 208192 20819 22727 109 1944 212713 21271 23165 109 1945 250173 25017 26785 107 1946 340880 34088 31874 94 1947 370894 37089 31193 84 1948 397957 39796 30775 77 1949 424461 42446 30246 71 1950 458246 45825 33186 72 1951 491093 49109 35309 72
1952 513581 51358 36088 70
Page 39 of 45
1953 544433 54443 36190 66 1954 561963 56196 33890 60 1955 605646 60565 36688 61 1956 627843 62784 37965 60 1957 647004 64700 36932 57 1958 664653 66465 35331 53 1959 700480 70048 36223 52 1960 718762 71876 36399 51 1961 737421 73742 36285 49 1962 766734 76673 38980 51 1963 805249 80525 41723 52 1964 846298 84630 45645 54 1965 887812 88781 47089 53 1966 925899 92590 50894 55 1967 964005 96401 50724 53 1968 1015869 101587 52725 52 1969 1061791 106179 53543 50 1970 1109724 110972 52627 47 1971 1178811 117881 52542 45 1972 1259786 125979 54589 43 1973 1313110 131311 54052 41 1974 1280544 128054 45196 35 1975 1327664 132766 44525 34 1976 1402380 140238 45523 32 1977 1467027 146703 47878 33 1978 1544704 154470 50331 33 1979 1529133 152913 51093 33 1980 1527295 152730 51091 33 1981 1555308 155531 49301 32 1982 1595010 159501 43945 28
Source Analysis of Significant Decline in Motor Vehicle Traffic Fatalities in
2008 httpwww-nrdnhtsadotgovPubs811346pdf see Table A1 page 31
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Page 40 of 45
Acknowledgements
The author is grateful for thoughtful comments provided by friends and colleagues
with whom this document was shared via email prior to it being uploaded as a
publicly available document for wider dissemination and study The comments
offered by Prof Subra Ganesan of Oakland University Electrical and Computer
Engineering Department are reproduced with permission in their entirety
About the author
The author obtained his Masterrsquos (S M) and Doctoral (Sc D) degrees in Materials Engineering
from the Massachusetts Institute of Technology Cambridge USA He then spent his entire
professional career at leading US research institutions (MIT NASA Case Western Reserve
University and General Motors R amp D Center in Warren MI) He holds four patents in advanced
materials processing has co-authored two books and has published several scientific papers in
leading peer-reviewed international journals His expertise includes developing simple
mathematical models to explain the behavior of complex systems He can be reached by email at
vlaxmananhotmailcom
Page 41 of 45
Please Buckle Up
httpwwwlakecountypublichealthorgindexphpbuckle-up-montana
Public Awareness
Respect the Cage Exhibit
The Department of Transportation hopes that showing the reality of the crash will reduce traffic
fatalities A crushed car crash dummies and a sobering message ndash all part of the ―Respect The
Cage exhibit that is traveling across Montana The exhibit sponsored by the Montana Department
of Transportation stopped in Ronan on November 6th and is aimed at raising awareness about the
importance of wearing seat belts
The car in the exhibit was in an actual wreck many years ago
the passenger in the vehicle died because he was not wearing a
seat belt the driver who was wearing his seat belt survived
Montanarsquos likeliest crash fatality scenario
A Pickup
A Rural road
And Seat belts that
arenrsquot used
Page 42 of 45
Occupants of pickups are less likely to wear seat belts and pickups are more likely to
roll over than passenger cars
Seat belts reduce the risk of death by 60 percent in pickups and SUVs
In Montana from 2006-2008 81 of those killed in a crash while riding in a pickup were not wearing seat belts
In Montana pickups make up 401 of the vehicle population
For more information on Respect the Cage click here
Page 43 of 45
Appendix 1
Lack of seat belts leading cause of Louisiana highway deaths
1251 AM May 28 2011 |
Written by Adam Duvernay
Crashes involving unbuckled motorists were the leading cause of highway fatalities
in Louisiana last year and cost $9888 million according to recent reports The
Louisiana Highway Safety Commission reported 59 percent of vehicle occupants
killed in Louisiana crashes last year mdash about one in four mdash werent wearing seat
belts
httpwwwshreveporttimescomarticle20110528NEWS01105280354Lack-seat-
belts-leading-cause-La-highway-deathsodyssey=tab|topnews|text|FRONTPAGE
Crash bull Stats Published by NHTSAlsquos National Center for Statistics and Analysis 1200 New Jersey Avenue SE Washington DC 20590
DOT HS 811 451
Early Estimate of Motor Vehicle Traffic Fatalities in 2010
httpwww-nrdnhtsadotgovPubs811451pdf
Summary
A statistical projection of traffic fatalities in 2010 shows that an estimated 32788
people died in motor vehicle traffic crashes This represents a decline of about 3
percent as compared to the 33808 fatalities in 2009 as shown in Table 1 If these
projections are realized fatalities will be lowest on record (since 1949)
Traffic Safety Facts Overview 2009 Data
httpwww-nrdnhtsadotgovPubs811392pdf
In 2009 33808 people were killed in the estimated 5505000 police-reported
motor vehicle traffic crashes 2217000 people were injured and 3957000
crashes involved property damage only Compared to 2008 this is a 10-
percent decrease in the number of fatalities and a 5-percent decrease in the
Page 44 of 45
number of police-reported motor vehicle traffic crashes people injured and
crashes involving property damage
An average of 93 people died each day in motor vehicle crashes in 2009 mdash
an average of one every 16 minutes
Traffic Safety Facts Overview 2008 Data
httpwww-nrdnhtsadotgovPubs811162pdf
In 2008 37261 people were killed in the estimated 5811000 police-reported
motor vehicle traffic crashes 2346000 people were injured and 4146000
crashes involved property damage only
Some comments and Feedback
The following comments were received from Prof Ganesan after his review of the
first draft of this document It was subsequently revised thanks to this input to
address some of the very important issues raised here
Dear Laxman
The write up is not enough
You are emphasizing that the speed limit reduces the fatal accidents (comparing 1966
to 2000 accident numbers)
Can you also add a few sentences why the number is decreasing from 1980 to 2000
values (May be due to better design of vehicles)
Can you say anything about the fuel consumption with the speed for any typical
vehicle in 2011 or 2010 (do not consider the fatalities issue)
Probably a speed between 55 and 60 mph gives a better mileage If so this is a
compelling reason to keep the speed limit low But cars probably can be tuned to
give better mileage at any high speed also
Page 45 of 45
Weather is also a major factor in fatal accidents Speed limit may be kept low during
winter and kept higher in summer Give your comments on this too
Driver distractions can cause more accidents Now cars have many multimedia and
internet features Automatic collision avoidance systems and sensors on the sides can
detect vehicles in the front and neighboring lanes and it can automatically decrease
speed even if the driver speeds at super high speeds
Give some comments on this too There is also Vehicle to Vehicle communications
vehicle to infrastructure communications and they can avoid collisions and accidents
Technology has changed from 1966 I cannot agree with you on the speed limit
without any discussion on the above and other factors
Have a great day
Subra Ganesan
Professor Subramaniam Ganesan
Director Real Time amp DSP Lab
Electrical and Computer Engineering Department
2200 Squirrel Road Dodge Hall Room 105
Oakland University Rochester MI 48309 USA
Phone 248 370 2206 Fax 248 370 4633
wwwsecsoaklandedu~ganesan
IEEE Distinguished Visiting Speaker (2005-2009) Coordinator
IEEE SEM CS chapter Chair Region 4 and CS Society Board member
SAE ASEE ACM member
Page 17 of 45
number of highway fatalities went up from 38702 in 1957 to 51524 in 1965
a 33 increase over the 1957 level and an additional 12822 deaths in 1965
compared to 1957 It was this carnage on the US highways that forced
Congress to hold its hearings on highway traffic fatalities in 1966
Nonetheless a careful examination of the fatality data in Table 1 shows that
notwithstanding the highly publicized Congressional hearings of 1966 and
new safety legislation that was enacted the absolute number of fatalities
continued to increase after 1966 and only started decreasing after 1973
Vehicle designs especially the introduction of safety features (even the
simplest like safety belts) did not change significantly between 1966 and
1973 Nonetheless post-1973 we begin to see a dramatic turnaround
Why
After the 1973 Arab oil embargo a nationwide maximum speed limit (NMSL)
of 55 mph was imposed and accepted in the USA (effective Jan 1 1974)
during the Nixon administration primarily as an effort to conserve fuel and
reduce the US vulnerability to oil imports The unintended and indeed
fortunate consequence of this reduced speed limit was the immediate
reduction in the fatalities revealed in Figures 2 and 3 This is the real reason
for the peaks in highway fatalities observed in these two graphs
The Congressional hearings of 1966 did eventually have an impact but it was
a delayed one The impact of the 1973 nationwide speed limit of 55 mph was
however immediate as we see from the magnified plot of the same data in
Figure 5 and a closer examination of the raw fatality data in Table 1
The number of highway-accident-related fatalities decreased immediately
from a high of 55704 in 1972 to just 46078 in 1974 a 173 drop see
arrows There were 9626 fewer deaths annually even with a slight increase
in the vehicle miles driven (see Table 1) Indeed the number of highway
death reached its absolute peak value in 1972 never to be seen again
Fatalities have been decreasing every since with slight fluctuations about
each new low value
Page 18 of 45
Figure 5 Expanded view of the fatality data showing the immediate impact of the
national speed limit of 55 mph following the Arab oil embargo of 1973 Note that
fatalities continued to rise between 1966 and 1973 in spite of the highly publicized
Congressional hearings in 1966 and the traffic safety legislation enacted soon after
Each new low is probably associated with vehicle safety innovations and the
improvements in vehicle design and engineering The combined beneficial
effect of improved vehicle designs primarily the introduction of seat belts
and the laws enforcing usage of seat belts aided by the reduced speed
limits contributed to the continued decline in the absolute number of fatalities
that started since 1973 and has continued to this day The subsequent
introduction of other safety features notably air bags has contributed to a
further reduction in highway fatalities
Page 19 of 45
State police Trooper First Class Jeffrey Flowers looking at a car in which a Boswell
Pennsylvania woman was injured Tuesday (May 31 2011) The accident occurred at
an intersection when a truck (seen behind the wrecked car) entered this accident
prone intersection (part of a highway safety corridor where signs are posted to
reduce unsafe driver behavior) There have been four accidents at this intersection
since 2006 none fatal httpwwwdailyamericancomnewssomersetda-ot-woman-
injured-in-route-30-wreck-2011053104165420story
5 Numerical calculations of decline in
fatalities and the impact of NMSL post-1973
Letlsquos consider the decline in fatalities between 1972 the last year before the
adoption of the NMSL and 1974 the first year following its adoption after the
Arab oil embargo There was an immediate decrease in the number of
fatalities by 9393 ie y = -9393 with a slight increase in the VMT ie x
= 20758 millions The NHTSA data used here may be found in the table at
the end of this document The numerical value of the rate of change per
billion VMT (ie neglecting the sign) was therefore
yx = 4525 fatalitiesbillion VMT (1972-1974)
Page 20 of 45
It is instructive to compare this rate of change in fatalities with similar short
periods of a decline in fatalities in the pre-1973 era when speed limits were
much higher The absolute number of fatalities declined over a relatively
short period with both an increase and a decrease in VMT The results are
given below and are self-explanatory
yx = 454 fatalitiesbillion VMT (1953-54) decline with increase in VMT
yx = 655 fatalitiesbillion VMT (1942-43) decline with decrease in VMT
yx = 1739 fatalitiesbillion VMT (1941-42) decline with decrease in VMT
yx = 4528 fatalitiesbillion VMT (1937-39) decline with increase in VMT
yx = 2548 fatalitiesbillion VMT (1931-32) decline with decrease in VMT
The rate of decline observed between 1953 and 1954 with an increase in
VMT was just one-tenth of that observed following the adoption of the 55
mph speed limit The war years (1941-43 WWII) and the Great Depression
era (1931-32) were accompanied by big declines in fatalities with decreasing
VMT but the rate of change was still significantly lower than observed after
the adoption of the NMSL
The only apparently inexplicable decline is that between 1937 and 1939
where a nearly identical high rate of decline was observed Notice also the
big drop in the traditional fatality rate between 1937 and 1938 This large drop
appears to coincide with the creation of the National Safety Council (NSC) by
William H Cameron in June 1937 (see link below) with its far-flung campaign
of education legislation research highway engineering and traffic training
undertaken by the NSC and some two dozen other groups with the backing of the
automotive industry through its Automotive Safety Foundation Other factors
unknown to the present author probably also played a role
httpwwwtimecomtimemagazinearticle0917188379700htmlixzz1O2G
7rnUg
Page 21 of 45
These simple computations here however reveal the significant effect of
reduced speed limits on highway fatalities much more so than other factors
6 Further Considerations Pros and Cons
The singular effect of increased speeds (or speeding) on highway fatalities
has been studied and demonstrated by a number of industry sources such
as the Insurance Institute for Highway Safety (IIHS) Consumers Union and
also by government researchers
httpwwwsmartmotoristcomtraffic-and-safety-guidelineexcessive-speed-is-
a-factor-in-one-third-of-all-fatal-crasheshtml
httpwwwconsumersunionorgotherspeedlimitsspeed031500a2htm
Speed ndash defined as exceeding the posted speed limit or driving too fast for
given conditions ndash is a factor in nearly one-third of all fatal crashes Besides
fatality in 1998 nearly 40000 people were critically injured in speed-related
crashes and nearly 72000 were moderately injured
The salutary and immediate beneficial effect of the nationwide 55 mph speed
limit has been noted by other researchers (see Susan Ferguson link below)
httpwwwnhtsagovpeopleinjuryenforcespeed_forum_presentationsfergu
sonpdf
After a partial repeal of this law in 1987 which granted states the authority to
increase speed limit (especially in rural interstates) a 1989 study showed a
15 increase in fatalities in rural interstates and a 5 increase in non-rural
interstates Unfortunately such studies often tend to be discounted by
advocates of increasing the speed limits as being produced by biased
industry sources
Similar conclusions were also presented by NHTSA in February 1998 in its
report to the Congress entitled ―Report to Congress The Effect of Increased
Speed Limits in the Post-NMSL Era see link given below Among its key
Page 22 of 45
findings is the following quoted in its entirety NMSL refers to the National
Maximum Speed Limit legislated after the Arab oil embargo of 1973
httpwww-nrdnhtsadotgovPubs808-637PDF
hellip Nevertheless it is important to note that data currently available from the
National Highway Traffic Safety Administrationrsquos (NHTSA) Fatality Analysis
Reporting System (FARS) shows that states that increased speed limits in 1996
experienced approximately 350 more Interstate fatalities than would have been
expected based on historical trends -- about 9 percent above expectations
Concurrently the Interstate fatalities experienced in states that did not increase speed
limits in 1996 was consistent with pre-1996 trends The estimated increase in
Interstate fatalities found in this study while smaller in magnitude compared to the
estimated change in fatalities found in 1987 following the increase of speed limits on
rural Interstates does follow the historical pattern of increases in fatalities being
associated with increases in posted speed limits
The annual crash reports compiled by NHTSA see Table 3 indicate that the
number of fatal crashes (and hence fatalities using the regression equation
developed in Figure 4) increase as the posted speed limits increase
Page 23 of 45
Table 3 Posted speed limits and number of crashes
Speed Limit Crashes (2008) Crashes (2009)
30 mph or less 3705 3277 35 or 40 mph 6115 5516 45 or 50 mph 6461 6074
55 mph 9794 8847 60 mph or higher 6908 6124
Total 34017 30797
Source httpwww-nrdnhtsadotgovPubs811402EEpdf
61 Studies cited in favor of lower speed limits
A detailed analysis of speeding related fatalities (see link below) by NHTSA
shows that a third of all crashes involve speeding ie at least one driver was
speeding
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Furthermore the above report which covers the period 1983-2002
indicates that immediately after the NMSL was completely abolished in
December 1995 the number of speeding related fatalities at speeds
above 65 mph increased from just 15 in 1995 to a 677 in 1996 (see Table
62 on page 43 of above report) It continued to increase in the years
since climbing to 930 in 2000
More detailed studies similar to that noted above by researchers at the
University of Illinois Chicago led by Lee S Friedman again lead to the
conclusion that higher speed limits lead to an increase in the number of
fatalities (see American Journal of Public Health online July 16 2009)
httphealthusnewscomhealth-newsmanaging-your-
healthcarearticles20090716deaths-injuries-increase-with-higher-speed-
limits
Page 24 of 45
httpwwwmedpagetodaycomPublicHealthPolicyPublicHealth15122
httpwwwamericaneercomspeed-limits
httpwwwactuarialoutpostcomactuarial_discussion_forumarchiveindexph
pt-171870html
For the study period 1995-2005 these researchers found that 12545 deaths
and 36582 injuries could be attributed to the increased speed limits The
benefits of reduced speed limits are stated quite eloquently by Dr Friedman
and are reproduced below (from above news article see link)
Reduced speed limits would save lives Friedman said They would also reduce
gas consumption cut emissions of air pollutants save valuable years of productivity
(lost due to injuries)and reduce the societal cost of motor vehicle crashes (due to
both fatal crashes and due to nonfatal and severe life-changing injuries) he added
Friedman and coworkers have also shown that increasing the speed limit led
to an immediate increase in the number of fatalities on Israeli roadways (see
link below)
httpinjurypreventionbmjcomcontent133156
The effect of speeding is very significant especially in rural areas resulting
in significantly higher fatalities Fatality rates are frequently double or triple
that in urban areas (see link below)
httpsafetyfhwadotgovspeedmgtdata_factsdocsspeeding_ruralpdf
As of Jan 1 2005 five Midwestern states had increased the speed limits to
above 65 mph (Illinois Iowa Kansas Minnesota Missouri Nebraska and
South Dakota) whereas three (Illinois Iowa and Wisconsin) had not All the
five states with increased speed limits showed a 7 to 13 increase in
fatalities The NHTSA study considered an eight year period before and after
the change in Dec 1995 (see Table 1 in link below) The collective experience
of the states that did NOT increase the speed limit was a 7 decline in
fatalities (see Table 2 of link below)
httpwwwiowadotgovmvdodsstats2006speedstudypdf
Page 25 of 45
Moreover Table 5 in the above study shows the effect of imposing the NMSL
of 55 mph in Iowa and its repeal in 1995 Considering a four-year average
before 1974 when the speed limit was 75 mph there were 35 fatal crashes
with 43 fatalities In the first four years after the 55 mph there were only 23
fatal crashes and 28 fatalities In the last four years before the repeal of 55
mph in 1995 there was a further decline to 14 fatal crashes with 17 fatalities
The Iowa fatality data will be discussed in more detail separately (in a later report)
since it provides the opportunity to assess the effect of a change in the speed limit
on the relationship between number of fatalities and fatal crashes (as seen in
Figure 4 for the US as a whole)
North of the US border Canadians seem to be citing the ―shocking increase
in highway fatalities in the US states where the speed limits were raised to
curb their own speed limits
httparchivesafety-councilorginfotrafficspeed-02html
httparchivesafety-councilorginfotrafficspeedhtml
Speed kills but speed also sells notes the second of the above news items
Manufacturers are producing more high performance cars (with higher horse
power to weight ratio) and ads feature enticing cars that race and swerve in
miraculous ways on empty roads These subliminal messages encourage
drivers especially young drivers to break the speed limit leading to the
absolute increase in highway fatalities (although the rate itself is going
down) The article emphasizes the need to enforce the speed limit on
Canadian highways and in cities where street racing is becoming a problem
62 Studies cited by opponents of lower speed limits
In fairness to quote the opponents on the other side of this debate Montana
reverted back to Reasonable and Prudent speed limits when the National
Maximum Speed Limit was repealed in 1995 and appears to have
experienced no significant increase in fatalities
Page 26 of 45
httpwwwhwysafetycomhwy_montanahtm
httpwwwmotoristsorgpressmontana-no-speed-limit-safety-paradox
httpwwwsouthbayriderscomforumsshowthreadphpt=81453amppage=1
Likewise studies in the state of Maryland showed no significant increase in
highway fatalities when the speed limit was increased from 55 mph to 75
mph The reason might simply be that drivers were already speeding much
more so when the speed limit was 55 mph than after the increase to 75 mph
In other words the fatalities data already reflects the effect of higher speeds
(not speed limits) on the number of fatalities
In Utah the experimental increase in the speed limit to 80 mph was
considered to be a success in terms of safety
httpautosaolcomarticleutah-speed-limit-tests
The UDOT Director noted that there was no increase in the number of
accidents on Interstate 15 But what happens in the event of an accident
when the speed limits are higher and drivers are driving at higher speeds and
two objects collide at this higher speed However no increase in the number
of accidents is not the same as no increase in fatalities due to the higher
speeds When accidents do occur do fatalities increase
Likewise in California when the speed limit went up from 55 mph to 65
mph in 1995 (after repeal of NMSL) fewer deaths were reported in 1998
compared to the peak year of 1979 or even 1987 Again the explanation
seems to be that motorists were already speeding when the limit was 55 mph
and that increasing the speed limit did not change driver behavior in any
significant way
httparticlessfgatecom1998-11-02news17735730_1_speed-limits-mph-
limit-death-rate
The National Motorists Association (NMA) a group which advocates higher
speed limits emphasizes the importance of considering fatality rates as
opposed to the raw fatalities The argument used is that fatality rates based
on the fatality per 100 million VMT is the legitimate way to look at the data
Page 27 of 45
This is a never ending debate Historically speaking fatality rates have been
going down ever since the compilation of traffic accidents data began Table
A1 in the appendix of a recent report by NHTSA (see link below) has highway
fatality rate data going back 1921
httpwww-nrdnhtsadotgovPubs811346pdf see appendix page 31
httpwwwmotoristsorgspeed-limitstruth
httpwwwmotoristsorgothercrash-data
httpwwwraisethespeedlimitorgmythshtml
httpwwwcatoorgpubspaspa346pdf
According to Stephen Moore of the Cato Institute (see last of the links above)
―All measures of highway safety show improvement not more deaths and
injuries since 1995 Despite the fact that 33 states raised their speed limits
immediately after the repeal of the mandatory federal speed limit the NHTSA
reported last October that the traffic death rate dropped to a record low level
in 1997lsquo Moreover the average fatality rate even fell in the states that raised
their speed limits
63 The Fatality rate Is it a reliable metric
In 1921 with fewer fatalities and fewer miles driven and the first year for
which the fatality rate could be computed the rate was 2408 It was down to
1479 in 1931 but the number of deaths had climbed to 31963 more than
double the 1921 absolute fatality number of 13253 It had dropped to 550 in
1966 the year of the highly publicized Congressional hearings but the
number of fatalities had climbed to 50984 in that fateful The Highway Safety
Act of 1966 ranks as one of the major acts of Congress and President
Johnson signed it saying that ―we have been tolerating a raging epidemic of
highway deathshellip see extract pasted below
httpwwwenotescommajor-acts-congresshighway-safety-act
Page 28 of 45
The act was motivated primarily by growing public concern over the rising number
of traffic fatalities in the United States Between 1960 and 1965 the annual number
of traffic fatalities increased by nearly thirty percent As President Lyndon B
Johnson stated at the signing of the act on September 9 1966 we have tolerated
a raging epidemic of highway death which has killed more of our youth than all
other diseases combined Through the Highway Safety Act we are going to find out
more about highway diseasemdashand we aim to cure it
Nonetheless highways fatalities continued to increase until the Arab oil
embargo of 1973 led to the NMSL of 55 mph all across the USA Do we just
ignore this undeniable historical record and focus only on the declining fatality
rate as the NMA and other proponents of higher speed limits seem to argue
(see links above)
The misleading nature of using fatality rates (per 100 M VMT) alone is also
obvious if one considers fatality data for individual states Take for example
the state of Montana which seems to have experienced no increase in
fatalities after repeal of NMSL
httpwww-nrdnhtsadotgovdepartmentsnrd-
30ncsaSTSI30_MT200930_MT_2009htm
For the period 2005-2009 the absolute number of fatalities for Montana
varied between a high of 277 in 2007 to a low of 229 in 2009 The fatality
rates per 100 M VMT on the other hand varied from a high of 245 for 2007
to a low of 201 for 2009 The corresponding US fatality rates varied from
136 to 114 Is the higher number for the fatality rate for Montana compared
to USA good or bad Likewise fatality rate per 100000 of population was
much higher for Montana than the US as a whole
This again highlights the pitfalls of using simple ratios to assess fatality statistics
without a full analysis of the underlying trends We will discuss this point
separately
As shown already the continuous decline in the fatality rate is a mathematical
artifact and essentially overlooks the unmistakable positive correlation
between the variables x and y of the type y = hx + c which becomes obvious
Page 29 of 45
only when we prepare the x-y scatter graph The ratio yx = h + (cx) can
decrease with increasing x (VMT) and increasing y (fatalities) since the
intercept c has a positive value when we consider only data spanning a short
period (such as 1994-2009 of more relevance to the current situation)
The debate between fatality rates and absolute number of fatalities is an
unending one A few years ago the Wall Street Journal carried an article
which was entitled (or something close) ―Unemployments rate in Ohio are
going down but why is the number of unemployed increasing The reason is
the same The graph of the number of unemployed (y) versus the number in
the labor market (x) is linear with a positive slope h and a positive intercept c
So the unemployment rate computed using the ratio yx keeps going down
year after year although the number unemployed keeps increasing Is it a
good thing that the unemployment rate is going down when more people
seem to be unable to find gainful unemployment
Or consider the situation with cancer death rates This too has been going
down in recent years but the actual number of cancer-related deaths has not
declined in any significant way Is it good that cancer death rates are going
down In all these situations the researchers or the socio-econo-politico
analysts involved in analyzing the trends in the data have failed to consider
the underlying x-y relation describing each problem
Hence it appears that the debate on the effect of increased speed limits
should not be focused on only the fatality rates (which have been decreasing
and proponents of higher speed limits cite this in their arguments) or even the
absolute number of fatalities (which has been the focus here) but on the
relationship between speed and the number of fatal crashes and the number
of fatalities within each speed segment (see Table 3 and also Figure 4)
Unfortunately details of number of fatalities and the number of fatal crashes
at each speed limit are not available even from NHTSA for detailed study
When a crash does occur (it is immaterial how many miles were driven) the
speed of the driver and vehicle design and engineering including safety
devices in place (seat belts airbags other impact absorbing technologies)
Page 30 of 45
determine if the occupants(s) will be killed One cannot argue that speed
does NOT kill That would be an absolute denial of the laws of physics
Studies show that setting the speed limit at the 85th percentile in any given
zone (this is the speed at or below which 85 of drivers are observed to
travel in traffic engineering studies) is the safest speed limit The majority of
drivers try to obey the posted speed limit while a few choose to drive at a
speed they consider is safe and prudent These are also perhaps the most
vociferous advocates of higher speed limits It is this tension caused due to
differences in speeds that leads to tailgating improper passing reckless
driving weaving from lane to lane and ultimately crashes and deaths in some
unfortunate cases
httpblogmotoristsorgspeed-limits-slower-safer
MARK TAYLOR
ANOTHER LOST A man was killed when his 4WD drive hit a tree east of Morrinsville (in New
Zealand) on Monday May 30 2011 The driver lost control of the vehicle on a bend probably tried
to correct his mistake and put the car into a ―yaw causing it to leave the road and smash sideways
into a tree Alerts to slow down had been posted since this was a high accident area but the driver
probably did not pay attention
64 Other factors
Many other factors besides speed no doubt affect highway fatalities The
vehicles of the 21st century are very different from the vehicles of the mid 20th
Page 31 of 45
century Technological innovations such as improvements in vehicle design
and engineering have greatly increased crash worthiness of vehicles even at
high speeds Environmental factors such as the weather also contribute to
accidents but not necessarily to increased fatalities Drivers actually tend to
slow down instinctively during adverse weather conditions (rain snow storms
etc) and although such weather may contribute to increased accidents the
lower speeds actually reduce fatalities
Yes technology has changed fundamentally from 1966 Drivers today are
more distracted by their cellmobile phone conversations (and also built-in
phones in luxury models) and text messaging than the drivers of the pre-1966
era High end cars now have many multimedia and internet features Again a
careful observation (even personal experience by the author) suggests that
such distracted drivers actually tend to (instinctively) drive more slowly and
hold up the traffic Perhaps such behavior leads to an increase in the number
of accidents but it does not necessarily lead to an increase in the number of
accident-related fatalities
Much talked about technological innovations such as automatic collision
avoidance systems and sensors (on the sides of vehicles) can indeed detect
vehicles in the front and neighboring lanes Furthermore vehicle-to-vehicle
communication systems vehicle-to-infrastructure communication systems
can no doubt avoid collisions and accidents Again such collision avoidance
systems work and are effective entirely because they automatically reduce
vehicle speeds - even if one of the offending vehicles is being at a super
high speed Also it must be remembered that such futuristic systems have
not yet been implemented widely nor can they be implemented widely since
the large majority of vehicles on the road are NOT luxury models Advanced
safety features come with a price and not all drivers can afford to pay that
price and ―buy that ―additional safety
Ultimately it is the laws of physics that govern what will happen when two or
more vehicles collide or even when a single vehicle collides with a stationary
infrastructural object (a bridge a wall a building or some impediment on the
road) The lower the number of crashes the lower the number of fatalities as
revealed by the 1994-2009 data graphed in Figure 5 The higher the speed of
Page 32 of 45
the object or objects that are involved in a collision the higher the kinetic
energy K that must be absorbed andor dissipated Increasing the posted
speed limit only increases the energy that must be absorbed when a crash
does occur This ultimately is the most important criterion determining the
number of fatalities
The kinetic energy increases as the square of the speed being given by the
well-known formula K = frac12 mv2 where m is the mass of the vehicle (in
laypersonlsquos language m increases directly with vehicle weight) and v is the
speed For the same vehicle mass an increase in the speed from 55 mph to
85 mph increases the kinetic energy K by a factor of 239 or roughly a 250
increase in the kinetic energy that must be absorbed in a collision
Ideally speaking the kinetic energy of the colliding object(s) is absorbed by
the vehicle infrastructure (a sturdy space frame the engine other vehicle
components etc) andor the surroundings However in the unfortunate
cases where this kinetic energy must be absorbed by the vehicle occupant(s)
the result is severe life-altering injuries andor death An unequivocal
relationship between an increase in vehicle speeds and fatal accidents can
be demonstrated by a careful examination of available traffic fatality data
This is a more involved discussion and is not the purpose of this short
communication These topics are no doubt very politically charged with many
social legal and financial implications with each interest group favoring a
different conclusion Nonetheless we cannot escape the laws of physics as
they govern the fundamental need to absorb higher and higher values of the
kinetic energy K with increasing vehicle speeds This same point is also
emphasized by Dr Friedman of the University of Illinois Chicago (see earlier
discussion)
Speed kills because of these energy transfer considerations and there can be
no doubt about it
Innovative 21st century solutions to speed management on the highways
such as strict enforcement of speed limits minimizing speed dispersion
(difference between speeds at which different drivers travel) while using
cameras to track the 15 of drivers who willfully violate the speed limit and
Page 33 of 45
create hazardous driving conditions is certainly recommended (Recall that
the optimum recommended speed limit is at or below which 85 of all drivers
travel ndash a policy also supported by NMA) Even on this score however the
results are confounding if we consider the Australian experience
httpwwwthenewspapercomnews282840asp
Up until 2007 there was no speed limit in the Northern Territory of
Australia Imposing a speed limit 130 kmph (80 mph) on some areas and
110 kmph (68 mph) in some others actually increased the number of deaths
The death toll in 2006 when there was no speed limit in this region was 44
and went up to 75 in 2009 see data table in link below
httpwwwthenewspapercomrlcdocs2009au-ntroadtollpdf
Furthermore it appears that installation of cameras to enforce speed limits
has proved to be a hazardous distraction to drivers and deaths actually
began to skyrocket between 2005 and 2007 in all Australian roadways
The main purpose here is to sound a cautionary note amid renewed attempts
in many states across the US to increase the speed limits on our highways by
calling attention to the historical facts regarding the ―epidemic levels of
highway traffic fatalities that engaged our national attention in the fateful year
of 1966 The graphical representation of the traffic fatality data in Figures 1
to 5 tells its own story
Indeed it would be tragic if highway-accident-related fatalities were to start
increasing once again and reach the historically high level that was last seen
in 1972 the year before the Arab oil embargo of 1973
Page 34 of 45
Conclusions
1 The graphical representation of the highway fatality data and the brief
summary of the historical facts of traffic safety legislation suggest that
recent attempts to increase the speed limits by various states (notably
Texas) may be misguided The distinct peak in the highway fatalities
observed in these graphs is highly alarming This appears to be related to
the enactment of the National Maximum Speed Limit (NSML) in 1974
following the 1973 Arab oil embargo Although NSML was motivated by a
desire to reduce gasoline consumption an unintended benefit might have
been a dramatic reduction in fatalities The fundamental reasons for the
peak in the fatalities-VMT curve must be examined carefully without
political posturing
2 The widely used fatality rate fatalities per 100 M vehicle miles traveled
has been declining since 1921 the first year for which a fatality rate could
be computed and has now reached a historical low The absolute number
of fatalities on the other hand was increasing in the 1950s and 1960s at
an alarming rate and the public outcry that ensued led to the highly
publicized Congressional hearing of 1966 and the subsequent traffic safety
legislations The fatality rate has been decreasing even in the most recent
15-year period (1994-2009) again with increasing fatalities although less
dramatically Thus it appears that fatality rate calculation based on vehicle
miles traveled (VMT) might not be a reliable indicator of the underlying
dynamics in the fatality trends
3 More detailed compilation of number of fatalities and the number of fatal
crashes within each speed limit segment is required to better understand
the effect of increasing speed limits on highway fatalities (and also fatality
rates) Such data is already available and is being compiled at the local
city and county levels in all jurisdictions and only needs to be reorganized
to highlight the effect of (posted) speed limits on the number of crashes
and fatalities This will require some minor rewriting and revisions to the
chapters named ―Crashes and ―States in the annual NHTSA reports
Page 35 of 45
Analysis of the fatalities-crashes data for several years with various
speed limits will be more revealing and meaningful than the current
fatality rates analysis and will be discussed separately in a follow up
report
4 One should not be lulled by the fact that vehicles of the 21st century are
now equipped with advanced safety features not available in the 1950s
and the 1960s In spite of these safety features the laws of physics dictate
that the higher the speed the higher kinetic energy of the colliding objects
and hence the greater the risk indeed near certainty of fatalities in a
higher speed collision compared to a lower speed one
5 The higher the speed at which the vehicle that is involved in a crash is
traveling the higher the kinetic energy that must be absorbed andor
dissipated without affecting the occupant(s) to avoid serious injuries andor
death This was true in the 1950s and the 1960s and will continue to be
true in the 21st century as well
Speed Kills for this just reason
6 It appears that higher fuel economies and reduced
highway fatalities were the twin societal benefits of 55
mph adopted after 1973 If so the current attempts to
increase the speed limits appear to be in conflict with
other important societal objectives
Page 36 of 45
Table 1 Annual US Street amp Highway
Fatalities from 1957
Year
Fatalities
Vehicle Miles
(millions)
Rate100M Vehicle Miles
1957 38702 646915 598
1958 36981 664915 556
1959 37910 700478 541
1960 38137 718845 531
1961 38091 737535 516
1962 40804 766852 532
1963 43564 805423 541
1964 47700 846500 563
1965 49163 887640 554
1966 51524 927915 555
1967 51559 965132 534
1968 53831 1019726 528
1969 55032 1066108 516
1970 53672 1114098 482
1971 53761 1183524 454
1972 55704 1264614 440
1973 55113 1316207 419
1974 46078 1282790 359
1975 45500 1330074 342
1976 45523 1402380 325
1977 47878 1467027 326
1978 50331 1544704 326
1979 51103 1529133 334
1980 51091 1527295 335
1981 49301 1552803 317
1982 43945 1595010 276
1983 42589 1652788 258
1984 44257 1720269 257
1985 43795 1774179 247
Page 37 of 45
1986 46056 1835000 251
1987 46385 1921000 241
1988 47093 2026000 232
1989 45555 2107040 216
1990 44529 2147501 207
1991 41162 2172214 189
1992 39235 2239828 175
1993 40115 2296585 175
1994 40676 2359984 172
1995 41798 2422696 173
1996 41907 2485848 169
1997 41967 2560373 164
Data from Federal Highway Administration
Source httpwwwpublicpurposecomhwy-fatal57+htm
Telephone +16186328507 - Facsimile +16186328538
WENDELL COX CONSULTANCY P O Box 841 - Belleville IL 62269 USA
Page 38 of 45
Fatality data for 1921-1982 compiled by NHTSA
Year
VMT
(Millions)
VMT
(Billions)
Fatalities
Fatality rate
per 100 M VMT
1921 55027 5503 13253 241 1922 67697 6770 14859 219 1923 84995 8500 17870 210 1924 104838 10484 18400 176 1925 122346 12235 20771 170 1926 140735 14074 22194 158 1927 158453 15845 24470 154 1928 172856 17286 26557 154 1929 197720 19772 29592 150 1930 206320 20632 31204 151 1931 216151 21615 31963 148 1932 200517 20052 27979 140 1933 200642 20064 29746 148 1934 215563 21556 34240 159 1935 228568 22857 34494 151 1936 252128 25213 36126 143 1937 270110 27011 37819 140 1938 271177 27118 31083 115 1939 285402 28540 30895 108 1940 302188 30219 32914 109 1941 333612 33361 38142 114 1942 268224 26822 27007 101 1943 208192 20819 22727 109 1944 212713 21271 23165 109 1945 250173 25017 26785 107 1946 340880 34088 31874 94 1947 370894 37089 31193 84 1948 397957 39796 30775 77 1949 424461 42446 30246 71 1950 458246 45825 33186 72 1951 491093 49109 35309 72
1952 513581 51358 36088 70
Page 39 of 45
1953 544433 54443 36190 66 1954 561963 56196 33890 60 1955 605646 60565 36688 61 1956 627843 62784 37965 60 1957 647004 64700 36932 57 1958 664653 66465 35331 53 1959 700480 70048 36223 52 1960 718762 71876 36399 51 1961 737421 73742 36285 49 1962 766734 76673 38980 51 1963 805249 80525 41723 52 1964 846298 84630 45645 54 1965 887812 88781 47089 53 1966 925899 92590 50894 55 1967 964005 96401 50724 53 1968 1015869 101587 52725 52 1969 1061791 106179 53543 50 1970 1109724 110972 52627 47 1971 1178811 117881 52542 45 1972 1259786 125979 54589 43 1973 1313110 131311 54052 41 1974 1280544 128054 45196 35 1975 1327664 132766 44525 34 1976 1402380 140238 45523 32 1977 1467027 146703 47878 33 1978 1544704 154470 50331 33 1979 1529133 152913 51093 33 1980 1527295 152730 51091 33 1981 1555308 155531 49301 32 1982 1595010 159501 43945 28
Source Analysis of Significant Decline in Motor Vehicle Traffic Fatalities in
2008 httpwww-nrdnhtsadotgovPubs811346pdf see Table A1 page 31
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Page 40 of 45
Acknowledgements
The author is grateful for thoughtful comments provided by friends and colleagues
with whom this document was shared via email prior to it being uploaded as a
publicly available document for wider dissemination and study The comments
offered by Prof Subra Ganesan of Oakland University Electrical and Computer
Engineering Department are reproduced with permission in their entirety
About the author
The author obtained his Masterrsquos (S M) and Doctoral (Sc D) degrees in Materials Engineering
from the Massachusetts Institute of Technology Cambridge USA He then spent his entire
professional career at leading US research institutions (MIT NASA Case Western Reserve
University and General Motors R amp D Center in Warren MI) He holds four patents in advanced
materials processing has co-authored two books and has published several scientific papers in
leading peer-reviewed international journals His expertise includes developing simple
mathematical models to explain the behavior of complex systems He can be reached by email at
vlaxmananhotmailcom
Page 41 of 45
Please Buckle Up
httpwwwlakecountypublichealthorgindexphpbuckle-up-montana
Public Awareness
Respect the Cage Exhibit
The Department of Transportation hopes that showing the reality of the crash will reduce traffic
fatalities A crushed car crash dummies and a sobering message ndash all part of the ―Respect The
Cage exhibit that is traveling across Montana The exhibit sponsored by the Montana Department
of Transportation stopped in Ronan on November 6th and is aimed at raising awareness about the
importance of wearing seat belts
The car in the exhibit was in an actual wreck many years ago
the passenger in the vehicle died because he was not wearing a
seat belt the driver who was wearing his seat belt survived
Montanarsquos likeliest crash fatality scenario
A Pickup
A Rural road
And Seat belts that
arenrsquot used
Page 42 of 45
Occupants of pickups are less likely to wear seat belts and pickups are more likely to
roll over than passenger cars
Seat belts reduce the risk of death by 60 percent in pickups and SUVs
In Montana from 2006-2008 81 of those killed in a crash while riding in a pickup were not wearing seat belts
In Montana pickups make up 401 of the vehicle population
For more information on Respect the Cage click here
Page 43 of 45
Appendix 1
Lack of seat belts leading cause of Louisiana highway deaths
1251 AM May 28 2011 |
Written by Adam Duvernay
Crashes involving unbuckled motorists were the leading cause of highway fatalities
in Louisiana last year and cost $9888 million according to recent reports The
Louisiana Highway Safety Commission reported 59 percent of vehicle occupants
killed in Louisiana crashes last year mdash about one in four mdash werent wearing seat
belts
httpwwwshreveporttimescomarticle20110528NEWS01105280354Lack-seat-
belts-leading-cause-La-highway-deathsodyssey=tab|topnews|text|FRONTPAGE
Crash bull Stats Published by NHTSAlsquos National Center for Statistics and Analysis 1200 New Jersey Avenue SE Washington DC 20590
DOT HS 811 451
Early Estimate of Motor Vehicle Traffic Fatalities in 2010
httpwww-nrdnhtsadotgovPubs811451pdf
Summary
A statistical projection of traffic fatalities in 2010 shows that an estimated 32788
people died in motor vehicle traffic crashes This represents a decline of about 3
percent as compared to the 33808 fatalities in 2009 as shown in Table 1 If these
projections are realized fatalities will be lowest on record (since 1949)
Traffic Safety Facts Overview 2009 Data
httpwww-nrdnhtsadotgovPubs811392pdf
In 2009 33808 people were killed in the estimated 5505000 police-reported
motor vehicle traffic crashes 2217000 people were injured and 3957000
crashes involved property damage only Compared to 2008 this is a 10-
percent decrease in the number of fatalities and a 5-percent decrease in the
Page 44 of 45
number of police-reported motor vehicle traffic crashes people injured and
crashes involving property damage
An average of 93 people died each day in motor vehicle crashes in 2009 mdash
an average of one every 16 minutes
Traffic Safety Facts Overview 2008 Data
httpwww-nrdnhtsadotgovPubs811162pdf
In 2008 37261 people were killed in the estimated 5811000 police-reported
motor vehicle traffic crashes 2346000 people were injured and 4146000
crashes involved property damage only
Some comments and Feedback
The following comments were received from Prof Ganesan after his review of the
first draft of this document It was subsequently revised thanks to this input to
address some of the very important issues raised here
Dear Laxman
The write up is not enough
You are emphasizing that the speed limit reduces the fatal accidents (comparing 1966
to 2000 accident numbers)
Can you also add a few sentences why the number is decreasing from 1980 to 2000
values (May be due to better design of vehicles)
Can you say anything about the fuel consumption with the speed for any typical
vehicle in 2011 or 2010 (do not consider the fatalities issue)
Probably a speed between 55 and 60 mph gives a better mileage If so this is a
compelling reason to keep the speed limit low But cars probably can be tuned to
give better mileage at any high speed also
Page 45 of 45
Weather is also a major factor in fatal accidents Speed limit may be kept low during
winter and kept higher in summer Give your comments on this too
Driver distractions can cause more accidents Now cars have many multimedia and
internet features Automatic collision avoidance systems and sensors on the sides can
detect vehicles in the front and neighboring lanes and it can automatically decrease
speed even if the driver speeds at super high speeds
Give some comments on this too There is also Vehicle to Vehicle communications
vehicle to infrastructure communications and they can avoid collisions and accidents
Technology has changed from 1966 I cannot agree with you on the speed limit
without any discussion on the above and other factors
Have a great day
Subra Ganesan
Professor Subramaniam Ganesan
Director Real Time amp DSP Lab
Electrical and Computer Engineering Department
2200 Squirrel Road Dodge Hall Room 105
Oakland University Rochester MI 48309 USA
Phone 248 370 2206 Fax 248 370 4633
wwwsecsoaklandedu~ganesan
IEEE Distinguished Visiting Speaker (2005-2009) Coordinator
IEEE SEM CS chapter Chair Region 4 and CS Society Board member
SAE ASEE ACM member
Page 18 of 45
Figure 5 Expanded view of the fatality data showing the immediate impact of the
national speed limit of 55 mph following the Arab oil embargo of 1973 Note that
fatalities continued to rise between 1966 and 1973 in spite of the highly publicized
Congressional hearings in 1966 and the traffic safety legislation enacted soon after
Each new low is probably associated with vehicle safety innovations and the
improvements in vehicle design and engineering The combined beneficial
effect of improved vehicle designs primarily the introduction of seat belts
and the laws enforcing usage of seat belts aided by the reduced speed
limits contributed to the continued decline in the absolute number of fatalities
that started since 1973 and has continued to this day The subsequent
introduction of other safety features notably air bags has contributed to a
further reduction in highway fatalities
Page 19 of 45
State police Trooper First Class Jeffrey Flowers looking at a car in which a Boswell
Pennsylvania woman was injured Tuesday (May 31 2011) The accident occurred at
an intersection when a truck (seen behind the wrecked car) entered this accident
prone intersection (part of a highway safety corridor where signs are posted to
reduce unsafe driver behavior) There have been four accidents at this intersection
since 2006 none fatal httpwwwdailyamericancomnewssomersetda-ot-woman-
injured-in-route-30-wreck-2011053104165420story
5 Numerical calculations of decline in
fatalities and the impact of NMSL post-1973
Letlsquos consider the decline in fatalities between 1972 the last year before the
adoption of the NMSL and 1974 the first year following its adoption after the
Arab oil embargo There was an immediate decrease in the number of
fatalities by 9393 ie y = -9393 with a slight increase in the VMT ie x
= 20758 millions The NHTSA data used here may be found in the table at
the end of this document The numerical value of the rate of change per
billion VMT (ie neglecting the sign) was therefore
yx = 4525 fatalitiesbillion VMT (1972-1974)
Page 20 of 45
It is instructive to compare this rate of change in fatalities with similar short
periods of a decline in fatalities in the pre-1973 era when speed limits were
much higher The absolute number of fatalities declined over a relatively
short period with both an increase and a decrease in VMT The results are
given below and are self-explanatory
yx = 454 fatalitiesbillion VMT (1953-54) decline with increase in VMT
yx = 655 fatalitiesbillion VMT (1942-43) decline with decrease in VMT
yx = 1739 fatalitiesbillion VMT (1941-42) decline with decrease in VMT
yx = 4528 fatalitiesbillion VMT (1937-39) decline with increase in VMT
yx = 2548 fatalitiesbillion VMT (1931-32) decline with decrease in VMT
The rate of decline observed between 1953 and 1954 with an increase in
VMT was just one-tenth of that observed following the adoption of the 55
mph speed limit The war years (1941-43 WWII) and the Great Depression
era (1931-32) were accompanied by big declines in fatalities with decreasing
VMT but the rate of change was still significantly lower than observed after
the adoption of the NMSL
The only apparently inexplicable decline is that between 1937 and 1939
where a nearly identical high rate of decline was observed Notice also the
big drop in the traditional fatality rate between 1937 and 1938 This large drop
appears to coincide with the creation of the National Safety Council (NSC) by
William H Cameron in June 1937 (see link below) with its far-flung campaign
of education legislation research highway engineering and traffic training
undertaken by the NSC and some two dozen other groups with the backing of the
automotive industry through its Automotive Safety Foundation Other factors
unknown to the present author probably also played a role
httpwwwtimecomtimemagazinearticle0917188379700htmlixzz1O2G
7rnUg
Page 21 of 45
These simple computations here however reveal the significant effect of
reduced speed limits on highway fatalities much more so than other factors
6 Further Considerations Pros and Cons
The singular effect of increased speeds (or speeding) on highway fatalities
has been studied and demonstrated by a number of industry sources such
as the Insurance Institute for Highway Safety (IIHS) Consumers Union and
also by government researchers
httpwwwsmartmotoristcomtraffic-and-safety-guidelineexcessive-speed-is-
a-factor-in-one-third-of-all-fatal-crasheshtml
httpwwwconsumersunionorgotherspeedlimitsspeed031500a2htm
Speed ndash defined as exceeding the posted speed limit or driving too fast for
given conditions ndash is a factor in nearly one-third of all fatal crashes Besides
fatality in 1998 nearly 40000 people were critically injured in speed-related
crashes and nearly 72000 were moderately injured
The salutary and immediate beneficial effect of the nationwide 55 mph speed
limit has been noted by other researchers (see Susan Ferguson link below)
httpwwwnhtsagovpeopleinjuryenforcespeed_forum_presentationsfergu
sonpdf
After a partial repeal of this law in 1987 which granted states the authority to
increase speed limit (especially in rural interstates) a 1989 study showed a
15 increase in fatalities in rural interstates and a 5 increase in non-rural
interstates Unfortunately such studies often tend to be discounted by
advocates of increasing the speed limits as being produced by biased
industry sources
Similar conclusions were also presented by NHTSA in February 1998 in its
report to the Congress entitled ―Report to Congress The Effect of Increased
Speed Limits in the Post-NMSL Era see link given below Among its key
Page 22 of 45
findings is the following quoted in its entirety NMSL refers to the National
Maximum Speed Limit legislated after the Arab oil embargo of 1973
httpwww-nrdnhtsadotgovPubs808-637PDF
hellip Nevertheless it is important to note that data currently available from the
National Highway Traffic Safety Administrationrsquos (NHTSA) Fatality Analysis
Reporting System (FARS) shows that states that increased speed limits in 1996
experienced approximately 350 more Interstate fatalities than would have been
expected based on historical trends -- about 9 percent above expectations
Concurrently the Interstate fatalities experienced in states that did not increase speed
limits in 1996 was consistent with pre-1996 trends The estimated increase in
Interstate fatalities found in this study while smaller in magnitude compared to the
estimated change in fatalities found in 1987 following the increase of speed limits on
rural Interstates does follow the historical pattern of increases in fatalities being
associated with increases in posted speed limits
The annual crash reports compiled by NHTSA see Table 3 indicate that the
number of fatal crashes (and hence fatalities using the regression equation
developed in Figure 4) increase as the posted speed limits increase
Page 23 of 45
Table 3 Posted speed limits and number of crashes
Speed Limit Crashes (2008) Crashes (2009)
30 mph or less 3705 3277 35 or 40 mph 6115 5516 45 or 50 mph 6461 6074
55 mph 9794 8847 60 mph or higher 6908 6124
Total 34017 30797
Source httpwww-nrdnhtsadotgovPubs811402EEpdf
61 Studies cited in favor of lower speed limits
A detailed analysis of speeding related fatalities (see link below) by NHTSA
shows that a third of all crashes involve speeding ie at least one driver was
speeding
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Furthermore the above report which covers the period 1983-2002
indicates that immediately after the NMSL was completely abolished in
December 1995 the number of speeding related fatalities at speeds
above 65 mph increased from just 15 in 1995 to a 677 in 1996 (see Table
62 on page 43 of above report) It continued to increase in the years
since climbing to 930 in 2000
More detailed studies similar to that noted above by researchers at the
University of Illinois Chicago led by Lee S Friedman again lead to the
conclusion that higher speed limits lead to an increase in the number of
fatalities (see American Journal of Public Health online July 16 2009)
httphealthusnewscomhealth-newsmanaging-your-
healthcarearticles20090716deaths-injuries-increase-with-higher-speed-
limits
Page 24 of 45
httpwwwmedpagetodaycomPublicHealthPolicyPublicHealth15122
httpwwwamericaneercomspeed-limits
httpwwwactuarialoutpostcomactuarial_discussion_forumarchiveindexph
pt-171870html
For the study period 1995-2005 these researchers found that 12545 deaths
and 36582 injuries could be attributed to the increased speed limits The
benefits of reduced speed limits are stated quite eloquently by Dr Friedman
and are reproduced below (from above news article see link)
Reduced speed limits would save lives Friedman said They would also reduce
gas consumption cut emissions of air pollutants save valuable years of productivity
(lost due to injuries)and reduce the societal cost of motor vehicle crashes (due to
both fatal crashes and due to nonfatal and severe life-changing injuries) he added
Friedman and coworkers have also shown that increasing the speed limit led
to an immediate increase in the number of fatalities on Israeli roadways (see
link below)
httpinjurypreventionbmjcomcontent133156
The effect of speeding is very significant especially in rural areas resulting
in significantly higher fatalities Fatality rates are frequently double or triple
that in urban areas (see link below)
httpsafetyfhwadotgovspeedmgtdata_factsdocsspeeding_ruralpdf
As of Jan 1 2005 five Midwestern states had increased the speed limits to
above 65 mph (Illinois Iowa Kansas Minnesota Missouri Nebraska and
South Dakota) whereas three (Illinois Iowa and Wisconsin) had not All the
five states with increased speed limits showed a 7 to 13 increase in
fatalities The NHTSA study considered an eight year period before and after
the change in Dec 1995 (see Table 1 in link below) The collective experience
of the states that did NOT increase the speed limit was a 7 decline in
fatalities (see Table 2 of link below)
httpwwwiowadotgovmvdodsstats2006speedstudypdf
Page 25 of 45
Moreover Table 5 in the above study shows the effect of imposing the NMSL
of 55 mph in Iowa and its repeal in 1995 Considering a four-year average
before 1974 when the speed limit was 75 mph there were 35 fatal crashes
with 43 fatalities In the first four years after the 55 mph there were only 23
fatal crashes and 28 fatalities In the last four years before the repeal of 55
mph in 1995 there was a further decline to 14 fatal crashes with 17 fatalities
The Iowa fatality data will be discussed in more detail separately (in a later report)
since it provides the opportunity to assess the effect of a change in the speed limit
on the relationship between number of fatalities and fatal crashes (as seen in
Figure 4 for the US as a whole)
North of the US border Canadians seem to be citing the ―shocking increase
in highway fatalities in the US states where the speed limits were raised to
curb their own speed limits
httparchivesafety-councilorginfotrafficspeed-02html
httparchivesafety-councilorginfotrafficspeedhtml
Speed kills but speed also sells notes the second of the above news items
Manufacturers are producing more high performance cars (with higher horse
power to weight ratio) and ads feature enticing cars that race and swerve in
miraculous ways on empty roads These subliminal messages encourage
drivers especially young drivers to break the speed limit leading to the
absolute increase in highway fatalities (although the rate itself is going
down) The article emphasizes the need to enforce the speed limit on
Canadian highways and in cities where street racing is becoming a problem
62 Studies cited by opponents of lower speed limits
In fairness to quote the opponents on the other side of this debate Montana
reverted back to Reasonable and Prudent speed limits when the National
Maximum Speed Limit was repealed in 1995 and appears to have
experienced no significant increase in fatalities
Page 26 of 45
httpwwwhwysafetycomhwy_montanahtm
httpwwwmotoristsorgpressmontana-no-speed-limit-safety-paradox
httpwwwsouthbayriderscomforumsshowthreadphpt=81453amppage=1
Likewise studies in the state of Maryland showed no significant increase in
highway fatalities when the speed limit was increased from 55 mph to 75
mph The reason might simply be that drivers were already speeding much
more so when the speed limit was 55 mph than after the increase to 75 mph
In other words the fatalities data already reflects the effect of higher speeds
(not speed limits) on the number of fatalities
In Utah the experimental increase in the speed limit to 80 mph was
considered to be a success in terms of safety
httpautosaolcomarticleutah-speed-limit-tests
The UDOT Director noted that there was no increase in the number of
accidents on Interstate 15 But what happens in the event of an accident
when the speed limits are higher and drivers are driving at higher speeds and
two objects collide at this higher speed However no increase in the number
of accidents is not the same as no increase in fatalities due to the higher
speeds When accidents do occur do fatalities increase
Likewise in California when the speed limit went up from 55 mph to 65
mph in 1995 (after repeal of NMSL) fewer deaths were reported in 1998
compared to the peak year of 1979 or even 1987 Again the explanation
seems to be that motorists were already speeding when the limit was 55 mph
and that increasing the speed limit did not change driver behavior in any
significant way
httparticlessfgatecom1998-11-02news17735730_1_speed-limits-mph-
limit-death-rate
The National Motorists Association (NMA) a group which advocates higher
speed limits emphasizes the importance of considering fatality rates as
opposed to the raw fatalities The argument used is that fatality rates based
on the fatality per 100 million VMT is the legitimate way to look at the data
Page 27 of 45
This is a never ending debate Historically speaking fatality rates have been
going down ever since the compilation of traffic accidents data began Table
A1 in the appendix of a recent report by NHTSA (see link below) has highway
fatality rate data going back 1921
httpwww-nrdnhtsadotgovPubs811346pdf see appendix page 31
httpwwwmotoristsorgspeed-limitstruth
httpwwwmotoristsorgothercrash-data
httpwwwraisethespeedlimitorgmythshtml
httpwwwcatoorgpubspaspa346pdf
According to Stephen Moore of the Cato Institute (see last of the links above)
―All measures of highway safety show improvement not more deaths and
injuries since 1995 Despite the fact that 33 states raised their speed limits
immediately after the repeal of the mandatory federal speed limit the NHTSA
reported last October that the traffic death rate dropped to a record low level
in 1997lsquo Moreover the average fatality rate even fell in the states that raised
their speed limits
63 The Fatality rate Is it a reliable metric
In 1921 with fewer fatalities and fewer miles driven and the first year for
which the fatality rate could be computed the rate was 2408 It was down to
1479 in 1931 but the number of deaths had climbed to 31963 more than
double the 1921 absolute fatality number of 13253 It had dropped to 550 in
1966 the year of the highly publicized Congressional hearings but the
number of fatalities had climbed to 50984 in that fateful The Highway Safety
Act of 1966 ranks as one of the major acts of Congress and President
Johnson signed it saying that ―we have been tolerating a raging epidemic of
highway deathshellip see extract pasted below
httpwwwenotescommajor-acts-congresshighway-safety-act
Page 28 of 45
The act was motivated primarily by growing public concern over the rising number
of traffic fatalities in the United States Between 1960 and 1965 the annual number
of traffic fatalities increased by nearly thirty percent As President Lyndon B
Johnson stated at the signing of the act on September 9 1966 we have tolerated
a raging epidemic of highway death which has killed more of our youth than all
other diseases combined Through the Highway Safety Act we are going to find out
more about highway diseasemdashand we aim to cure it
Nonetheless highways fatalities continued to increase until the Arab oil
embargo of 1973 led to the NMSL of 55 mph all across the USA Do we just
ignore this undeniable historical record and focus only on the declining fatality
rate as the NMA and other proponents of higher speed limits seem to argue
(see links above)
The misleading nature of using fatality rates (per 100 M VMT) alone is also
obvious if one considers fatality data for individual states Take for example
the state of Montana which seems to have experienced no increase in
fatalities after repeal of NMSL
httpwww-nrdnhtsadotgovdepartmentsnrd-
30ncsaSTSI30_MT200930_MT_2009htm
For the period 2005-2009 the absolute number of fatalities for Montana
varied between a high of 277 in 2007 to a low of 229 in 2009 The fatality
rates per 100 M VMT on the other hand varied from a high of 245 for 2007
to a low of 201 for 2009 The corresponding US fatality rates varied from
136 to 114 Is the higher number for the fatality rate for Montana compared
to USA good or bad Likewise fatality rate per 100000 of population was
much higher for Montana than the US as a whole
This again highlights the pitfalls of using simple ratios to assess fatality statistics
without a full analysis of the underlying trends We will discuss this point
separately
As shown already the continuous decline in the fatality rate is a mathematical
artifact and essentially overlooks the unmistakable positive correlation
between the variables x and y of the type y = hx + c which becomes obvious
Page 29 of 45
only when we prepare the x-y scatter graph The ratio yx = h + (cx) can
decrease with increasing x (VMT) and increasing y (fatalities) since the
intercept c has a positive value when we consider only data spanning a short
period (such as 1994-2009 of more relevance to the current situation)
The debate between fatality rates and absolute number of fatalities is an
unending one A few years ago the Wall Street Journal carried an article
which was entitled (or something close) ―Unemployments rate in Ohio are
going down but why is the number of unemployed increasing The reason is
the same The graph of the number of unemployed (y) versus the number in
the labor market (x) is linear with a positive slope h and a positive intercept c
So the unemployment rate computed using the ratio yx keeps going down
year after year although the number unemployed keeps increasing Is it a
good thing that the unemployment rate is going down when more people
seem to be unable to find gainful unemployment
Or consider the situation with cancer death rates This too has been going
down in recent years but the actual number of cancer-related deaths has not
declined in any significant way Is it good that cancer death rates are going
down In all these situations the researchers or the socio-econo-politico
analysts involved in analyzing the trends in the data have failed to consider
the underlying x-y relation describing each problem
Hence it appears that the debate on the effect of increased speed limits
should not be focused on only the fatality rates (which have been decreasing
and proponents of higher speed limits cite this in their arguments) or even the
absolute number of fatalities (which has been the focus here) but on the
relationship between speed and the number of fatal crashes and the number
of fatalities within each speed segment (see Table 3 and also Figure 4)
Unfortunately details of number of fatalities and the number of fatal crashes
at each speed limit are not available even from NHTSA for detailed study
When a crash does occur (it is immaterial how many miles were driven) the
speed of the driver and vehicle design and engineering including safety
devices in place (seat belts airbags other impact absorbing technologies)
Page 30 of 45
determine if the occupants(s) will be killed One cannot argue that speed
does NOT kill That would be an absolute denial of the laws of physics
Studies show that setting the speed limit at the 85th percentile in any given
zone (this is the speed at or below which 85 of drivers are observed to
travel in traffic engineering studies) is the safest speed limit The majority of
drivers try to obey the posted speed limit while a few choose to drive at a
speed they consider is safe and prudent These are also perhaps the most
vociferous advocates of higher speed limits It is this tension caused due to
differences in speeds that leads to tailgating improper passing reckless
driving weaving from lane to lane and ultimately crashes and deaths in some
unfortunate cases
httpblogmotoristsorgspeed-limits-slower-safer
MARK TAYLOR
ANOTHER LOST A man was killed when his 4WD drive hit a tree east of Morrinsville (in New
Zealand) on Monday May 30 2011 The driver lost control of the vehicle on a bend probably tried
to correct his mistake and put the car into a ―yaw causing it to leave the road and smash sideways
into a tree Alerts to slow down had been posted since this was a high accident area but the driver
probably did not pay attention
64 Other factors
Many other factors besides speed no doubt affect highway fatalities The
vehicles of the 21st century are very different from the vehicles of the mid 20th
Page 31 of 45
century Technological innovations such as improvements in vehicle design
and engineering have greatly increased crash worthiness of vehicles even at
high speeds Environmental factors such as the weather also contribute to
accidents but not necessarily to increased fatalities Drivers actually tend to
slow down instinctively during adverse weather conditions (rain snow storms
etc) and although such weather may contribute to increased accidents the
lower speeds actually reduce fatalities
Yes technology has changed fundamentally from 1966 Drivers today are
more distracted by their cellmobile phone conversations (and also built-in
phones in luxury models) and text messaging than the drivers of the pre-1966
era High end cars now have many multimedia and internet features Again a
careful observation (even personal experience by the author) suggests that
such distracted drivers actually tend to (instinctively) drive more slowly and
hold up the traffic Perhaps such behavior leads to an increase in the number
of accidents but it does not necessarily lead to an increase in the number of
accident-related fatalities
Much talked about technological innovations such as automatic collision
avoidance systems and sensors (on the sides of vehicles) can indeed detect
vehicles in the front and neighboring lanes Furthermore vehicle-to-vehicle
communication systems vehicle-to-infrastructure communication systems
can no doubt avoid collisions and accidents Again such collision avoidance
systems work and are effective entirely because they automatically reduce
vehicle speeds - even if one of the offending vehicles is being at a super
high speed Also it must be remembered that such futuristic systems have
not yet been implemented widely nor can they be implemented widely since
the large majority of vehicles on the road are NOT luxury models Advanced
safety features come with a price and not all drivers can afford to pay that
price and ―buy that ―additional safety
Ultimately it is the laws of physics that govern what will happen when two or
more vehicles collide or even when a single vehicle collides with a stationary
infrastructural object (a bridge a wall a building or some impediment on the
road) The lower the number of crashes the lower the number of fatalities as
revealed by the 1994-2009 data graphed in Figure 5 The higher the speed of
Page 32 of 45
the object or objects that are involved in a collision the higher the kinetic
energy K that must be absorbed andor dissipated Increasing the posted
speed limit only increases the energy that must be absorbed when a crash
does occur This ultimately is the most important criterion determining the
number of fatalities
The kinetic energy increases as the square of the speed being given by the
well-known formula K = frac12 mv2 where m is the mass of the vehicle (in
laypersonlsquos language m increases directly with vehicle weight) and v is the
speed For the same vehicle mass an increase in the speed from 55 mph to
85 mph increases the kinetic energy K by a factor of 239 or roughly a 250
increase in the kinetic energy that must be absorbed in a collision
Ideally speaking the kinetic energy of the colliding object(s) is absorbed by
the vehicle infrastructure (a sturdy space frame the engine other vehicle
components etc) andor the surroundings However in the unfortunate
cases where this kinetic energy must be absorbed by the vehicle occupant(s)
the result is severe life-altering injuries andor death An unequivocal
relationship between an increase in vehicle speeds and fatal accidents can
be demonstrated by a careful examination of available traffic fatality data
This is a more involved discussion and is not the purpose of this short
communication These topics are no doubt very politically charged with many
social legal and financial implications with each interest group favoring a
different conclusion Nonetheless we cannot escape the laws of physics as
they govern the fundamental need to absorb higher and higher values of the
kinetic energy K with increasing vehicle speeds This same point is also
emphasized by Dr Friedman of the University of Illinois Chicago (see earlier
discussion)
Speed kills because of these energy transfer considerations and there can be
no doubt about it
Innovative 21st century solutions to speed management on the highways
such as strict enforcement of speed limits minimizing speed dispersion
(difference between speeds at which different drivers travel) while using
cameras to track the 15 of drivers who willfully violate the speed limit and
Page 33 of 45
create hazardous driving conditions is certainly recommended (Recall that
the optimum recommended speed limit is at or below which 85 of all drivers
travel ndash a policy also supported by NMA) Even on this score however the
results are confounding if we consider the Australian experience
httpwwwthenewspapercomnews282840asp
Up until 2007 there was no speed limit in the Northern Territory of
Australia Imposing a speed limit 130 kmph (80 mph) on some areas and
110 kmph (68 mph) in some others actually increased the number of deaths
The death toll in 2006 when there was no speed limit in this region was 44
and went up to 75 in 2009 see data table in link below
httpwwwthenewspapercomrlcdocs2009au-ntroadtollpdf
Furthermore it appears that installation of cameras to enforce speed limits
has proved to be a hazardous distraction to drivers and deaths actually
began to skyrocket between 2005 and 2007 in all Australian roadways
The main purpose here is to sound a cautionary note amid renewed attempts
in many states across the US to increase the speed limits on our highways by
calling attention to the historical facts regarding the ―epidemic levels of
highway traffic fatalities that engaged our national attention in the fateful year
of 1966 The graphical representation of the traffic fatality data in Figures 1
to 5 tells its own story
Indeed it would be tragic if highway-accident-related fatalities were to start
increasing once again and reach the historically high level that was last seen
in 1972 the year before the Arab oil embargo of 1973
Page 34 of 45
Conclusions
1 The graphical representation of the highway fatality data and the brief
summary of the historical facts of traffic safety legislation suggest that
recent attempts to increase the speed limits by various states (notably
Texas) may be misguided The distinct peak in the highway fatalities
observed in these graphs is highly alarming This appears to be related to
the enactment of the National Maximum Speed Limit (NSML) in 1974
following the 1973 Arab oil embargo Although NSML was motivated by a
desire to reduce gasoline consumption an unintended benefit might have
been a dramatic reduction in fatalities The fundamental reasons for the
peak in the fatalities-VMT curve must be examined carefully without
political posturing
2 The widely used fatality rate fatalities per 100 M vehicle miles traveled
has been declining since 1921 the first year for which a fatality rate could
be computed and has now reached a historical low The absolute number
of fatalities on the other hand was increasing in the 1950s and 1960s at
an alarming rate and the public outcry that ensued led to the highly
publicized Congressional hearing of 1966 and the subsequent traffic safety
legislations The fatality rate has been decreasing even in the most recent
15-year period (1994-2009) again with increasing fatalities although less
dramatically Thus it appears that fatality rate calculation based on vehicle
miles traveled (VMT) might not be a reliable indicator of the underlying
dynamics in the fatality trends
3 More detailed compilation of number of fatalities and the number of fatal
crashes within each speed limit segment is required to better understand
the effect of increasing speed limits on highway fatalities (and also fatality
rates) Such data is already available and is being compiled at the local
city and county levels in all jurisdictions and only needs to be reorganized
to highlight the effect of (posted) speed limits on the number of crashes
and fatalities This will require some minor rewriting and revisions to the
chapters named ―Crashes and ―States in the annual NHTSA reports
Page 35 of 45
Analysis of the fatalities-crashes data for several years with various
speed limits will be more revealing and meaningful than the current
fatality rates analysis and will be discussed separately in a follow up
report
4 One should not be lulled by the fact that vehicles of the 21st century are
now equipped with advanced safety features not available in the 1950s
and the 1960s In spite of these safety features the laws of physics dictate
that the higher the speed the higher kinetic energy of the colliding objects
and hence the greater the risk indeed near certainty of fatalities in a
higher speed collision compared to a lower speed one
5 The higher the speed at which the vehicle that is involved in a crash is
traveling the higher the kinetic energy that must be absorbed andor
dissipated without affecting the occupant(s) to avoid serious injuries andor
death This was true in the 1950s and the 1960s and will continue to be
true in the 21st century as well
Speed Kills for this just reason
6 It appears that higher fuel economies and reduced
highway fatalities were the twin societal benefits of 55
mph adopted after 1973 If so the current attempts to
increase the speed limits appear to be in conflict with
other important societal objectives
Page 36 of 45
Table 1 Annual US Street amp Highway
Fatalities from 1957
Year
Fatalities
Vehicle Miles
(millions)
Rate100M Vehicle Miles
1957 38702 646915 598
1958 36981 664915 556
1959 37910 700478 541
1960 38137 718845 531
1961 38091 737535 516
1962 40804 766852 532
1963 43564 805423 541
1964 47700 846500 563
1965 49163 887640 554
1966 51524 927915 555
1967 51559 965132 534
1968 53831 1019726 528
1969 55032 1066108 516
1970 53672 1114098 482
1971 53761 1183524 454
1972 55704 1264614 440
1973 55113 1316207 419
1974 46078 1282790 359
1975 45500 1330074 342
1976 45523 1402380 325
1977 47878 1467027 326
1978 50331 1544704 326
1979 51103 1529133 334
1980 51091 1527295 335
1981 49301 1552803 317
1982 43945 1595010 276
1983 42589 1652788 258
1984 44257 1720269 257
1985 43795 1774179 247
Page 37 of 45
1986 46056 1835000 251
1987 46385 1921000 241
1988 47093 2026000 232
1989 45555 2107040 216
1990 44529 2147501 207
1991 41162 2172214 189
1992 39235 2239828 175
1993 40115 2296585 175
1994 40676 2359984 172
1995 41798 2422696 173
1996 41907 2485848 169
1997 41967 2560373 164
Data from Federal Highway Administration
Source httpwwwpublicpurposecomhwy-fatal57+htm
Telephone +16186328507 - Facsimile +16186328538
WENDELL COX CONSULTANCY P O Box 841 - Belleville IL 62269 USA
Page 38 of 45
Fatality data for 1921-1982 compiled by NHTSA
Year
VMT
(Millions)
VMT
(Billions)
Fatalities
Fatality rate
per 100 M VMT
1921 55027 5503 13253 241 1922 67697 6770 14859 219 1923 84995 8500 17870 210 1924 104838 10484 18400 176 1925 122346 12235 20771 170 1926 140735 14074 22194 158 1927 158453 15845 24470 154 1928 172856 17286 26557 154 1929 197720 19772 29592 150 1930 206320 20632 31204 151 1931 216151 21615 31963 148 1932 200517 20052 27979 140 1933 200642 20064 29746 148 1934 215563 21556 34240 159 1935 228568 22857 34494 151 1936 252128 25213 36126 143 1937 270110 27011 37819 140 1938 271177 27118 31083 115 1939 285402 28540 30895 108 1940 302188 30219 32914 109 1941 333612 33361 38142 114 1942 268224 26822 27007 101 1943 208192 20819 22727 109 1944 212713 21271 23165 109 1945 250173 25017 26785 107 1946 340880 34088 31874 94 1947 370894 37089 31193 84 1948 397957 39796 30775 77 1949 424461 42446 30246 71 1950 458246 45825 33186 72 1951 491093 49109 35309 72
1952 513581 51358 36088 70
Page 39 of 45
1953 544433 54443 36190 66 1954 561963 56196 33890 60 1955 605646 60565 36688 61 1956 627843 62784 37965 60 1957 647004 64700 36932 57 1958 664653 66465 35331 53 1959 700480 70048 36223 52 1960 718762 71876 36399 51 1961 737421 73742 36285 49 1962 766734 76673 38980 51 1963 805249 80525 41723 52 1964 846298 84630 45645 54 1965 887812 88781 47089 53 1966 925899 92590 50894 55 1967 964005 96401 50724 53 1968 1015869 101587 52725 52 1969 1061791 106179 53543 50 1970 1109724 110972 52627 47 1971 1178811 117881 52542 45 1972 1259786 125979 54589 43 1973 1313110 131311 54052 41 1974 1280544 128054 45196 35 1975 1327664 132766 44525 34 1976 1402380 140238 45523 32 1977 1467027 146703 47878 33 1978 1544704 154470 50331 33 1979 1529133 152913 51093 33 1980 1527295 152730 51091 33 1981 1555308 155531 49301 32 1982 1595010 159501 43945 28
Source Analysis of Significant Decline in Motor Vehicle Traffic Fatalities in
2008 httpwww-nrdnhtsadotgovPubs811346pdf see Table A1 page 31
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Page 40 of 45
Acknowledgements
The author is grateful for thoughtful comments provided by friends and colleagues
with whom this document was shared via email prior to it being uploaded as a
publicly available document for wider dissemination and study The comments
offered by Prof Subra Ganesan of Oakland University Electrical and Computer
Engineering Department are reproduced with permission in their entirety
About the author
The author obtained his Masterrsquos (S M) and Doctoral (Sc D) degrees in Materials Engineering
from the Massachusetts Institute of Technology Cambridge USA He then spent his entire
professional career at leading US research institutions (MIT NASA Case Western Reserve
University and General Motors R amp D Center in Warren MI) He holds four patents in advanced
materials processing has co-authored two books and has published several scientific papers in
leading peer-reviewed international journals His expertise includes developing simple
mathematical models to explain the behavior of complex systems He can be reached by email at
vlaxmananhotmailcom
Page 41 of 45
Please Buckle Up
httpwwwlakecountypublichealthorgindexphpbuckle-up-montana
Public Awareness
Respect the Cage Exhibit
The Department of Transportation hopes that showing the reality of the crash will reduce traffic
fatalities A crushed car crash dummies and a sobering message ndash all part of the ―Respect The
Cage exhibit that is traveling across Montana The exhibit sponsored by the Montana Department
of Transportation stopped in Ronan on November 6th and is aimed at raising awareness about the
importance of wearing seat belts
The car in the exhibit was in an actual wreck many years ago
the passenger in the vehicle died because he was not wearing a
seat belt the driver who was wearing his seat belt survived
Montanarsquos likeliest crash fatality scenario
A Pickup
A Rural road
And Seat belts that
arenrsquot used
Page 42 of 45
Occupants of pickups are less likely to wear seat belts and pickups are more likely to
roll over than passenger cars
Seat belts reduce the risk of death by 60 percent in pickups and SUVs
In Montana from 2006-2008 81 of those killed in a crash while riding in a pickup were not wearing seat belts
In Montana pickups make up 401 of the vehicle population
For more information on Respect the Cage click here
Page 43 of 45
Appendix 1
Lack of seat belts leading cause of Louisiana highway deaths
1251 AM May 28 2011 |
Written by Adam Duvernay
Crashes involving unbuckled motorists were the leading cause of highway fatalities
in Louisiana last year and cost $9888 million according to recent reports The
Louisiana Highway Safety Commission reported 59 percent of vehicle occupants
killed in Louisiana crashes last year mdash about one in four mdash werent wearing seat
belts
httpwwwshreveporttimescomarticle20110528NEWS01105280354Lack-seat-
belts-leading-cause-La-highway-deathsodyssey=tab|topnews|text|FRONTPAGE
Crash bull Stats Published by NHTSAlsquos National Center for Statistics and Analysis 1200 New Jersey Avenue SE Washington DC 20590
DOT HS 811 451
Early Estimate of Motor Vehicle Traffic Fatalities in 2010
httpwww-nrdnhtsadotgovPubs811451pdf
Summary
A statistical projection of traffic fatalities in 2010 shows that an estimated 32788
people died in motor vehicle traffic crashes This represents a decline of about 3
percent as compared to the 33808 fatalities in 2009 as shown in Table 1 If these
projections are realized fatalities will be lowest on record (since 1949)
Traffic Safety Facts Overview 2009 Data
httpwww-nrdnhtsadotgovPubs811392pdf
In 2009 33808 people were killed in the estimated 5505000 police-reported
motor vehicle traffic crashes 2217000 people were injured and 3957000
crashes involved property damage only Compared to 2008 this is a 10-
percent decrease in the number of fatalities and a 5-percent decrease in the
Page 44 of 45
number of police-reported motor vehicle traffic crashes people injured and
crashes involving property damage
An average of 93 people died each day in motor vehicle crashes in 2009 mdash
an average of one every 16 minutes
Traffic Safety Facts Overview 2008 Data
httpwww-nrdnhtsadotgovPubs811162pdf
In 2008 37261 people were killed in the estimated 5811000 police-reported
motor vehicle traffic crashes 2346000 people were injured and 4146000
crashes involved property damage only
Some comments and Feedback
The following comments were received from Prof Ganesan after his review of the
first draft of this document It was subsequently revised thanks to this input to
address some of the very important issues raised here
Dear Laxman
The write up is not enough
You are emphasizing that the speed limit reduces the fatal accidents (comparing 1966
to 2000 accident numbers)
Can you also add a few sentences why the number is decreasing from 1980 to 2000
values (May be due to better design of vehicles)
Can you say anything about the fuel consumption with the speed for any typical
vehicle in 2011 or 2010 (do not consider the fatalities issue)
Probably a speed between 55 and 60 mph gives a better mileage If so this is a
compelling reason to keep the speed limit low But cars probably can be tuned to
give better mileage at any high speed also
Page 45 of 45
Weather is also a major factor in fatal accidents Speed limit may be kept low during
winter and kept higher in summer Give your comments on this too
Driver distractions can cause more accidents Now cars have many multimedia and
internet features Automatic collision avoidance systems and sensors on the sides can
detect vehicles in the front and neighboring lanes and it can automatically decrease
speed even if the driver speeds at super high speeds
Give some comments on this too There is also Vehicle to Vehicle communications
vehicle to infrastructure communications and they can avoid collisions and accidents
Technology has changed from 1966 I cannot agree with you on the speed limit
without any discussion on the above and other factors
Have a great day
Subra Ganesan
Professor Subramaniam Ganesan
Director Real Time amp DSP Lab
Electrical and Computer Engineering Department
2200 Squirrel Road Dodge Hall Room 105
Oakland University Rochester MI 48309 USA
Phone 248 370 2206 Fax 248 370 4633
wwwsecsoaklandedu~ganesan
IEEE Distinguished Visiting Speaker (2005-2009) Coordinator
IEEE SEM CS chapter Chair Region 4 and CS Society Board member
SAE ASEE ACM member
Page 19 of 45
State police Trooper First Class Jeffrey Flowers looking at a car in which a Boswell
Pennsylvania woman was injured Tuesday (May 31 2011) The accident occurred at
an intersection when a truck (seen behind the wrecked car) entered this accident
prone intersection (part of a highway safety corridor where signs are posted to
reduce unsafe driver behavior) There have been four accidents at this intersection
since 2006 none fatal httpwwwdailyamericancomnewssomersetda-ot-woman-
injured-in-route-30-wreck-2011053104165420story
5 Numerical calculations of decline in
fatalities and the impact of NMSL post-1973
Letlsquos consider the decline in fatalities between 1972 the last year before the
adoption of the NMSL and 1974 the first year following its adoption after the
Arab oil embargo There was an immediate decrease in the number of
fatalities by 9393 ie y = -9393 with a slight increase in the VMT ie x
= 20758 millions The NHTSA data used here may be found in the table at
the end of this document The numerical value of the rate of change per
billion VMT (ie neglecting the sign) was therefore
yx = 4525 fatalitiesbillion VMT (1972-1974)
Page 20 of 45
It is instructive to compare this rate of change in fatalities with similar short
periods of a decline in fatalities in the pre-1973 era when speed limits were
much higher The absolute number of fatalities declined over a relatively
short period with both an increase and a decrease in VMT The results are
given below and are self-explanatory
yx = 454 fatalitiesbillion VMT (1953-54) decline with increase in VMT
yx = 655 fatalitiesbillion VMT (1942-43) decline with decrease in VMT
yx = 1739 fatalitiesbillion VMT (1941-42) decline with decrease in VMT
yx = 4528 fatalitiesbillion VMT (1937-39) decline with increase in VMT
yx = 2548 fatalitiesbillion VMT (1931-32) decline with decrease in VMT
The rate of decline observed between 1953 and 1954 with an increase in
VMT was just one-tenth of that observed following the adoption of the 55
mph speed limit The war years (1941-43 WWII) and the Great Depression
era (1931-32) were accompanied by big declines in fatalities with decreasing
VMT but the rate of change was still significantly lower than observed after
the adoption of the NMSL
The only apparently inexplicable decline is that between 1937 and 1939
where a nearly identical high rate of decline was observed Notice also the
big drop in the traditional fatality rate between 1937 and 1938 This large drop
appears to coincide with the creation of the National Safety Council (NSC) by
William H Cameron in June 1937 (see link below) with its far-flung campaign
of education legislation research highway engineering and traffic training
undertaken by the NSC and some two dozen other groups with the backing of the
automotive industry through its Automotive Safety Foundation Other factors
unknown to the present author probably also played a role
httpwwwtimecomtimemagazinearticle0917188379700htmlixzz1O2G
7rnUg
Page 21 of 45
These simple computations here however reveal the significant effect of
reduced speed limits on highway fatalities much more so than other factors
6 Further Considerations Pros and Cons
The singular effect of increased speeds (or speeding) on highway fatalities
has been studied and demonstrated by a number of industry sources such
as the Insurance Institute for Highway Safety (IIHS) Consumers Union and
also by government researchers
httpwwwsmartmotoristcomtraffic-and-safety-guidelineexcessive-speed-is-
a-factor-in-one-third-of-all-fatal-crasheshtml
httpwwwconsumersunionorgotherspeedlimitsspeed031500a2htm
Speed ndash defined as exceeding the posted speed limit or driving too fast for
given conditions ndash is a factor in nearly one-third of all fatal crashes Besides
fatality in 1998 nearly 40000 people were critically injured in speed-related
crashes and nearly 72000 were moderately injured
The salutary and immediate beneficial effect of the nationwide 55 mph speed
limit has been noted by other researchers (see Susan Ferguson link below)
httpwwwnhtsagovpeopleinjuryenforcespeed_forum_presentationsfergu
sonpdf
After a partial repeal of this law in 1987 which granted states the authority to
increase speed limit (especially in rural interstates) a 1989 study showed a
15 increase in fatalities in rural interstates and a 5 increase in non-rural
interstates Unfortunately such studies often tend to be discounted by
advocates of increasing the speed limits as being produced by biased
industry sources
Similar conclusions were also presented by NHTSA in February 1998 in its
report to the Congress entitled ―Report to Congress The Effect of Increased
Speed Limits in the Post-NMSL Era see link given below Among its key
Page 22 of 45
findings is the following quoted in its entirety NMSL refers to the National
Maximum Speed Limit legislated after the Arab oil embargo of 1973
httpwww-nrdnhtsadotgovPubs808-637PDF
hellip Nevertheless it is important to note that data currently available from the
National Highway Traffic Safety Administrationrsquos (NHTSA) Fatality Analysis
Reporting System (FARS) shows that states that increased speed limits in 1996
experienced approximately 350 more Interstate fatalities than would have been
expected based on historical trends -- about 9 percent above expectations
Concurrently the Interstate fatalities experienced in states that did not increase speed
limits in 1996 was consistent with pre-1996 trends The estimated increase in
Interstate fatalities found in this study while smaller in magnitude compared to the
estimated change in fatalities found in 1987 following the increase of speed limits on
rural Interstates does follow the historical pattern of increases in fatalities being
associated with increases in posted speed limits
The annual crash reports compiled by NHTSA see Table 3 indicate that the
number of fatal crashes (and hence fatalities using the regression equation
developed in Figure 4) increase as the posted speed limits increase
Page 23 of 45
Table 3 Posted speed limits and number of crashes
Speed Limit Crashes (2008) Crashes (2009)
30 mph or less 3705 3277 35 or 40 mph 6115 5516 45 or 50 mph 6461 6074
55 mph 9794 8847 60 mph or higher 6908 6124
Total 34017 30797
Source httpwww-nrdnhtsadotgovPubs811402EEpdf
61 Studies cited in favor of lower speed limits
A detailed analysis of speeding related fatalities (see link below) by NHTSA
shows that a third of all crashes involve speeding ie at least one driver was
speeding
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Furthermore the above report which covers the period 1983-2002
indicates that immediately after the NMSL was completely abolished in
December 1995 the number of speeding related fatalities at speeds
above 65 mph increased from just 15 in 1995 to a 677 in 1996 (see Table
62 on page 43 of above report) It continued to increase in the years
since climbing to 930 in 2000
More detailed studies similar to that noted above by researchers at the
University of Illinois Chicago led by Lee S Friedman again lead to the
conclusion that higher speed limits lead to an increase in the number of
fatalities (see American Journal of Public Health online July 16 2009)
httphealthusnewscomhealth-newsmanaging-your-
healthcarearticles20090716deaths-injuries-increase-with-higher-speed-
limits
Page 24 of 45
httpwwwmedpagetodaycomPublicHealthPolicyPublicHealth15122
httpwwwamericaneercomspeed-limits
httpwwwactuarialoutpostcomactuarial_discussion_forumarchiveindexph
pt-171870html
For the study period 1995-2005 these researchers found that 12545 deaths
and 36582 injuries could be attributed to the increased speed limits The
benefits of reduced speed limits are stated quite eloquently by Dr Friedman
and are reproduced below (from above news article see link)
Reduced speed limits would save lives Friedman said They would also reduce
gas consumption cut emissions of air pollutants save valuable years of productivity
(lost due to injuries)and reduce the societal cost of motor vehicle crashes (due to
both fatal crashes and due to nonfatal and severe life-changing injuries) he added
Friedman and coworkers have also shown that increasing the speed limit led
to an immediate increase in the number of fatalities on Israeli roadways (see
link below)
httpinjurypreventionbmjcomcontent133156
The effect of speeding is very significant especially in rural areas resulting
in significantly higher fatalities Fatality rates are frequently double or triple
that in urban areas (see link below)
httpsafetyfhwadotgovspeedmgtdata_factsdocsspeeding_ruralpdf
As of Jan 1 2005 five Midwestern states had increased the speed limits to
above 65 mph (Illinois Iowa Kansas Minnesota Missouri Nebraska and
South Dakota) whereas three (Illinois Iowa and Wisconsin) had not All the
five states with increased speed limits showed a 7 to 13 increase in
fatalities The NHTSA study considered an eight year period before and after
the change in Dec 1995 (see Table 1 in link below) The collective experience
of the states that did NOT increase the speed limit was a 7 decline in
fatalities (see Table 2 of link below)
httpwwwiowadotgovmvdodsstats2006speedstudypdf
Page 25 of 45
Moreover Table 5 in the above study shows the effect of imposing the NMSL
of 55 mph in Iowa and its repeal in 1995 Considering a four-year average
before 1974 when the speed limit was 75 mph there were 35 fatal crashes
with 43 fatalities In the first four years after the 55 mph there were only 23
fatal crashes and 28 fatalities In the last four years before the repeal of 55
mph in 1995 there was a further decline to 14 fatal crashes with 17 fatalities
The Iowa fatality data will be discussed in more detail separately (in a later report)
since it provides the opportunity to assess the effect of a change in the speed limit
on the relationship between number of fatalities and fatal crashes (as seen in
Figure 4 for the US as a whole)
North of the US border Canadians seem to be citing the ―shocking increase
in highway fatalities in the US states where the speed limits were raised to
curb their own speed limits
httparchivesafety-councilorginfotrafficspeed-02html
httparchivesafety-councilorginfotrafficspeedhtml
Speed kills but speed also sells notes the second of the above news items
Manufacturers are producing more high performance cars (with higher horse
power to weight ratio) and ads feature enticing cars that race and swerve in
miraculous ways on empty roads These subliminal messages encourage
drivers especially young drivers to break the speed limit leading to the
absolute increase in highway fatalities (although the rate itself is going
down) The article emphasizes the need to enforce the speed limit on
Canadian highways and in cities where street racing is becoming a problem
62 Studies cited by opponents of lower speed limits
In fairness to quote the opponents on the other side of this debate Montana
reverted back to Reasonable and Prudent speed limits when the National
Maximum Speed Limit was repealed in 1995 and appears to have
experienced no significant increase in fatalities
Page 26 of 45
httpwwwhwysafetycomhwy_montanahtm
httpwwwmotoristsorgpressmontana-no-speed-limit-safety-paradox
httpwwwsouthbayriderscomforumsshowthreadphpt=81453amppage=1
Likewise studies in the state of Maryland showed no significant increase in
highway fatalities when the speed limit was increased from 55 mph to 75
mph The reason might simply be that drivers were already speeding much
more so when the speed limit was 55 mph than after the increase to 75 mph
In other words the fatalities data already reflects the effect of higher speeds
(not speed limits) on the number of fatalities
In Utah the experimental increase in the speed limit to 80 mph was
considered to be a success in terms of safety
httpautosaolcomarticleutah-speed-limit-tests
The UDOT Director noted that there was no increase in the number of
accidents on Interstate 15 But what happens in the event of an accident
when the speed limits are higher and drivers are driving at higher speeds and
two objects collide at this higher speed However no increase in the number
of accidents is not the same as no increase in fatalities due to the higher
speeds When accidents do occur do fatalities increase
Likewise in California when the speed limit went up from 55 mph to 65
mph in 1995 (after repeal of NMSL) fewer deaths were reported in 1998
compared to the peak year of 1979 or even 1987 Again the explanation
seems to be that motorists were already speeding when the limit was 55 mph
and that increasing the speed limit did not change driver behavior in any
significant way
httparticlessfgatecom1998-11-02news17735730_1_speed-limits-mph-
limit-death-rate
The National Motorists Association (NMA) a group which advocates higher
speed limits emphasizes the importance of considering fatality rates as
opposed to the raw fatalities The argument used is that fatality rates based
on the fatality per 100 million VMT is the legitimate way to look at the data
Page 27 of 45
This is a never ending debate Historically speaking fatality rates have been
going down ever since the compilation of traffic accidents data began Table
A1 in the appendix of a recent report by NHTSA (see link below) has highway
fatality rate data going back 1921
httpwww-nrdnhtsadotgovPubs811346pdf see appendix page 31
httpwwwmotoristsorgspeed-limitstruth
httpwwwmotoristsorgothercrash-data
httpwwwraisethespeedlimitorgmythshtml
httpwwwcatoorgpubspaspa346pdf
According to Stephen Moore of the Cato Institute (see last of the links above)
―All measures of highway safety show improvement not more deaths and
injuries since 1995 Despite the fact that 33 states raised their speed limits
immediately after the repeal of the mandatory federal speed limit the NHTSA
reported last October that the traffic death rate dropped to a record low level
in 1997lsquo Moreover the average fatality rate even fell in the states that raised
their speed limits
63 The Fatality rate Is it a reliable metric
In 1921 with fewer fatalities and fewer miles driven and the first year for
which the fatality rate could be computed the rate was 2408 It was down to
1479 in 1931 but the number of deaths had climbed to 31963 more than
double the 1921 absolute fatality number of 13253 It had dropped to 550 in
1966 the year of the highly publicized Congressional hearings but the
number of fatalities had climbed to 50984 in that fateful The Highway Safety
Act of 1966 ranks as one of the major acts of Congress and President
Johnson signed it saying that ―we have been tolerating a raging epidemic of
highway deathshellip see extract pasted below
httpwwwenotescommajor-acts-congresshighway-safety-act
Page 28 of 45
The act was motivated primarily by growing public concern over the rising number
of traffic fatalities in the United States Between 1960 and 1965 the annual number
of traffic fatalities increased by nearly thirty percent As President Lyndon B
Johnson stated at the signing of the act on September 9 1966 we have tolerated
a raging epidemic of highway death which has killed more of our youth than all
other diseases combined Through the Highway Safety Act we are going to find out
more about highway diseasemdashand we aim to cure it
Nonetheless highways fatalities continued to increase until the Arab oil
embargo of 1973 led to the NMSL of 55 mph all across the USA Do we just
ignore this undeniable historical record and focus only on the declining fatality
rate as the NMA and other proponents of higher speed limits seem to argue
(see links above)
The misleading nature of using fatality rates (per 100 M VMT) alone is also
obvious if one considers fatality data for individual states Take for example
the state of Montana which seems to have experienced no increase in
fatalities after repeal of NMSL
httpwww-nrdnhtsadotgovdepartmentsnrd-
30ncsaSTSI30_MT200930_MT_2009htm
For the period 2005-2009 the absolute number of fatalities for Montana
varied between a high of 277 in 2007 to a low of 229 in 2009 The fatality
rates per 100 M VMT on the other hand varied from a high of 245 for 2007
to a low of 201 for 2009 The corresponding US fatality rates varied from
136 to 114 Is the higher number for the fatality rate for Montana compared
to USA good or bad Likewise fatality rate per 100000 of population was
much higher for Montana than the US as a whole
This again highlights the pitfalls of using simple ratios to assess fatality statistics
without a full analysis of the underlying trends We will discuss this point
separately
As shown already the continuous decline in the fatality rate is a mathematical
artifact and essentially overlooks the unmistakable positive correlation
between the variables x and y of the type y = hx + c which becomes obvious
Page 29 of 45
only when we prepare the x-y scatter graph The ratio yx = h + (cx) can
decrease with increasing x (VMT) and increasing y (fatalities) since the
intercept c has a positive value when we consider only data spanning a short
period (such as 1994-2009 of more relevance to the current situation)
The debate between fatality rates and absolute number of fatalities is an
unending one A few years ago the Wall Street Journal carried an article
which was entitled (or something close) ―Unemployments rate in Ohio are
going down but why is the number of unemployed increasing The reason is
the same The graph of the number of unemployed (y) versus the number in
the labor market (x) is linear with a positive slope h and a positive intercept c
So the unemployment rate computed using the ratio yx keeps going down
year after year although the number unemployed keeps increasing Is it a
good thing that the unemployment rate is going down when more people
seem to be unable to find gainful unemployment
Or consider the situation with cancer death rates This too has been going
down in recent years but the actual number of cancer-related deaths has not
declined in any significant way Is it good that cancer death rates are going
down In all these situations the researchers or the socio-econo-politico
analysts involved in analyzing the trends in the data have failed to consider
the underlying x-y relation describing each problem
Hence it appears that the debate on the effect of increased speed limits
should not be focused on only the fatality rates (which have been decreasing
and proponents of higher speed limits cite this in their arguments) or even the
absolute number of fatalities (which has been the focus here) but on the
relationship between speed and the number of fatal crashes and the number
of fatalities within each speed segment (see Table 3 and also Figure 4)
Unfortunately details of number of fatalities and the number of fatal crashes
at each speed limit are not available even from NHTSA for detailed study
When a crash does occur (it is immaterial how many miles were driven) the
speed of the driver and vehicle design and engineering including safety
devices in place (seat belts airbags other impact absorbing technologies)
Page 30 of 45
determine if the occupants(s) will be killed One cannot argue that speed
does NOT kill That would be an absolute denial of the laws of physics
Studies show that setting the speed limit at the 85th percentile in any given
zone (this is the speed at or below which 85 of drivers are observed to
travel in traffic engineering studies) is the safest speed limit The majority of
drivers try to obey the posted speed limit while a few choose to drive at a
speed they consider is safe and prudent These are also perhaps the most
vociferous advocates of higher speed limits It is this tension caused due to
differences in speeds that leads to tailgating improper passing reckless
driving weaving from lane to lane and ultimately crashes and deaths in some
unfortunate cases
httpblogmotoristsorgspeed-limits-slower-safer
MARK TAYLOR
ANOTHER LOST A man was killed when his 4WD drive hit a tree east of Morrinsville (in New
Zealand) on Monday May 30 2011 The driver lost control of the vehicle on a bend probably tried
to correct his mistake and put the car into a ―yaw causing it to leave the road and smash sideways
into a tree Alerts to slow down had been posted since this was a high accident area but the driver
probably did not pay attention
64 Other factors
Many other factors besides speed no doubt affect highway fatalities The
vehicles of the 21st century are very different from the vehicles of the mid 20th
Page 31 of 45
century Technological innovations such as improvements in vehicle design
and engineering have greatly increased crash worthiness of vehicles even at
high speeds Environmental factors such as the weather also contribute to
accidents but not necessarily to increased fatalities Drivers actually tend to
slow down instinctively during adverse weather conditions (rain snow storms
etc) and although such weather may contribute to increased accidents the
lower speeds actually reduce fatalities
Yes technology has changed fundamentally from 1966 Drivers today are
more distracted by their cellmobile phone conversations (and also built-in
phones in luxury models) and text messaging than the drivers of the pre-1966
era High end cars now have many multimedia and internet features Again a
careful observation (even personal experience by the author) suggests that
such distracted drivers actually tend to (instinctively) drive more slowly and
hold up the traffic Perhaps such behavior leads to an increase in the number
of accidents but it does not necessarily lead to an increase in the number of
accident-related fatalities
Much talked about technological innovations such as automatic collision
avoidance systems and sensors (on the sides of vehicles) can indeed detect
vehicles in the front and neighboring lanes Furthermore vehicle-to-vehicle
communication systems vehicle-to-infrastructure communication systems
can no doubt avoid collisions and accidents Again such collision avoidance
systems work and are effective entirely because they automatically reduce
vehicle speeds - even if one of the offending vehicles is being at a super
high speed Also it must be remembered that such futuristic systems have
not yet been implemented widely nor can they be implemented widely since
the large majority of vehicles on the road are NOT luxury models Advanced
safety features come with a price and not all drivers can afford to pay that
price and ―buy that ―additional safety
Ultimately it is the laws of physics that govern what will happen when two or
more vehicles collide or even when a single vehicle collides with a stationary
infrastructural object (a bridge a wall a building or some impediment on the
road) The lower the number of crashes the lower the number of fatalities as
revealed by the 1994-2009 data graphed in Figure 5 The higher the speed of
Page 32 of 45
the object or objects that are involved in a collision the higher the kinetic
energy K that must be absorbed andor dissipated Increasing the posted
speed limit only increases the energy that must be absorbed when a crash
does occur This ultimately is the most important criterion determining the
number of fatalities
The kinetic energy increases as the square of the speed being given by the
well-known formula K = frac12 mv2 where m is the mass of the vehicle (in
laypersonlsquos language m increases directly with vehicle weight) and v is the
speed For the same vehicle mass an increase in the speed from 55 mph to
85 mph increases the kinetic energy K by a factor of 239 or roughly a 250
increase in the kinetic energy that must be absorbed in a collision
Ideally speaking the kinetic energy of the colliding object(s) is absorbed by
the vehicle infrastructure (a sturdy space frame the engine other vehicle
components etc) andor the surroundings However in the unfortunate
cases where this kinetic energy must be absorbed by the vehicle occupant(s)
the result is severe life-altering injuries andor death An unequivocal
relationship between an increase in vehicle speeds and fatal accidents can
be demonstrated by a careful examination of available traffic fatality data
This is a more involved discussion and is not the purpose of this short
communication These topics are no doubt very politically charged with many
social legal and financial implications with each interest group favoring a
different conclusion Nonetheless we cannot escape the laws of physics as
they govern the fundamental need to absorb higher and higher values of the
kinetic energy K with increasing vehicle speeds This same point is also
emphasized by Dr Friedman of the University of Illinois Chicago (see earlier
discussion)
Speed kills because of these energy transfer considerations and there can be
no doubt about it
Innovative 21st century solutions to speed management on the highways
such as strict enforcement of speed limits minimizing speed dispersion
(difference between speeds at which different drivers travel) while using
cameras to track the 15 of drivers who willfully violate the speed limit and
Page 33 of 45
create hazardous driving conditions is certainly recommended (Recall that
the optimum recommended speed limit is at or below which 85 of all drivers
travel ndash a policy also supported by NMA) Even on this score however the
results are confounding if we consider the Australian experience
httpwwwthenewspapercomnews282840asp
Up until 2007 there was no speed limit in the Northern Territory of
Australia Imposing a speed limit 130 kmph (80 mph) on some areas and
110 kmph (68 mph) in some others actually increased the number of deaths
The death toll in 2006 when there was no speed limit in this region was 44
and went up to 75 in 2009 see data table in link below
httpwwwthenewspapercomrlcdocs2009au-ntroadtollpdf
Furthermore it appears that installation of cameras to enforce speed limits
has proved to be a hazardous distraction to drivers and deaths actually
began to skyrocket between 2005 and 2007 in all Australian roadways
The main purpose here is to sound a cautionary note amid renewed attempts
in many states across the US to increase the speed limits on our highways by
calling attention to the historical facts regarding the ―epidemic levels of
highway traffic fatalities that engaged our national attention in the fateful year
of 1966 The graphical representation of the traffic fatality data in Figures 1
to 5 tells its own story
Indeed it would be tragic if highway-accident-related fatalities were to start
increasing once again and reach the historically high level that was last seen
in 1972 the year before the Arab oil embargo of 1973
Page 34 of 45
Conclusions
1 The graphical representation of the highway fatality data and the brief
summary of the historical facts of traffic safety legislation suggest that
recent attempts to increase the speed limits by various states (notably
Texas) may be misguided The distinct peak in the highway fatalities
observed in these graphs is highly alarming This appears to be related to
the enactment of the National Maximum Speed Limit (NSML) in 1974
following the 1973 Arab oil embargo Although NSML was motivated by a
desire to reduce gasoline consumption an unintended benefit might have
been a dramatic reduction in fatalities The fundamental reasons for the
peak in the fatalities-VMT curve must be examined carefully without
political posturing
2 The widely used fatality rate fatalities per 100 M vehicle miles traveled
has been declining since 1921 the first year for which a fatality rate could
be computed and has now reached a historical low The absolute number
of fatalities on the other hand was increasing in the 1950s and 1960s at
an alarming rate and the public outcry that ensued led to the highly
publicized Congressional hearing of 1966 and the subsequent traffic safety
legislations The fatality rate has been decreasing even in the most recent
15-year period (1994-2009) again with increasing fatalities although less
dramatically Thus it appears that fatality rate calculation based on vehicle
miles traveled (VMT) might not be a reliable indicator of the underlying
dynamics in the fatality trends
3 More detailed compilation of number of fatalities and the number of fatal
crashes within each speed limit segment is required to better understand
the effect of increasing speed limits on highway fatalities (and also fatality
rates) Such data is already available and is being compiled at the local
city and county levels in all jurisdictions and only needs to be reorganized
to highlight the effect of (posted) speed limits on the number of crashes
and fatalities This will require some minor rewriting and revisions to the
chapters named ―Crashes and ―States in the annual NHTSA reports
Page 35 of 45
Analysis of the fatalities-crashes data for several years with various
speed limits will be more revealing and meaningful than the current
fatality rates analysis and will be discussed separately in a follow up
report
4 One should not be lulled by the fact that vehicles of the 21st century are
now equipped with advanced safety features not available in the 1950s
and the 1960s In spite of these safety features the laws of physics dictate
that the higher the speed the higher kinetic energy of the colliding objects
and hence the greater the risk indeed near certainty of fatalities in a
higher speed collision compared to a lower speed one
5 The higher the speed at which the vehicle that is involved in a crash is
traveling the higher the kinetic energy that must be absorbed andor
dissipated without affecting the occupant(s) to avoid serious injuries andor
death This was true in the 1950s and the 1960s and will continue to be
true in the 21st century as well
Speed Kills for this just reason
6 It appears that higher fuel economies and reduced
highway fatalities were the twin societal benefits of 55
mph adopted after 1973 If so the current attempts to
increase the speed limits appear to be in conflict with
other important societal objectives
Page 36 of 45
Table 1 Annual US Street amp Highway
Fatalities from 1957
Year
Fatalities
Vehicle Miles
(millions)
Rate100M Vehicle Miles
1957 38702 646915 598
1958 36981 664915 556
1959 37910 700478 541
1960 38137 718845 531
1961 38091 737535 516
1962 40804 766852 532
1963 43564 805423 541
1964 47700 846500 563
1965 49163 887640 554
1966 51524 927915 555
1967 51559 965132 534
1968 53831 1019726 528
1969 55032 1066108 516
1970 53672 1114098 482
1971 53761 1183524 454
1972 55704 1264614 440
1973 55113 1316207 419
1974 46078 1282790 359
1975 45500 1330074 342
1976 45523 1402380 325
1977 47878 1467027 326
1978 50331 1544704 326
1979 51103 1529133 334
1980 51091 1527295 335
1981 49301 1552803 317
1982 43945 1595010 276
1983 42589 1652788 258
1984 44257 1720269 257
1985 43795 1774179 247
Page 37 of 45
1986 46056 1835000 251
1987 46385 1921000 241
1988 47093 2026000 232
1989 45555 2107040 216
1990 44529 2147501 207
1991 41162 2172214 189
1992 39235 2239828 175
1993 40115 2296585 175
1994 40676 2359984 172
1995 41798 2422696 173
1996 41907 2485848 169
1997 41967 2560373 164
Data from Federal Highway Administration
Source httpwwwpublicpurposecomhwy-fatal57+htm
Telephone +16186328507 - Facsimile +16186328538
WENDELL COX CONSULTANCY P O Box 841 - Belleville IL 62269 USA
Page 38 of 45
Fatality data for 1921-1982 compiled by NHTSA
Year
VMT
(Millions)
VMT
(Billions)
Fatalities
Fatality rate
per 100 M VMT
1921 55027 5503 13253 241 1922 67697 6770 14859 219 1923 84995 8500 17870 210 1924 104838 10484 18400 176 1925 122346 12235 20771 170 1926 140735 14074 22194 158 1927 158453 15845 24470 154 1928 172856 17286 26557 154 1929 197720 19772 29592 150 1930 206320 20632 31204 151 1931 216151 21615 31963 148 1932 200517 20052 27979 140 1933 200642 20064 29746 148 1934 215563 21556 34240 159 1935 228568 22857 34494 151 1936 252128 25213 36126 143 1937 270110 27011 37819 140 1938 271177 27118 31083 115 1939 285402 28540 30895 108 1940 302188 30219 32914 109 1941 333612 33361 38142 114 1942 268224 26822 27007 101 1943 208192 20819 22727 109 1944 212713 21271 23165 109 1945 250173 25017 26785 107 1946 340880 34088 31874 94 1947 370894 37089 31193 84 1948 397957 39796 30775 77 1949 424461 42446 30246 71 1950 458246 45825 33186 72 1951 491093 49109 35309 72
1952 513581 51358 36088 70
Page 39 of 45
1953 544433 54443 36190 66 1954 561963 56196 33890 60 1955 605646 60565 36688 61 1956 627843 62784 37965 60 1957 647004 64700 36932 57 1958 664653 66465 35331 53 1959 700480 70048 36223 52 1960 718762 71876 36399 51 1961 737421 73742 36285 49 1962 766734 76673 38980 51 1963 805249 80525 41723 52 1964 846298 84630 45645 54 1965 887812 88781 47089 53 1966 925899 92590 50894 55 1967 964005 96401 50724 53 1968 1015869 101587 52725 52 1969 1061791 106179 53543 50 1970 1109724 110972 52627 47 1971 1178811 117881 52542 45 1972 1259786 125979 54589 43 1973 1313110 131311 54052 41 1974 1280544 128054 45196 35 1975 1327664 132766 44525 34 1976 1402380 140238 45523 32 1977 1467027 146703 47878 33 1978 1544704 154470 50331 33 1979 1529133 152913 51093 33 1980 1527295 152730 51091 33 1981 1555308 155531 49301 32 1982 1595010 159501 43945 28
Source Analysis of Significant Decline in Motor Vehicle Traffic Fatalities in
2008 httpwww-nrdnhtsadotgovPubs811346pdf see Table A1 page 31
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Page 40 of 45
Acknowledgements
The author is grateful for thoughtful comments provided by friends and colleagues
with whom this document was shared via email prior to it being uploaded as a
publicly available document for wider dissemination and study The comments
offered by Prof Subra Ganesan of Oakland University Electrical and Computer
Engineering Department are reproduced with permission in their entirety
About the author
The author obtained his Masterrsquos (S M) and Doctoral (Sc D) degrees in Materials Engineering
from the Massachusetts Institute of Technology Cambridge USA He then spent his entire
professional career at leading US research institutions (MIT NASA Case Western Reserve
University and General Motors R amp D Center in Warren MI) He holds four patents in advanced
materials processing has co-authored two books and has published several scientific papers in
leading peer-reviewed international journals His expertise includes developing simple
mathematical models to explain the behavior of complex systems He can be reached by email at
vlaxmananhotmailcom
Page 41 of 45
Please Buckle Up
httpwwwlakecountypublichealthorgindexphpbuckle-up-montana
Public Awareness
Respect the Cage Exhibit
The Department of Transportation hopes that showing the reality of the crash will reduce traffic
fatalities A crushed car crash dummies and a sobering message ndash all part of the ―Respect The
Cage exhibit that is traveling across Montana The exhibit sponsored by the Montana Department
of Transportation stopped in Ronan on November 6th and is aimed at raising awareness about the
importance of wearing seat belts
The car in the exhibit was in an actual wreck many years ago
the passenger in the vehicle died because he was not wearing a
seat belt the driver who was wearing his seat belt survived
Montanarsquos likeliest crash fatality scenario
A Pickup
A Rural road
And Seat belts that
arenrsquot used
Page 42 of 45
Occupants of pickups are less likely to wear seat belts and pickups are more likely to
roll over than passenger cars
Seat belts reduce the risk of death by 60 percent in pickups and SUVs
In Montana from 2006-2008 81 of those killed in a crash while riding in a pickup were not wearing seat belts
In Montana pickups make up 401 of the vehicle population
For more information on Respect the Cage click here
Page 43 of 45
Appendix 1
Lack of seat belts leading cause of Louisiana highway deaths
1251 AM May 28 2011 |
Written by Adam Duvernay
Crashes involving unbuckled motorists were the leading cause of highway fatalities
in Louisiana last year and cost $9888 million according to recent reports The
Louisiana Highway Safety Commission reported 59 percent of vehicle occupants
killed in Louisiana crashes last year mdash about one in four mdash werent wearing seat
belts
httpwwwshreveporttimescomarticle20110528NEWS01105280354Lack-seat-
belts-leading-cause-La-highway-deathsodyssey=tab|topnews|text|FRONTPAGE
Crash bull Stats Published by NHTSAlsquos National Center for Statistics and Analysis 1200 New Jersey Avenue SE Washington DC 20590
DOT HS 811 451
Early Estimate of Motor Vehicle Traffic Fatalities in 2010
httpwww-nrdnhtsadotgovPubs811451pdf
Summary
A statistical projection of traffic fatalities in 2010 shows that an estimated 32788
people died in motor vehicle traffic crashes This represents a decline of about 3
percent as compared to the 33808 fatalities in 2009 as shown in Table 1 If these
projections are realized fatalities will be lowest on record (since 1949)
Traffic Safety Facts Overview 2009 Data
httpwww-nrdnhtsadotgovPubs811392pdf
In 2009 33808 people were killed in the estimated 5505000 police-reported
motor vehicle traffic crashes 2217000 people were injured and 3957000
crashes involved property damage only Compared to 2008 this is a 10-
percent decrease in the number of fatalities and a 5-percent decrease in the
Page 44 of 45
number of police-reported motor vehicle traffic crashes people injured and
crashes involving property damage
An average of 93 people died each day in motor vehicle crashes in 2009 mdash
an average of one every 16 minutes
Traffic Safety Facts Overview 2008 Data
httpwww-nrdnhtsadotgovPubs811162pdf
In 2008 37261 people were killed in the estimated 5811000 police-reported
motor vehicle traffic crashes 2346000 people were injured and 4146000
crashes involved property damage only
Some comments and Feedback
The following comments were received from Prof Ganesan after his review of the
first draft of this document It was subsequently revised thanks to this input to
address some of the very important issues raised here
Dear Laxman
The write up is not enough
You are emphasizing that the speed limit reduces the fatal accidents (comparing 1966
to 2000 accident numbers)
Can you also add a few sentences why the number is decreasing from 1980 to 2000
values (May be due to better design of vehicles)
Can you say anything about the fuel consumption with the speed for any typical
vehicle in 2011 or 2010 (do not consider the fatalities issue)
Probably a speed between 55 and 60 mph gives a better mileage If so this is a
compelling reason to keep the speed limit low But cars probably can be tuned to
give better mileage at any high speed also
Page 45 of 45
Weather is also a major factor in fatal accidents Speed limit may be kept low during
winter and kept higher in summer Give your comments on this too
Driver distractions can cause more accidents Now cars have many multimedia and
internet features Automatic collision avoidance systems and sensors on the sides can
detect vehicles in the front and neighboring lanes and it can automatically decrease
speed even if the driver speeds at super high speeds
Give some comments on this too There is also Vehicle to Vehicle communications
vehicle to infrastructure communications and they can avoid collisions and accidents
Technology has changed from 1966 I cannot agree with you on the speed limit
without any discussion on the above and other factors
Have a great day
Subra Ganesan
Professor Subramaniam Ganesan
Director Real Time amp DSP Lab
Electrical and Computer Engineering Department
2200 Squirrel Road Dodge Hall Room 105
Oakland University Rochester MI 48309 USA
Phone 248 370 2206 Fax 248 370 4633
wwwsecsoaklandedu~ganesan
IEEE Distinguished Visiting Speaker (2005-2009) Coordinator
IEEE SEM CS chapter Chair Region 4 and CS Society Board member
SAE ASEE ACM member
Page 20 of 45
It is instructive to compare this rate of change in fatalities with similar short
periods of a decline in fatalities in the pre-1973 era when speed limits were
much higher The absolute number of fatalities declined over a relatively
short period with both an increase and a decrease in VMT The results are
given below and are self-explanatory
yx = 454 fatalitiesbillion VMT (1953-54) decline with increase in VMT
yx = 655 fatalitiesbillion VMT (1942-43) decline with decrease in VMT
yx = 1739 fatalitiesbillion VMT (1941-42) decline with decrease in VMT
yx = 4528 fatalitiesbillion VMT (1937-39) decline with increase in VMT
yx = 2548 fatalitiesbillion VMT (1931-32) decline with decrease in VMT
The rate of decline observed between 1953 and 1954 with an increase in
VMT was just one-tenth of that observed following the adoption of the 55
mph speed limit The war years (1941-43 WWII) and the Great Depression
era (1931-32) were accompanied by big declines in fatalities with decreasing
VMT but the rate of change was still significantly lower than observed after
the adoption of the NMSL
The only apparently inexplicable decline is that between 1937 and 1939
where a nearly identical high rate of decline was observed Notice also the
big drop in the traditional fatality rate between 1937 and 1938 This large drop
appears to coincide with the creation of the National Safety Council (NSC) by
William H Cameron in June 1937 (see link below) with its far-flung campaign
of education legislation research highway engineering and traffic training
undertaken by the NSC and some two dozen other groups with the backing of the
automotive industry through its Automotive Safety Foundation Other factors
unknown to the present author probably also played a role
httpwwwtimecomtimemagazinearticle0917188379700htmlixzz1O2G
7rnUg
Page 21 of 45
These simple computations here however reveal the significant effect of
reduced speed limits on highway fatalities much more so than other factors
6 Further Considerations Pros and Cons
The singular effect of increased speeds (or speeding) on highway fatalities
has been studied and demonstrated by a number of industry sources such
as the Insurance Institute for Highway Safety (IIHS) Consumers Union and
also by government researchers
httpwwwsmartmotoristcomtraffic-and-safety-guidelineexcessive-speed-is-
a-factor-in-one-third-of-all-fatal-crasheshtml
httpwwwconsumersunionorgotherspeedlimitsspeed031500a2htm
Speed ndash defined as exceeding the posted speed limit or driving too fast for
given conditions ndash is a factor in nearly one-third of all fatal crashes Besides
fatality in 1998 nearly 40000 people were critically injured in speed-related
crashes and nearly 72000 were moderately injured
The salutary and immediate beneficial effect of the nationwide 55 mph speed
limit has been noted by other researchers (see Susan Ferguson link below)
httpwwwnhtsagovpeopleinjuryenforcespeed_forum_presentationsfergu
sonpdf
After a partial repeal of this law in 1987 which granted states the authority to
increase speed limit (especially in rural interstates) a 1989 study showed a
15 increase in fatalities in rural interstates and a 5 increase in non-rural
interstates Unfortunately such studies often tend to be discounted by
advocates of increasing the speed limits as being produced by biased
industry sources
Similar conclusions were also presented by NHTSA in February 1998 in its
report to the Congress entitled ―Report to Congress The Effect of Increased
Speed Limits in the Post-NMSL Era see link given below Among its key
Page 22 of 45
findings is the following quoted in its entirety NMSL refers to the National
Maximum Speed Limit legislated after the Arab oil embargo of 1973
httpwww-nrdnhtsadotgovPubs808-637PDF
hellip Nevertheless it is important to note that data currently available from the
National Highway Traffic Safety Administrationrsquos (NHTSA) Fatality Analysis
Reporting System (FARS) shows that states that increased speed limits in 1996
experienced approximately 350 more Interstate fatalities than would have been
expected based on historical trends -- about 9 percent above expectations
Concurrently the Interstate fatalities experienced in states that did not increase speed
limits in 1996 was consistent with pre-1996 trends The estimated increase in
Interstate fatalities found in this study while smaller in magnitude compared to the
estimated change in fatalities found in 1987 following the increase of speed limits on
rural Interstates does follow the historical pattern of increases in fatalities being
associated with increases in posted speed limits
The annual crash reports compiled by NHTSA see Table 3 indicate that the
number of fatal crashes (and hence fatalities using the regression equation
developed in Figure 4) increase as the posted speed limits increase
Page 23 of 45
Table 3 Posted speed limits and number of crashes
Speed Limit Crashes (2008) Crashes (2009)
30 mph or less 3705 3277 35 or 40 mph 6115 5516 45 or 50 mph 6461 6074
55 mph 9794 8847 60 mph or higher 6908 6124
Total 34017 30797
Source httpwww-nrdnhtsadotgovPubs811402EEpdf
61 Studies cited in favor of lower speed limits
A detailed analysis of speeding related fatalities (see link below) by NHTSA
shows that a third of all crashes involve speeding ie at least one driver was
speeding
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Furthermore the above report which covers the period 1983-2002
indicates that immediately after the NMSL was completely abolished in
December 1995 the number of speeding related fatalities at speeds
above 65 mph increased from just 15 in 1995 to a 677 in 1996 (see Table
62 on page 43 of above report) It continued to increase in the years
since climbing to 930 in 2000
More detailed studies similar to that noted above by researchers at the
University of Illinois Chicago led by Lee S Friedman again lead to the
conclusion that higher speed limits lead to an increase in the number of
fatalities (see American Journal of Public Health online July 16 2009)
httphealthusnewscomhealth-newsmanaging-your-
healthcarearticles20090716deaths-injuries-increase-with-higher-speed-
limits
Page 24 of 45
httpwwwmedpagetodaycomPublicHealthPolicyPublicHealth15122
httpwwwamericaneercomspeed-limits
httpwwwactuarialoutpostcomactuarial_discussion_forumarchiveindexph
pt-171870html
For the study period 1995-2005 these researchers found that 12545 deaths
and 36582 injuries could be attributed to the increased speed limits The
benefits of reduced speed limits are stated quite eloquently by Dr Friedman
and are reproduced below (from above news article see link)
Reduced speed limits would save lives Friedman said They would also reduce
gas consumption cut emissions of air pollutants save valuable years of productivity
(lost due to injuries)and reduce the societal cost of motor vehicle crashes (due to
both fatal crashes and due to nonfatal and severe life-changing injuries) he added
Friedman and coworkers have also shown that increasing the speed limit led
to an immediate increase in the number of fatalities on Israeli roadways (see
link below)
httpinjurypreventionbmjcomcontent133156
The effect of speeding is very significant especially in rural areas resulting
in significantly higher fatalities Fatality rates are frequently double or triple
that in urban areas (see link below)
httpsafetyfhwadotgovspeedmgtdata_factsdocsspeeding_ruralpdf
As of Jan 1 2005 five Midwestern states had increased the speed limits to
above 65 mph (Illinois Iowa Kansas Minnesota Missouri Nebraska and
South Dakota) whereas three (Illinois Iowa and Wisconsin) had not All the
five states with increased speed limits showed a 7 to 13 increase in
fatalities The NHTSA study considered an eight year period before and after
the change in Dec 1995 (see Table 1 in link below) The collective experience
of the states that did NOT increase the speed limit was a 7 decline in
fatalities (see Table 2 of link below)
httpwwwiowadotgovmvdodsstats2006speedstudypdf
Page 25 of 45
Moreover Table 5 in the above study shows the effect of imposing the NMSL
of 55 mph in Iowa and its repeal in 1995 Considering a four-year average
before 1974 when the speed limit was 75 mph there were 35 fatal crashes
with 43 fatalities In the first four years after the 55 mph there were only 23
fatal crashes and 28 fatalities In the last four years before the repeal of 55
mph in 1995 there was a further decline to 14 fatal crashes with 17 fatalities
The Iowa fatality data will be discussed in more detail separately (in a later report)
since it provides the opportunity to assess the effect of a change in the speed limit
on the relationship between number of fatalities and fatal crashes (as seen in
Figure 4 for the US as a whole)
North of the US border Canadians seem to be citing the ―shocking increase
in highway fatalities in the US states where the speed limits were raised to
curb their own speed limits
httparchivesafety-councilorginfotrafficspeed-02html
httparchivesafety-councilorginfotrafficspeedhtml
Speed kills but speed also sells notes the second of the above news items
Manufacturers are producing more high performance cars (with higher horse
power to weight ratio) and ads feature enticing cars that race and swerve in
miraculous ways on empty roads These subliminal messages encourage
drivers especially young drivers to break the speed limit leading to the
absolute increase in highway fatalities (although the rate itself is going
down) The article emphasizes the need to enforce the speed limit on
Canadian highways and in cities where street racing is becoming a problem
62 Studies cited by opponents of lower speed limits
In fairness to quote the opponents on the other side of this debate Montana
reverted back to Reasonable and Prudent speed limits when the National
Maximum Speed Limit was repealed in 1995 and appears to have
experienced no significant increase in fatalities
Page 26 of 45
httpwwwhwysafetycomhwy_montanahtm
httpwwwmotoristsorgpressmontana-no-speed-limit-safety-paradox
httpwwwsouthbayriderscomforumsshowthreadphpt=81453amppage=1
Likewise studies in the state of Maryland showed no significant increase in
highway fatalities when the speed limit was increased from 55 mph to 75
mph The reason might simply be that drivers were already speeding much
more so when the speed limit was 55 mph than after the increase to 75 mph
In other words the fatalities data already reflects the effect of higher speeds
(not speed limits) on the number of fatalities
In Utah the experimental increase in the speed limit to 80 mph was
considered to be a success in terms of safety
httpautosaolcomarticleutah-speed-limit-tests
The UDOT Director noted that there was no increase in the number of
accidents on Interstate 15 But what happens in the event of an accident
when the speed limits are higher and drivers are driving at higher speeds and
two objects collide at this higher speed However no increase in the number
of accidents is not the same as no increase in fatalities due to the higher
speeds When accidents do occur do fatalities increase
Likewise in California when the speed limit went up from 55 mph to 65
mph in 1995 (after repeal of NMSL) fewer deaths were reported in 1998
compared to the peak year of 1979 or even 1987 Again the explanation
seems to be that motorists were already speeding when the limit was 55 mph
and that increasing the speed limit did not change driver behavior in any
significant way
httparticlessfgatecom1998-11-02news17735730_1_speed-limits-mph-
limit-death-rate
The National Motorists Association (NMA) a group which advocates higher
speed limits emphasizes the importance of considering fatality rates as
opposed to the raw fatalities The argument used is that fatality rates based
on the fatality per 100 million VMT is the legitimate way to look at the data
Page 27 of 45
This is a never ending debate Historically speaking fatality rates have been
going down ever since the compilation of traffic accidents data began Table
A1 in the appendix of a recent report by NHTSA (see link below) has highway
fatality rate data going back 1921
httpwww-nrdnhtsadotgovPubs811346pdf see appendix page 31
httpwwwmotoristsorgspeed-limitstruth
httpwwwmotoristsorgothercrash-data
httpwwwraisethespeedlimitorgmythshtml
httpwwwcatoorgpubspaspa346pdf
According to Stephen Moore of the Cato Institute (see last of the links above)
―All measures of highway safety show improvement not more deaths and
injuries since 1995 Despite the fact that 33 states raised their speed limits
immediately after the repeal of the mandatory federal speed limit the NHTSA
reported last October that the traffic death rate dropped to a record low level
in 1997lsquo Moreover the average fatality rate even fell in the states that raised
their speed limits
63 The Fatality rate Is it a reliable metric
In 1921 with fewer fatalities and fewer miles driven and the first year for
which the fatality rate could be computed the rate was 2408 It was down to
1479 in 1931 but the number of deaths had climbed to 31963 more than
double the 1921 absolute fatality number of 13253 It had dropped to 550 in
1966 the year of the highly publicized Congressional hearings but the
number of fatalities had climbed to 50984 in that fateful The Highway Safety
Act of 1966 ranks as one of the major acts of Congress and President
Johnson signed it saying that ―we have been tolerating a raging epidemic of
highway deathshellip see extract pasted below
httpwwwenotescommajor-acts-congresshighway-safety-act
Page 28 of 45
The act was motivated primarily by growing public concern over the rising number
of traffic fatalities in the United States Between 1960 and 1965 the annual number
of traffic fatalities increased by nearly thirty percent As President Lyndon B
Johnson stated at the signing of the act on September 9 1966 we have tolerated
a raging epidemic of highway death which has killed more of our youth than all
other diseases combined Through the Highway Safety Act we are going to find out
more about highway diseasemdashand we aim to cure it
Nonetheless highways fatalities continued to increase until the Arab oil
embargo of 1973 led to the NMSL of 55 mph all across the USA Do we just
ignore this undeniable historical record and focus only on the declining fatality
rate as the NMA and other proponents of higher speed limits seem to argue
(see links above)
The misleading nature of using fatality rates (per 100 M VMT) alone is also
obvious if one considers fatality data for individual states Take for example
the state of Montana which seems to have experienced no increase in
fatalities after repeal of NMSL
httpwww-nrdnhtsadotgovdepartmentsnrd-
30ncsaSTSI30_MT200930_MT_2009htm
For the period 2005-2009 the absolute number of fatalities for Montana
varied between a high of 277 in 2007 to a low of 229 in 2009 The fatality
rates per 100 M VMT on the other hand varied from a high of 245 for 2007
to a low of 201 for 2009 The corresponding US fatality rates varied from
136 to 114 Is the higher number for the fatality rate for Montana compared
to USA good or bad Likewise fatality rate per 100000 of population was
much higher for Montana than the US as a whole
This again highlights the pitfalls of using simple ratios to assess fatality statistics
without a full analysis of the underlying trends We will discuss this point
separately
As shown already the continuous decline in the fatality rate is a mathematical
artifact and essentially overlooks the unmistakable positive correlation
between the variables x and y of the type y = hx + c which becomes obvious
Page 29 of 45
only when we prepare the x-y scatter graph The ratio yx = h + (cx) can
decrease with increasing x (VMT) and increasing y (fatalities) since the
intercept c has a positive value when we consider only data spanning a short
period (such as 1994-2009 of more relevance to the current situation)
The debate between fatality rates and absolute number of fatalities is an
unending one A few years ago the Wall Street Journal carried an article
which was entitled (or something close) ―Unemployments rate in Ohio are
going down but why is the number of unemployed increasing The reason is
the same The graph of the number of unemployed (y) versus the number in
the labor market (x) is linear with a positive slope h and a positive intercept c
So the unemployment rate computed using the ratio yx keeps going down
year after year although the number unemployed keeps increasing Is it a
good thing that the unemployment rate is going down when more people
seem to be unable to find gainful unemployment
Or consider the situation with cancer death rates This too has been going
down in recent years but the actual number of cancer-related deaths has not
declined in any significant way Is it good that cancer death rates are going
down In all these situations the researchers or the socio-econo-politico
analysts involved in analyzing the trends in the data have failed to consider
the underlying x-y relation describing each problem
Hence it appears that the debate on the effect of increased speed limits
should not be focused on only the fatality rates (which have been decreasing
and proponents of higher speed limits cite this in their arguments) or even the
absolute number of fatalities (which has been the focus here) but on the
relationship between speed and the number of fatal crashes and the number
of fatalities within each speed segment (see Table 3 and also Figure 4)
Unfortunately details of number of fatalities and the number of fatal crashes
at each speed limit are not available even from NHTSA for detailed study
When a crash does occur (it is immaterial how many miles were driven) the
speed of the driver and vehicle design and engineering including safety
devices in place (seat belts airbags other impact absorbing technologies)
Page 30 of 45
determine if the occupants(s) will be killed One cannot argue that speed
does NOT kill That would be an absolute denial of the laws of physics
Studies show that setting the speed limit at the 85th percentile in any given
zone (this is the speed at or below which 85 of drivers are observed to
travel in traffic engineering studies) is the safest speed limit The majority of
drivers try to obey the posted speed limit while a few choose to drive at a
speed they consider is safe and prudent These are also perhaps the most
vociferous advocates of higher speed limits It is this tension caused due to
differences in speeds that leads to tailgating improper passing reckless
driving weaving from lane to lane and ultimately crashes and deaths in some
unfortunate cases
httpblogmotoristsorgspeed-limits-slower-safer
MARK TAYLOR
ANOTHER LOST A man was killed when his 4WD drive hit a tree east of Morrinsville (in New
Zealand) on Monday May 30 2011 The driver lost control of the vehicle on a bend probably tried
to correct his mistake and put the car into a ―yaw causing it to leave the road and smash sideways
into a tree Alerts to slow down had been posted since this was a high accident area but the driver
probably did not pay attention
64 Other factors
Many other factors besides speed no doubt affect highway fatalities The
vehicles of the 21st century are very different from the vehicles of the mid 20th
Page 31 of 45
century Technological innovations such as improvements in vehicle design
and engineering have greatly increased crash worthiness of vehicles even at
high speeds Environmental factors such as the weather also contribute to
accidents but not necessarily to increased fatalities Drivers actually tend to
slow down instinctively during adverse weather conditions (rain snow storms
etc) and although such weather may contribute to increased accidents the
lower speeds actually reduce fatalities
Yes technology has changed fundamentally from 1966 Drivers today are
more distracted by their cellmobile phone conversations (and also built-in
phones in luxury models) and text messaging than the drivers of the pre-1966
era High end cars now have many multimedia and internet features Again a
careful observation (even personal experience by the author) suggests that
such distracted drivers actually tend to (instinctively) drive more slowly and
hold up the traffic Perhaps such behavior leads to an increase in the number
of accidents but it does not necessarily lead to an increase in the number of
accident-related fatalities
Much talked about technological innovations such as automatic collision
avoidance systems and sensors (on the sides of vehicles) can indeed detect
vehicles in the front and neighboring lanes Furthermore vehicle-to-vehicle
communication systems vehicle-to-infrastructure communication systems
can no doubt avoid collisions and accidents Again such collision avoidance
systems work and are effective entirely because they automatically reduce
vehicle speeds - even if one of the offending vehicles is being at a super
high speed Also it must be remembered that such futuristic systems have
not yet been implemented widely nor can they be implemented widely since
the large majority of vehicles on the road are NOT luxury models Advanced
safety features come with a price and not all drivers can afford to pay that
price and ―buy that ―additional safety
Ultimately it is the laws of physics that govern what will happen when two or
more vehicles collide or even when a single vehicle collides with a stationary
infrastructural object (a bridge a wall a building or some impediment on the
road) The lower the number of crashes the lower the number of fatalities as
revealed by the 1994-2009 data graphed in Figure 5 The higher the speed of
Page 32 of 45
the object or objects that are involved in a collision the higher the kinetic
energy K that must be absorbed andor dissipated Increasing the posted
speed limit only increases the energy that must be absorbed when a crash
does occur This ultimately is the most important criterion determining the
number of fatalities
The kinetic energy increases as the square of the speed being given by the
well-known formula K = frac12 mv2 where m is the mass of the vehicle (in
laypersonlsquos language m increases directly with vehicle weight) and v is the
speed For the same vehicle mass an increase in the speed from 55 mph to
85 mph increases the kinetic energy K by a factor of 239 or roughly a 250
increase in the kinetic energy that must be absorbed in a collision
Ideally speaking the kinetic energy of the colliding object(s) is absorbed by
the vehicle infrastructure (a sturdy space frame the engine other vehicle
components etc) andor the surroundings However in the unfortunate
cases where this kinetic energy must be absorbed by the vehicle occupant(s)
the result is severe life-altering injuries andor death An unequivocal
relationship between an increase in vehicle speeds and fatal accidents can
be demonstrated by a careful examination of available traffic fatality data
This is a more involved discussion and is not the purpose of this short
communication These topics are no doubt very politically charged with many
social legal and financial implications with each interest group favoring a
different conclusion Nonetheless we cannot escape the laws of physics as
they govern the fundamental need to absorb higher and higher values of the
kinetic energy K with increasing vehicle speeds This same point is also
emphasized by Dr Friedman of the University of Illinois Chicago (see earlier
discussion)
Speed kills because of these energy transfer considerations and there can be
no doubt about it
Innovative 21st century solutions to speed management on the highways
such as strict enforcement of speed limits minimizing speed dispersion
(difference between speeds at which different drivers travel) while using
cameras to track the 15 of drivers who willfully violate the speed limit and
Page 33 of 45
create hazardous driving conditions is certainly recommended (Recall that
the optimum recommended speed limit is at or below which 85 of all drivers
travel ndash a policy also supported by NMA) Even on this score however the
results are confounding if we consider the Australian experience
httpwwwthenewspapercomnews282840asp
Up until 2007 there was no speed limit in the Northern Territory of
Australia Imposing a speed limit 130 kmph (80 mph) on some areas and
110 kmph (68 mph) in some others actually increased the number of deaths
The death toll in 2006 when there was no speed limit in this region was 44
and went up to 75 in 2009 see data table in link below
httpwwwthenewspapercomrlcdocs2009au-ntroadtollpdf
Furthermore it appears that installation of cameras to enforce speed limits
has proved to be a hazardous distraction to drivers and deaths actually
began to skyrocket between 2005 and 2007 in all Australian roadways
The main purpose here is to sound a cautionary note amid renewed attempts
in many states across the US to increase the speed limits on our highways by
calling attention to the historical facts regarding the ―epidemic levels of
highway traffic fatalities that engaged our national attention in the fateful year
of 1966 The graphical representation of the traffic fatality data in Figures 1
to 5 tells its own story
Indeed it would be tragic if highway-accident-related fatalities were to start
increasing once again and reach the historically high level that was last seen
in 1972 the year before the Arab oil embargo of 1973
Page 34 of 45
Conclusions
1 The graphical representation of the highway fatality data and the brief
summary of the historical facts of traffic safety legislation suggest that
recent attempts to increase the speed limits by various states (notably
Texas) may be misguided The distinct peak in the highway fatalities
observed in these graphs is highly alarming This appears to be related to
the enactment of the National Maximum Speed Limit (NSML) in 1974
following the 1973 Arab oil embargo Although NSML was motivated by a
desire to reduce gasoline consumption an unintended benefit might have
been a dramatic reduction in fatalities The fundamental reasons for the
peak in the fatalities-VMT curve must be examined carefully without
political posturing
2 The widely used fatality rate fatalities per 100 M vehicle miles traveled
has been declining since 1921 the first year for which a fatality rate could
be computed and has now reached a historical low The absolute number
of fatalities on the other hand was increasing in the 1950s and 1960s at
an alarming rate and the public outcry that ensued led to the highly
publicized Congressional hearing of 1966 and the subsequent traffic safety
legislations The fatality rate has been decreasing even in the most recent
15-year period (1994-2009) again with increasing fatalities although less
dramatically Thus it appears that fatality rate calculation based on vehicle
miles traveled (VMT) might not be a reliable indicator of the underlying
dynamics in the fatality trends
3 More detailed compilation of number of fatalities and the number of fatal
crashes within each speed limit segment is required to better understand
the effect of increasing speed limits on highway fatalities (and also fatality
rates) Such data is already available and is being compiled at the local
city and county levels in all jurisdictions and only needs to be reorganized
to highlight the effect of (posted) speed limits on the number of crashes
and fatalities This will require some minor rewriting and revisions to the
chapters named ―Crashes and ―States in the annual NHTSA reports
Page 35 of 45
Analysis of the fatalities-crashes data for several years with various
speed limits will be more revealing and meaningful than the current
fatality rates analysis and will be discussed separately in a follow up
report
4 One should not be lulled by the fact that vehicles of the 21st century are
now equipped with advanced safety features not available in the 1950s
and the 1960s In spite of these safety features the laws of physics dictate
that the higher the speed the higher kinetic energy of the colliding objects
and hence the greater the risk indeed near certainty of fatalities in a
higher speed collision compared to a lower speed one
5 The higher the speed at which the vehicle that is involved in a crash is
traveling the higher the kinetic energy that must be absorbed andor
dissipated without affecting the occupant(s) to avoid serious injuries andor
death This was true in the 1950s and the 1960s and will continue to be
true in the 21st century as well
Speed Kills for this just reason
6 It appears that higher fuel economies and reduced
highway fatalities were the twin societal benefits of 55
mph adopted after 1973 If so the current attempts to
increase the speed limits appear to be in conflict with
other important societal objectives
Page 36 of 45
Table 1 Annual US Street amp Highway
Fatalities from 1957
Year
Fatalities
Vehicle Miles
(millions)
Rate100M Vehicle Miles
1957 38702 646915 598
1958 36981 664915 556
1959 37910 700478 541
1960 38137 718845 531
1961 38091 737535 516
1962 40804 766852 532
1963 43564 805423 541
1964 47700 846500 563
1965 49163 887640 554
1966 51524 927915 555
1967 51559 965132 534
1968 53831 1019726 528
1969 55032 1066108 516
1970 53672 1114098 482
1971 53761 1183524 454
1972 55704 1264614 440
1973 55113 1316207 419
1974 46078 1282790 359
1975 45500 1330074 342
1976 45523 1402380 325
1977 47878 1467027 326
1978 50331 1544704 326
1979 51103 1529133 334
1980 51091 1527295 335
1981 49301 1552803 317
1982 43945 1595010 276
1983 42589 1652788 258
1984 44257 1720269 257
1985 43795 1774179 247
Page 37 of 45
1986 46056 1835000 251
1987 46385 1921000 241
1988 47093 2026000 232
1989 45555 2107040 216
1990 44529 2147501 207
1991 41162 2172214 189
1992 39235 2239828 175
1993 40115 2296585 175
1994 40676 2359984 172
1995 41798 2422696 173
1996 41907 2485848 169
1997 41967 2560373 164
Data from Federal Highway Administration
Source httpwwwpublicpurposecomhwy-fatal57+htm
Telephone +16186328507 - Facsimile +16186328538
WENDELL COX CONSULTANCY P O Box 841 - Belleville IL 62269 USA
Page 38 of 45
Fatality data for 1921-1982 compiled by NHTSA
Year
VMT
(Millions)
VMT
(Billions)
Fatalities
Fatality rate
per 100 M VMT
1921 55027 5503 13253 241 1922 67697 6770 14859 219 1923 84995 8500 17870 210 1924 104838 10484 18400 176 1925 122346 12235 20771 170 1926 140735 14074 22194 158 1927 158453 15845 24470 154 1928 172856 17286 26557 154 1929 197720 19772 29592 150 1930 206320 20632 31204 151 1931 216151 21615 31963 148 1932 200517 20052 27979 140 1933 200642 20064 29746 148 1934 215563 21556 34240 159 1935 228568 22857 34494 151 1936 252128 25213 36126 143 1937 270110 27011 37819 140 1938 271177 27118 31083 115 1939 285402 28540 30895 108 1940 302188 30219 32914 109 1941 333612 33361 38142 114 1942 268224 26822 27007 101 1943 208192 20819 22727 109 1944 212713 21271 23165 109 1945 250173 25017 26785 107 1946 340880 34088 31874 94 1947 370894 37089 31193 84 1948 397957 39796 30775 77 1949 424461 42446 30246 71 1950 458246 45825 33186 72 1951 491093 49109 35309 72
1952 513581 51358 36088 70
Page 39 of 45
1953 544433 54443 36190 66 1954 561963 56196 33890 60 1955 605646 60565 36688 61 1956 627843 62784 37965 60 1957 647004 64700 36932 57 1958 664653 66465 35331 53 1959 700480 70048 36223 52 1960 718762 71876 36399 51 1961 737421 73742 36285 49 1962 766734 76673 38980 51 1963 805249 80525 41723 52 1964 846298 84630 45645 54 1965 887812 88781 47089 53 1966 925899 92590 50894 55 1967 964005 96401 50724 53 1968 1015869 101587 52725 52 1969 1061791 106179 53543 50 1970 1109724 110972 52627 47 1971 1178811 117881 52542 45 1972 1259786 125979 54589 43 1973 1313110 131311 54052 41 1974 1280544 128054 45196 35 1975 1327664 132766 44525 34 1976 1402380 140238 45523 32 1977 1467027 146703 47878 33 1978 1544704 154470 50331 33 1979 1529133 152913 51093 33 1980 1527295 152730 51091 33 1981 1555308 155531 49301 32 1982 1595010 159501 43945 28
Source Analysis of Significant Decline in Motor Vehicle Traffic Fatalities in
2008 httpwww-nrdnhtsadotgovPubs811346pdf see Table A1 page 31
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Page 40 of 45
Acknowledgements
The author is grateful for thoughtful comments provided by friends and colleagues
with whom this document was shared via email prior to it being uploaded as a
publicly available document for wider dissemination and study The comments
offered by Prof Subra Ganesan of Oakland University Electrical and Computer
Engineering Department are reproduced with permission in their entirety
About the author
The author obtained his Masterrsquos (S M) and Doctoral (Sc D) degrees in Materials Engineering
from the Massachusetts Institute of Technology Cambridge USA He then spent his entire
professional career at leading US research institutions (MIT NASA Case Western Reserve
University and General Motors R amp D Center in Warren MI) He holds four patents in advanced
materials processing has co-authored two books and has published several scientific papers in
leading peer-reviewed international journals His expertise includes developing simple
mathematical models to explain the behavior of complex systems He can be reached by email at
vlaxmananhotmailcom
Page 41 of 45
Please Buckle Up
httpwwwlakecountypublichealthorgindexphpbuckle-up-montana
Public Awareness
Respect the Cage Exhibit
The Department of Transportation hopes that showing the reality of the crash will reduce traffic
fatalities A crushed car crash dummies and a sobering message ndash all part of the ―Respect The
Cage exhibit that is traveling across Montana The exhibit sponsored by the Montana Department
of Transportation stopped in Ronan on November 6th and is aimed at raising awareness about the
importance of wearing seat belts
The car in the exhibit was in an actual wreck many years ago
the passenger in the vehicle died because he was not wearing a
seat belt the driver who was wearing his seat belt survived
Montanarsquos likeliest crash fatality scenario
A Pickup
A Rural road
And Seat belts that
arenrsquot used
Page 42 of 45
Occupants of pickups are less likely to wear seat belts and pickups are more likely to
roll over than passenger cars
Seat belts reduce the risk of death by 60 percent in pickups and SUVs
In Montana from 2006-2008 81 of those killed in a crash while riding in a pickup were not wearing seat belts
In Montana pickups make up 401 of the vehicle population
For more information on Respect the Cage click here
Page 43 of 45
Appendix 1
Lack of seat belts leading cause of Louisiana highway deaths
1251 AM May 28 2011 |
Written by Adam Duvernay
Crashes involving unbuckled motorists were the leading cause of highway fatalities
in Louisiana last year and cost $9888 million according to recent reports The
Louisiana Highway Safety Commission reported 59 percent of vehicle occupants
killed in Louisiana crashes last year mdash about one in four mdash werent wearing seat
belts
httpwwwshreveporttimescomarticle20110528NEWS01105280354Lack-seat-
belts-leading-cause-La-highway-deathsodyssey=tab|topnews|text|FRONTPAGE
Crash bull Stats Published by NHTSAlsquos National Center for Statistics and Analysis 1200 New Jersey Avenue SE Washington DC 20590
DOT HS 811 451
Early Estimate of Motor Vehicle Traffic Fatalities in 2010
httpwww-nrdnhtsadotgovPubs811451pdf
Summary
A statistical projection of traffic fatalities in 2010 shows that an estimated 32788
people died in motor vehicle traffic crashes This represents a decline of about 3
percent as compared to the 33808 fatalities in 2009 as shown in Table 1 If these
projections are realized fatalities will be lowest on record (since 1949)
Traffic Safety Facts Overview 2009 Data
httpwww-nrdnhtsadotgovPubs811392pdf
In 2009 33808 people were killed in the estimated 5505000 police-reported
motor vehicle traffic crashes 2217000 people were injured and 3957000
crashes involved property damage only Compared to 2008 this is a 10-
percent decrease in the number of fatalities and a 5-percent decrease in the
Page 44 of 45
number of police-reported motor vehicle traffic crashes people injured and
crashes involving property damage
An average of 93 people died each day in motor vehicle crashes in 2009 mdash
an average of one every 16 minutes
Traffic Safety Facts Overview 2008 Data
httpwww-nrdnhtsadotgovPubs811162pdf
In 2008 37261 people were killed in the estimated 5811000 police-reported
motor vehicle traffic crashes 2346000 people were injured and 4146000
crashes involved property damage only
Some comments and Feedback
The following comments were received from Prof Ganesan after his review of the
first draft of this document It was subsequently revised thanks to this input to
address some of the very important issues raised here
Dear Laxman
The write up is not enough
You are emphasizing that the speed limit reduces the fatal accidents (comparing 1966
to 2000 accident numbers)
Can you also add a few sentences why the number is decreasing from 1980 to 2000
values (May be due to better design of vehicles)
Can you say anything about the fuel consumption with the speed for any typical
vehicle in 2011 or 2010 (do not consider the fatalities issue)
Probably a speed between 55 and 60 mph gives a better mileage If so this is a
compelling reason to keep the speed limit low But cars probably can be tuned to
give better mileage at any high speed also
Page 45 of 45
Weather is also a major factor in fatal accidents Speed limit may be kept low during
winter and kept higher in summer Give your comments on this too
Driver distractions can cause more accidents Now cars have many multimedia and
internet features Automatic collision avoidance systems and sensors on the sides can
detect vehicles in the front and neighboring lanes and it can automatically decrease
speed even if the driver speeds at super high speeds
Give some comments on this too There is also Vehicle to Vehicle communications
vehicle to infrastructure communications and they can avoid collisions and accidents
Technology has changed from 1966 I cannot agree with you on the speed limit
without any discussion on the above and other factors
Have a great day
Subra Ganesan
Professor Subramaniam Ganesan
Director Real Time amp DSP Lab
Electrical and Computer Engineering Department
2200 Squirrel Road Dodge Hall Room 105
Oakland University Rochester MI 48309 USA
Phone 248 370 2206 Fax 248 370 4633
wwwsecsoaklandedu~ganesan
IEEE Distinguished Visiting Speaker (2005-2009) Coordinator
IEEE SEM CS chapter Chair Region 4 and CS Society Board member
SAE ASEE ACM member
Page 21 of 45
These simple computations here however reveal the significant effect of
reduced speed limits on highway fatalities much more so than other factors
6 Further Considerations Pros and Cons
The singular effect of increased speeds (or speeding) on highway fatalities
has been studied and demonstrated by a number of industry sources such
as the Insurance Institute for Highway Safety (IIHS) Consumers Union and
also by government researchers
httpwwwsmartmotoristcomtraffic-and-safety-guidelineexcessive-speed-is-
a-factor-in-one-third-of-all-fatal-crasheshtml
httpwwwconsumersunionorgotherspeedlimitsspeed031500a2htm
Speed ndash defined as exceeding the posted speed limit or driving too fast for
given conditions ndash is a factor in nearly one-third of all fatal crashes Besides
fatality in 1998 nearly 40000 people were critically injured in speed-related
crashes and nearly 72000 were moderately injured
The salutary and immediate beneficial effect of the nationwide 55 mph speed
limit has been noted by other researchers (see Susan Ferguson link below)
httpwwwnhtsagovpeopleinjuryenforcespeed_forum_presentationsfergu
sonpdf
After a partial repeal of this law in 1987 which granted states the authority to
increase speed limit (especially in rural interstates) a 1989 study showed a
15 increase in fatalities in rural interstates and a 5 increase in non-rural
interstates Unfortunately such studies often tend to be discounted by
advocates of increasing the speed limits as being produced by biased
industry sources
Similar conclusions were also presented by NHTSA in February 1998 in its
report to the Congress entitled ―Report to Congress The Effect of Increased
Speed Limits in the Post-NMSL Era see link given below Among its key
Page 22 of 45
findings is the following quoted in its entirety NMSL refers to the National
Maximum Speed Limit legislated after the Arab oil embargo of 1973
httpwww-nrdnhtsadotgovPubs808-637PDF
hellip Nevertheless it is important to note that data currently available from the
National Highway Traffic Safety Administrationrsquos (NHTSA) Fatality Analysis
Reporting System (FARS) shows that states that increased speed limits in 1996
experienced approximately 350 more Interstate fatalities than would have been
expected based on historical trends -- about 9 percent above expectations
Concurrently the Interstate fatalities experienced in states that did not increase speed
limits in 1996 was consistent with pre-1996 trends The estimated increase in
Interstate fatalities found in this study while smaller in magnitude compared to the
estimated change in fatalities found in 1987 following the increase of speed limits on
rural Interstates does follow the historical pattern of increases in fatalities being
associated with increases in posted speed limits
The annual crash reports compiled by NHTSA see Table 3 indicate that the
number of fatal crashes (and hence fatalities using the regression equation
developed in Figure 4) increase as the posted speed limits increase
Page 23 of 45
Table 3 Posted speed limits and number of crashes
Speed Limit Crashes (2008) Crashes (2009)
30 mph or less 3705 3277 35 or 40 mph 6115 5516 45 or 50 mph 6461 6074
55 mph 9794 8847 60 mph or higher 6908 6124
Total 34017 30797
Source httpwww-nrdnhtsadotgovPubs811402EEpdf
61 Studies cited in favor of lower speed limits
A detailed analysis of speeding related fatalities (see link below) by NHTSA
shows that a third of all crashes involve speeding ie at least one driver was
speeding
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Furthermore the above report which covers the period 1983-2002
indicates that immediately after the NMSL was completely abolished in
December 1995 the number of speeding related fatalities at speeds
above 65 mph increased from just 15 in 1995 to a 677 in 1996 (see Table
62 on page 43 of above report) It continued to increase in the years
since climbing to 930 in 2000
More detailed studies similar to that noted above by researchers at the
University of Illinois Chicago led by Lee S Friedman again lead to the
conclusion that higher speed limits lead to an increase in the number of
fatalities (see American Journal of Public Health online July 16 2009)
httphealthusnewscomhealth-newsmanaging-your-
healthcarearticles20090716deaths-injuries-increase-with-higher-speed-
limits
Page 24 of 45
httpwwwmedpagetodaycomPublicHealthPolicyPublicHealth15122
httpwwwamericaneercomspeed-limits
httpwwwactuarialoutpostcomactuarial_discussion_forumarchiveindexph
pt-171870html
For the study period 1995-2005 these researchers found that 12545 deaths
and 36582 injuries could be attributed to the increased speed limits The
benefits of reduced speed limits are stated quite eloquently by Dr Friedman
and are reproduced below (from above news article see link)
Reduced speed limits would save lives Friedman said They would also reduce
gas consumption cut emissions of air pollutants save valuable years of productivity
(lost due to injuries)and reduce the societal cost of motor vehicle crashes (due to
both fatal crashes and due to nonfatal and severe life-changing injuries) he added
Friedman and coworkers have also shown that increasing the speed limit led
to an immediate increase in the number of fatalities on Israeli roadways (see
link below)
httpinjurypreventionbmjcomcontent133156
The effect of speeding is very significant especially in rural areas resulting
in significantly higher fatalities Fatality rates are frequently double or triple
that in urban areas (see link below)
httpsafetyfhwadotgovspeedmgtdata_factsdocsspeeding_ruralpdf
As of Jan 1 2005 five Midwestern states had increased the speed limits to
above 65 mph (Illinois Iowa Kansas Minnesota Missouri Nebraska and
South Dakota) whereas three (Illinois Iowa and Wisconsin) had not All the
five states with increased speed limits showed a 7 to 13 increase in
fatalities The NHTSA study considered an eight year period before and after
the change in Dec 1995 (see Table 1 in link below) The collective experience
of the states that did NOT increase the speed limit was a 7 decline in
fatalities (see Table 2 of link below)
httpwwwiowadotgovmvdodsstats2006speedstudypdf
Page 25 of 45
Moreover Table 5 in the above study shows the effect of imposing the NMSL
of 55 mph in Iowa and its repeal in 1995 Considering a four-year average
before 1974 when the speed limit was 75 mph there were 35 fatal crashes
with 43 fatalities In the first four years after the 55 mph there were only 23
fatal crashes and 28 fatalities In the last four years before the repeal of 55
mph in 1995 there was a further decline to 14 fatal crashes with 17 fatalities
The Iowa fatality data will be discussed in more detail separately (in a later report)
since it provides the opportunity to assess the effect of a change in the speed limit
on the relationship between number of fatalities and fatal crashes (as seen in
Figure 4 for the US as a whole)
North of the US border Canadians seem to be citing the ―shocking increase
in highway fatalities in the US states where the speed limits were raised to
curb their own speed limits
httparchivesafety-councilorginfotrafficspeed-02html
httparchivesafety-councilorginfotrafficspeedhtml
Speed kills but speed also sells notes the second of the above news items
Manufacturers are producing more high performance cars (with higher horse
power to weight ratio) and ads feature enticing cars that race and swerve in
miraculous ways on empty roads These subliminal messages encourage
drivers especially young drivers to break the speed limit leading to the
absolute increase in highway fatalities (although the rate itself is going
down) The article emphasizes the need to enforce the speed limit on
Canadian highways and in cities where street racing is becoming a problem
62 Studies cited by opponents of lower speed limits
In fairness to quote the opponents on the other side of this debate Montana
reverted back to Reasonable and Prudent speed limits when the National
Maximum Speed Limit was repealed in 1995 and appears to have
experienced no significant increase in fatalities
Page 26 of 45
httpwwwhwysafetycomhwy_montanahtm
httpwwwmotoristsorgpressmontana-no-speed-limit-safety-paradox
httpwwwsouthbayriderscomforumsshowthreadphpt=81453amppage=1
Likewise studies in the state of Maryland showed no significant increase in
highway fatalities when the speed limit was increased from 55 mph to 75
mph The reason might simply be that drivers were already speeding much
more so when the speed limit was 55 mph than after the increase to 75 mph
In other words the fatalities data already reflects the effect of higher speeds
(not speed limits) on the number of fatalities
In Utah the experimental increase in the speed limit to 80 mph was
considered to be a success in terms of safety
httpautosaolcomarticleutah-speed-limit-tests
The UDOT Director noted that there was no increase in the number of
accidents on Interstate 15 But what happens in the event of an accident
when the speed limits are higher and drivers are driving at higher speeds and
two objects collide at this higher speed However no increase in the number
of accidents is not the same as no increase in fatalities due to the higher
speeds When accidents do occur do fatalities increase
Likewise in California when the speed limit went up from 55 mph to 65
mph in 1995 (after repeal of NMSL) fewer deaths were reported in 1998
compared to the peak year of 1979 or even 1987 Again the explanation
seems to be that motorists were already speeding when the limit was 55 mph
and that increasing the speed limit did not change driver behavior in any
significant way
httparticlessfgatecom1998-11-02news17735730_1_speed-limits-mph-
limit-death-rate
The National Motorists Association (NMA) a group which advocates higher
speed limits emphasizes the importance of considering fatality rates as
opposed to the raw fatalities The argument used is that fatality rates based
on the fatality per 100 million VMT is the legitimate way to look at the data
Page 27 of 45
This is a never ending debate Historically speaking fatality rates have been
going down ever since the compilation of traffic accidents data began Table
A1 in the appendix of a recent report by NHTSA (see link below) has highway
fatality rate data going back 1921
httpwww-nrdnhtsadotgovPubs811346pdf see appendix page 31
httpwwwmotoristsorgspeed-limitstruth
httpwwwmotoristsorgothercrash-data
httpwwwraisethespeedlimitorgmythshtml
httpwwwcatoorgpubspaspa346pdf
According to Stephen Moore of the Cato Institute (see last of the links above)
―All measures of highway safety show improvement not more deaths and
injuries since 1995 Despite the fact that 33 states raised their speed limits
immediately after the repeal of the mandatory federal speed limit the NHTSA
reported last October that the traffic death rate dropped to a record low level
in 1997lsquo Moreover the average fatality rate even fell in the states that raised
their speed limits
63 The Fatality rate Is it a reliable metric
In 1921 with fewer fatalities and fewer miles driven and the first year for
which the fatality rate could be computed the rate was 2408 It was down to
1479 in 1931 but the number of deaths had climbed to 31963 more than
double the 1921 absolute fatality number of 13253 It had dropped to 550 in
1966 the year of the highly publicized Congressional hearings but the
number of fatalities had climbed to 50984 in that fateful The Highway Safety
Act of 1966 ranks as one of the major acts of Congress and President
Johnson signed it saying that ―we have been tolerating a raging epidemic of
highway deathshellip see extract pasted below
httpwwwenotescommajor-acts-congresshighway-safety-act
Page 28 of 45
The act was motivated primarily by growing public concern over the rising number
of traffic fatalities in the United States Between 1960 and 1965 the annual number
of traffic fatalities increased by nearly thirty percent As President Lyndon B
Johnson stated at the signing of the act on September 9 1966 we have tolerated
a raging epidemic of highway death which has killed more of our youth than all
other diseases combined Through the Highway Safety Act we are going to find out
more about highway diseasemdashand we aim to cure it
Nonetheless highways fatalities continued to increase until the Arab oil
embargo of 1973 led to the NMSL of 55 mph all across the USA Do we just
ignore this undeniable historical record and focus only on the declining fatality
rate as the NMA and other proponents of higher speed limits seem to argue
(see links above)
The misleading nature of using fatality rates (per 100 M VMT) alone is also
obvious if one considers fatality data for individual states Take for example
the state of Montana which seems to have experienced no increase in
fatalities after repeal of NMSL
httpwww-nrdnhtsadotgovdepartmentsnrd-
30ncsaSTSI30_MT200930_MT_2009htm
For the period 2005-2009 the absolute number of fatalities for Montana
varied between a high of 277 in 2007 to a low of 229 in 2009 The fatality
rates per 100 M VMT on the other hand varied from a high of 245 for 2007
to a low of 201 for 2009 The corresponding US fatality rates varied from
136 to 114 Is the higher number for the fatality rate for Montana compared
to USA good or bad Likewise fatality rate per 100000 of population was
much higher for Montana than the US as a whole
This again highlights the pitfalls of using simple ratios to assess fatality statistics
without a full analysis of the underlying trends We will discuss this point
separately
As shown already the continuous decline in the fatality rate is a mathematical
artifact and essentially overlooks the unmistakable positive correlation
between the variables x and y of the type y = hx + c which becomes obvious
Page 29 of 45
only when we prepare the x-y scatter graph The ratio yx = h + (cx) can
decrease with increasing x (VMT) and increasing y (fatalities) since the
intercept c has a positive value when we consider only data spanning a short
period (such as 1994-2009 of more relevance to the current situation)
The debate between fatality rates and absolute number of fatalities is an
unending one A few years ago the Wall Street Journal carried an article
which was entitled (or something close) ―Unemployments rate in Ohio are
going down but why is the number of unemployed increasing The reason is
the same The graph of the number of unemployed (y) versus the number in
the labor market (x) is linear with a positive slope h and a positive intercept c
So the unemployment rate computed using the ratio yx keeps going down
year after year although the number unemployed keeps increasing Is it a
good thing that the unemployment rate is going down when more people
seem to be unable to find gainful unemployment
Or consider the situation with cancer death rates This too has been going
down in recent years but the actual number of cancer-related deaths has not
declined in any significant way Is it good that cancer death rates are going
down In all these situations the researchers or the socio-econo-politico
analysts involved in analyzing the trends in the data have failed to consider
the underlying x-y relation describing each problem
Hence it appears that the debate on the effect of increased speed limits
should not be focused on only the fatality rates (which have been decreasing
and proponents of higher speed limits cite this in their arguments) or even the
absolute number of fatalities (which has been the focus here) but on the
relationship between speed and the number of fatal crashes and the number
of fatalities within each speed segment (see Table 3 and also Figure 4)
Unfortunately details of number of fatalities and the number of fatal crashes
at each speed limit are not available even from NHTSA for detailed study
When a crash does occur (it is immaterial how many miles were driven) the
speed of the driver and vehicle design and engineering including safety
devices in place (seat belts airbags other impact absorbing technologies)
Page 30 of 45
determine if the occupants(s) will be killed One cannot argue that speed
does NOT kill That would be an absolute denial of the laws of physics
Studies show that setting the speed limit at the 85th percentile in any given
zone (this is the speed at or below which 85 of drivers are observed to
travel in traffic engineering studies) is the safest speed limit The majority of
drivers try to obey the posted speed limit while a few choose to drive at a
speed they consider is safe and prudent These are also perhaps the most
vociferous advocates of higher speed limits It is this tension caused due to
differences in speeds that leads to tailgating improper passing reckless
driving weaving from lane to lane and ultimately crashes and deaths in some
unfortunate cases
httpblogmotoristsorgspeed-limits-slower-safer
MARK TAYLOR
ANOTHER LOST A man was killed when his 4WD drive hit a tree east of Morrinsville (in New
Zealand) on Monday May 30 2011 The driver lost control of the vehicle on a bend probably tried
to correct his mistake and put the car into a ―yaw causing it to leave the road and smash sideways
into a tree Alerts to slow down had been posted since this was a high accident area but the driver
probably did not pay attention
64 Other factors
Many other factors besides speed no doubt affect highway fatalities The
vehicles of the 21st century are very different from the vehicles of the mid 20th
Page 31 of 45
century Technological innovations such as improvements in vehicle design
and engineering have greatly increased crash worthiness of vehicles even at
high speeds Environmental factors such as the weather also contribute to
accidents but not necessarily to increased fatalities Drivers actually tend to
slow down instinctively during adverse weather conditions (rain snow storms
etc) and although such weather may contribute to increased accidents the
lower speeds actually reduce fatalities
Yes technology has changed fundamentally from 1966 Drivers today are
more distracted by their cellmobile phone conversations (and also built-in
phones in luxury models) and text messaging than the drivers of the pre-1966
era High end cars now have many multimedia and internet features Again a
careful observation (even personal experience by the author) suggests that
such distracted drivers actually tend to (instinctively) drive more slowly and
hold up the traffic Perhaps such behavior leads to an increase in the number
of accidents but it does not necessarily lead to an increase in the number of
accident-related fatalities
Much talked about technological innovations such as automatic collision
avoidance systems and sensors (on the sides of vehicles) can indeed detect
vehicles in the front and neighboring lanes Furthermore vehicle-to-vehicle
communication systems vehicle-to-infrastructure communication systems
can no doubt avoid collisions and accidents Again such collision avoidance
systems work and are effective entirely because they automatically reduce
vehicle speeds - even if one of the offending vehicles is being at a super
high speed Also it must be remembered that such futuristic systems have
not yet been implemented widely nor can they be implemented widely since
the large majority of vehicles on the road are NOT luxury models Advanced
safety features come with a price and not all drivers can afford to pay that
price and ―buy that ―additional safety
Ultimately it is the laws of physics that govern what will happen when two or
more vehicles collide or even when a single vehicle collides with a stationary
infrastructural object (a bridge a wall a building or some impediment on the
road) The lower the number of crashes the lower the number of fatalities as
revealed by the 1994-2009 data graphed in Figure 5 The higher the speed of
Page 32 of 45
the object or objects that are involved in a collision the higher the kinetic
energy K that must be absorbed andor dissipated Increasing the posted
speed limit only increases the energy that must be absorbed when a crash
does occur This ultimately is the most important criterion determining the
number of fatalities
The kinetic energy increases as the square of the speed being given by the
well-known formula K = frac12 mv2 where m is the mass of the vehicle (in
laypersonlsquos language m increases directly with vehicle weight) and v is the
speed For the same vehicle mass an increase in the speed from 55 mph to
85 mph increases the kinetic energy K by a factor of 239 or roughly a 250
increase in the kinetic energy that must be absorbed in a collision
Ideally speaking the kinetic energy of the colliding object(s) is absorbed by
the vehicle infrastructure (a sturdy space frame the engine other vehicle
components etc) andor the surroundings However in the unfortunate
cases where this kinetic energy must be absorbed by the vehicle occupant(s)
the result is severe life-altering injuries andor death An unequivocal
relationship between an increase in vehicle speeds and fatal accidents can
be demonstrated by a careful examination of available traffic fatality data
This is a more involved discussion and is not the purpose of this short
communication These topics are no doubt very politically charged with many
social legal and financial implications with each interest group favoring a
different conclusion Nonetheless we cannot escape the laws of physics as
they govern the fundamental need to absorb higher and higher values of the
kinetic energy K with increasing vehicle speeds This same point is also
emphasized by Dr Friedman of the University of Illinois Chicago (see earlier
discussion)
Speed kills because of these energy transfer considerations and there can be
no doubt about it
Innovative 21st century solutions to speed management on the highways
such as strict enforcement of speed limits minimizing speed dispersion
(difference between speeds at which different drivers travel) while using
cameras to track the 15 of drivers who willfully violate the speed limit and
Page 33 of 45
create hazardous driving conditions is certainly recommended (Recall that
the optimum recommended speed limit is at or below which 85 of all drivers
travel ndash a policy also supported by NMA) Even on this score however the
results are confounding if we consider the Australian experience
httpwwwthenewspapercomnews282840asp
Up until 2007 there was no speed limit in the Northern Territory of
Australia Imposing a speed limit 130 kmph (80 mph) on some areas and
110 kmph (68 mph) in some others actually increased the number of deaths
The death toll in 2006 when there was no speed limit in this region was 44
and went up to 75 in 2009 see data table in link below
httpwwwthenewspapercomrlcdocs2009au-ntroadtollpdf
Furthermore it appears that installation of cameras to enforce speed limits
has proved to be a hazardous distraction to drivers and deaths actually
began to skyrocket between 2005 and 2007 in all Australian roadways
The main purpose here is to sound a cautionary note amid renewed attempts
in many states across the US to increase the speed limits on our highways by
calling attention to the historical facts regarding the ―epidemic levels of
highway traffic fatalities that engaged our national attention in the fateful year
of 1966 The graphical representation of the traffic fatality data in Figures 1
to 5 tells its own story
Indeed it would be tragic if highway-accident-related fatalities were to start
increasing once again and reach the historically high level that was last seen
in 1972 the year before the Arab oil embargo of 1973
Page 34 of 45
Conclusions
1 The graphical representation of the highway fatality data and the brief
summary of the historical facts of traffic safety legislation suggest that
recent attempts to increase the speed limits by various states (notably
Texas) may be misguided The distinct peak in the highway fatalities
observed in these graphs is highly alarming This appears to be related to
the enactment of the National Maximum Speed Limit (NSML) in 1974
following the 1973 Arab oil embargo Although NSML was motivated by a
desire to reduce gasoline consumption an unintended benefit might have
been a dramatic reduction in fatalities The fundamental reasons for the
peak in the fatalities-VMT curve must be examined carefully without
political posturing
2 The widely used fatality rate fatalities per 100 M vehicle miles traveled
has been declining since 1921 the first year for which a fatality rate could
be computed and has now reached a historical low The absolute number
of fatalities on the other hand was increasing in the 1950s and 1960s at
an alarming rate and the public outcry that ensued led to the highly
publicized Congressional hearing of 1966 and the subsequent traffic safety
legislations The fatality rate has been decreasing even in the most recent
15-year period (1994-2009) again with increasing fatalities although less
dramatically Thus it appears that fatality rate calculation based on vehicle
miles traveled (VMT) might not be a reliable indicator of the underlying
dynamics in the fatality trends
3 More detailed compilation of number of fatalities and the number of fatal
crashes within each speed limit segment is required to better understand
the effect of increasing speed limits on highway fatalities (and also fatality
rates) Such data is already available and is being compiled at the local
city and county levels in all jurisdictions and only needs to be reorganized
to highlight the effect of (posted) speed limits on the number of crashes
and fatalities This will require some minor rewriting and revisions to the
chapters named ―Crashes and ―States in the annual NHTSA reports
Page 35 of 45
Analysis of the fatalities-crashes data for several years with various
speed limits will be more revealing and meaningful than the current
fatality rates analysis and will be discussed separately in a follow up
report
4 One should not be lulled by the fact that vehicles of the 21st century are
now equipped with advanced safety features not available in the 1950s
and the 1960s In spite of these safety features the laws of physics dictate
that the higher the speed the higher kinetic energy of the colliding objects
and hence the greater the risk indeed near certainty of fatalities in a
higher speed collision compared to a lower speed one
5 The higher the speed at which the vehicle that is involved in a crash is
traveling the higher the kinetic energy that must be absorbed andor
dissipated without affecting the occupant(s) to avoid serious injuries andor
death This was true in the 1950s and the 1960s and will continue to be
true in the 21st century as well
Speed Kills for this just reason
6 It appears that higher fuel economies and reduced
highway fatalities were the twin societal benefits of 55
mph adopted after 1973 If so the current attempts to
increase the speed limits appear to be in conflict with
other important societal objectives
Page 36 of 45
Table 1 Annual US Street amp Highway
Fatalities from 1957
Year
Fatalities
Vehicle Miles
(millions)
Rate100M Vehicle Miles
1957 38702 646915 598
1958 36981 664915 556
1959 37910 700478 541
1960 38137 718845 531
1961 38091 737535 516
1962 40804 766852 532
1963 43564 805423 541
1964 47700 846500 563
1965 49163 887640 554
1966 51524 927915 555
1967 51559 965132 534
1968 53831 1019726 528
1969 55032 1066108 516
1970 53672 1114098 482
1971 53761 1183524 454
1972 55704 1264614 440
1973 55113 1316207 419
1974 46078 1282790 359
1975 45500 1330074 342
1976 45523 1402380 325
1977 47878 1467027 326
1978 50331 1544704 326
1979 51103 1529133 334
1980 51091 1527295 335
1981 49301 1552803 317
1982 43945 1595010 276
1983 42589 1652788 258
1984 44257 1720269 257
1985 43795 1774179 247
Page 37 of 45
1986 46056 1835000 251
1987 46385 1921000 241
1988 47093 2026000 232
1989 45555 2107040 216
1990 44529 2147501 207
1991 41162 2172214 189
1992 39235 2239828 175
1993 40115 2296585 175
1994 40676 2359984 172
1995 41798 2422696 173
1996 41907 2485848 169
1997 41967 2560373 164
Data from Federal Highway Administration
Source httpwwwpublicpurposecomhwy-fatal57+htm
Telephone +16186328507 - Facsimile +16186328538
WENDELL COX CONSULTANCY P O Box 841 - Belleville IL 62269 USA
Page 38 of 45
Fatality data for 1921-1982 compiled by NHTSA
Year
VMT
(Millions)
VMT
(Billions)
Fatalities
Fatality rate
per 100 M VMT
1921 55027 5503 13253 241 1922 67697 6770 14859 219 1923 84995 8500 17870 210 1924 104838 10484 18400 176 1925 122346 12235 20771 170 1926 140735 14074 22194 158 1927 158453 15845 24470 154 1928 172856 17286 26557 154 1929 197720 19772 29592 150 1930 206320 20632 31204 151 1931 216151 21615 31963 148 1932 200517 20052 27979 140 1933 200642 20064 29746 148 1934 215563 21556 34240 159 1935 228568 22857 34494 151 1936 252128 25213 36126 143 1937 270110 27011 37819 140 1938 271177 27118 31083 115 1939 285402 28540 30895 108 1940 302188 30219 32914 109 1941 333612 33361 38142 114 1942 268224 26822 27007 101 1943 208192 20819 22727 109 1944 212713 21271 23165 109 1945 250173 25017 26785 107 1946 340880 34088 31874 94 1947 370894 37089 31193 84 1948 397957 39796 30775 77 1949 424461 42446 30246 71 1950 458246 45825 33186 72 1951 491093 49109 35309 72
1952 513581 51358 36088 70
Page 39 of 45
1953 544433 54443 36190 66 1954 561963 56196 33890 60 1955 605646 60565 36688 61 1956 627843 62784 37965 60 1957 647004 64700 36932 57 1958 664653 66465 35331 53 1959 700480 70048 36223 52 1960 718762 71876 36399 51 1961 737421 73742 36285 49 1962 766734 76673 38980 51 1963 805249 80525 41723 52 1964 846298 84630 45645 54 1965 887812 88781 47089 53 1966 925899 92590 50894 55 1967 964005 96401 50724 53 1968 1015869 101587 52725 52 1969 1061791 106179 53543 50 1970 1109724 110972 52627 47 1971 1178811 117881 52542 45 1972 1259786 125979 54589 43 1973 1313110 131311 54052 41 1974 1280544 128054 45196 35 1975 1327664 132766 44525 34 1976 1402380 140238 45523 32 1977 1467027 146703 47878 33 1978 1544704 154470 50331 33 1979 1529133 152913 51093 33 1980 1527295 152730 51091 33 1981 1555308 155531 49301 32 1982 1595010 159501 43945 28
Source Analysis of Significant Decline in Motor Vehicle Traffic Fatalities in
2008 httpwww-nrdnhtsadotgovPubs811346pdf see Table A1 page 31
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Page 40 of 45
Acknowledgements
The author is grateful for thoughtful comments provided by friends and colleagues
with whom this document was shared via email prior to it being uploaded as a
publicly available document for wider dissemination and study The comments
offered by Prof Subra Ganesan of Oakland University Electrical and Computer
Engineering Department are reproduced with permission in their entirety
About the author
The author obtained his Masterrsquos (S M) and Doctoral (Sc D) degrees in Materials Engineering
from the Massachusetts Institute of Technology Cambridge USA He then spent his entire
professional career at leading US research institutions (MIT NASA Case Western Reserve
University and General Motors R amp D Center in Warren MI) He holds four patents in advanced
materials processing has co-authored two books and has published several scientific papers in
leading peer-reviewed international journals His expertise includes developing simple
mathematical models to explain the behavior of complex systems He can be reached by email at
vlaxmananhotmailcom
Page 41 of 45
Please Buckle Up
httpwwwlakecountypublichealthorgindexphpbuckle-up-montana
Public Awareness
Respect the Cage Exhibit
The Department of Transportation hopes that showing the reality of the crash will reduce traffic
fatalities A crushed car crash dummies and a sobering message ndash all part of the ―Respect The
Cage exhibit that is traveling across Montana The exhibit sponsored by the Montana Department
of Transportation stopped in Ronan on November 6th and is aimed at raising awareness about the
importance of wearing seat belts
The car in the exhibit was in an actual wreck many years ago
the passenger in the vehicle died because he was not wearing a
seat belt the driver who was wearing his seat belt survived
Montanarsquos likeliest crash fatality scenario
A Pickup
A Rural road
And Seat belts that
arenrsquot used
Page 42 of 45
Occupants of pickups are less likely to wear seat belts and pickups are more likely to
roll over than passenger cars
Seat belts reduce the risk of death by 60 percent in pickups and SUVs
In Montana from 2006-2008 81 of those killed in a crash while riding in a pickup were not wearing seat belts
In Montana pickups make up 401 of the vehicle population
For more information on Respect the Cage click here
Page 43 of 45
Appendix 1
Lack of seat belts leading cause of Louisiana highway deaths
1251 AM May 28 2011 |
Written by Adam Duvernay
Crashes involving unbuckled motorists were the leading cause of highway fatalities
in Louisiana last year and cost $9888 million according to recent reports The
Louisiana Highway Safety Commission reported 59 percent of vehicle occupants
killed in Louisiana crashes last year mdash about one in four mdash werent wearing seat
belts
httpwwwshreveporttimescomarticle20110528NEWS01105280354Lack-seat-
belts-leading-cause-La-highway-deathsodyssey=tab|topnews|text|FRONTPAGE
Crash bull Stats Published by NHTSAlsquos National Center for Statistics and Analysis 1200 New Jersey Avenue SE Washington DC 20590
DOT HS 811 451
Early Estimate of Motor Vehicle Traffic Fatalities in 2010
httpwww-nrdnhtsadotgovPubs811451pdf
Summary
A statistical projection of traffic fatalities in 2010 shows that an estimated 32788
people died in motor vehicle traffic crashes This represents a decline of about 3
percent as compared to the 33808 fatalities in 2009 as shown in Table 1 If these
projections are realized fatalities will be lowest on record (since 1949)
Traffic Safety Facts Overview 2009 Data
httpwww-nrdnhtsadotgovPubs811392pdf
In 2009 33808 people were killed in the estimated 5505000 police-reported
motor vehicle traffic crashes 2217000 people were injured and 3957000
crashes involved property damage only Compared to 2008 this is a 10-
percent decrease in the number of fatalities and a 5-percent decrease in the
Page 44 of 45
number of police-reported motor vehicle traffic crashes people injured and
crashes involving property damage
An average of 93 people died each day in motor vehicle crashes in 2009 mdash
an average of one every 16 minutes
Traffic Safety Facts Overview 2008 Data
httpwww-nrdnhtsadotgovPubs811162pdf
In 2008 37261 people were killed in the estimated 5811000 police-reported
motor vehicle traffic crashes 2346000 people were injured and 4146000
crashes involved property damage only
Some comments and Feedback
The following comments were received from Prof Ganesan after his review of the
first draft of this document It was subsequently revised thanks to this input to
address some of the very important issues raised here
Dear Laxman
The write up is not enough
You are emphasizing that the speed limit reduces the fatal accidents (comparing 1966
to 2000 accident numbers)
Can you also add a few sentences why the number is decreasing from 1980 to 2000
values (May be due to better design of vehicles)
Can you say anything about the fuel consumption with the speed for any typical
vehicle in 2011 or 2010 (do not consider the fatalities issue)
Probably a speed between 55 and 60 mph gives a better mileage If so this is a
compelling reason to keep the speed limit low But cars probably can be tuned to
give better mileage at any high speed also
Page 45 of 45
Weather is also a major factor in fatal accidents Speed limit may be kept low during
winter and kept higher in summer Give your comments on this too
Driver distractions can cause more accidents Now cars have many multimedia and
internet features Automatic collision avoidance systems and sensors on the sides can
detect vehicles in the front and neighboring lanes and it can automatically decrease
speed even if the driver speeds at super high speeds
Give some comments on this too There is also Vehicle to Vehicle communications
vehicle to infrastructure communications and they can avoid collisions and accidents
Technology has changed from 1966 I cannot agree with you on the speed limit
without any discussion on the above and other factors
Have a great day
Subra Ganesan
Professor Subramaniam Ganesan
Director Real Time amp DSP Lab
Electrical and Computer Engineering Department
2200 Squirrel Road Dodge Hall Room 105
Oakland University Rochester MI 48309 USA
Phone 248 370 2206 Fax 248 370 4633
wwwsecsoaklandedu~ganesan
IEEE Distinguished Visiting Speaker (2005-2009) Coordinator
IEEE SEM CS chapter Chair Region 4 and CS Society Board member
SAE ASEE ACM member
Page 22 of 45
findings is the following quoted in its entirety NMSL refers to the National
Maximum Speed Limit legislated after the Arab oil embargo of 1973
httpwww-nrdnhtsadotgovPubs808-637PDF
hellip Nevertheless it is important to note that data currently available from the
National Highway Traffic Safety Administrationrsquos (NHTSA) Fatality Analysis
Reporting System (FARS) shows that states that increased speed limits in 1996
experienced approximately 350 more Interstate fatalities than would have been
expected based on historical trends -- about 9 percent above expectations
Concurrently the Interstate fatalities experienced in states that did not increase speed
limits in 1996 was consistent with pre-1996 trends The estimated increase in
Interstate fatalities found in this study while smaller in magnitude compared to the
estimated change in fatalities found in 1987 following the increase of speed limits on
rural Interstates does follow the historical pattern of increases in fatalities being
associated with increases in posted speed limits
The annual crash reports compiled by NHTSA see Table 3 indicate that the
number of fatal crashes (and hence fatalities using the regression equation
developed in Figure 4) increase as the posted speed limits increase
Page 23 of 45
Table 3 Posted speed limits and number of crashes
Speed Limit Crashes (2008) Crashes (2009)
30 mph or less 3705 3277 35 or 40 mph 6115 5516 45 or 50 mph 6461 6074
55 mph 9794 8847 60 mph or higher 6908 6124
Total 34017 30797
Source httpwww-nrdnhtsadotgovPubs811402EEpdf
61 Studies cited in favor of lower speed limits
A detailed analysis of speeding related fatalities (see link below) by NHTSA
shows that a third of all crashes involve speeding ie at least one driver was
speeding
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Furthermore the above report which covers the period 1983-2002
indicates that immediately after the NMSL was completely abolished in
December 1995 the number of speeding related fatalities at speeds
above 65 mph increased from just 15 in 1995 to a 677 in 1996 (see Table
62 on page 43 of above report) It continued to increase in the years
since climbing to 930 in 2000
More detailed studies similar to that noted above by researchers at the
University of Illinois Chicago led by Lee S Friedman again lead to the
conclusion that higher speed limits lead to an increase in the number of
fatalities (see American Journal of Public Health online July 16 2009)
httphealthusnewscomhealth-newsmanaging-your-
healthcarearticles20090716deaths-injuries-increase-with-higher-speed-
limits
Page 24 of 45
httpwwwmedpagetodaycomPublicHealthPolicyPublicHealth15122
httpwwwamericaneercomspeed-limits
httpwwwactuarialoutpostcomactuarial_discussion_forumarchiveindexph
pt-171870html
For the study period 1995-2005 these researchers found that 12545 deaths
and 36582 injuries could be attributed to the increased speed limits The
benefits of reduced speed limits are stated quite eloquently by Dr Friedman
and are reproduced below (from above news article see link)
Reduced speed limits would save lives Friedman said They would also reduce
gas consumption cut emissions of air pollutants save valuable years of productivity
(lost due to injuries)and reduce the societal cost of motor vehicle crashes (due to
both fatal crashes and due to nonfatal and severe life-changing injuries) he added
Friedman and coworkers have also shown that increasing the speed limit led
to an immediate increase in the number of fatalities on Israeli roadways (see
link below)
httpinjurypreventionbmjcomcontent133156
The effect of speeding is very significant especially in rural areas resulting
in significantly higher fatalities Fatality rates are frequently double or triple
that in urban areas (see link below)
httpsafetyfhwadotgovspeedmgtdata_factsdocsspeeding_ruralpdf
As of Jan 1 2005 five Midwestern states had increased the speed limits to
above 65 mph (Illinois Iowa Kansas Minnesota Missouri Nebraska and
South Dakota) whereas three (Illinois Iowa and Wisconsin) had not All the
five states with increased speed limits showed a 7 to 13 increase in
fatalities The NHTSA study considered an eight year period before and after
the change in Dec 1995 (see Table 1 in link below) The collective experience
of the states that did NOT increase the speed limit was a 7 decline in
fatalities (see Table 2 of link below)
httpwwwiowadotgovmvdodsstats2006speedstudypdf
Page 25 of 45
Moreover Table 5 in the above study shows the effect of imposing the NMSL
of 55 mph in Iowa and its repeal in 1995 Considering a four-year average
before 1974 when the speed limit was 75 mph there were 35 fatal crashes
with 43 fatalities In the first four years after the 55 mph there were only 23
fatal crashes and 28 fatalities In the last four years before the repeal of 55
mph in 1995 there was a further decline to 14 fatal crashes with 17 fatalities
The Iowa fatality data will be discussed in more detail separately (in a later report)
since it provides the opportunity to assess the effect of a change in the speed limit
on the relationship between number of fatalities and fatal crashes (as seen in
Figure 4 for the US as a whole)
North of the US border Canadians seem to be citing the ―shocking increase
in highway fatalities in the US states where the speed limits were raised to
curb their own speed limits
httparchivesafety-councilorginfotrafficspeed-02html
httparchivesafety-councilorginfotrafficspeedhtml
Speed kills but speed also sells notes the second of the above news items
Manufacturers are producing more high performance cars (with higher horse
power to weight ratio) and ads feature enticing cars that race and swerve in
miraculous ways on empty roads These subliminal messages encourage
drivers especially young drivers to break the speed limit leading to the
absolute increase in highway fatalities (although the rate itself is going
down) The article emphasizes the need to enforce the speed limit on
Canadian highways and in cities where street racing is becoming a problem
62 Studies cited by opponents of lower speed limits
In fairness to quote the opponents on the other side of this debate Montana
reverted back to Reasonable and Prudent speed limits when the National
Maximum Speed Limit was repealed in 1995 and appears to have
experienced no significant increase in fatalities
Page 26 of 45
httpwwwhwysafetycomhwy_montanahtm
httpwwwmotoristsorgpressmontana-no-speed-limit-safety-paradox
httpwwwsouthbayriderscomforumsshowthreadphpt=81453amppage=1
Likewise studies in the state of Maryland showed no significant increase in
highway fatalities when the speed limit was increased from 55 mph to 75
mph The reason might simply be that drivers were already speeding much
more so when the speed limit was 55 mph than after the increase to 75 mph
In other words the fatalities data already reflects the effect of higher speeds
(not speed limits) on the number of fatalities
In Utah the experimental increase in the speed limit to 80 mph was
considered to be a success in terms of safety
httpautosaolcomarticleutah-speed-limit-tests
The UDOT Director noted that there was no increase in the number of
accidents on Interstate 15 But what happens in the event of an accident
when the speed limits are higher and drivers are driving at higher speeds and
two objects collide at this higher speed However no increase in the number
of accidents is not the same as no increase in fatalities due to the higher
speeds When accidents do occur do fatalities increase
Likewise in California when the speed limit went up from 55 mph to 65
mph in 1995 (after repeal of NMSL) fewer deaths were reported in 1998
compared to the peak year of 1979 or even 1987 Again the explanation
seems to be that motorists were already speeding when the limit was 55 mph
and that increasing the speed limit did not change driver behavior in any
significant way
httparticlessfgatecom1998-11-02news17735730_1_speed-limits-mph-
limit-death-rate
The National Motorists Association (NMA) a group which advocates higher
speed limits emphasizes the importance of considering fatality rates as
opposed to the raw fatalities The argument used is that fatality rates based
on the fatality per 100 million VMT is the legitimate way to look at the data
Page 27 of 45
This is a never ending debate Historically speaking fatality rates have been
going down ever since the compilation of traffic accidents data began Table
A1 in the appendix of a recent report by NHTSA (see link below) has highway
fatality rate data going back 1921
httpwww-nrdnhtsadotgovPubs811346pdf see appendix page 31
httpwwwmotoristsorgspeed-limitstruth
httpwwwmotoristsorgothercrash-data
httpwwwraisethespeedlimitorgmythshtml
httpwwwcatoorgpubspaspa346pdf
According to Stephen Moore of the Cato Institute (see last of the links above)
―All measures of highway safety show improvement not more deaths and
injuries since 1995 Despite the fact that 33 states raised their speed limits
immediately after the repeal of the mandatory federal speed limit the NHTSA
reported last October that the traffic death rate dropped to a record low level
in 1997lsquo Moreover the average fatality rate even fell in the states that raised
their speed limits
63 The Fatality rate Is it a reliable metric
In 1921 with fewer fatalities and fewer miles driven and the first year for
which the fatality rate could be computed the rate was 2408 It was down to
1479 in 1931 but the number of deaths had climbed to 31963 more than
double the 1921 absolute fatality number of 13253 It had dropped to 550 in
1966 the year of the highly publicized Congressional hearings but the
number of fatalities had climbed to 50984 in that fateful The Highway Safety
Act of 1966 ranks as one of the major acts of Congress and President
Johnson signed it saying that ―we have been tolerating a raging epidemic of
highway deathshellip see extract pasted below
httpwwwenotescommajor-acts-congresshighway-safety-act
Page 28 of 45
The act was motivated primarily by growing public concern over the rising number
of traffic fatalities in the United States Between 1960 and 1965 the annual number
of traffic fatalities increased by nearly thirty percent As President Lyndon B
Johnson stated at the signing of the act on September 9 1966 we have tolerated
a raging epidemic of highway death which has killed more of our youth than all
other diseases combined Through the Highway Safety Act we are going to find out
more about highway diseasemdashand we aim to cure it
Nonetheless highways fatalities continued to increase until the Arab oil
embargo of 1973 led to the NMSL of 55 mph all across the USA Do we just
ignore this undeniable historical record and focus only on the declining fatality
rate as the NMA and other proponents of higher speed limits seem to argue
(see links above)
The misleading nature of using fatality rates (per 100 M VMT) alone is also
obvious if one considers fatality data for individual states Take for example
the state of Montana which seems to have experienced no increase in
fatalities after repeal of NMSL
httpwww-nrdnhtsadotgovdepartmentsnrd-
30ncsaSTSI30_MT200930_MT_2009htm
For the period 2005-2009 the absolute number of fatalities for Montana
varied between a high of 277 in 2007 to a low of 229 in 2009 The fatality
rates per 100 M VMT on the other hand varied from a high of 245 for 2007
to a low of 201 for 2009 The corresponding US fatality rates varied from
136 to 114 Is the higher number for the fatality rate for Montana compared
to USA good or bad Likewise fatality rate per 100000 of population was
much higher for Montana than the US as a whole
This again highlights the pitfalls of using simple ratios to assess fatality statistics
without a full analysis of the underlying trends We will discuss this point
separately
As shown already the continuous decline in the fatality rate is a mathematical
artifact and essentially overlooks the unmistakable positive correlation
between the variables x and y of the type y = hx + c which becomes obvious
Page 29 of 45
only when we prepare the x-y scatter graph The ratio yx = h + (cx) can
decrease with increasing x (VMT) and increasing y (fatalities) since the
intercept c has a positive value when we consider only data spanning a short
period (such as 1994-2009 of more relevance to the current situation)
The debate between fatality rates and absolute number of fatalities is an
unending one A few years ago the Wall Street Journal carried an article
which was entitled (or something close) ―Unemployments rate in Ohio are
going down but why is the number of unemployed increasing The reason is
the same The graph of the number of unemployed (y) versus the number in
the labor market (x) is linear with a positive slope h and a positive intercept c
So the unemployment rate computed using the ratio yx keeps going down
year after year although the number unemployed keeps increasing Is it a
good thing that the unemployment rate is going down when more people
seem to be unable to find gainful unemployment
Or consider the situation with cancer death rates This too has been going
down in recent years but the actual number of cancer-related deaths has not
declined in any significant way Is it good that cancer death rates are going
down In all these situations the researchers or the socio-econo-politico
analysts involved in analyzing the trends in the data have failed to consider
the underlying x-y relation describing each problem
Hence it appears that the debate on the effect of increased speed limits
should not be focused on only the fatality rates (which have been decreasing
and proponents of higher speed limits cite this in their arguments) or even the
absolute number of fatalities (which has been the focus here) but on the
relationship between speed and the number of fatal crashes and the number
of fatalities within each speed segment (see Table 3 and also Figure 4)
Unfortunately details of number of fatalities and the number of fatal crashes
at each speed limit are not available even from NHTSA for detailed study
When a crash does occur (it is immaterial how many miles were driven) the
speed of the driver and vehicle design and engineering including safety
devices in place (seat belts airbags other impact absorbing technologies)
Page 30 of 45
determine if the occupants(s) will be killed One cannot argue that speed
does NOT kill That would be an absolute denial of the laws of physics
Studies show that setting the speed limit at the 85th percentile in any given
zone (this is the speed at or below which 85 of drivers are observed to
travel in traffic engineering studies) is the safest speed limit The majority of
drivers try to obey the posted speed limit while a few choose to drive at a
speed they consider is safe and prudent These are also perhaps the most
vociferous advocates of higher speed limits It is this tension caused due to
differences in speeds that leads to tailgating improper passing reckless
driving weaving from lane to lane and ultimately crashes and deaths in some
unfortunate cases
httpblogmotoristsorgspeed-limits-slower-safer
MARK TAYLOR
ANOTHER LOST A man was killed when his 4WD drive hit a tree east of Morrinsville (in New
Zealand) on Monday May 30 2011 The driver lost control of the vehicle on a bend probably tried
to correct his mistake and put the car into a ―yaw causing it to leave the road and smash sideways
into a tree Alerts to slow down had been posted since this was a high accident area but the driver
probably did not pay attention
64 Other factors
Many other factors besides speed no doubt affect highway fatalities The
vehicles of the 21st century are very different from the vehicles of the mid 20th
Page 31 of 45
century Technological innovations such as improvements in vehicle design
and engineering have greatly increased crash worthiness of vehicles even at
high speeds Environmental factors such as the weather also contribute to
accidents but not necessarily to increased fatalities Drivers actually tend to
slow down instinctively during adverse weather conditions (rain snow storms
etc) and although such weather may contribute to increased accidents the
lower speeds actually reduce fatalities
Yes technology has changed fundamentally from 1966 Drivers today are
more distracted by their cellmobile phone conversations (and also built-in
phones in luxury models) and text messaging than the drivers of the pre-1966
era High end cars now have many multimedia and internet features Again a
careful observation (even personal experience by the author) suggests that
such distracted drivers actually tend to (instinctively) drive more slowly and
hold up the traffic Perhaps such behavior leads to an increase in the number
of accidents but it does not necessarily lead to an increase in the number of
accident-related fatalities
Much talked about technological innovations such as automatic collision
avoidance systems and sensors (on the sides of vehicles) can indeed detect
vehicles in the front and neighboring lanes Furthermore vehicle-to-vehicle
communication systems vehicle-to-infrastructure communication systems
can no doubt avoid collisions and accidents Again such collision avoidance
systems work and are effective entirely because they automatically reduce
vehicle speeds - even if one of the offending vehicles is being at a super
high speed Also it must be remembered that such futuristic systems have
not yet been implemented widely nor can they be implemented widely since
the large majority of vehicles on the road are NOT luxury models Advanced
safety features come with a price and not all drivers can afford to pay that
price and ―buy that ―additional safety
Ultimately it is the laws of physics that govern what will happen when two or
more vehicles collide or even when a single vehicle collides with a stationary
infrastructural object (a bridge a wall a building or some impediment on the
road) The lower the number of crashes the lower the number of fatalities as
revealed by the 1994-2009 data graphed in Figure 5 The higher the speed of
Page 32 of 45
the object or objects that are involved in a collision the higher the kinetic
energy K that must be absorbed andor dissipated Increasing the posted
speed limit only increases the energy that must be absorbed when a crash
does occur This ultimately is the most important criterion determining the
number of fatalities
The kinetic energy increases as the square of the speed being given by the
well-known formula K = frac12 mv2 where m is the mass of the vehicle (in
laypersonlsquos language m increases directly with vehicle weight) and v is the
speed For the same vehicle mass an increase in the speed from 55 mph to
85 mph increases the kinetic energy K by a factor of 239 or roughly a 250
increase in the kinetic energy that must be absorbed in a collision
Ideally speaking the kinetic energy of the colliding object(s) is absorbed by
the vehicle infrastructure (a sturdy space frame the engine other vehicle
components etc) andor the surroundings However in the unfortunate
cases where this kinetic energy must be absorbed by the vehicle occupant(s)
the result is severe life-altering injuries andor death An unequivocal
relationship between an increase in vehicle speeds and fatal accidents can
be demonstrated by a careful examination of available traffic fatality data
This is a more involved discussion and is not the purpose of this short
communication These topics are no doubt very politically charged with many
social legal and financial implications with each interest group favoring a
different conclusion Nonetheless we cannot escape the laws of physics as
they govern the fundamental need to absorb higher and higher values of the
kinetic energy K with increasing vehicle speeds This same point is also
emphasized by Dr Friedman of the University of Illinois Chicago (see earlier
discussion)
Speed kills because of these energy transfer considerations and there can be
no doubt about it
Innovative 21st century solutions to speed management on the highways
such as strict enforcement of speed limits minimizing speed dispersion
(difference between speeds at which different drivers travel) while using
cameras to track the 15 of drivers who willfully violate the speed limit and
Page 33 of 45
create hazardous driving conditions is certainly recommended (Recall that
the optimum recommended speed limit is at or below which 85 of all drivers
travel ndash a policy also supported by NMA) Even on this score however the
results are confounding if we consider the Australian experience
httpwwwthenewspapercomnews282840asp
Up until 2007 there was no speed limit in the Northern Territory of
Australia Imposing a speed limit 130 kmph (80 mph) on some areas and
110 kmph (68 mph) in some others actually increased the number of deaths
The death toll in 2006 when there was no speed limit in this region was 44
and went up to 75 in 2009 see data table in link below
httpwwwthenewspapercomrlcdocs2009au-ntroadtollpdf
Furthermore it appears that installation of cameras to enforce speed limits
has proved to be a hazardous distraction to drivers and deaths actually
began to skyrocket between 2005 and 2007 in all Australian roadways
The main purpose here is to sound a cautionary note amid renewed attempts
in many states across the US to increase the speed limits on our highways by
calling attention to the historical facts regarding the ―epidemic levels of
highway traffic fatalities that engaged our national attention in the fateful year
of 1966 The graphical representation of the traffic fatality data in Figures 1
to 5 tells its own story
Indeed it would be tragic if highway-accident-related fatalities were to start
increasing once again and reach the historically high level that was last seen
in 1972 the year before the Arab oil embargo of 1973
Page 34 of 45
Conclusions
1 The graphical representation of the highway fatality data and the brief
summary of the historical facts of traffic safety legislation suggest that
recent attempts to increase the speed limits by various states (notably
Texas) may be misguided The distinct peak in the highway fatalities
observed in these graphs is highly alarming This appears to be related to
the enactment of the National Maximum Speed Limit (NSML) in 1974
following the 1973 Arab oil embargo Although NSML was motivated by a
desire to reduce gasoline consumption an unintended benefit might have
been a dramatic reduction in fatalities The fundamental reasons for the
peak in the fatalities-VMT curve must be examined carefully without
political posturing
2 The widely used fatality rate fatalities per 100 M vehicle miles traveled
has been declining since 1921 the first year for which a fatality rate could
be computed and has now reached a historical low The absolute number
of fatalities on the other hand was increasing in the 1950s and 1960s at
an alarming rate and the public outcry that ensued led to the highly
publicized Congressional hearing of 1966 and the subsequent traffic safety
legislations The fatality rate has been decreasing even in the most recent
15-year period (1994-2009) again with increasing fatalities although less
dramatically Thus it appears that fatality rate calculation based on vehicle
miles traveled (VMT) might not be a reliable indicator of the underlying
dynamics in the fatality trends
3 More detailed compilation of number of fatalities and the number of fatal
crashes within each speed limit segment is required to better understand
the effect of increasing speed limits on highway fatalities (and also fatality
rates) Such data is already available and is being compiled at the local
city and county levels in all jurisdictions and only needs to be reorganized
to highlight the effect of (posted) speed limits on the number of crashes
and fatalities This will require some minor rewriting and revisions to the
chapters named ―Crashes and ―States in the annual NHTSA reports
Page 35 of 45
Analysis of the fatalities-crashes data for several years with various
speed limits will be more revealing and meaningful than the current
fatality rates analysis and will be discussed separately in a follow up
report
4 One should not be lulled by the fact that vehicles of the 21st century are
now equipped with advanced safety features not available in the 1950s
and the 1960s In spite of these safety features the laws of physics dictate
that the higher the speed the higher kinetic energy of the colliding objects
and hence the greater the risk indeed near certainty of fatalities in a
higher speed collision compared to a lower speed one
5 The higher the speed at which the vehicle that is involved in a crash is
traveling the higher the kinetic energy that must be absorbed andor
dissipated without affecting the occupant(s) to avoid serious injuries andor
death This was true in the 1950s and the 1960s and will continue to be
true in the 21st century as well
Speed Kills for this just reason
6 It appears that higher fuel economies and reduced
highway fatalities were the twin societal benefits of 55
mph adopted after 1973 If so the current attempts to
increase the speed limits appear to be in conflict with
other important societal objectives
Page 36 of 45
Table 1 Annual US Street amp Highway
Fatalities from 1957
Year
Fatalities
Vehicle Miles
(millions)
Rate100M Vehicle Miles
1957 38702 646915 598
1958 36981 664915 556
1959 37910 700478 541
1960 38137 718845 531
1961 38091 737535 516
1962 40804 766852 532
1963 43564 805423 541
1964 47700 846500 563
1965 49163 887640 554
1966 51524 927915 555
1967 51559 965132 534
1968 53831 1019726 528
1969 55032 1066108 516
1970 53672 1114098 482
1971 53761 1183524 454
1972 55704 1264614 440
1973 55113 1316207 419
1974 46078 1282790 359
1975 45500 1330074 342
1976 45523 1402380 325
1977 47878 1467027 326
1978 50331 1544704 326
1979 51103 1529133 334
1980 51091 1527295 335
1981 49301 1552803 317
1982 43945 1595010 276
1983 42589 1652788 258
1984 44257 1720269 257
1985 43795 1774179 247
Page 37 of 45
1986 46056 1835000 251
1987 46385 1921000 241
1988 47093 2026000 232
1989 45555 2107040 216
1990 44529 2147501 207
1991 41162 2172214 189
1992 39235 2239828 175
1993 40115 2296585 175
1994 40676 2359984 172
1995 41798 2422696 173
1996 41907 2485848 169
1997 41967 2560373 164
Data from Federal Highway Administration
Source httpwwwpublicpurposecomhwy-fatal57+htm
Telephone +16186328507 - Facsimile +16186328538
WENDELL COX CONSULTANCY P O Box 841 - Belleville IL 62269 USA
Page 38 of 45
Fatality data for 1921-1982 compiled by NHTSA
Year
VMT
(Millions)
VMT
(Billions)
Fatalities
Fatality rate
per 100 M VMT
1921 55027 5503 13253 241 1922 67697 6770 14859 219 1923 84995 8500 17870 210 1924 104838 10484 18400 176 1925 122346 12235 20771 170 1926 140735 14074 22194 158 1927 158453 15845 24470 154 1928 172856 17286 26557 154 1929 197720 19772 29592 150 1930 206320 20632 31204 151 1931 216151 21615 31963 148 1932 200517 20052 27979 140 1933 200642 20064 29746 148 1934 215563 21556 34240 159 1935 228568 22857 34494 151 1936 252128 25213 36126 143 1937 270110 27011 37819 140 1938 271177 27118 31083 115 1939 285402 28540 30895 108 1940 302188 30219 32914 109 1941 333612 33361 38142 114 1942 268224 26822 27007 101 1943 208192 20819 22727 109 1944 212713 21271 23165 109 1945 250173 25017 26785 107 1946 340880 34088 31874 94 1947 370894 37089 31193 84 1948 397957 39796 30775 77 1949 424461 42446 30246 71 1950 458246 45825 33186 72 1951 491093 49109 35309 72
1952 513581 51358 36088 70
Page 39 of 45
1953 544433 54443 36190 66 1954 561963 56196 33890 60 1955 605646 60565 36688 61 1956 627843 62784 37965 60 1957 647004 64700 36932 57 1958 664653 66465 35331 53 1959 700480 70048 36223 52 1960 718762 71876 36399 51 1961 737421 73742 36285 49 1962 766734 76673 38980 51 1963 805249 80525 41723 52 1964 846298 84630 45645 54 1965 887812 88781 47089 53 1966 925899 92590 50894 55 1967 964005 96401 50724 53 1968 1015869 101587 52725 52 1969 1061791 106179 53543 50 1970 1109724 110972 52627 47 1971 1178811 117881 52542 45 1972 1259786 125979 54589 43 1973 1313110 131311 54052 41 1974 1280544 128054 45196 35 1975 1327664 132766 44525 34 1976 1402380 140238 45523 32 1977 1467027 146703 47878 33 1978 1544704 154470 50331 33 1979 1529133 152913 51093 33 1980 1527295 152730 51091 33 1981 1555308 155531 49301 32 1982 1595010 159501 43945 28
Source Analysis of Significant Decline in Motor Vehicle Traffic Fatalities in
2008 httpwww-nrdnhtsadotgovPubs811346pdf see Table A1 page 31
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Page 40 of 45
Acknowledgements
The author is grateful for thoughtful comments provided by friends and colleagues
with whom this document was shared via email prior to it being uploaded as a
publicly available document for wider dissemination and study The comments
offered by Prof Subra Ganesan of Oakland University Electrical and Computer
Engineering Department are reproduced with permission in their entirety
About the author
The author obtained his Masterrsquos (S M) and Doctoral (Sc D) degrees in Materials Engineering
from the Massachusetts Institute of Technology Cambridge USA He then spent his entire
professional career at leading US research institutions (MIT NASA Case Western Reserve
University and General Motors R amp D Center in Warren MI) He holds four patents in advanced
materials processing has co-authored two books and has published several scientific papers in
leading peer-reviewed international journals His expertise includes developing simple
mathematical models to explain the behavior of complex systems He can be reached by email at
vlaxmananhotmailcom
Page 41 of 45
Please Buckle Up
httpwwwlakecountypublichealthorgindexphpbuckle-up-montana
Public Awareness
Respect the Cage Exhibit
The Department of Transportation hopes that showing the reality of the crash will reduce traffic
fatalities A crushed car crash dummies and a sobering message ndash all part of the ―Respect The
Cage exhibit that is traveling across Montana The exhibit sponsored by the Montana Department
of Transportation stopped in Ronan on November 6th and is aimed at raising awareness about the
importance of wearing seat belts
The car in the exhibit was in an actual wreck many years ago
the passenger in the vehicle died because he was not wearing a
seat belt the driver who was wearing his seat belt survived
Montanarsquos likeliest crash fatality scenario
A Pickup
A Rural road
And Seat belts that
arenrsquot used
Page 42 of 45
Occupants of pickups are less likely to wear seat belts and pickups are more likely to
roll over than passenger cars
Seat belts reduce the risk of death by 60 percent in pickups and SUVs
In Montana from 2006-2008 81 of those killed in a crash while riding in a pickup were not wearing seat belts
In Montana pickups make up 401 of the vehicle population
For more information on Respect the Cage click here
Page 43 of 45
Appendix 1
Lack of seat belts leading cause of Louisiana highway deaths
1251 AM May 28 2011 |
Written by Adam Duvernay
Crashes involving unbuckled motorists were the leading cause of highway fatalities
in Louisiana last year and cost $9888 million according to recent reports The
Louisiana Highway Safety Commission reported 59 percent of vehicle occupants
killed in Louisiana crashes last year mdash about one in four mdash werent wearing seat
belts
httpwwwshreveporttimescomarticle20110528NEWS01105280354Lack-seat-
belts-leading-cause-La-highway-deathsodyssey=tab|topnews|text|FRONTPAGE
Crash bull Stats Published by NHTSAlsquos National Center for Statistics and Analysis 1200 New Jersey Avenue SE Washington DC 20590
DOT HS 811 451
Early Estimate of Motor Vehicle Traffic Fatalities in 2010
httpwww-nrdnhtsadotgovPubs811451pdf
Summary
A statistical projection of traffic fatalities in 2010 shows that an estimated 32788
people died in motor vehicle traffic crashes This represents a decline of about 3
percent as compared to the 33808 fatalities in 2009 as shown in Table 1 If these
projections are realized fatalities will be lowest on record (since 1949)
Traffic Safety Facts Overview 2009 Data
httpwww-nrdnhtsadotgovPubs811392pdf
In 2009 33808 people were killed in the estimated 5505000 police-reported
motor vehicle traffic crashes 2217000 people were injured and 3957000
crashes involved property damage only Compared to 2008 this is a 10-
percent decrease in the number of fatalities and a 5-percent decrease in the
Page 44 of 45
number of police-reported motor vehicle traffic crashes people injured and
crashes involving property damage
An average of 93 people died each day in motor vehicle crashes in 2009 mdash
an average of one every 16 minutes
Traffic Safety Facts Overview 2008 Data
httpwww-nrdnhtsadotgovPubs811162pdf
In 2008 37261 people were killed in the estimated 5811000 police-reported
motor vehicle traffic crashes 2346000 people were injured and 4146000
crashes involved property damage only
Some comments and Feedback
The following comments were received from Prof Ganesan after his review of the
first draft of this document It was subsequently revised thanks to this input to
address some of the very important issues raised here
Dear Laxman
The write up is not enough
You are emphasizing that the speed limit reduces the fatal accidents (comparing 1966
to 2000 accident numbers)
Can you also add a few sentences why the number is decreasing from 1980 to 2000
values (May be due to better design of vehicles)
Can you say anything about the fuel consumption with the speed for any typical
vehicle in 2011 or 2010 (do not consider the fatalities issue)
Probably a speed between 55 and 60 mph gives a better mileage If so this is a
compelling reason to keep the speed limit low But cars probably can be tuned to
give better mileage at any high speed also
Page 45 of 45
Weather is also a major factor in fatal accidents Speed limit may be kept low during
winter and kept higher in summer Give your comments on this too
Driver distractions can cause more accidents Now cars have many multimedia and
internet features Automatic collision avoidance systems and sensors on the sides can
detect vehicles in the front and neighboring lanes and it can automatically decrease
speed even if the driver speeds at super high speeds
Give some comments on this too There is also Vehicle to Vehicle communications
vehicle to infrastructure communications and they can avoid collisions and accidents
Technology has changed from 1966 I cannot agree with you on the speed limit
without any discussion on the above and other factors
Have a great day
Subra Ganesan
Professor Subramaniam Ganesan
Director Real Time amp DSP Lab
Electrical and Computer Engineering Department
2200 Squirrel Road Dodge Hall Room 105
Oakland University Rochester MI 48309 USA
Phone 248 370 2206 Fax 248 370 4633
wwwsecsoaklandedu~ganesan
IEEE Distinguished Visiting Speaker (2005-2009) Coordinator
IEEE SEM CS chapter Chair Region 4 and CS Society Board member
SAE ASEE ACM member
Page 23 of 45
Table 3 Posted speed limits and number of crashes
Speed Limit Crashes (2008) Crashes (2009)
30 mph or less 3705 3277 35 or 40 mph 6115 5516 45 or 50 mph 6461 6074
55 mph 9794 8847 60 mph or higher 6908 6124
Total 34017 30797
Source httpwww-nrdnhtsadotgovPubs811402EEpdf
61 Studies cited in favor of lower speed limits
A detailed analysis of speeding related fatalities (see link below) by NHTSA
shows that a third of all crashes involve speeding ie at least one driver was
speeding
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Furthermore the above report which covers the period 1983-2002
indicates that immediately after the NMSL was completely abolished in
December 1995 the number of speeding related fatalities at speeds
above 65 mph increased from just 15 in 1995 to a 677 in 1996 (see Table
62 on page 43 of above report) It continued to increase in the years
since climbing to 930 in 2000
More detailed studies similar to that noted above by researchers at the
University of Illinois Chicago led by Lee S Friedman again lead to the
conclusion that higher speed limits lead to an increase in the number of
fatalities (see American Journal of Public Health online July 16 2009)
httphealthusnewscomhealth-newsmanaging-your-
healthcarearticles20090716deaths-injuries-increase-with-higher-speed-
limits
Page 24 of 45
httpwwwmedpagetodaycomPublicHealthPolicyPublicHealth15122
httpwwwamericaneercomspeed-limits
httpwwwactuarialoutpostcomactuarial_discussion_forumarchiveindexph
pt-171870html
For the study period 1995-2005 these researchers found that 12545 deaths
and 36582 injuries could be attributed to the increased speed limits The
benefits of reduced speed limits are stated quite eloquently by Dr Friedman
and are reproduced below (from above news article see link)
Reduced speed limits would save lives Friedman said They would also reduce
gas consumption cut emissions of air pollutants save valuable years of productivity
(lost due to injuries)and reduce the societal cost of motor vehicle crashes (due to
both fatal crashes and due to nonfatal and severe life-changing injuries) he added
Friedman and coworkers have also shown that increasing the speed limit led
to an immediate increase in the number of fatalities on Israeli roadways (see
link below)
httpinjurypreventionbmjcomcontent133156
The effect of speeding is very significant especially in rural areas resulting
in significantly higher fatalities Fatality rates are frequently double or triple
that in urban areas (see link below)
httpsafetyfhwadotgovspeedmgtdata_factsdocsspeeding_ruralpdf
As of Jan 1 2005 five Midwestern states had increased the speed limits to
above 65 mph (Illinois Iowa Kansas Minnesota Missouri Nebraska and
South Dakota) whereas three (Illinois Iowa and Wisconsin) had not All the
five states with increased speed limits showed a 7 to 13 increase in
fatalities The NHTSA study considered an eight year period before and after
the change in Dec 1995 (see Table 1 in link below) The collective experience
of the states that did NOT increase the speed limit was a 7 decline in
fatalities (see Table 2 of link below)
httpwwwiowadotgovmvdodsstats2006speedstudypdf
Page 25 of 45
Moreover Table 5 in the above study shows the effect of imposing the NMSL
of 55 mph in Iowa and its repeal in 1995 Considering a four-year average
before 1974 when the speed limit was 75 mph there were 35 fatal crashes
with 43 fatalities In the first four years after the 55 mph there were only 23
fatal crashes and 28 fatalities In the last four years before the repeal of 55
mph in 1995 there was a further decline to 14 fatal crashes with 17 fatalities
The Iowa fatality data will be discussed in more detail separately (in a later report)
since it provides the opportunity to assess the effect of a change in the speed limit
on the relationship between number of fatalities and fatal crashes (as seen in
Figure 4 for the US as a whole)
North of the US border Canadians seem to be citing the ―shocking increase
in highway fatalities in the US states where the speed limits were raised to
curb their own speed limits
httparchivesafety-councilorginfotrafficspeed-02html
httparchivesafety-councilorginfotrafficspeedhtml
Speed kills but speed also sells notes the second of the above news items
Manufacturers are producing more high performance cars (with higher horse
power to weight ratio) and ads feature enticing cars that race and swerve in
miraculous ways on empty roads These subliminal messages encourage
drivers especially young drivers to break the speed limit leading to the
absolute increase in highway fatalities (although the rate itself is going
down) The article emphasizes the need to enforce the speed limit on
Canadian highways and in cities where street racing is becoming a problem
62 Studies cited by opponents of lower speed limits
In fairness to quote the opponents on the other side of this debate Montana
reverted back to Reasonable and Prudent speed limits when the National
Maximum Speed Limit was repealed in 1995 and appears to have
experienced no significant increase in fatalities
Page 26 of 45
httpwwwhwysafetycomhwy_montanahtm
httpwwwmotoristsorgpressmontana-no-speed-limit-safety-paradox
httpwwwsouthbayriderscomforumsshowthreadphpt=81453amppage=1
Likewise studies in the state of Maryland showed no significant increase in
highway fatalities when the speed limit was increased from 55 mph to 75
mph The reason might simply be that drivers were already speeding much
more so when the speed limit was 55 mph than after the increase to 75 mph
In other words the fatalities data already reflects the effect of higher speeds
(not speed limits) on the number of fatalities
In Utah the experimental increase in the speed limit to 80 mph was
considered to be a success in terms of safety
httpautosaolcomarticleutah-speed-limit-tests
The UDOT Director noted that there was no increase in the number of
accidents on Interstate 15 But what happens in the event of an accident
when the speed limits are higher and drivers are driving at higher speeds and
two objects collide at this higher speed However no increase in the number
of accidents is not the same as no increase in fatalities due to the higher
speeds When accidents do occur do fatalities increase
Likewise in California when the speed limit went up from 55 mph to 65
mph in 1995 (after repeal of NMSL) fewer deaths were reported in 1998
compared to the peak year of 1979 or even 1987 Again the explanation
seems to be that motorists were already speeding when the limit was 55 mph
and that increasing the speed limit did not change driver behavior in any
significant way
httparticlessfgatecom1998-11-02news17735730_1_speed-limits-mph-
limit-death-rate
The National Motorists Association (NMA) a group which advocates higher
speed limits emphasizes the importance of considering fatality rates as
opposed to the raw fatalities The argument used is that fatality rates based
on the fatality per 100 million VMT is the legitimate way to look at the data
Page 27 of 45
This is a never ending debate Historically speaking fatality rates have been
going down ever since the compilation of traffic accidents data began Table
A1 in the appendix of a recent report by NHTSA (see link below) has highway
fatality rate data going back 1921
httpwww-nrdnhtsadotgovPubs811346pdf see appendix page 31
httpwwwmotoristsorgspeed-limitstruth
httpwwwmotoristsorgothercrash-data
httpwwwraisethespeedlimitorgmythshtml
httpwwwcatoorgpubspaspa346pdf
According to Stephen Moore of the Cato Institute (see last of the links above)
―All measures of highway safety show improvement not more deaths and
injuries since 1995 Despite the fact that 33 states raised their speed limits
immediately after the repeal of the mandatory federal speed limit the NHTSA
reported last October that the traffic death rate dropped to a record low level
in 1997lsquo Moreover the average fatality rate even fell in the states that raised
their speed limits
63 The Fatality rate Is it a reliable metric
In 1921 with fewer fatalities and fewer miles driven and the first year for
which the fatality rate could be computed the rate was 2408 It was down to
1479 in 1931 but the number of deaths had climbed to 31963 more than
double the 1921 absolute fatality number of 13253 It had dropped to 550 in
1966 the year of the highly publicized Congressional hearings but the
number of fatalities had climbed to 50984 in that fateful The Highway Safety
Act of 1966 ranks as one of the major acts of Congress and President
Johnson signed it saying that ―we have been tolerating a raging epidemic of
highway deathshellip see extract pasted below
httpwwwenotescommajor-acts-congresshighway-safety-act
Page 28 of 45
The act was motivated primarily by growing public concern over the rising number
of traffic fatalities in the United States Between 1960 and 1965 the annual number
of traffic fatalities increased by nearly thirty percent As President Lyndon B
Johnson stated at the signing of the act on September 9 1966 we have tolerated
a raging epidemic of highway death which has killed more of our youth than all
other diseases combined Through the Highway Safety Act we are going to find out
more about highway diseasemdashand we aim to cure it
Nonetheless highways fatalities continued to increase until the Arab oil
embargo of 1973 led to the NMSL of 55 mph all across the USA Do we just
ignore this undeniable historical record and focus only on the declining fatality
rate as the NMA and other proponents of higher speed limits seem to argue
(see links above)
The misleading nature of using fatality rates (per 100 M VMT) alone is also
obvious if one considers fatality data for individual states Take for example
the state of Montana which seems to have experienced no increase in
fatalities after repeal of NMSL
httpwww-nrdnhtsadotgovdepartmentsnrd-
30ncsaSTSI30_MT200930_MT_2009htm
For the period 2005-2009 the absolute number of fatalities for Montana
varied between a high of 277 in 2007 to a low of 229 in 2009 The fatality
rates per 100 M VMT on the other hand varied from a high of 245 for 2007
to a low of 201 for 2009 The corresponding US fatality rates varied from
136 to 114 Is the higher number for the fatality rate for Montana compared
to USA good or bad Likewise fatality rate per 100000 of population was
much higher for Montana than the US as a whole
This again highlights the pitfalls of using simple ratios to assess fatality statistics
without a full analysis of the underlying trends We will discuss this point
separately
As shown already the continuous decline in the fatality rate is a mathematical
artifact and essentially overlooks the unmistakable positive correlation
between the variables x and y of the type y = hx + c which becomes obvious
Page 29 of 45
only when we prepare the x-y scatter graph The ratio yx = h + (cx) can
decrease with increasing x (VMT) and increasing y (fatalities) since the
intercept c has a positive value when we consider only data spanning a short
period (such as 1994-2009 of more relevance to the current situation)
The debate between fatality rates and absolute number of fatalities is an
unending one A few years ago the Wall Street Journal carried an article
which was entitled (or something close) ―Unemployments rate in Ohio are
going down but why is the number of unemployed increasing The reason is
the same The graph of the number of unemployed (y) versus the number in
the labor market (x) is linear with a positive slope h and a positive intercept c
So the unemployment rate computed using the ratio yx keeps going down
year after year although the number unemployed keeps increasing Is it a
good thing that the unemployment rate is going down when more people
seem to be unable to find gainful unemployment
Or consider the situation with cancer death rates This too has been going
down in recent years but the actual number of cancer-related deaths has not
declined in any significant way Is it good that cancer death rates are going
down In all these situations the researchers or the socio-econo-politico
analysts involved in analyzing the trends in the data have failed to consider
the underlying x-y relation describing each problem
Hence it appears that the debate on the effect of increased speed limits
should not be focused on only the fatality rates (which have been decreasing
and proponents of higher speed limits cite this in their arguments) or even the
absolute number of fatalities (which has been the focus here) but on the
relationship between speed and the number of fatal crashes and the number
of fatalities within each speed segment (see Table 3 and also Figure 4)
Unfortunately details of number of fatalities and the number of fatal crashes
at each speed limit are not available even from NHTSA for detailed study
When a crash does occur (it is immaterial how many miles were driven) the
speed of the driver and vehicle design and engineering including safety
devices in place (seat belts airbags other impact absorbing technologies)
Page 30 of 45
determine if the occupants(s) will be killed One cannot argue that speed
does NOT kill That would be an absolute denial of the laws of physics
Studies show that setting the speed limit at the 85th percentile in any given
zone (this is the speed at or below which 85 of drivers are observed to
travel in traffic engineering studies) is the safest speed limit The majority of
drivers try to obey the posted speed limit while a few choose to drive at a
speed they consider is safe and prudent These are also perhaps the most
vociferous advocates of higher speed limits It is this tension caused due to
differences in speeds that leads to tailgating improper passing reckless
driving weaving from lane to lane and ultimately crashes and deaths in some
unfortunate cases
httpblogmotoristsorgspeed-limits-slower-safer
MARK TAYLOR
ANOTHER LOST A man was killed when his 4WD drive hit a tree east of Morrinsville (in New
Zealand) on Monday May 30 2011 The driver lost control of the vehicle on a bend probably tried
to correct his mistake and put the car into a ―yaw causing it to leave the road and smash sideways
into a tree Alerts to slow down had been posted since this was a high accident area but the driver
probably did not pay attention
64 Other factors
Many other factors besides speed no doubt affect highway fatalities The
vehicles of the 21st century are very different from the vehicles of the mid 20th
Page 31 of 45
century Technological innovations such as improvements in vehicle design
and engineering have greatly increased crash worthiness of vehicles even at
high speeds Environmental factors such as the weather also contribute to
accidents but not necessarily to increased fatalities Drivers actually tend to
slow down instinctively during adverse weather conditions (rain snow storms
etc) and although such weather may contribute to increased accidents the
lower speeds actually reduce fatalities
Yes technology has changed fundamentally from 1966 Drivers today are
more distracted by their cellmobile phone conversations (and also built-in
phones in luxury models) and text messaging than the drivers of the pre-1966
era High end cars now have many multimedia and internet features Again a
careful observation (even personal experience by the author) suggests that
such distracted drivers actually tend to (instinctively) drive more slowly and
hold up the traffic Perhaps such behavior leads to an increase in the number
of accidents but it does not necessarily lead to an increase in the number of
accident-related fatalities
Much talked about technological innovations such as automatic collision
avoidance systems and sensors (on the sides of vehicles) can indeed detect
vehicles in the front and neighboring lanes Furthermore vehicle-to-vehicle
communication systems vehicle-to-infrastructure communication systems
can no doubt avoid collisions and accidents Again such collision avoidance
systems work and are effective entirely because they automatically reduce
vehicle speeds - even if one of the offending vehicles is being at a super
high speed Also it must be remembered that such futuristic systems have
not yet been implemented widely nor can they be implemented widely since
the large majority of vehicles on the road are NOT luxury models Advanced
safety features come with a price and not all drivers can afford to pay that
price and ―buy that ―additional safety
Ultimately it is the laws of physics that govern what will happen when two or
more vehicles collide or even when a single vehicle collides with a stationary
infrastructural object (a bridge a wall a building or some impediment on the
road) The lower the number of crashes the lower the number of fatalities as
revealed by the 1994-2009 data graphed in Figure 5 The higher the speed of
Page 32 of 45
the object or objects that are involved in a collision the higher the kinetic
energy K that must be absorbed andor dissipated Increasing the posted
speed limit only increases the energy that must be absorbed when a crash
does occur This ultimately is the most important criterion determining the
number of fatalities
The kinetic energy increases as the square of the speed being given by the
well-known formula K = frac12 mv2 where m is the mass of the vehicle (in
laypersonlsquos language m increases directly with vehicle weight) and v is the
speed For the same vehicle mass an increase in the speed from 55 mph to
85 mph increases the kinetic energy K by a factor of 239 or roughly a 250
increase in the kinetic energy that must be absorbed in a collision
Ideally speaking the kinetic energy of the colliding object(s) is absorbed by
the vehicle infrastructure (a sturdy space frame the engine other vehicle
components etc) andor the surroundings However in the unfortunate
cases where this kinetic energy must be absorbed by the vehicle occupant(s)
the result is severe life-altering injuries andor death An unequivocal
relationship between an increase in vehicle speeds and fatal accidents can
be demonstrated by a careful examination of available traffic fatality data
This is a more involved discussion and is not the purpose of this short
communication These topics are no doubt very politically charged with many
social legal and financial implications with each interest group favoring a
different conclusion Nonetheless we cannot escape the laws of physics as
they govern the fundamental need to absorb higher and higher values of the
kinetic energy K with increasing vehicle speeds This same point is also
emphasized by Dr Friedman of the University of Illinois Chicago (see earlier
discussion)
Speed kills because of these energy transfer considerations and there can be
no doubt about it
Innovative 21st century solutions to speed management on the highways
such as strict enforcement of speed limits minimizing speed dispersion
(difference between speeds at which different drivers travel) while using
cameras to track the 15 of drivers who willfully violate the speed limit and
Page 33 of 45
create hazardous driving conditions is certainly recommended (Recall that
the optimum recommended speed limit is at or below which 85 of all drivers
travel ndash a policy also supported by NMA) Even on this score however the
results are confounding if we consider the Australian experience
httpwwwthenewspapercomnews282840asp
Up until 2007 there was no speed limit in the Northern Territory of
Australia Imposing a speed limit 130 kmph (80 mph) on some areas and
110 kmph (68 mph) in some others actually increased the number of deaths
The death toll in 2006 when there was no speed limit in this region was 44
and went up to 75 in 2009 see data table in link below
httpwwwthenewspapercomrlcdocs2009au-ntroadtollpdf
Furthermore it appears that installation of cameras to enforce speed limits
has proved to be a hazardous distraction to drivers and deaths actually
began to skyrocket between 2005 and 2007 in all Australian roadways
The main purpose here is to sound a cautionary note amid renewed attempts
in many states across the US to increase the speed limits on our highways by
calling attention to the historical facts regarding the ―epidemic levels of
highway traffic fatalities that engaged our national attention in the fateful year
of 1966 The graphical representation of the traffic fatality data in Figures 1
to 5 tells its own story
Indeed it would be tragic if highway-accident-related fatalities were to start
increasing once again and reach the historically high level that was last seen
in 1972 the year before the Arab oil embargo of 1973
Page 34 of 45
Conclusions
1 The graphical representation of the highway fatality data and the brief
summary of the historical facts of traffic safety legislation suggest that
recent attempts to increase the speed limits by various states (notably
Texas) may be misguided The distinct peak in the highway fatalities
observed in these graphs is highly alarming This appears to be related to
the enactment of the National Maximum Speed Limit (NSML) in 1974
following the 1973 Arab oil embargo Although NSML was motivated by a
desire to reduce gasoline consumption an unintended benefit might have
been a dramatic reduction in fatalities The fundamental reasons for the
peak in the fatalities-VMT curve must be examined carefully without
political posturing
2 The widely used fatality rate fatalities per 100 M vehicle miles traveled
has been declining since 1921 the first year for which a fatality rate could
be computed and has now reached a historical low The absolute number
of fatalities on the other hand was increasing in the 1950s and 1960s at
an alarming rate and the public outcry that ensued led to the highly
publicized Congressional hearing of 1966 and the subsequent traffic safety
legislations The fatality rate has been decreasing even in the most recent
15-year period (1994-2009) again with increasing fatalities although less
dramatically Thus it appears that fatality rate calculation based on vehicle
miles traveled (VMT) might not be a reliable indicator of the underlying
dynamics in the fatality trends
3 More detailed compilation of number of fatalities and the number of fatal
crashes within each speed limit segment is required to better understand
the effect of increasing speed limits on highway fatalities (and also fatality
rates) Such data is already available and is being compiled at the local
city and county levels in all jurisdictions and only needs to be reorganized
to highlight the effect of (posted) speed limits on the number of crashes
and fatalities This will require some minor rewriting and revisions to the
chapters named ―Crashes and ―States in the annual NHTSA reports
Page 35 of 45
Analysis of the fatalities-crashes data for several years with various
speed limits will be more revealing and meaningful than the current
fatality rates analysis and will be discussed separately in a follow up
report
4 One should not be lulled by the fact that vehicles of the 21st century are
now equipped with advanced safety features not available in the 1950s
and the 1960s In spite of these safety features the laws of physics dictate
that the higher the speed the higher kinetic energy of the colliding objects
and hence the greater the risk indeed near certainty of fatalities in a
higher speed collision compared to a lower speed one
5 The higher the speed at which the vehicle that is involved in a crash is
traveling the higher the kinetic energy that must be absorbed andor
dissipated without affecting the occupant(s) to avoid serious injuries andor
death This was true in the 1950s and the 1960s and will continue to be
true in the 21st century as well
Speed Kills for this just reason
6 It appears that higher fuel economies and reduced
highway fatalities were the twin societal benefits of 55
mph adopted after 1973 If so the current attempts to
increase the speed limits appear to be in conflict with
other important societal objectives
Page 36 of 45
Table 1 Annual US Street amp Highway
Fatalities from 1957
Year
Fatalities
Vehicle Miles
(millions)
Rate100M Vehicle Miles
1957 38702 646915 598
1958 36981 664915 556
1959 37910 700478 541
1960 38137 718845 531
1961 38091 737535 516
1962 40804 766852 532
1963 43564 805423 541
1964 47700 846500 563
1965 49163 887640 554
1966 51524 927915 555
1967 51559 965132 534
1968 53831 1019726 528
1969 55032 1066108 516
1970 53672 1114098 482
1971 53761 1183524 454
1972 55704 1264614 440
1973 55113 1316207 419
1974 46078 1282790 359
1975 45500 1330074 342
1976 45523 1402380 325
1977 47878 1467027 326
1978 50331 1544704 326
1979 51103 1529133 334
1980 51091 1527295 335
1981 49301 1552803 317
1982 43945 1595010 276
1983 42589 1652788 258
1984 44257 1720269 257
1985 43795 1774179 247
Page 37 of 45
1986 46056 1835000 251
1987 46385 1921000 241
1988 47093 2026000 232
1989 45555 2107040 216
1990 44529 2147501 207
1991 41162 2172214 189
1992 39235 2239828 175
1993 40115 2296585 175
1994 40676 2359984 172
1995 41798 2422696 173
1996 41907 2485848 169
1997 41967 2560373 164
Data from Federal Highway Administration
Source httpwwwpublicpurposecomhwy-fatal57+htm
Telephone +16186328507 - Facsimile +16186328538
WENDELL COX CONSULTANCY P O Box 841 - Belleville IL 62269 USA
Page 38 of 45
Fatality data for 1921-1982 compiled by NHTSA
Year
VMT
(Millions)
VMT
(Billions)
Fatalities
Fatality rate
per 100 M VMT
1921 55027 5503 13253 241 1922 67697 6770 14859 219 1923 84995 8500 17870 210 1924 104838 10484 18400 176 1925 122346 12235 20771 170 1926 140735 14074 22194 158 1927 158453 15845 24470 154 1928 172856 17286 26557 154 1929 197720 19772 29592 150 1930 206320 20632 31204 151 1931 216151 21615 31963 148 1932 200517 20052 27979 140 1933 200642 20064 29746 148 1934 215563 21556 34240 159 1935 228568 22857 34494 151 1936 252128 25213 36126 143 1937 270110 27011 37819 140 1938 271177 27118 31083 115 1939 285402 28540 30895 108 1940 302188 30219 32914 109 1941 333612 33361 38142 114 1942 268224 26822 27007 101 1943 208192 20819 22727 109 1944 212713 21271 23165 109 1945 250173 25017 26785 107 1946 340880 34088 31874 94 1947 370894 37089 31193 84 1948 397957 39796 30775 77 1949 424461 42446 30246 71 1950 458246 45825 33186 72 1951 491093 49109 35309 72
1952 513581 51358 36088 70
Page 39 of 45
1953 544433 54443 36190 66 1954 561963 56196 33890 60 1955 605646 60565 36688 61 1956 627843 62784 37965 60 1957 647004 64700 36932 57 1958 664653 66465 35331 53 1959 700480 70048 36223 52 1960 718762 71876 36399 51 1961 737421 73742 36285 49 1962 766734 76673 38980 51 1963 805249 80525 41723 52 1964 846298 84630 45645 54 1965 887812 88781 47089 53 1966 925899 92590 50894 55 1967 964005 96401 50724 53 1968 1015869 101587 52725 52 1969 1061791 106179 53543 50 1970 1109724 110972 52627 47 1971 1178811 117881 52542 45 1972 1259786 125979 54589 43 1973 1313110 131311 54052 41 1974 1280544 128054 45196 35 1975 1327664 132766 44525 34 1976 1402380 140238 45523 32 1977 1467027 146703 47878 33 1978 1544704 154470 50331 33 1979 1529133 152913 51093 33 1980 1527295 152730 51091 33 1981 1555308 155531 49301 32 1982 1595010 159501 43945 28
Source Analysis of Significant Decline in Motor Vehicle Traffic Fatalities in
2008 httpwww-nrdnhtsadotgovPubs811346pdf see Table A1 page 31
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Page 40 of 45
Acknowledgements
The author is grateful for thoughtful comments provided by friends and colleagues
with whom this document was shared via email prior to it being uploaded as a
publicly available document for wider dissemination and study The comments
offered by Prof Subra Ganesan of Oakland University Electrical and Computer
Engineering Department are reproduced with permission in their entirety
About the author
The author obtained his Masterrsquos (S M) and Doctoral (Sc D) degrees in Materials Engineering
from the Massachusetts Institute of Technology Cambridge USA He then spent his entire
professional career at leading US research institutions (MIT NASA Case Western Reserve
University and General Motors R amp D Center in Warren MI) He holds four patents in advanced
materials processing has co-authored two books and has published several scientific papers in
leading peer-reviewed international journals His expertise includes developing simple
mathematical models to explain the behavior of complex systems He can be reached by email at
vlaxmananhotmailcom
Page 41 of 45
Please Buckle Up
httpwwwlakecountypublichealthorgindexphpbuckle-up-montana
Public Awareness
Respect the Cage Exhibit
The Department of Transportation hopes that showing the reality of the crash will reduce traffic
fatalities A crushed car crash dummies and a sobering message ndash all part of the ―Respect The
Cage exhibit that is traveling across Montana The exhibit sponsored by the Montana Department
of Transportation stopped in Ronan on November 6th and is aimed at raising awareness about the
importance of wearing seat belts
The car in the exhibit was in an actual wreck many years ago
the passenger in the vehicle died because he was not wearing a
seat belt the driver who was wearing his seat belt survived
Montanarsquos likeliest crash fatality scenario
A Pickup
A Rural road
And Seat belts that
arenrsquot used
Page 42 of 45
Occupants of pickups are less likely to wear seat belts and pickups are more likely to
roll over than passenger cars
Seat belts reduce the risk of death by 60 percent in pickups and SUVs
In Montana from 2006-2008 81 of those killed in a crash while riding in a pickup were not wearing seat belts
In Montana pickups make up 401 of the vehicle population
For more information on Respect the Cage click here
Page 43 of 45
Appendix 1
Lack of seat belts leading cause of Louisiana highway deaths
1251 AM May 28 2011 |
Written by Adam Duvernay
Crashes involving unbuckled motorists were the leading cause of highway fatalities
in Louisiana last year and cost $9888 million according to recent reports The
Louisiana Highway Safety Commission reported 59 percent of vehicle occupants
killed in Louisiana crashes last year mdash about one in four mdash werent wearing seat
belts
httpwwwshreveporttimescomarticle20110528NEWS01105280354Lack-seat-
belts-leading-cause-La-highway-deathsodyssey=tab|topnews|text|FRONTPAGE
Crash bull Stats Published by NHTSAlsquos National Center for Statistics and Analysis 1200 New Jersey Avenue SE Washington DC 20590
DOT HS 811 451
Early Estimate of Motor Vehicle Traffic Fatalities in 2010
httpwww-nrdnhtsadotgovPubs811451pdf
Summary
A statistical projection of traffic fatalities in 2010 shows that an estimated 32788
people died in motor vehicle traffic crashes This represents a decline of about 3
percent as compared to the 33808 fatalities in 2009 as shown in Table 1 If these
projections are realized fatalities will be lowest on record (since 1949)
Traffic Safety Facts Overview 2009 Data
httpwww-nrdnhtsadotgovPubs811392pdf
In 2009 33808 people were killed in the estimated 5505000 police-reported
motor vehicle traffic crashes 2217000 people were injured and 3957000
crashes involved property damage only Compared to 2008 this is a 10-
percent decrease in the number of fatalities and a 5-percent decrease in the
Page 44 of 45
number of police-reported motor vehicle traffic crashes people injured and
crashes involving property damage
An average of 93 people died each day in motor vehicle crashes in 2009 mdash
an average of one every 16 minutes
Traffic Safety Facts Overview 2008 Data
httpwww-nrdnhtsadotgovPubs811162pdf
In 2008 37261 people were killed in the estimated 5811000 police-reported
motor vehicle traffic crashes 2346000 people were injured and 4146000
crashes involved property damage only
Some comments and Feedback
The following comments were received from Prof Ganesan after his review of the
first draft of this document It was subsequently revised thanks to this input to
address some of the very important issues raised here
Dear Laxman
The write up is not enough
You are emphasizing that the speed limit reduces the fatal accidents (comparing 1966
to 2000 accident numbers)
Can you also add a few sentences why the number is decreasing from 1980 to 2000
values (May be due to better design of vehicles)
Can you say anything about the fuel consumption with the speed for any typical
vehicle in 2011 or 2010 (do not consider the fatalities issue)
Probably a speed between 55 and 60 mph gives a better mileage If so this is a
compelling reason to keep the speed limit low But cars probably can be tuned to
give better mileage at any high speed also
Page 45 of 45
Weather is also a major factor in fatal accidents Speed limit may be kept low during
winter and kept higher in summer Give your comments on this too
Driver distractions can cause more accidents Now cars have many multimedia and
internet features Automatic collision avoidance systems and sensors on the sides can
detect vehicles in the front and neighboring lanes and it can automatically decrease
speed even if the driver speeds at super high speeds
Give some comments on this too There is also Vehicle to Vehicle communications
vehicle to infrastructure communications and they can avoid collisions and accidents
Technology has changed from 1966 I cannot agree with you on the speed limit
without any discussion on the above and other factors
Have a great day
Subra Ganesan
Professor Subramaniam Ganesan
Director Real Time amp DSP Lab
Electrical and Computer Engineering Department
2200 Squirrel Road Dodge Hall Room 105
Oakland University Rochester MI 48309 USA
Phone 248 370 2206 Fax 248 370 4633
wwwsecsoaklandedu~ganesan
IEEE Distinguished Visiting Speaker (2005-2009) Coordinator
IEEE SEM CS chapter Chair Region 4 and CS Society Board member
SAE ASEE ACM member
Page 24 of 45
httpwwwmedpagetodaycomPublicHealthPolicyPublicHealth15122
httpwwwamericaneercomspeed-limits
httpwwwactuarialoutpostcomactuarial_discussion_forumarchiveindexph
pt-171870html
For the study period 1995-2005 these researchers found that 12545 deaths
and 36582 injuries could be attributed to the increased speed limits The
benefits of reduced speed limits are stated quite eloquently by Dr Friedman
and are reproduced below (from above news article see link)
Reduced speed limits would save lives Friedman said They would also reduce
gas consumption cut emissions of air pollutants save valuable years of productivity
(lost due to injuries)and reduce the societal cost of motor vehicle crashes (due to
both fatal crashes and due to nonfatal and severe life-changing injuries) he added
Friedman and coworkers have also shown that increasing the speed limit led
to an immediate increase in the number of fatalities on Israeli roadways (see
link below)
httpinjurypreventionbmjcomcontent133156
The effect of speeding is very significant especially in rural areas resulting
in significantly higher fatalities Fatality rates are frequently double or triple
that in urban areas (see link below)
httpsafetyfhwadotgovspeedmgtdata_factsdocsspeeding_ruralpdf
As of Jan 1 2005 five Midwestern states had increased the speed limits to
above 65 mph (Illinois Iowa Kansas Minnesota Missouri Nebraska and
South Dakota) whereas three (Illinois Iowa and Wisconsin) had not All the
five states with increased speed limits showed a 7 to 13 increase in
fatalities The NHTSA study considered an eight year period before and after
the change in Dec 1995 (see Table 1 in link below) The collective experience
of the states that did NOT increase the speed limit was a 7 decline in
fatalities (see Table 2 of link below)
httpwwwiowadotgovmvdodsstats2006speedstudypdf
Page 25 of 45
Moreover Table 5 in the above study shows the effect of imposing the NMSL
of 55 mph in Iowa and its repeal in 1995 Considering a four-year average
before 1974 when the speed limit was 75 mph there were 35 fatal crashes
with 43 fatalities In the first four years after the 55 mph there were only 23
fatal crashes and 28 fatalities In the last four years before the repeal of 55
mph in 1995 there was a further decline to 14 fatal crashes with 17 fatalities
The Iowa fatality data will be discussed in more detail separately (in a later report)
since it provides the opportunity to assess the effect of a change in the speed limit
on the relationship between number of fatalities and fatal crashes (as seen in
Figure 4 for the US as a whole)
North of the US border Canadians seem to be citing the ―shocking increase
in highway fatalities in the US states where the speed limits were raised to
curb their own speed limits
httparchivesafety-councilorginfotrafficspeed-02html
httparchivesafety-councilorginfotrafficspeedhtml
Speed kills but speed also sells notes the second of the above news items
Manufacturers are producing more high performance cars (with higher horse
power to weight ratio) and ads feature enticing cars that race and swerve in
miraculous ways on empty roads These subliminal messages encourage
drivers especially young drivers to break the speed limit leading to the
absolute increase in highway fatalities (although the rate itself is going
down) The article emphasizes the need to enforce the speed limit on
Canadian highways and in cities where street racing is becoming a problem
62 Studies cited by opponents of lower speed limits
In fairness to quote the opponents on the other side of this debate Montana
reverted back to Reasonable and Prudent speed limits when the National
Maximum Speed Limit was repealed in 1995 and appears to have
experienced no significant increase in fatalities
Page 26 of 45
httpwwwhwysafetycomhwy_montanahtm
httpwwwmotoristsorgpressmontana-no-speed-limit-safety-paradox
httpwwwsouthbayriderscomforumsshowthreadphpt=81453amppage=1
Likewise studies in the state of Maryland showed no significant increase in
highway fatalities when the speed limit was increased from 55 mph to 75
mph The reason might simply be that drivers were already speeding much
more so when the speed limit was 55 mph than after the increase to 75 mph
In other words the fatalities data already reflects the effect of higher speeds
(not speed limits) on the number of fatalities
In Utah the experimental increase in the speed limit to 80 mph was
considered to be a success in terms of safety
httpautosaolcomarticleutah-speed-limit-tests
The UDOT Director noted that there was no increase in the number of
accidents on Interstate 15 But what happens in the event of an accident
when the speed limits are higher and drivers are driving at higher speeds and
two objects collide at this higher speed However no increase in the number
of accidents is not the same as no increase in fatalities due to the higher
speeds When accidents do occur do fatalities increase
Likewise in California when the speed limit went up from 55 mph to 65
mph in 1995 (after repeal of NMSL) fewer deaths were reported in 1998
compared to the peak year of 1979 or even 1987 Again the explanation
seems to be that motorists were already speeding when the limit was 55 mph
and that increasing the speed limit did not change driver behavior in any
significant way
httparticlessfgatecom1998-11-02news17735730_1_speed-limits-mph-
limit-death-rate
The National Motorists Association (NMA) a group which advocates higher
speed limits emphasizes the importance of considering fatality rates as
opposed to the raw fatalities The argument used is that fatality rates based
on the fatality per 100 million VMT is the legitimate way to look at the data
Page 27 of 45
This is a never ending debate Historically speaking fatality rates have been
going down ever since the compilation of traffic accidents data began Table
A1 in the appendix of a recent report by NHTSA (see link below) has highway
fatality rate data going back 1921
httpwww-nrdnhtsadotgovPubs811346pdf see appendix page 31
httpwwwmotoristsorgspeed-limitstruth
httpwwwmotoristsorgothercrash-data
httpwwwraisethespeedlimitorgmythshtml
httpwwwcatoorgpubspaspa346pdf
According to Stephen Moore of the Cato Institute (see last of the links above)
―All measures of highway safety show improvement not more deaths and
injuries since 1995 Despite the fact that 33 states raised their speed limits
immediately after the repeal of the mandatory federal speed limit the NHTSA
reported last October that the traffic death rate dropped to a record low level
in 1997lsquo Moreover the average fatality rate even fell in the states that raised
their speed limits
63 The Fatality rate Is it a reliable metric
In 1921 with fewer fatalities and fewer miles driven and the first year for
which the fatality rate could be computed the rate was 2408 It was down to
1479 in 1931 but the number of deaths had climbed to 31963 more than
double the 1921 absolute fatality number of 13253 It had dropped to 550 in
1966 the year of the highly publicized Congressional hearings but the
number of fatalities had climbed to 50984 in that fateful The Highway Safety
Act of 1966 ranks as one of the major acts of Congress and President
Johnson signed it saying that ―we have been tolerating a raging epidemic of
highway deathshellip see extract pasted below
httpwwwenotescommajor-acts-congresshighway-safety-act
Page 28 of 45
The act was motivated primarily by growing public concern over the rising number
of traffic fatalities in the United States Between 1960 and 1965 the annual number
of traffic fatalities increased by nearly thirty percent As President Lyndon B
Johnson stated at the signing of the act on September 9 1966 we have tolerated
a raging epidemic of highway death which has killed more of our youth than all
other diseases combined Through the Highway Safety Act we are going to find out
more about highway diseasemdashand we aim to cure it
Nonetheless highways fatalities continued to increase until the Arab oil
embargo of 1973 led to the NMSL of 55 mph all across the USA Do we just
ignore this undeniable historical record and focus only on the declining fatality
rate as the NMA and other proponents of higher speed limits seem to argue
(see links above)
The misleading nature of using fatality rates (per 100 M VMT) alone is also
obvious if one considers fatality data for individual states Take for example
the state of Montana which seems to have experienced no increase in
fatalities after repeal of NMSL
httpwww-nrdnhtsadotgovdepartmentsnrd-
30ncsaSTSI30_MT200930_MT_2009htm
For the period 2005-2009 the absolute number of fatalities for Montana
varied between a high of 277 in 2007 to a low of 229 in 2009 The fatality
rates per 100 M VMT on the other hand varied from a high of 245 for 2007
to a low of 201 for 2009 The corresponding US fatality rates varied from
136 to 114 Is the higher number for the fatality rate for Montana compared
to USA good or bad Likewise fatality rate per 100000 of population was
much higher for Montana than the US as a whole
This again highlights the pitfalls of using simple ratios to assess fatality statistics
without a full analysis of the underlying trends We will discuss this point
separately
As shown already the continuous decline in the fatality rate is a mathematical
artifact and essentially overlooks the unmistakable positive correlation
between the variables x and y of the type y = hx + c which becomes obvious
Page 29 of 45
only when we prepare the x-y scatter graph The ratio yx = h + (cx) can
decrease with increasing x (VMT) and increasing y (fatalities) since the
intercept c has a positive value when we consider only data spanning a short
period (such as 1994-2009 of more relevance to the current situation)
The debate between fatality rates and absolute number of fatalities is an
unending one A few years ago the Wall Street Journal carried an article
which was entitled (or something close) ―Unemployments rate in Ohio are
going down but why is the number of unemployed increasing The reason is
the same The graph of the number of unemployed (y) versus the number in
the labor market (x) is linear with a positive slope h and a positive intercept c
So the unemployment rate computed using the ratio yx keeps going down
year after year although the number unemployed keeps increasing Is it a
good thing that the unemployment rate is going down when more people
seem to be unable to find gainful unemployment
Or consider the situation with cancer death rates This too has been going
down in recent years but the actual number of cancer-related deaths has not
declined in any significant way Is it good that cancer death rates are going
down In all these situations the researchers or the socio-econo-politico
analysts involved in analyzing the trends in the data have failed to consider
the underlying x-y relation describing each problem
Hence it appears that the debate on the effect of increased speed limits
should not be focused on only the fatality rates (which have been decreasing
and proponents of higher speed limits cite this in their arguments) or even the
absolute number of fatalities (which has been the focus here) but on the
relationship between speed and the number of fatal crashes and the number
of fatalities within each speed segment (see Table 3 and also Figure 4)
Unfortunately details of number of fatalities and the number of fatal crashes
at each speed limit are not available even from NHTSA for detailed study
When a crash does occur (it is immaterial how many miles were driven) the
speed of the driver and vehicle design and engineering including safety
devices in place (seat belts airbags other impact absorbing technologies)
Page 30 of 45
determine if the occupants(s) will be killed One cannot argue that speed
does NOT kill That would be an absolute denial of the laws of physics
Studies show that setting the speed limit at the 85th percentile in any given
zone (this is the speed at or below which 85 of drivers are observed to
travel in traffic engineering studies) is the safest speed limit The majority of
drivers try to obey the posted speed limit while a few choose to drive at a
speed they consider is safe and prudent These are also perhaps the most
vociferous advocates of higher speed limits It is this tension caused due to
differences in speeds that leads to tailgating improper passing reckless
driving weaving from lane to lane and ultimately crashes and deaths in some
unfortunate cases
httpblogmotoristsorgspeed-limits-slower-safer
MARK TAYLOR
ANOTHER LOST A man was killed when his 4WD drive hit a tree east of Morrinsville (in New
Zealand) on Monday May 30 2011 The driver lost control of the vehicle on a bend probably tried
to correct his mistake and put the car into a ―yaw causing it to leave the road and smash sideways
into a tree Alerts to slow down had been posted since this was a high accident area but the driver
probably did not pay attention
64 Other factors
Many other factors besides speed no doubt affect highway fatalities The
vehicles of the 21st century are very different from the vehicles of the mid 20th
Page 31 of 45
century Technological innovations such as improvements in vehicle design
and engineering have greatly increased crash worthiness of vehicles even at
high speeds Environmental factors such as the weather also contribute to
accidents but not necessarily to increased fatalities Drivers actually tend to
slow down instinctively during adverse weather conditions (rain snow storms
etc) and although such weather may contribute to increased accidents the
lower speeds actually reduce fatalities
Yes technology has changed fundamentally from 1966 Drivers today are
more distracted by their cellmobile phone conversations (and also built-in
phones in luxury models) and text messaging than the drivers of the pre-1966
era High end cars now have many multimedia and internet features Again a
careful observation (even personal experience by the author) suggests that
such distracted drivers actually tend to (instinctively) drive more slowly and
hold up the traffic Perhaps such behavior leads to an increase in the number
of accidents but it does not necessarily lead to an increase in the number of
accident-related fatalities
Much talked about technological innovations such as automatic collision
avoidance systems and sensors (on the sides of vehicles) can indeed detect
vehicles in the front and neighboring lanes Furthermore vehicle-to-vehicle
communication systems vehicle-to-infrastructure communication systems
can no doubt avoid collisions and accidents Again such collision avoidance
systems work and are effective entirely because they automatically reduce
vehicle speeds - even if one of the offending vehicles is being at a super
high speed Also it must be remembered that such futuristic systems have
not yet been implemented widely nor can they be implemented widely since
the large majority of vehicles on the road are NOT luxury models Advanced
safety features come with a price and not all drivers can afford to pay that
price and ―buy that ―additional safety
Ultimately it is the laws of physics that govern what will happen when two or
more vehicles collide or even when a single vehicle collides with a stationary
infrastructural object (a bridge a wall a building or some impediment on the
road) The lower the number of crashes the lower the number of fatalities as
revealed by the 1994-2009 data graphed in Figure 5 The higher the speed of
Page 32 of 45
the object or objects that are involved in a collision the higher the kinetic
energy K that must be absorbed andor dissipated Increasing the posted
speed limit only increases the energy that must be absorbed when a crash
does occur This ultimately is the most important criterion determining the
number of fatalities
The kinetic energy increases as the square of the speed being given by the
well-known formula K = frac12 mv2 where m is the mass of the vehicle (in
laypersonlsquos language m increases directly with vehicle weight) and v is the
speed For the same vehicle mass an increase in the speed from 55 mph to
85 mph increases the kinetic energy K by a factor of 239 or roughly a 250
increase in the kinetic energy that must be absorbed in a collision
Ideally speaking the kinetic energy of the colliding object(s) is absorbed by
the vehicle infrastructure (a sturdy space frame the engine other vehicle
components etc) andor the surroundings However in the unfortunate
cases where this kinetic energy must be absorbed by the vehicle occupant(s)
the result is severe life-altering injuries andor death An unequivocal
relationship between an increase in vehicle speeds and fatal accidents can
be demonstrated by a careful examination of available traffic fatality data
This is a more involved discussion and is not the purpose of this short
communication These topics are no doubt very politically charged with many
social legal and financial implications with each interest group favoring a
different conclusion Nonetheless we cannot escape the laws of physics as
they govern the fundamental need to absorb higher and higher values of the
kinetic energy K with increasing vehicle speeds This same point is also
emphasized by Dr Friedman of the University of Illinois Chicago (see earlier
discussion)
Speed kills because of these energy transfer considerations and there can be
no doubt about it
Innovative 21st century solutions to speed management on the highways
such as strict enforcement of speed limits minimizing speed dispersion
(difference between speeds at which different drivers travel) while using
cameras to track the 15 of drivers who willfully violate the speed limit and
Page 33 of 45
create hazardous driving conditions is certainly recommended (Recall that
the optimum recommended speed limit is at or below which 85 of all drivers
travel ndash a policy also supported by NMA) Even on this score however the
results are confounding if we consider the Australian experience
httpwwwthenewspapercomnews282840asp
Up until 2007 there was no speed limit in the Northern Territory of
Australia Imposing a speed limit 130 kmph (80 mph) on some areas and
110 kmph (68 mph) in some others actually increased the number of deaths
The death toll in 2006 when there was no speed limit in this region was 44
and went up to 75 in 2009 see data table in link below
httpwwwthenewspapercomrlcdocs2009au-ntroadtollpdf
Furthermore it appears that installation of cameras to enforce speed limits
has proved to be a hazardous distraction to drivers and deaths actually
began to skyrocket between 2005 and 2007 in all Australian roadways
The main purpose here is to sound a cautionary note amid renewed attempts
in many states across the US to increase the speed limits on our highways by
calling attention to the historical facts regarding the ―epidemic levels of
highway traffic fatalities that engaged our national attention in the fateful year
of 1966 The graphical representation of the traffic fatality data in Figures 1
to 5 tells its own story
Indeed it would be tragic if highway-accident-related fatalities were to start
increasing once again and reach the historically high level that was last seen
in 1972 the year before the Arab oil embargo of 1973
Page 34 of 45
Conclusions
1 The graphical representation of the highway fatality data and the brief
summary of the historical facts of traffic safety legislation suggest that
recent attempts to increase the speed limits by various states (notably
Texas) may be misguided The distinct peak in the highway fatalities
observed in these graphs is highly alarming This appears to be related to
the enactment of the National Maximum Speed Limit (NSML) in 1974
following the 1973 Arab oil embargo Although NSML was motivated by a
desire to reduce gasoline consumption an unintended benefit might have
been a dramatic reduction in fatalities The fundamental reasons for the
peak in the fatalities-VMT curve must be examined carefully without
political posturing
2 The widely used fatality rate fatalities per 100 M vehicle miles traveled
has been declining since 1921 the first year for which a fatality rate could
be computed and has now reached a historical low The absolute number
of fatalities on the other hand was increasing in the 1950s and 1960s at
an alarming rate and the public outcry that ensued led to the highly
publicized Congressional hearing of 1966 and the subsequent traffic safety
legislations The fatality rate has been decreasing even in the most recent
15-year period (1994-2009) again with increasing fatalities although less
dramatically Thus it appears that fatality rate calculation based on vehicle
miles traveled (VMT) might not be a reliable indicator of the underlying
dynamics in the fatality trends
3 More detailed compilation of number of fatalities and the number of fatal
crashes within each speed limit segment is required to better understand
the effect of increasing speed limits on highway fatalities (and also fatality
rates) Such data is already available and is being compiled at the local
city and county levels in all jurisdictions and only needs to be reorganized
to highlight the effect of (posted) speed limits on the number of crashes
and fatalities This will require some minor rewriting and revisions to the
chapters named ―Crashes and ―States in the annual NHTSA reports
Page 35 of 45
Analysis of the fatalities-crashes data for several years with various
speed limits will be more revealing and meaningful than the current
fatality rates analysis and will be discussed separately in a follow up
report
4 One should not be lulled by the fact that vehicles of the 21st century are
now equipped with advanced safety features not available in the 1950s
and the 1960s In spite of these safety features the laws of physics dictate
that the higher the speed the higher kinetic energy of the colliding objects
and hence the greater the risk indeed near certainty of fatalities in a
higher speed collision compared to a lower speed one
5 The higher the speed at which the vehicle that is involved in a crash is
traveling the higher the kinetic energy that must be absorbed andor
dissipated without affecting the occupant(s) to avoid serious injuries andor
death This was true in the 1950s and the 1960s and will continue to be
true in the 21st century as well
Speed Kills for this just reason
6 It appears that higher fuel economies and reduced
highway fatalities were the twin societal benefits of 55
mph adopted after 1973 If so the current attempts to
increase the speed limits appear to be in conflict with
other important societal objectives
Page 36 of 45
Table 1 Annual US Street amp Highway
Fatalities from 1957
Year
Fatalities
Vehicle Miles
(millions)
Rate100M Vehicle Miles
1957 38702 646915 598
1958 36981 664915 556
1959 37910 700478 541
1960 38137 718845 531
1961 38091 737535 516
1962 40804 766852 532
1963 43564 805423 541
1964 47700 846500 563
1965 49163 887640 554
1966 51524 927915 555
1967 51559 965132 534
1968 53831 1019726 528
1969 55032 1066108 516
1970 53672 1114098 482
1971 53761 1183524 454
1972 55704 1264614 440
1973 55113 1316207 419
1974 46078 1282790 359
1975 45500 1330074 342
1976 45523 1402380 325
1977 47878 1467027 326
1978 50331 1544704 326
1979 51103 1529133 334
1980 51091 1527295 335
1981 49301 1552803 317
1982 43945 1595010 276
1983 42589 1652788 258
1984 44257 1720269 257
1985 43795 1774179 247
Page 37 of 45
1986 46056 1835000 251
1987 46385 1921000 241
1988 47093 2026000 232
1989 45555 2107040 216
1990 44529 2147501 207
1991 41162 2172214 189
1992 39235 2239828 175
1993 40115 2296585 175
1994 40676 2359984 172
1995 41798 2422696 173
1996 41907 2485848 169
1997 41967 2560373 164
Data from Federal Highway Administration
Source httpwwwpublicpurposecomhwy-fatal57+htm
Telephone +16186328507 - Facsimile +16186328538
WENDELL COX CONSULTANCY P O Box 841 - Belleville IL 62269 USA
Page 38 of 45
Fatality data for 1921-1982 compiled by NHTSA
Year
VMT
(Millions)
VMT
(Billions)
Fatalities
Fatality rate
per 100 M VMT
1921 55027 5503 13253 241 1922 67697 6770 14859 219 1923 84995 8500 17870 210 1924 104838 10484 18400 176 1925 122346 12235 20771 170 1926 140735 14074 22194 158 1927 158453 15845 24470 154 1928 172856 17286 26557 154 1929 197720 19772 29592 150 1930 206320 20632 31204 151 1931 216151 21615 31963 148 1932 200517 20052 27979 140 1933 200642 20064 29746 148 1934 215563 21556 34240 159 1935 228568 22857 34494 151 1936 252128 25213 36126 143 1937 270110 27011 37819 140 1938 271177 27118 31083 115 1939 285402 28540 30895 108 1940 302188 30219 32914 109 1941 333612 33361 38142 114 1942 268224 26822 27007 101 1943 208192 20819 22727 109 1944 212713 21271 23165 109 1945 250173 25017 26785 107 1946 340880 34088 31874 94 1947 370894 37089 31193 84 1948 397957 39796 30775 77 1949 424461 42446 30246 71 1950 458246 45825 33186 72 1951 491093 49109 35309 72
1952 513581 51358 36088 70
Page 39 of 45
1953 544433 54443 36190 66 1954 561963 56196 33890 60 1955 605646 60565 36688 61 1956 627843 62784 37965 60 1957 647004 64700 36932 57 1958 664653 66465 35331 53 1959 700480 70048 36223 52 1960 718762 71876 36399 51 1961 737421 73742 36285 49 1962 766734 76673 38980 51 1963 805249 80525 41723 52 1964 846298 84630 45645 54 1965 887812 88781 47089 53 1966 925899 92590 50894 55 1967 964005 96401 50724 53 1968 1015869 101587 52725 52 1969 1061791 106179 53543 50 1970 1109724 110972 52627 47 1971 1178811 117881 52542 45 1972 1259786 125979 54589 43 1973 1313110 131311 54052 41 1974 1280544 128054 45196 35 1975 1327664 132766 44525 34 1976 1402380 140238 45523 32 1977 1467027 146703 47878 33 1978 1544704 154470 50331 33 1979 1529133 152913 51093 33 1980 1527295 152730 51091 33 1981 1555308 155531 49301 32 1982 1595010 159501 43945 28
Source Analysis of Significant Decline in Motor Vehicle Traffic Fatalities in
2008 httpwww-nrdnhtsadotgovPubs811346pdf see Table A1 page 31
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Page 40 of 45
Acknowledgements
The author is grateful for thoughtful comments provided by friends and colleagues
with whom this document was shared via email prior to it being uploaded as a
publicly available document for wider dissemination and study The comments
offered by Prof Subra Ganesan of Oakland University Electrical and Computer
Engineering Department are reproduced with permission in their entirety
About the author
The author obtained his Masterrsquos (S M) and Doctoral (Sc D) degrees in Materials Engineering
from the Massachusetts Institute of Technology Cambridge USA He then spent his entire
professional career at leading US research institutions (MIT NASA Case Western Reserve
University and General Motors R amp D Center in Warren MI) He holds four patents in advanced
materials processing has co-authored two books and has published several scientific papers in
leading peer-reviewed international journals His expertise includes developing simple
mathematical models to explain the behavior of complex systems He can be reached by email at
vlaxmananhotmailcom
Page 41 of 45
Please Buckle Up
httpwwwlakecountypublichealthorgindexphpbuckle-up-montana
Public Awareness
Respect the Cage Exhibit
The Department of Transportation hopes that showing the reality of the crash will reduce traffic
fatalities A crushed car crash dummies and a sobering message ndash all part of the ―Respect The
Cage exhibit that is traveling across Montana The exhibit sponsored by the Montana Department
of Transportation stopped in Ronan on November 6th and is aimed at raising awareness about the
importance of wearing seat belts
The car in the exhibit was in an actual wreck many years ago
the passenger in the vehicle died because he was not wearing a
seat belt the driver who was wearing his seat belt survived
Montanarsquos likeliest crash fatality scenario
A Pickup
A Rural road
And Seat belts that
arenrsquot used
Page 42 of 45
Occupants of pickups are less likely to wear seat belts and pickups are more likely to
roll over than passenger cars
Seat belts reduce the risk of death by 60 percent in pickups and SUVs
In Montana from 2006-2008 81 of those killed in a crash while riding in a pickup were not wearing seat belts
In Montana pickups make up 401 of the vehicle population
For more information on Respect the Cage click here
Page 43 of 45
Appendix 1
Lack of seat belts leading cause of Louisiana highway deaths
1251 AM May 28 2011 |
Written by Adam Duvernay
Crashes involving unbuckled motorists were the leading cause of highway fatalities
in Louisiana last year and cost $9888 million according to recent reports The
Louisiana Highway Safety Commission reported 59 percent of vehicle occupants
killed in Louisiana crashes last year mdash about one in four mdash werent wearing seat
belts
httpwwwshreveporttimescomarticle20110528NEWS01105280354Lack-seat-
belts-leading-cause-La-highway-deathsodyssey=tab|topnews|text|FRONTPAGE
Crash bull Stats Published by NHTSAlsquos National Center for Statistics and Analysis 1200 New Jersey Avenue SE Washington DC 20590
DOT HS 811 451
Early Estimate of Motor Vehicle Traffic Fatalities in 2010
httpwww-nrdnhtsadotgovPubs811451pdf
Summary
A statistical projection of traffic fatalities in 2010 shows that an estimated 32788
people died in motor vehicle traffic crashes This represents a decline of about 3
percent as compared to the 33808 fatalities in 2009 as shown in Table 1 If these
projections are realized fatalities will be lowest on record (since 1949)
Traffic Safety Facts Overview 2009 Data
httpwww-nrdnhtsadotgovPubs811392pdf
In 2009 33808 people were killed in the estimated 5505000 police-reported
motor vehicle traffic crashes 2217000 people were injured and 3957000
crashes involved property damage only Compared to 2008 this is a 10-
percent decrease in the number of fatalities and a 5-percent decrease in the
Page 44 of 45
number of police-reported motor vehicle traffic crashes people injured and
crashes involving property damage
An average of 93 people died each day in motor vehicle crashes in 2009 mdash
an average of one every 16 minutes
Traffic Safety Facts Overview 2008 Data
httpwww-nrdnhtsadotgovPubs811162pdf
In 2008 37261 people were killed in the estimated 5811000 police-reported
motor vehicle traffic crashes 2346000 people were injured and 4146000
crashes involved property damage only
Some comments and Feedback
The following comments were received from Prof Ganesan after his review of the
first draft of this document It was subsequently revised thanks to this input to
address some of the very important issues raised here
Dear Laxman
The write up is not enough
You are emphasizing that the speed limit reduces the fatal accidents (comparing 1966
to 2000 accident numbers)
Can you also add a few sentences why the number is decreasing from 1980 to 2000
values (May be due to better design of vehicles)
Can you say anything about the fuel consumption with the speed for any typical
vehicle in 2011 or 2010 (do not consider the fatalities issue)
Probably a speed between 55 and 60 mph gives a better mileage If so this is a
compelling reason to keep the speed limit low But cars probably can be tuned to
give better mileage at any high speed also
Page 45 of 45
Weather is also a major factor in fatal accidents Speed limit may be kept low during
winter and kept higher in summer Give your comments on this too
Driver distractions can cause more accidents Now cars have many multimedia and
internet features Automatic collision avoidance systems and sensors on the sides can
detect vehicles in the front and neighboring lanes and it can automatically decrease
speed even if the driver speeds at super high speeds
Give some comments on this too There is also Vehicle to Vehicle communications
vehicle to infrastructure communications and they can avoid collisions and accidents
Technology has changed from 1966 I cannot agree with you on the speed limit
without any discussion on the above and other factors
Have a great day
Subra Ganesan
Professor Subramaniam Ganesan
Director Real Time amp DSP Lab
Electrical and Computer Engineering Department
2200 Squirrel Road Dodge Hall Room 105
Oakland University Rochester MI 48309 USA
Phone 248 370 2206 Fax 248 370 4633
wwwsecsoaklandedu~ganesan
IEEE Distinguished Visiting Speaker (2005-2009) Coordinator
IEEE SEM CS chapter Chair Region 4 and CS Society Board member
SAE ASEE ACM member
Page 25 of 45
Moreover Table 5 in the above study shows the effect of imposing the NMSL
of 55 mph in Iowa and its repeal in 1995 Considering a four-year average
before 1974 when the speed limit was 75 mph there were 35 fatal crashes
with 43 fatalities In the first four years after the 55 mph there were only 23
fatal crashes and 28 fatalities In the last four years before the repeal of 55
mph in 1995 there was a further decline to 14 fatal crashes with 17 fatalities
The Iowa fatality data will be discussed in more detail separately (in a later report)
since it provides the opportunity to assess the effect of a change in the speed limit
on the relationship between number of fatalities and fatal crashes (as seen in
Figure 4 for the US as a whole)
North of the US border Canadians seem to be citing the ―shocking increase
in highway fatalities in the US states where the speed limits were raised to
curb their own speed limits
httparchivesafety-councilorginfotrafficspeed-02html
httparchivesafety-councilorginfotrafficspeedhtml
Speed kills but speed also sells notes the second of the above news items
Manufacturers are producing more high performance cars (with higher horse
power to weight ratio) and ads feature enticing cars that race and swerve in
miraculous ways on empty roads These subliminal messages encourage
drivers especially young drivers to break the speed limit leading to the
absolute increase in highway fatalities (although the rate itself is going
down) The article emphasizes the need to enforce the speed limit on
Canadian highways and in cities where street racing is becoming a problem
62 Studies cited by opponents of lower speed limits
In fairness to quote the opponents on the other side of this debate Montana
reverted back to Reasonable and Prudent speed limits when the National
Maximum Speed Limit was repealed in 1995 and appears to have
experienced no significant increase in fatalities
Page 26 of 45
httpwwwhwysafetycomhwy_montanahtm
httpwwwmotoristsorgpressmontana-no-speed-limit-safety-paradox
httpwwwsouthbayriderscomforumsshowthreadphpt=81453amppage=1
Likewise studies in the state of Maryland showed no significant increase in
highway fatalities when the speed limit was increased from 55 mph to 75
mph The reason might simply be that drivers were already speeding much
more so when the speed limit was 55 mph than after the increase to 75 mph
In other words the fatalities data already reflects the effect of higher speeds
(not speed limits) on the number of fatalities
In Utah the experimental increase in the speed limit to 80 mph was
considered to be a success in terms of safety
httpautosaolcomarticleutah-speed-limit-tests
The UDOT Director noted that there was no increase in the number of
accidents on Interstate 15 But what happens in the event of an accident
when the speed limits are higher and drivers are driving at higher speeds and
two objects collide at this higher speed However no increase in the number
of accidents is not the same as no increase in fatalities due to the higher
speeds When accidents do occur do fatalities increase
Likewise in California when the speed limit went up from 55 mph to 65
mph in 1995 (after repeal of NMSL) fewer deaths were reported in 1998
compared to the peak year of 1979 or even 1987 Again the explanation
seems to be that motorists were already speeding when the limit was 55 mph
and that increasing the speed limit did not change driver behavior in any
significant way
httparticlessfgatecom1998-11-02news17735730_1_speed-limits-mph-
limit-death-rate
The National Motorists Association (NMA) a group which advocates higher
speed limits emphasizes the importance of considering fatality rates as
opposed to the raw fatalities The argument used is that fatality rates based
on the fatality per 100 million VMT is the legitimate way to look at the data
Page 27 of 45
This is a never ending debate Historically speaking fatality rates have been
going down ever since the compilation of traffic accidents data began Table
A1 in the appendix of a recent report by NHTSA (see link below) has highway
fatality rate data going back 1921
httpwww-nrdnhtsadotgovPubs811346pdf see appendix page 31
httpwwwmotoristsorgspeed-limitstruth
httpwwwmotoristsorgothercrash-data
httpwwwraisethespeedlimitorgmythshtml
httpwwwcatoorgpubspaspa346pdf
According to Stephen Moore of the Cato Institute (see last of the links above)
―All measures of highway safety show improvement not more deaths and
injuries since 1995 Despite the fact that 33 states raised their speed limits
immediately after the repeal of the mandatory federal speed limit the NHTSA
reported last October that the traffic death rate dropped to a record low level
in 1997lsquo Moreover the average fatality rate even fell in the states that raised
their speed limits
63 The Fatality rate Is it a reliable metric
In 1921 with fewer fatalities and fewer miles driven and the first year for
which the fatality rate could be computed the rate was 2408 It was down to
1479 in 1931 but the number of deaths had climbed to 31963 more than
double the 1921 absolute fatality number of 13253 It had dropped to 550 in
1966 the year of the highly publicized Congressional hearings but the
number of fatalities had climbed to 50984 in that fateful The Highway Safety
Act of 1966 ranks as one of the major acts of Congress and President
Johnson signed it saying that ―we have been tolerating a raging epidemic of
highway deathshellip see extract pasted below
httpwwwenotescommajor-acts-congresshighway-safety-act
Page 28 of 45
The act was motivated primarily by growing public concern over the rising number
of traffic fatalities in the United States Between 1960 and 1965 the annual number
of traffic fatalities increased by nearly thirty percent As President Lyndon B
Johnson stated at the signing of the act on September 9 1966 we have tolerated
a raging epidemic of highway death which has killed more of our youth than all
other diseases combined Through the Highway Safety Act we are going to find out
more about highway diseasemdashand we aim to cure it
Nonetheless highways fatalities continued to increase until the Arab oil
embargo of 1973 led to the NMSL of 55 mph all across the USA Do we just
ignore this undeniable historical record and focus only on the declining fatality
rate as the NMA and other proponents of higher speed limits seem to argue
(see links above)
The misleading nature of using fatality rates (per 100 M VMT) alone is also
obvious if one considers fatality data for individual states Take for example
the state of Montana which seems to have experienced no increase in
fatalities after repeal of NMSL
httpwww-nrdnhtsadotgovdepartmentsnrd-
30ncsaSTSI30_MT200930_MT_2009htm
For the period 2005-2009 the absolute number of fatalities for Montana
varied between a high of 277 in 2007 to a low of 229 in 2009 The fatality
rates per 100 M VMT on the other hand varied from a high of 245 for 2007
to a low of 201 for 2009 The corresponding US fatality rates varied from
136 to 114 Is the higher number for the fatality rate for Montana compared
to USA good or bad Likewise fatality rate per 100000 of population was
much higher for Montana than the US as a whole
This again highlights the pitfalls of using simple ratios to assess fatality statistics
without a full analysis of the underlying trends We will discuss this point
separately
As shown already the continuous decline in the fatality rate is a mathematical
artifact and essentially overlooks the unmistakable positive correlation
between the variables x and y of the type y = hx + c which becomes obvious
Page 29 of 45
only when we prepare the x-y scatter graph The ratio yx = h + (cx) can
decrease with increasing x (VMT) and increasing y (fatalities) since the
intercept c has a positive value when we consider only data spanning a short
period (such as 1994-2009 of more relevance to the current situation)
The debate between fatality rates and absolute number of fatalities is an
unending one A few years ago the Wall Street Journal carried an article
which was entitled (or something close) ―Unemployments rate in Ohio are
going down but why is the number of unemployed increasing The reason is
the same The graph of the number of unemployed (y) versus the number in
the labor market (x) is linear with a positive slope h and a positive intercept c
So the unemployment rate computed using the ratio yx keeps going down
year after year although the number unemployed keeps increasing Is it a
good thing that the unemployment rate is going down when more people
seem to be unable to find gainful unemployment
Or consider the situation with cancer death rates This too has been going
down in recent years but the actual number of cancer-related deaths has not
declined in any significant way Is it good that cancer death rates are going
down In all these situations the researchers or the socio-econo-politico
analysts involved in analyzing the trends in the data have failed to consider
the underlying x-y relation describing each problem
Hence it appears that the debate on the effect of increased speed limits
should not be focused on only the fatality rates (which have been decreasing
and proponents of higher speed limits cite this in their arguments) or even the
absolute number of fatalities (which has been the focus here) but on the
relationship between speed and the number of fatal crashes and the number
of fatalities within each speed segment (see Table 3 and also Figure 4)
Unfortunately details of number of fatalities and the number of fatal crashes
at each speed limit are not available even from NHTSA for detailed study
When a crash does occur (it is immaterial how many miles were driven) the
speed of the driver and vehicle design and engineering including safety
devices in place (seat belts airbags other impact absorbing technologies)
Page 30 of 45
determine if the occupants(s) will be killed One cannot argue that speed
does NOT kill That would be an absolute denial of the laws of physics
Studies show that setting the speed limit at the 85th percentile in any given
zone (this is the speed at or below which 85 of drivers are observed to
travel in traffic engineering studies) is the safest speed limit The majority of
drivers try to obey the posted speed limit while a few choose to drive at a
speed they consider is safe and prudent These are also perhaps the most
vociferous advocates of higher speed limits It is this tension caused due to
differences in speeds that leads to tailgating improper passing reckless
driving weaving from lane to lane and ultimately crashes and deaths in some
unfortunate cases
httpblogmotoristsorgspeed-limits-slower-safer
MARK TAYLOR
ANOTHER LOST A man was killed when his 4WD drive hit a tree east of Morrinsville (in New
Zealand) on Monday May 30 2011 The driver lost control of the vehicle on a bend probably tried
to correct his mistake and put the car into a ―yaw causing it to leave the road and smash sideways
into a tree Alerts to slow down had been posted since this was a high accident area but the driver
probably did not pay attention
64 Other factors
Many other factors besides speed no doubt affect highway fatalities The
vehicles of the 21st century are very different from the vehicles of the mid 20th
Page 31 of 45
century Technological innovations such as improvements in vehicle design
and engineering have greatly increased crash worthiness of vehicles even at
high speeds Environmental factors such as the weather also contribute to
accidents but not necessarily to increased fatalities Drivers actually tend to
slow down instinctively during adverse weather conditions (rain snow storms
etc) and although such weather may contribute to increased accidents the
lower speeds actually reduce fatalities
Yes technology has changed fundamentally from 1966 Drivers today are
more distracted by their cellmobile phone conversations (and also built-in
phones in luxury models) and text messaging than the drivers of the pre-1966
era High end cars now have many multimedia and internet features Again a
careful observation (even personal experience by the author) suggests that
such distracted drivers actually tend to (instinctively) drive more slowly and
hold up the traffic Perhaps such behavior leads to an increase in the number
of accidents but it does not necessarily lead to an increase in the number of
accident-related fatalities
Much talked about technological innovations such as automatic collision
avoidance systems and sensors (on the sides of vehicles) can indeed detect
vehicles in the front and neighboring lanes Furthermore vehicle-to-vehicle
communication systems vehicle-to-infrastructure communication systems
can no doubt avoid collisions and accidents Again such collision avoidance
systems work and are effective entirely because they automatically reduce
vehicle speeds - even if one of the offending vehicles is being at a super
high speed Also it must be remembered that such futuristic systems have
not yet been implemented widely nor can they be implemented widely since
the large majority of vehicles on the road are NOT luxury models Advanced
safety features come with a price and not all drivers can afford to pay that
price and ―buy that ―additional safety
Ultimately it is the laws of physics that govern what will happen when two or
more vehicles collide or even when a single vehicle collides with a stationary
infrastructural object (a bridge a wall a building or some impediment on the
road) The lower the number of crashes the lower the number of fatalities as
revealed by the 1994-2009 data graphed in Figure 5 The higher the speed of
Page 32 of 45
the object or objects that are involved in a collision the higher the kinetic
energy K that must be absorbed andor dissipated Increasing the posted
speed limit only increases the energy that must be absorbed when a crash
does occur This ultimately is the most important criterion determining the
number of fatalities
The kinetic energy increases as the square of the speed being given by the
well-known formula K = frac12 mv2 where m is the mass of the vehicle (in
laypersonlsquos language m increases directly with vehicle weight) and v is the
speed For the same vehicle mass an increase in the speed from 55 mph to
85 mph increases the kinetic energy K by a factor of 239 or roughly a 250
increase in the kinetic energy that must be absorbed in a collision
Ideally speaking the kinetic energy of the colliding object(s) is absorbed by
the vehicle infrastructure (a sturdy space frame the engine other vehicle
components etc) andor the surroundings However in the unfortunate
cases where this kinetic energy must be absorbed by the vehicle occupant(s)
the result is severe life-altering injuries andor death An unequivocal
relationship between an increase in vehicle speeds and fatal accidents can
be demonstrated by a careful examination of available traffic fatality data
This is a more involved discussion and is not the purpose of this short
communication These topics are no doubt very politically charged with many
social legal and financial implications with each interest group favoring a
different conclusion Nonetheless we cannot escape the laws of physics as
they govern the fundamental need to absorb higher and higher values of the
kinetic energy K with increasing vehicle speeds This same point is also
emphasized by Dr Friedman of the University of Illinois Chicago (see earlier
discussion)
Speed kills because of these energy transfer considerations and there can be
no doubt about it
Innovative 21st century solutions to speed management on the highways
such as strict enforcement of speed limits minimizing speed dispersion
(difference between speeds at which different drivers travel) while using
cameras to track the 15 of drivers who willfully violate the speed limit and
Page 33 of 45
create hazardous driving conditions is certainly recommended (Recall that
the optimum recommended speed limit is at or below which 85 of all drivers
travel ndash a policy also supported by NMA) Even on this score however the
results are confounding if we consider the Australian experience
httpwwwthenewspapercomnews282840asp
Up until 2007 there was no speed limit in the Northern Territory of
Australia Imposing a speed limit 130 kmph (80 mph) on some areas and
110 kmph (68 mph) in some others actually increased the number of deaths
The death toll in 2006 when there was no speed limit in this region was 44
and went up to 75 in 2009 see data table in link below
httpwwwthenewspapercomrlcdocs2009au-ntroadtollpdf
Furthermore it appears that installation of cameras to enforce speed limits
has proved to be a hazardous distraction to drivers and deaths actually
began to skyrocket between 2005 and 2007 in all Australian roadways
The main purpose here is to sound a cautionary note amid renewed attempts
in many states across the US to increase the speed limits on our highways by
calling attention to the historical facts regarding the ―epidemic levels of
highway traffic fatalities that engaged our national attention in the fateful year
of 1966 The graphical representation of the traffic fatality data in Figures 1
to 5 tells its own story
Indeed it would be tragic if highway-accident-related fatalities were to start
increasing once again and reach the historically high level that was last seen
in 1972 the year before the Arab oil embargo of 1973
Page 34 of 45
Conclusions
1 The graphical representation of the highway fatality data and the brief
summary of the historical facts of traffic safety legislation suggest that
recent attempts to increase the speed limits by various states (notably
Texas) may be misguided The distinct peak in the highway fatalities
observed in these graphs is highly alarming This appears to be related to
the enactment of the National Maximum Speed Limit (NSML) in 1974
following the 1973 Arab oil embargo Although NSML was motivated by a
desire to reduce gasoline consumption an unintended benefit might have
been a dramatic reduction in fatalities The fundamental reasons for the
peak in the fatalities-VMT curve must be examined carefully without
political posturing
2 The widely used fatality rate fatalities per 100 M vehicle miles traveled
has been declining since 1921 the first year for which a fatality rate could
be computed and has now reached a historical low The absolute number
of fatalities on the other hand was increasing in the 1950s and 1960s at
an alarming rate and the public outcry that ensued led to the highly
publicized Congressional hearing of 1966 and the subsequent traffic safety
legislations The fatality rate has been decreasing even in the most recent
15-year period (1994-2009) again with increasing fatalities although less
dramatically Thus it appears that fatality rate calculation based on vehicle
miles traveled (VMT) might not be a reliable indicator of the underlying
dynamics in the fatality trends
3 More detailed compilation of number of fatalities and the number of fatal
crashes within each speed limit segment is required to better understand
the effect of increasing speed limits on highway fatalities (and also fatality
rates) Such data is already available and is being compiled at the local
city and county levels in all jurisdictions and only needs to be reorganized
to highlight the effect of (posted) speed limits on the number of crashes
and fatalities This will require some minor rewriting and revisions to the
chapters named ―Crashes and ―States in the annual NHTSA reports
Page 35 of 45
Analysis of the fatalities-crashes data for several years with various
speed limits will be more revealing and meaningful than the current
fatality rates analysis and will be discussed separately in a follow up
report
4 One should not be lulled by the fact that vehicles of the 21st century are
now equipped with advanced safety features not available in the 1950s
and the 1960s In spite of these safety features the laws of physics dictate
that the higher the speed the higher kinetic energy of the colliding objects
and hence the greater the risk indeed near certainty of fatalities in a
higher speed collision compared to a lower speed one
5 The higher the speed at which the vehicle that is involved in a crash is
traveling the higher the kinetic energy that must be absorbed andor
dissipated without affecting the occupant(s) to avoid serious injuries andor
death This was true in the 1950s and the 1960s and will continue to be
true in the 21st century as well
Speed Kills for this just reason
6 It appears that higher fuel economies and reduced
highway fatalities were the twin societal benefits of 55
mph adopted after 1973 If so the current attempts to
increase the speed limits appear to be in conflict with
other important societal objectives
Page 36 of 45
Table 1 Annual US Street amp Highway
Fatalities from 1957
Year
Fatalities
Vehicle Miles
(millions)
Rate100M Vehicle Miles
1957 38702 646915 598
1958 36981 664915 556
1959 37910 700478 541
1960 38137 718845 531
1961 38091 737535 516
1962 40804 766852 532
1963 43564 805423 541
1964 47700 846500 563
1965 49163 887640 554
1966 51524 927915 555
1967 51559 965132 534
1968 53831 1019726 528
1969 55032 1066108 516
1970 53672 1114098 482
1971 53761 1183524 454
1972 55704 1264614 440
1973 55113 1316207 419
1974 46078 1282790 359
1975 45500 1330074 342
1976 45523 1402380 325
1977 47878 1467027 326
1978 50331 1544704 326
1979 51103 1529133 334
1980 51091 1527295 335
1981 49301 1552803 317
1982 43945 1595010 276
1983 42589 1652788 258
1984 44257 1720269 257
1985 43795 1774179 247
Page 37 of 45
1986 46056 1835000 251
1987 46385 1921000 241
1988 47093 2026000 232
1989 45555 2107040 216
1990 44529 2147501 207
1991 41162 2172214 189
1992 39235 2239828 175
1993 40115 2296585 175
1994 40676 2359984 172
1995 41798 2422696 173
1996 41907 2485848 169
1997 41967 2560373 164
Data from Federal Highway Administration
Source httpwwwpublicpurposecomhwy-fatal57+htm
Telephone +16186328507 - Facsimile +16186328538
WENDELL COX CONSULTANCY P O Box 841 - Belleville IL 62269 USA
Page 38 of 45
Fatality data for 1921-1982 compiled by NHTSA
Year
VMT
(Millions)
VMT
(Billions)
Fatalities
Fatality rate
per 100 M VMT
1921 55027 5503 13253 241 1922 67697 6770 14859 219 1923 84995 8500 17870 210 1924 104838 10484 18400 176 1925 122346 12235 20771 170 1926 140735 14074 22194 158 1927 158453 15845 24470 154 1928 172856 17286 26557 154 1929 197720 19772 29592 150 1930 206320 20632 31204 151 1931 216151 21615 31963 148 1932 200517 20052 27979 140 1933 200642 20064 29746 148 1934 215563 21556 34240 159 1935 228568 22857 34494 151 1936 252128 25213 36126 143 1937 270110 27011 37819 140 1938 271177 27118 31083 115 1939 285402 28540 30895 108 1940 302188 30219 32914 109 1941 333612 33361 38142 114 1942 268224 26822 27007 101 1943 208192 20819 22727 109 1944 212713 21271 23165 109 1945 250173 25017 26785 107 1946 340880 34088 31874 94 1947 370894 37089 31193 84 1948 397957 39796 30775 77 1949 424461 42446 30246 71 1950 458246 45825 33186 72 1951 491093 49109 35309 72
1952 513581 51358 36088 70
Page 39 of 45
1953 544433 54443 36190 66 1954 561963 56196 33890 60 1955 605646 60565 36688 61 1956 627843 62784 37965 60 1957 647004 64700 36932 57 1958 664653 66465 35331 53 1959 700480 70048 36223 52 1960 718762 71876 36399 51 1961 737421 73742 36285 49 1962 766734 76673 38980 51 1963 805249 80525 41723 52 1964 846298 84630 45645 54 1965 887812 88781 47089 53 1966 925899 92590 50894 55 1967 964005 96401 50724 53 1968 1015869 101587 52725 52 1969 1061791 106179 53543 50 1970 1109724 110972 52627 47 1971 1178811 117881 52542 45 1972 1259786 125979 54589 43 1973 1313110 131311 54052 41 1974 1280544 128054 45196 35 1975 1327664 132766 44525 34 1976 1402380 140238 45523 32 1977 1467027 146703 47878 33 1978 1544704 154470 50331 33 1979 1529133 152913 51093 33 1980 1527295 152730 51091 33 1981 1555308 155531 49301 32 1982 1595010 159501 43945 28
Source Analysis of Significant Decline in Motor Vehicle Traffic Fatalities in
2008 httpwww-nrdnhtsadotgovPubs811346pdf see Table A1 page 31
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Page 40 of 45
Acknowledgements
The author is grateful for thoughtful comments provided by friends and colleagues
with whom this document was shared via email prior to it being uploaded as a
publicly available document for wider dissemination and study The comments
offered by Prof Subra Ganesan of Oakland University Electrical and Computer
Engineering Department are reproduced with permission in their entirety
About the author
The author obtained his Masterrsquos (S M) and Doctoral (Sc D) degrees in Materials Engineering
from the Massachusetts Institute of Technology Cambridge USA He then spent his entire
professional career at leading US research institutions (MIT NASA Case Western Reserve
University and General Motors R amp D Center in Warren MI) He holds four patents in advanced
materials processing has co-authored two books and has published several scientific papers in
leading peer-reviewed international journals His expertise includes developing simple
mathematical models to explain the behavior of complex systems He can be reached by email at
vlaxmananhotmailcom
Page 41 of 45
Please Buckle Up
httpwwwlakecountypublichealthorgindexphpbuckle-up-montana
Public Awareness
Respect the Cage Exhibit
The Department of Transportation hopes that showing the reality of the crash will reduce traffic
fatalities A crushed car crash dummies and a sobering message ndash all part of the ―Respect The
Cage exhibit that is traveling across Montana The exhibit sponsored by the Montana Department
of Transportation stopped in Ronan on November 6th and is aimed at raising awareness about the
importance of wearing seat belts
The car in the exhibit was in an actual wreck many years ago
the passenger in the vehicle died because he was not wearing a
seat belt the driver who was wearing his seat belt survived
Montanarsquos likeliest crash fatality scenario
A Pickup
A Rural road
And Seat belts that
arenrsquot used
Page 42 of 45
Occupants of pickups are less likely to wear seat belts and pickups are more likely to
roll over than passenger cars
Seat belts reduce the risk of death by 60 percent in pickups and SUVs
In Montana from 2006-2008 81 of those killed in a crash while riding in a pickup were not wearing seat belts
In Montana pickups make up 401 of the vehicle population
For more information on Respect the Cage click here
Page 43 of 45
Appendix 1
Lack of seat belts leading cause of Louisiana highway deaths
1251 AM May 28 2011 |
Written by Adam Duvernay
Crashes involving unbuckled motorists were the leading cause of highway fatalities
in Louisiana last year and cost $9888 million according to recent reports The
Louisiana Highway Safety Commission reported 59 percent of vehicle occupants
killed in Louisiana crashes last year mdash about one in four mdash werent wearing seat
belts
httpwwwshreveporttimescomarticle20110528NEWS01105280354Lack-seat-
belts-leading-cause-La-highway-deathsodyssey=tab|topnews|text|FRONTPAGE
Crash bull Stats Published by NHTSAlsquos National Center for Statistics and Analysis 1200 New Jersey Avenue SE Washington DC 20590
DOT HS 811 451
Early Estimate of Motor Vehicle Traffic Fatalities in 2010
httpwww-nrdnhtsadotgovPubs811451pdf
Summary
A statistical projection of traffic fatalities in 2010 shows that an estimated 32788
people died in motor vehicle traffic crashes This represents a decline of about 3
percent as compared to the 33808 fatalities in 2009 as shown in Table 1 If these
projections are realized fatalities will be lowest on record (since 1949)
Traffic Safety Facts Overview 2009 Data
httpwww-nrdnhtsadotgovPubs811392pdf
In 2009 33808 people were killed in the estimated 5505000 police-reported
motor vehicle traffic crashes 2217000 people were injured and 3957000
crashes involved property damage only Compared to 2008 this is a 10-
percent decrease in the number of fatalities and a 5-percent decrease in the
Page 44 of 45
number of police-reported motor vehicle traffic crashes people injured and
crashes involving property damage
An average of 93 people died each day in motor vehicle crashes in 2009 mdash
an average of one every 16 minutes
Traffic Safety Facts Overview 2008 Data
httpwww-nrdnhtsadotgovPubs811162pdf
In 2008 37261 people were killed in the estimated 5811000 police-reported
motor vehicle traffic crashes 2346000 people were injured and 4146000
crashes involved property damage only
Some comments and Feedback
The following comments were received from Prof Ganesan after his review of the
first draft of this document It was subsequently revised thanks to this input to
address some of the very important issues raised here
Dear Laxman
The write up is not enough
You are emphasizing that the speed limit reduces the fatal accidents (comparing 1966
to 2000 accident numbers)
Can you also add a few sentences why the number is decreasing from 1980 to 2000
values (May be due to better design of vehicles)
Can you say anything about the fuel consumption with the speed for any typical
vehicle in 2011 or 2010 (do not consider the fatalities issue)
Probably a speed between 55 and 60 mph gives a better mileage If so this is a
compelling reason to keep the speed limit low But cars probably can be tuned to
give better mileage at any high speed also
Page 45 of 45
Weather is also a major factor in fatal accidents Speed limit may be kept low during
winter and kept higher in summer Give your comments on this too
Driver distractions can cause more accidents Now cars have many multimedia and
internet features Automatic collision avoidance systems and sensors on the sides can
detect vehicles in the front and neighboring lanes and it can automatically decrease
speed even if the driver speeds at super high speeds
Give some comments on this too There is also Vehicle to Vehicle communications
vehicle to infrastructure communications and they can avoid collisions and accidents
Technology has changed from 1966 I cannot agree with you on the speed limit
without any discussion on the above and other factors
Have a great day
Subra Ganesan
Professor Subramaniam Ganesan
Director Real Time amp DSP Lab
Electrical and Computer Engineering Department
2200 Squirrel Road Dodge Hall Room 105
Oakland University Rochester MI 48309 USA
Phone 248 370 2206 Fax 248 370 4633
wwwsecsoaklandedu~ganesan
IEEE Distinguished Visiting Speaker (2005-2009) Coordinator
IEEE SEM CS chapter Chair Region 4 and CS Society Board member
SAE ASEE ACM member
Page 26 of 45
httpwwwhwysafetycomhwy_montanahtm
httpwwwmotoristsorgpressmontana-no-speed-limit-safety-paradox
httpwwwsouthbayriderscomforumsshowthreadphpt=81453amppage=1
Likewise studies in the state of Maryland showed no significant increase in
highway fatalities when the speed limit was increased from 55 mph to 75
mph The reason might simply be that drivers were already speeding much
more so when the speed limit was 55 mph than after the increase to 75 mph
In other words the fatalities data already reflects the effect of higher speeds
(not speed limits) on the number of fatalities
In Utah the experimental increase in the speed limit to 80 mph was
considered to be a success in terms of safety
httpautosaolcomarticleutah-speed-limit-tests
The UDOT Director noted that there was no increase in the number of
accidents on Interstate 15 But what happens in the event of an accident
when the speed limits are higher and drivers are driving at higher speeds and
two objects collide at this higher speed However no increase in the number
of accidents is not the same as no increase in fatalities due to the higher
speeds When accidents do occur do fatalities increase
Likewise in California when the speed limit went up from 55 mph to 65
mph in 1995 (after repeal of NMSL) fewer deaths were reported in 1998
compared to the peak year of 1979 or even 1987 Again the explanation
seems to be that motorists were already speeding when the limit was 55 mph
and that increasing the speed limit did not change driver behavior in any
significant way
httparticlessfgatecom1998-11-02news17735730_1_speed-limits-mph-
limit-death-rate
The National Motorists Association (NMA) a group which advocates higher
speed limits emphasizes the importance of considering fatality rates as
opposed to the raw fatalities The argument used is that fatality rates based
on the fatality per 100 million VMT is the legitimate way to look at the data
Page 27 of 45
This is a never ending debate Historically speaking fatality rates have been
going down ever since the compilation of traffic accidents data began Table
A1 in the appendix of a recent report by NHTSA (see link below) has highway
fatality rate data going back 1921
httpwww-nrdnhtsadotgovPubs811346pdf see appendix page 31
httpwwwmotoristsorgspeed-limitstruth
httpwwwmotoristsorgothercrash-data
httpwwwraisethespeedlimitorgmythshtml
httpwwwcatoorgpubspaspa346pdf
According to Stephen Moore of the Cato Institute (see last of the links above)
―All measures of highway safety show improvement not more deaths and
injuries since 1995 Despite the fact that 33 states raised their speed limits
immediately after the repeal of the mandatory federal speed limit the NHTSA
reported last October that the traffic death rate dropped to a record low level
in 1997lsquo Moreover the average fatality rate even fell in the states that raised
their speed limits
63 The Fatality rate Is it a reliable metric
In 1921 with fewer fatalities and fewer miles driven and the first year for
which the fatality rate could be computed the rate was 2408 It was down to
1479 in 1931 but the number of deaths had climbed to 31963 more than
double the 1921 absolute fatality number of 13253 It had dropped to 550 in
1966 the year of the highly publicized Congressional hearings but the
number of fatalities had climbed to 50984 in that fateful The Highway Safety
Act of 1966 ranks as one of the major acts of Congress and President
Johnson signed it saying that ―we have been tolerating a raging epidemic of
highway deathshellip see extract pasted below
httpwwwenotescommajor-acts-congresshighway-safety-act
Page 28 of 45
The act was motivated primarily by growing public concern over the rising number
of traffic fatalities in the United States Between 1960 and 1965 the annual number
of traffic fatalities increased by nearly thirty percent As President Lyndon B
Johnson stated at the signing of the act on September 9 1966 we have tolerated
a raging epidemic of highway death which has killed more of our youth than all
other diseases combined Through the Highway Safety Act we are going to find out
more about highway diseasemdashand we aim to cure it
Nonetheless highways fatalities continued to increase until the Arab oil
embargo of 1973 led to the NMSL of 55 mph all across the USA Do we just
ignore this undeniable historical record and focus only on the declining fatality
rate as the NMA and other proponents of higher speed limits seem to argue
(see links above)
The misleading nature of using fatality rates (per 100 M VMT) alone is also
obvious if one considers fatality data for individual states Take for example
the state of Montana which seems to have experienced no increase in
fatalities after repeal of NMSL
httpwww-nrdnhtsadotgovdepartmentsnrd-
30ncsaSTSI30_MT200930_MT_2009htm
For the period 2005-2009 the absolute number of fatalities for Montana
varied between a high of 277 in 2007 to a low of 229 in 2009 The fatality
rates per 100 M VMT on the other hand varied from a high of 245 for 2007
to a low of 201 for 2009 The corresponding US fatality rates varied from
136 to 114 Is the higher number for the fatality rate for Montana compared
to USA good or bad Likewise fatality rate per 100000 of population was
much higher for Montana than the US as a whole
This again highlights the pitfalls of using simple ratios to assess fatality statistics
without a full analysis of the underlying trends We will discuss this point
separately
As shown already the continuous decline in the fatality rate is a mathematical
artifact and essentially overlooks the unmistakable positive correlation
between the variables x and y of the type y = hx + c which becomes obvious
Page 29 of 45
only when we prepare the x-y scatter graph The ratio yx = h + (cx) can
decrease with increasing x (VMT) and increasing y (fatalities) since the
intercept c has a positive value when we consider only data spanning a short
period (such as 1994-2009 of more relevance to the current situation)
The debate between fatality rates and absolute number of fatalities is an
unending one A few years ago the Wall Street Journal carried an article
which was entitled (or something close) ―Unemployments rate in Ohio are
going down but why is the number of unemployed increasing The reason is
the same The graph of the number of unemployed (y) versus the number in
the labor market (x) is linear with a positive slope h and a positive intercept c
So the unemployment rate computed using the ratio yx keeps going down
year after year although the number unemployed keeps increasing Is it a
good thing that the unemployment rate is going down when more people
seem to be unable to find gainful unemployment
Or consider the situation with cancer death rates This too has been going
down in recent years but the actual number of cancer-related deaths has not
declined in any significant way Is it good that cancer death rates are going
down In all these situations the researchers or the socio-econo-politico
analysts involved in analyzing the trends in the data have failed to consider
the underlying x-y relation describing each problem
Hence it appears that the debate on the effect of increased speed limits
should not be focused on only the fatality rates (which have been decreasing
and proponents of higher speed limits cite this in their arguments) or even the
absolute number of fatalities (which has been the focus here) but on the
relationship between speed and the number of fatal crashes and the number
of fatalities within each speed segment (see Table 3 and also Figure 4)
Unfortunately details of number of fatalities and the number of fatal crashes
at each speed limit are not available even from NHTSA for detailed study
When a crash does occur (it is immaterial how many miles were driven) the
speed of the driver and vehicle design and engineering including safety
devices in place (seat belts airbags other impact absorbing technologies)
Page 30 of 45
determine if the occupants(s) will be killed One cannot argue that speed
does NOT kill That would be an absolute denial of the laws of physics
Studies show that setting the speed limit at the 85th percentile in any given
zone (this is the speed at or below which 85 of drivers are observed to
travel in traffic engineering studies) is the safest speed limit The majority of
drivers try to obey the posted speed limit while a few choose to drive at a
speed they consider is safe and prudent These are also perhaps the most
vociferous advocates of higher speed limits It is this tension caused due to
differences in speeds that leads to tailgating improper passing reckless
driving weaving from lane to lane and ultimately crashes and deaths in some
unfortunate cases
httpblogmotoristsorgspeed-limits-slower-safer
MARK TAYLOR
ANOTHER LOST A man was killed when his 4WD drive hit a tree east of Morrinsville (in New
Zealand) on Monday May 30 2011 The driver lost control of the vehicle on a bend probably tried
to correct his mistake and put the car into a ―yaw causing it to leave the road and smash sideways
into a tree Alerts to slow down had been posted since this was a high accident area but the driver
probably did not pay attention
64 Other factors
Many other factors besides speed no doubt affect highway fatalities The
vehicles of the 21st century are very different from the vehicles of the mid 20th
Page 31 of 45
century Technological innovations such as improvements in vehicle design
and engineering have greatly increased crash worthiness of vehicles even at
high speeds Environmental factors such as the weather also contribute to
accidents but not necessarily to increased fatalities Drivers actually tend to
slow down instinctively during adverse weather conditions (rain snow storms
etc) and although such weather may contribute to increased accidents the
lower speeds actually reduce fatalities
Yes technology has changed fundamentally from 1966 Drivers today are
more distracted by their cellmobile phone conversations (and also built-in
phones in luxury models) and text messaging than the drivers of the pre-1966
era High end cars now have many multimedia and internet features Again a
careful observation (even personal experience by the author) suggests that
such distracted drivers actually tend to (instinctively) drive more slowly and
hold up the traffic Perhaps such behavior leads to an increase in the number
of accidents but it does not necessarily lead to an increase in the number of
accident-related fatalities
Much talked about technological innovations such as automatic collision
avoidance systems and sensors (on the sides of vehicles) can indeed detect
vehicles in the front and neighboring lanes Furthermore vehicle-to-vehicle
communication systems vehicle-to-infrastructure communication systems
can no doubt avoid collisions and accidents Again such collision avoidance
systems work and are effective entirely because they automatically reduce
vehicle speeds - even if one of the offending vehicles is being at a super
high speed Also it must be remembered that such futuristic systems have
not yet been implemented widely nor can they be implemented widely since
the large majority of vehicles on the road are NOT luxury models Advanced
safety features come with a price and not all drivers can afford to pay that
price and ―buy that ―additional safety
Ultimately it is the laws of physics that govern what will happen when two or
more vehicles collide or even when a single vehicle collides with a stationary
infrastructural object (a bridge a wall a building or some impediment on the
road) The lower the number of crashes the lower the number of fatalities as
revealed by the 1994-2009 data graphed in Figure 5 The higher the speed of
Page 32 of 45
the object or objects that are involved in a collision the higher the kinetic
energy K that must be absorbed andor dissipated Increasing the posted
speed limit only increases the energy that must be absorbed when a crash
does occur This ultimately is the most important criterion determining the
number of fatalities
The kinetic energy increases as the square of the speed being given by the
well-known formula K = frac12 mv2 where m is the mass of the vehicle (in
laypersonlsquos language m increases directly with vehicle weight) and v is the
speed For the same vehicle mass an increase in the speed from 55 mph to
85 mph increases the kinetic energy K by a factor of 239 or roughly a 250
increase in the kinetic energy that must be absorbed in a collision
Ideally speaking the kinetic energy of the colliding object(s) is absorbed by
the vehicle infrastructure (a sturdy space frame the engine other vehicle
components etc) andor the surroundings However in the unfortunate
cases where this kinetic energy must be absorbed by the vehicle occupant(s)
the result is severe life-altering injuries andor death An unequivocal
relationship between an increase in vehicle speeds and fatal accidents can
be demonstrated by a careful examination of available traffic fatality data
This is a more involved discussion and is not the purpose of this short
communication These topics are no doubt very politically charged with many
social legal and financial implications with each interest group favoring a
different conclusion Nonetheless we cannot escape the laws of physics as
they govern the fundamental need to absorb higher and higher values of the
kinetic energy K with increasing vehicle speeds This same point is also
emphasized by Dr Friedman of the University of Illinois Chicago (see earlier
discussion)
Speed kills because of these energy transfer considerations and there can be
no doubt about it
Innovative 21st century solutions to speed management on the highways
such as strict enforcement of speed limits minimizing speed dispersion
(difference between speeds at which different drivers travel) while using
cameras to track the 15 of drivers who willfully violate the speed limit and
Page 33 of 45
create hazardous driving conditions is certainly recommended (Recall that
the optimum recommended speed limit is at or below which 85 of all drivers
travel ndash a policy also supported by NMA) Even on this score however the
results are confounding if we consider the Australian experience
httpwwwthenewspapercomnews282840asp
Up until 2007 there was no speed limit in the Northern Territory of
Australia Imposing a speed limit 130 kmph (80 mph) on some areas and
110 kmph (68 mph) in some others actually increased the number of deaths
The death toll in 2006 when there was no speed limit in this region was 44
and went up to 75 in 2009 see data table in link below
httpwwwthenewspapercomrlcdocs2009au-ntroadtollpdf
Furthermore it appears that installation of cameras to enforce speed limits
has proved to be a hazardous distraction to drivers and deaths actually
began to skyrocket between 2005 and 2007 in all Australian roadways
The main purpose here is to sound a cautionary note amid renewed attempts
in many states across the US to increase the speed limits on our highways by
calling attention to the historical facts regarding the ―epidemic levels of
highway traffic fatalities that engaged our national attention in the fateful year
of 1966 The graphical representation of the traffic fatality data in Figures 1
to 5 tells its own story
Indeed it would be tragic if highway-accident-related fatalities were to start
increasing once again and reach the historically high level that was last seen
in 1972 the year before the Arab oil embargo of 1973
Page 34 of 45
Conclusions
1 The graphical representation of the highway fatality data and the brief
summary of the historical facts of traffic safety legislation suggest that
recent attempts to increase the speed limits by various states (notably
Texas) may be misguided The distinct peak in the highway fatalities
observed in these graphs is highly alarming This appears to be related to
the enactment of the National Maximum Speed Limit (NSML) in 1974
following the 1973 Arab oil embargo Although NSML was motivated by a
desire to reduce gasoline consumption an unintended benefit might have
been a dramatic reduction in fatalities The fundamental reasons for the
peak in the fatalities-VMT curve must be examined carefully without
political posturing
2 The widely used fatality rate fatalities per 100 M vehicle miles traveled
has been declining since 1921 the first year for which a fatality rate could
be computed and has now reached a historical low The absolute number
of fatalities on the other hand was increasing in the 1950s and 1960s at
an alarming rate and the public outcry that ensued led to the highly
publicized Congressional hearing of 1966 and the subsequent traffic safety
legislations The fatality rate has been decreasing even in the most recent
15-year period (1994-2009) again with increasing fatalities although less
dramatically Thus it appears that fatality rate calculation based on vehicle
miles traveled (VMT) might not be a reliable indicator of the underlying
dynamics in the fatality trends
3 More detailed compilation of number of fatalities and the number of fatal
crashes within each speed limit segment is required to better understand
the effect of increasing speed limits on highway fatalities (and also fatality
rates) Such data is already available and is being compiled at the local
city and county levels in all jurisdictions and only needs to be reorganized
to highlight the effect of (posted) speed limits on the number of crashes
and fatalities This will require some minor rewriting and revisions to the
chapters named ―Crashes and ―States in the annual NHTSA reports
Page 35 of 45
Analysis of the fatalities-crashes data for several years with various
speed limits will be more revealing and meaningful than the current
fatality rates analysis and will be discussed separately in a follow up
report
4 One should not be lulled by the fact that vehicles of the 21st century are
now equipped with advanced safety features not available in the 1950s
and the 1960s In spite of these safety features the laws of physics dictate
that the higher the speed the higher kinetic energy of the colliding objects
and hence the greater the risk indeed near certainty of fatalities in a
higher speed collision compared to a lower speed one
5 The higher the speed at which the vehicle that is involved in a crash is
traveling the higher the kinetic energy that must be absorbed andor
dissipated without affecting the occupant(s) to avoid serious injuries andor
death This was true in the 1950s and the 1960s and will continue to be
true in the 21st century as well
Speed Kills for this just reason
6 It appears that higher fuel economies and reduced
highway fatalities were the twin societal benefits of 55
mph adopted after 1973 If so the current attempts to
increase the speed limits appear to be in conflict with
other important societal objectives
Page 36 of 45
Table 1 Annual US Street amp Highway
Fatalities from 1957
Year
Fatalities
Vehicle Miles
(millions)
Rate100M Vehicle Miles
1957 38702 646915 598
1958 36981 664915 556
1959 37910 700478 541
1960 38137 718845 531
1961 38091 737535 516
1962 40804 766852 532
1963 43564 805423 541
1964 47700 846500 563
1965 49163 887640 554
1966 51524 927915 555
1967 51559 965132 534
1968 53831 1019726 528
1969 55032 1066108 516
1970 53672 1114098 482
1971 53761 1183524 454
1972 55704 1264614 440
1973 55113 1316207 419
1974 46078 1282790 359
1975 45500 1330074 342
1976 45523 1402380 325
1977 47878 1467027 326
1978 50331 1544704 326
1979 51103 1529133 334
1980 51091 1527295 335
1981 49301 1552803 317
1982 43945 1595010 276
1983 42589 1652788 258
1984 44257 1720269 257
1985 43795 1774179 247
Page 37 of 45
1986 46056 1835000 251
1987 46385 1921000 241
1988 47093 2026000 232
1989 45555 2107040 216
1990 44529 2147501 207
1991 41162 2172214 189
1992 39235 2239828 175
1993 40115 2296585 175
1994 40676 2359984 172
1995 41798 2422696 173
1996 41907 2485848 169
1997 41967 2560373 164
Data from Federal Highway Administration
Source httpwwwpublicpurposecomhwy-fatal57+htm
Telephone +16186328507 - Facsimile +16186328538
WENDELL COX CONSULTANCY P O Box 841 - Belleville IL 62269 USA
Page 38 of 45
Fatality data for 1921-1982 compiled by NHTSA
Year
VMT
(Millions)
VMT
(Billions)
Fatalities
Fatality rate
per 100 M VMT
1921 55027 5503 13253 241 1922 67697 6770 14859 219 1923 84995 8500 17870 210 1924 104838 10484 18400 176 1925 122346 12235 20771 170 1926 140735 14074 22194 158 1927 158453 15845 24470 154 1928 172856 17286 26557 154 1929 197720 19772 29592 150 1930 206320 20632 31204 151 1931 216151 21615 31963 148 1932 200517 20052 27979 140 1933 200642 20064 29746 148 1934 215563 21556 34240 159 1935 228568 22857 34494 151 1936 252128 25213 36126 143 1937 270110 27011 37819 140 1938 271177 27118 31083 115 1939 285402 28540 30895 108 1940 302188 30219 32914 109 1941 333612 33361 38142 114 1942 268224 26822 27007 101 1943 208192 20819 22727 109 1944 212713 21271 23165 109 1945 250173 25017 26785 107 1946 340880 34088 31874 94 1947 370894 37089 31193 84 1948 397957 39796 30775 77 1949 424461 42446 30246 71 1950 458246 45825 33186 72 1951 491093 49109 35309 72
1952 513581 51358 36088 70
Page 39 of 45
1953 544433 54443 36190 66 1954 561963 56196 33890 60 1955 605646 60565 36688 61 1956 627843 62784 37965 60 1957 647004 64700 36932 57 1958 664653 66465 35331 53 1959 700480 70048 36223 52 1960 718762 71876 36399 51 1961 737421 73742 36285 49 1962 766734 76673 38980 51 1963 805249 80525 41723 52 1964 846298 84630 45645 54 1965 887812 88781 47089 53 1966 925899 92590 50894 55 1967 964005 96401 50724 53 1968 1015869 101587 52725 52 1969 1061791 106179 53543 50 1970 1109724 110972 52627 47 1971 1178811 117881 52542 45 1972 1259786 125979 54589 43 1973 1313110 131311 54052 41 1974 1280544 128054 45196 35 1975 1327664 132766 44525 34 1976 1402380 140238 45523 32 1977 1467027 146703 47878 33 1978 1544704 154470 50331 33 1979 1529133 152913 51093 33 1980 1527295 152730 51091 33 1981 1555308 155531 49301 32 1982 1595010 159501 43945 28
Source Analysis of Significant Decline in Motor Vehicle Traffic Fatalities in
2008 httpwww-nrdnhtsadotgovPubs811346pdf see Table A1 page 31
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Page 40 of 45
Acknowledgements
The author is grateful for thoughtful comments provided by friends and colleagues
with whom this document was shared via email prior to it being uploaded as a
publicly available document for wider dissemination and study The comments
offered by Prof Subra Ganesan of Oakland University Electrical and Computer
Engineering Department are reproduced with permission in their entirety
About the author
The author obtained his Masterrsquos (S M) and Doctoral (Sc D) degrees in Materials Engineering
from the Massachusetts Institute of Technology Cambridge USA He then spent his entire
professional career at leading US research institutions (MIT NASA Case Western Reserve
University and General Motors R amp D Center in Warren MI) He holds four patents in advanced
materials processing has co-authored two books and has published several scientific papers in
leading peer-reviewed international journals His expertise includes developing simple
mathematical models to explain the behavior of complex systems He can be reached by email at
vlaxmananhotmailcom
Page 41 of 45
Please Buckle Up
httpwwwlakecountypublichealthorgindexphpbuckle-up-montana
Public Awareness
Respect the Cage Exhibit
The Department of Transportation hopes that showing the reality of the crash will reduce traffic
fatalities A crushed car crash dummies and a sobering message ndash all part of the ―Respect The
Cage exhibit that is traveling across Montana The exhibit sponsored by the Montana Department
of Transportation stopped in Ronan on November 6th and is aimed at raising awareness about the
importance of wearing seat belts
The car in the exhibit was in an actual wreck many years ago
the passenger in the vehicle died because he was not wearing a
seat belt the driver who was wearing his seat belt survived
Montanarsquos likeliest crash fatality scenario
A Pickup
A Rural road
And Seat belts that
arenrsquot used
Page 42 of 45
Occupants of pickups are less likely to wear seat belts and pickups are more likely to
roll over than passenger cars
Seat belts reduce the risk of death by 60 percent in pickups and SUVs
In Montana from 2006-2008 81 of those killed in a crash while riding in a pickup were not wearing seat belts
In Montana pickups make up 401 of the vehicle population
For more information on Respect the Cage click here
Page 43 of 45
Appendix 1
Lack of seat belts leading cause of Louisiana highway deaths
1251 AM May 28 2011 |
Written by Adam Duvernay
Crashes involving unbuckled motorists were the leading cause of highway fatalities
in Louisiana last year and cost $9888 million according to recent reports The
Louisiana Highway Safety Commission reported 59 percent of vehicle occupants
killed in Louisiana crashes last year mdash about one in four mdash werent wearing seat
belts
httpwwwshreveporttimescomarticle20110528NEWS01105280354Lack-seat-
belts-leading-cause-La-highway-deathsodyssey=tab|topnews|text|FRONTPAGE
Crash bull Stats Published by NHTSAlsquos National Center for Statistics and Analysis 1200 New Jersey Avenue SE Washington DC 20590
DOT HS 811 451
Early Estimate of Motor Vehicle Traffic Fatalities in 2010
httpwww-nrdnhtsadotgovPubs811451pdf
Summary
A statistical projection of traffic fatalities in 2010 shows that an estimated 32788
people died in motor vehicle traffic crashes This represents a decline of about 3
percent as compared to the 33808 fatalities in 2009 as shown in Table 1 If these
projections are realized fatalities will be lowest on record (since 1949)
Traffic Safety Facts Overview 2009 Data
httpwww-nrdnhtsadotgovPubs811392pdf
In 2009 33808 people were killed in the estimated 5505000 police-reported
motor vehicle traffic crashes 2217000 people were injured and 3957000
crashes involved property damage only Compared to 2008 this is a 10-
percent decrease in the number of fatalities and a 5-percent decrease in the
Page 44 of 45
number of police-reported motor vehicle traffic crashes people injured and
crashes involving property damage
An average of 93 people died each day in motor vehicle crashes in 2009 mdash
an average of one every 16 minutes
Traffic Safety Facts Overview 2008 Data
httpwww-nrdnhtsadotgovPubs811162pdf
In 2008 37261 people were killed in the estimated 5811000 police-reported
motor vehicle traffic crashes 2346000 people were injured and 4146000
crashes involved property damage only
Some comments and Feedback
The following comments were received from Prof Ganesan after his review of the
first draft of this document It was subsequently revised thanks to this input to
address some of the very important issues raised here
Dear Laxman
The write up is not enough
You are emphasizing that the speed limit reduces the fatal accidents (comparing 1966
to 2000 accident numbers)
Can you also add a few sentences why the number is decreasing from 1980 to 2000
values (May be due to better design of vehicles)
Can you say anything about the fuel consumption with the speed for any typical
vehicle in 2011 or 2010 (do not consider the fatalities issue)
Probably a speed between 55 and 60 mph gives a better mileage If so this is a
compelling reason to keep the speed limit low But cars probably can be tuned to
give better mileage at any high speed also
Page 45 of 45
Weather is also a major factor in fatal accidents Speed limit may be kept low during
winter and kept higher in summer Give your comments on this too
Driver distractions can cause more accidents Now cars have many multimedia and
internet features Automatic collision avoidance systems and sensors on the sides can
detect vehicles in the front and neighboring lanes and it can automatically decrease
speed even if the driver speeds at super high speeds
Give some comments on this too There is also Vehicle to Vehicle communications
vehicle to infrastructure communications and they can avoid collisions and accidents
Technology has changed from 1966 I cannot agree with you on the speed limit
without any discussion on the above and other factors
Have a great day
Subra Ganesan
Professor Subramaniam Ganesan
Director Real Time amp DSP Lab
Electrical and Computer Engineering Department
2200 Squirrel Road Dodge Hall Room 105
Oakland University Rochester MI 48309 USA
Phone 248 370 2206 Fax 248 370 4633
wwwsecsoaklandedu~ganesan
IEEE Distinguished Visiting Speaker (2005-2009) Coordinator
IEEE SEM CS chapter Chair Region 4 and CS Society Board member
SAE ASEE ACM member
Page 27 of 45
This is a never ending debate Historically speaking fatality rates have been
going down ever since the compilation of traffic accidents data began Table
A1 in the appendix of a recent report by NHTSA (see link below) has highway
fatality rate data going back 1921
httpwww-nrdnhtsadotgovPubs811346pdf see appendix page 31
httpwwwmotoristsorgspeed-limitstruth
httpwwwmotoristsorgothercrash-data
httpwwwraisethespeedlimitorgmythshtml
httpwwwcatoorgpubspaspa346pdf
According to Stephen Moore of the Cato Institute (see last of the links above)
―All measures of highway safety show improvement not more deaths and
injuries since 1995 Despite the fact that 33 states raised their speed limits
immediately after the repeal of the mandatory federal speed limit the NHTSA
reported last October that the traffic death rate dropped to a record low level
in 1997lsquo Moreover the average fatality rate even fell in the states that raised
their speed limits
63 The Fatality rate Is it a reliable metric
In 1921 with fewer fatalities and fewer miles driven and the first year for
which the fatality rate could be computed the rate was 2408 It was down to
1479 in 1931 but the number of deaths had climbed to 31963 more than
double the 1921 absolute fatality number of 13253 It had dropped to 550 in
1966 the year of the highly publicized Congressional hearings but the
number of fatalities had climbed to 50984 in that fateful The Highway Safety
Act of 1966 ranks as one of the major acts of Congress and President
Johnson signed it saying that ―we have been tolerating a raging epidemic of
highway deathshellip see extract pasted below
httpwwwenotescommajor-acts-congresshighway-safety-act
Page 28 of 45
The act was motivated primarily by growing public concern over the rising number
of traffic fatalities in the United States Between 1960 and 1965 the annual number
of traffic fatalities increased by nearly thirty percent As President Lyndon B
Johnson stated at the signing of the act on September 9 1966 we have tolerated
a raging epidemic of highway death which has killed more of our youth than all
other diseases combined Through the Highway Safety Act we are going to find out
more about highway diseasemdashand we aim to cure it
Nonetheless highways fatalities continued to increase until the Arab oil
embargo of 1973 led to the NMSL of 55 mph all across the USA Do we just
ignore this undeniable historical record and focus only on the declining fatality
rate as the NMA and other proponents of higher speed limits seem to argue
(see links above)
The misleading nature of using fatality rates (per 100 M VMT) alone is also
obvious if one considers fatality data for individual states Take for example
the state of Montana which seems to have experienced no increase in
fatalities after repeal of NMSL
httpwww-nrdnhtsadotgovdepartmentsnrd-
30ncsaSTSI30_MT200930_MT_2009htm
For the period 2005-2009 the absolute number of fatalities for Montana
varied between a high of 277 in 2007 to a low of 229 in 2009 The fatality
rates per 100 M VMT on the other hand varied from a high of 245 for 2007
to a low of 201 for 2009 The corresponding US fatality rates varied from
136 to 114 Is the higher number for the fatality rate for Montana compared
to USA good or bad Likewise fatality rate per 100000 of population was
much higher for Montana than the US as a whole
This again highlights the pitfalls of using simple ratios to assess fatality statistics
without a full analysis of the underlying trends We will discuss this point
separately
As shown already the continuous decline in the fatality rate is a mathematical
artifact and essentially overlooks the unmistakable positive correlation
between the variables x and y of the type y = hx + c which becomes obvious
Page 29 of 45
only when we prepare the x-y scatter graph The ratio yx = h + (cx) can
decrease with increasing x (VMT) and increasing y (fatalities) since the
intercept c has a positive value when we consider only data spanning a short
period (such as 1994-2009 of more relevance to the current situation)
The debate between fatality rates and absolute number of fatalities is an
unending one A few years ago the Wall Street Journal carried an article
which was entitled (or something close) ―Unemployments rate in Ohio are
going down but why is the number of unemployed increasing The reason is
the same The graph of the number of unemployed (y) versus the number in
the labor market (x) is linear with a positive slope h and a positive intercept c
So the unemployment rate computed using the ratio yx keeps going down
year after year although the number unemployed keeps increasing Is it a
good thing that the unemployment rate is going down when more people
seem to be unable to find gainful unemployment
Or consider the situation with cancer death rates This too has been going
down in recent years but the actual number of cancer-related deaths has not
declined in any significant way Is it good that cancer death rates are going
down In all these situations the researchers or the socio-econo-politico
analysts involved in analyzing the trends in the data have failed to consider
the underlying x-y relation describing each problem
Hence it appears that the debate on the effect of increased speed limits
should not be focused on only the fatality rates (which have been decreasing
and proponents of higher speed limits cite this in their arguments) or even the
absolute number of fatalities (which has been the focus here) but on the
relationship between speed and the number of fatal crashes and the number
of fatalities within each speed segment (see Table 3 and also Figure 4)
Unfortunately details of number of fatalities and the number of fatal crashes
at each speed limit are not available even from NHTSA for detailed study
When a crash does occur (it is immaterial how many miles were driven) the
speed of the driver and vehicle design and engineering including safety
devices in place (seat belts airbags other impact absorbing technologies)
Page 30 of 45
determine if the occupants(s) will be killed One cannot argue that speed
does NOT kill That would be an absolute denial of the laws of physics
Studies show that setting the speed limit at the 85th percentile in any given
zone (this is the speed at or below which 85 of drivers are observed to
travel in traffic engineering studies) is the safest speed limit The majority of
drivers try to obey the posted speed limit while a few choose to drive at a
speed they consider is safe and prudent These are also perhaps the most
vociferous advocates of higher speed limits It is this tension caused due to
differences in speeds that leads to tailgating improper passing reckless
driving weaving from lane to lane and ultimately crashes and deaths in some
unfortunate cases
httpblogmotoristsorgspeed-limits-slower-safer
MARK TAYLOR
ANOTHER LOST A man was killed when his 4WD drive hit a tree east of Morrinsville (in New
Zealand) on Monday May 30 2011 The driver lost control of the vehicle on a bend probably tried
to correct his mistake and put the car into a ―yaw causing it to leave the road and smash sideways
into a tree Alerts to slow down had been posted since this was a high accident area but the driver
probably did not pay attention
64 Other factors
Many other factors besides speed no doubt affect highway fatalities The
vehicles of the 21st century are very different from the vehicles of the mid 20th
Page 31 of 45
century Technological innovations such as improvements in vehicle design
and engineering have greatly increased crash worthiness of vehicles even at
high speeds Environmental factors such as the weather also contribute to
accidents but not necessarily to increased fatalities Drivers actually tend to
slow down instinctively during adverse weather conditions (rain snow storms
etc) and although such weather may contribute to increased accidents the
lower speeds actually reduce fatalities
Yes technology has changed fundamentally from 1966 Drivers today are
more distracted by their cellmobile phone conversations (and also built-in
phones in luxury models) and text messaging than the drivers of the pre-1966
era High end cars now have many multimedia and internet features Again a
careful observation (even personal experience by the author) suggests that
such distracted drivers actually tend to (instinctively) drive more slowly and
hold up the traffic Perhaps such behavior leads to an increase in the number
of accidents but it does not necessarily lead to an increase in the number of
accident-related fatalities
Much talked about technological innovations such as automatic collision
avoidance systems and sensors (on the sides of vehicles) can indeed detect
vehicles in the front and neighboring lanes Furthermore vehicle-to-vehicle
communication systems vehicle-to-infrastructure communication systems
can no doubt avoid collisions and accidents Again such collision avoidance
systems work and are effective entirely because they automatically reduce
vehicle speeds - even if one of the offending vehicles is being at a super
high speed Also it must be remembered that such futuristic systems have
not yet been implemented widely nor can they be implemented widely since
the large majority of vehicles on the road are NOT luxury models Advanced
safety features come with a price and not all drivers can afford to pay that
price and ―buy that ―additional safety
Ultimately it is the laws of physics that govern what will happen when two or
more vehicles collide or even when a single vehicle collides with a stationary
infrastructural object (a bridge a wall a building or some impediment on the
road) The lower the number of crashes the lower the number of fatalities as
revealed by the 1994-2009 data graphed in Figure 5 The higher the speed of
Page 32 of 45
the object or objects that are involved in a collision the higher the kinetic
energy K that must be absorbed andor dissipated Increasing the posted
speed limit only increases the energy that must be absorbed when a crash
does occur This ultimately is the most important criterion determining the
number of fatalities
The kinetic energy increases as the square of the speed being given by the
well-known formula K = frac12 mv2 where m is the mass of the vehicle (in
laypersonlsquos language m increases directly with vehicle weight) and v is the
speed For the same vehicle mass an increase in the speed from 55 mph to
85 mph increases the kinetic energy K by a factor of 239 or roughly a 250
increase in the kinetic energy that must be absorbed in a collision
Ideally speaking the kinetic energy of the colliding object(s) is absorbed by
the vehicle infrastructure (a sturdy space frame the engine other vehicle
components etc) andor the surroundings However in the unfortunate
cases where this kinetic energy must be absorbed by the vehicle occupant(s)
the result is severe life-altering injuries andor death An unequivocal
relationship between an increase in vehicle speeds and fatal accidents can
be demonstrated by a careful examination of available traffic fatality data
This is a more involved discussion and is not the purpose of this short
communication These topics are no doubt very politically charged with many
social legal and financial implications with each interest group favoring a
different conclusion Nonetheless we cannot escape the laws of physics as
they govern the fundamental need to absorb higher and higher values of the
kinetic energy K with increasing vehicle speeds This same point is also
emphasized by Dr Friedman of the University of Illinois Chicago (see earlier
discussion)
Speed kills because of these energy transfer considerations and there can be
no doubt about it
Innovative 21st century solutions to speed management on the highways
such as strict enforcement of speed limits minimizing speed dispersion
(difference between speeds at which different drivers travel) while using
cameras to track the 15 of drivers who willfully violate the speed limit and
Page 33 of 45
create hazardous driving conditions is certainly recommended (Recall that
the optimum recommended speed limit is at or below which 85 of all drivers
travel ndash a policy also supported by NMA) Even on this score however the
results are confounding if we consider the Australian experience
httpwwwthenewspapercomnews282840asp
Up until 2007 there was no speed limit in the Northern Territory of
Australia Imposing a speed limit 130 kmph (80 mph) on some areas and
110 kmph (68 mph) in some others actually increased the number of deaths
The death toll in 2006 when there was no speed limit in this region was 44
and went up to 75 in 2009 see data table in link below
httpwwwthenewspapercomrlcdocs2009au-ntroadtollpdf
Furthermore it appears that installation of cameras to enforce speed limits
has proved to be a hazardous distraction to drivers and deaths actually
began to skyrocket between 2005 and 2007 in all Australian roadways
The main purpose here is to sound a cautionary note amid renewed attempts
in many states across the US to increase the speed limits on our highways by
calling attention to the historical facts regarding the ―epidemic levels of
highway traffic fatalities that engaged our national attention in the fateful year
of 1966 The graphical representation of the traffic fatality data in Figures 1
to 5 tells its own story
Indeed it would be tragic if highway-accident-related fatalities were to start
increasing once again and reach the historically high level that was last seen
in 1972 the year before the Arab oil embargo of 1973
Page 34 of 45
Conclusions
1 The graphical representation of the highway fatality data and the brief
summary of the historical facts of traffic safety legislation suggest that
recent attempts to increase the speed limits by various states (notably
Texas) may be misguided The distinct peak in the highway fatalities
observed in these graphs is highly alarming This appears to be related to
the enactment of the National Maximum Speed Limit (NSML) in 1974
following the 1973 Arab oil embargo Although NSML was motivated by a
desire to reduce gasoline consumption an unintended benefit might have
been a dramatic reduction in fatalities The fundamental reasons for the
peak in the fatalities-VMT curve must be examined carefully without
political posturing
2 The widely used fatality rate fatalities per 100 M vehicle miles traveled
has been declining since 1921 the first year for which a fatality rate could
be computed and has now reached a historical low The absolute number
of fatalities on the other hand was increasing in the 1950s and 1960s at
an alarming rate and the public outcry that ensued led to the highly
publicized Congressional hearing of 1966 and the subsequent traffic safety
legislations The fatality rate has been decreasing even in the most recent
15-year period (1994-2009) again with increasing fatalities although less
dramatically Thus it appears that fatality rate calculation based on vehicle
miles traveled (VMT) might not be a reliable indicator of the underlying
dynamics in the fatality trends
3 More detailed compilation of number of fatalities and the number of fatal
crashes within each speed limit segment is required to better understand
the effect of increasing speed limits on highway fatalities (and also fatality
rates) Such data is already available and is being compiled at the local
city and county levels in all jurisdictions and only needs to be reorganized
to highlight the effect of (posted) speed limits on the number of crashes
and fatalities This will require some minor rewriting and revisions to the
chapters named ―Crashes and ―States in the annual NHTSA reports
Page 35 of 45
Analysis of the fatalities-crashes data for several years with various
speed limits will be more revealing and meaningful than the current
fatality rates analysis and will be discussed separately in a follow up
report
4 One should not be lulled by the fact that vehicles of the 21st century are
now equipped with advanced safety features not available in the 1950s
and the 1960s In spite of these safety features the laws of physics dictate
that the higher the speed the higher kinetic energy of the colliding objects
and hence the greater the risk indeed near certainty of fatalities in a
higher speed collision compared to a lower speed one
5 The higher the speed at which the vehicle that is involved in a crash is
traveling the higher the kinetic energy that must be absorbed andor
dissipated without affecting the occupant(s) to avoid serious injuries andor
death This was true in the 1950s and the 1960s and will continue to be
true in the 21st century as well
Speed Kills for this just reason
6 It appears that higher fuel economies and reduced
highway fatalities were the twin societal benefits of 55
mph adopted after 1973 If so the current attempts to
increase the speed limits appear to be in conflict with
other important societal objectives
Page 36 of 45
Table 1 Annual US Street amp Highway
Fatalities from 1957
Year
Fatalities
Vehicle Miles
(millions)
Rate100M Vehicle Miles
1957 38702 646915 598
1958 36981 664915 556
1959 37910 700478 541
1960 38137 718845 531
1961 38091 737535 516
1962 40804 766852 532
1963 43564 805423 541
1964 47700 846500 563
1965 49163 887640 554
1966 51524 927915 555
1967 51559 965132 534
1968 53831 1019726 528
1969 55032 1066108 516
1970 53672 1114098 482
1971 53761 1183524 454
1972 55704 1264614 440
1973 55113 1316207 419
1974 46078 1282790 359
1975 45500 1330074 342
1976 45523 1402380 325
1977 47878 1467027 326
1978 50331 1544704 326
1979 51103 1529133 334
1980 51091 1527295 335
1981 49301 1552803 317
1982 43945 1595010 276
1983 42589 1652788 258
1984 44257 1720269 257
1985 43795 1774179 247
Page 37 of 45
1986 46056 1835000 251
1987 46385 1921000 241
1988 47093 2026000 232
1989 45555 2107040 216
1990 44529 2147501 207
1991 41162 2172214 189
1992 39235 2239828 175
1993 40115 2296585 175
1994 40676 2359984 172
1995 41798 2422696 173
1996 41907 2485848 169
1997 41967 2560373 164
Data from Federal Highway Administration
Source httpwwwpublicpurposecomhwy-fatal57+htm
Telephone +16186328507 - Facsimile +16186328538
WENDELL COX CONSULTANCY P O Box 841 - Belleville IL 62269 USA
Page 38 of 45
Fatality data for 1921-1982 compiled by NHTSA
Year
VMT
(Millions)
VMT
(Billions)
Fatalities
Fatality rate
per 100 M VMT
1921 55027 5503 13253 241 1922 67697 6770 14859 219 1923 84995 8500 17870 210 1924 104838 10484 18400 176 1925 122346 12235 20771 170 1926 140735 14074 22194 158 1927 158453 15845 24470 154 1928 172856 17286 26557 154 1929 197720 19772 29592 150 1930 206320 20632 31204 151 1931 216151 21615 31963 148 1932 200517 20052 27979 140 1933 200642 20064 29746 148 1934 215563 21556 34240 159 1935 228568 22857 34494 151 1936 252128 25213 36126 143 1937 270110 27011 37819 140 1938 271177 27118 31083 115 1939 285402 28540 30895 108 1940 302188 30219 32914 109 1941 333612 33361 38142 114 1942 268224 26822 27007 101 1943 208192 20819 22727 109 1944 212713 21271 23165 109 1945 250173 25017 26785 107 1946 340880 34088 31874 94 1947 370894 37089 31193 84 1948 397957 39796 30775 77 1949 424461 42446 30246 71 1950 458246 45825 33186 72 1951 491093 49109 35309 72
1952 513581 51358 36088 70
Page 39 of 45
1953 544433 54443 36190 66 1954 561963 56196 33890 60 1955 605646 60565 36688 61 1956 627843 62784 37965 60 1957 647004 64700 36932 57 1958 664653 66465 35331 53 1959 700480 70048 36223 52 1960 718762 71876 36399 51 1961 737421 73742 36285 49 1962 766734 76673 38980 51 1963 805249 80525 41723 52 1964 846298 84630 45645 54 1965 887812 88781 47089 53 1966 925899 92590 50894 55 1967 964005 96401 50724 53 1968 1015869 101587 52725 52 1969 1061791 106179 53543 50 1970 1109724 110972 52627 47 1971 1178811 117881 52542 45 1972 1259786 125979 54589 43 1973 1313110 131311 54052 41 1974 1280544 128054 45196 35 1975 1327664 132766 44525 34 1976 1402380 140238 45523 32 1977 1467027 146703 47878 33 1978 1544704 154470 50331 33 1979 1529133 152913 51093 33 1980 1527295 152730 51091 33 1981 1555308 155531 49301 32 1982 1595010 159501 43945 28
Source Analysis of Significant Decline in Motor Vehicle Traffic Fatalities in
2008 httpwww-nrdnhtsadotgovPubs811346pdf see Table A1 page 31
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Page 40 of 45
Acknowledgements
The author is grateful for thoughtful comments provided by friends and colleagues
with whom this document was shared via email prior to it being uploaded as a
publicly available document for wider dissemination and study The comments
offered by Prof Subra Ganesan of Oakland University Electrical and Computer
Engineering Department are reproduced with permission in their entirety
About the author
The author obtained his Masterrsquos (S M) and Doctoral (Sc D) degrees in Materials Engineering
from the Massachusetts Institute of Technology Cambridge USA He then spent his entire
professional career at leading US research institutions (MIT NASA Case Western Reserve
University and General Motors R amp D Center in Warren MI) He holds four patents in advanced
materials processing has co-authored two books and has published several scientific papers in
leading peer-reviewed international journals His expertise includes developing simple
mathematical models to explain the behavior of complex systems He can be reached by email at
vlaxmananhotmailcom
Page 41 of 45
Please Buckle Up
httpwwwlakecountypublichealthorgindexphpbuckle-up-montana
Public Awareness
Respect the Cage Exhibit
The Department of Transportation hopes that showing the reality of the crash will reduce traffic
fatalities A crushed car crash dummies and a sobering message ndash all part of the ―Respect The
Cage exhibit that is traveling across Montana The exhibit sponsored by the Montana Department
of Transportation stopped in Ronan on November 6th and is aimed at raising awareness about the
importance of wearing seat belts
The car in the exhibit was in an actual wreck many years ago
the passenger in the vehicle died because he was not wearing a
seat belt the driver who was wearing his seat belt survived
Montanarsquos likeliest crash fatality scenario
A Pickup
A Rural road
And Seat belts that
arenrsquot used
Page 42 of 45
Occupants of pickups are less likely to wear seat belts and pickups are more likely to
roll over than passenger cars
Seat belts reduce the risk of death by 60 percent in pickups and SUVs
In Montana from 2006-2008 81 of those killed in a crash while riding in a pickup were not wearing seat belts
In Montana pickups make up 401 of the vehicle population
For more information on Respect the Cage click here
Page 43 of 45
Appendix 1
Lack of seat belts leading cause of Louisiana highway deaths
1251 AM May 28 2011 |
Written by Adam Duvernay
Crashes involving unbuckled motorists were the leading cause of highway fatalities
in Louisiana last year and cost $9888 million according to recent reports The
Louisiana Highway Safety Commission reported 59 percent of vehicle occupants
killed in Louisiana crashes last year mdash about one in four mdash werent wearing seat
belts
httpwwwshreveporttimescomarticle20110528NEWS01105280354Lack-seat-
belts-leading-cause-La-highway-deathsodyssey=tab|topnews|text|FRONTPAGE
Crash bull Stats Published by NHTSAlsquos National Center for Statistics and Analysis 1200 New Jersey Avenue SE Washington DC 20590
DOT HS 811 451
Early Estimate of Motor Vehicle Traffic Fatalities in 2010
httpwww-nrdnhtsadotgovPubs811451pdf
Summary
A statistical projection of traffic fatalities in 2010 shows that an estimated 32788
people died in motor vehicle traffic crashes This represents a decline of about 3
percent as compared to the 33808 fatalities in 2009 as shown in Table 1 If these
projections are realized fatalities will be lowest on record (since 1949)
Traffic Safety Facts Overview 2009 Data
httpwww-nrdnhtsadotgovPubs811392pdf
In 2009 33808 people were killed in the estimated 5505000 police-reported
motor vehicle traffic crashes 2217000 people were injured and 3957000
crashes involved property damage only Compared to 2008 this is a 10-
percent decrease in the number of fatalities and a 5-percent decrease in the
Page 44 of 45
number of police-reported motor vehicle traffic crashes people injured and
crashes involving property damage
An average of 93 people died each day in motor vehicle crashes in 2009 mdash
an average of one every 16 minutes
Traffic Safety Facts Overview 2008 Data
httpwww-nrdnhtsadotgovPubs811162pdf
In 2008 37261 people were killed in the estimated 5811000 police-reported
motor vehicle traffic crashes 2346000 people were injured and 4146000
crashes involved property damage only
Some comments and Feedback
The following comments were received from Prof Ganesan after his review of the
first draft of this document It was subsequently revised thanks to this input to
address some of the very important issues raised here
Dear Laxman
The write up is not enough
You are emphasizing that the speed limit reduces the fatal accidents (comparing 1966
to 2000 accident numbers)
Can you also add a few sentences why the number is decreasing from 1980 to 2000
values (May be due to better design of vehicles)
Can you say anything about the fuel consumption with the speed for any typical
vehicle in 2011 or 2010 (do not consider the fatalities issue)
Probably a speed between 55 and 60 mph gives a better mileage If so this is a
compelling reason to keep the speed limit low But cars probably can be tuned to
give better mileage at any high speed also
Page 45 of 45
Weather is also a major factor in fatal accidents Speed limit may be kept low during
winter and kept higher in summer Give your comments on this too
Driver distractions can cause more accidents Now cars have many multimedia and
internet features Automatic collision avoidance systems and sensors on the sides can
detect vehicles in the front and neighboring lanes and it can automatically decrease
speed even if the driver speeds at super high speeds
Give some comments on this too There is also Vehicle to Vehicle communications
vehicle to infrastructure communications and they can avoid collisions and accidents
Technology has changed from 1966 I cannot agree with you on the speed limit
without any discussion on the above and other factors
Have a great day
Subra Ganesan
Professor Subramaniam Ganesan
Director Real Time amp DSP Lab
Electrical and Computer Engineering Department
2200 Squirrel Road Dodge Hall Room 105
Oakland University Rochester MI 48309 USA
Phone 248 370 2206 Fax 248 370 4633
wwwsecsoaklandedu~ganesan
IEEE Distinguished Visiting Speaker (2005-2009) Coordinator
IEEE SEM CS chapter Chair Region 4 and CS Society Board member
SAE ASEE ACM member
Page 28 of 45
The act was motivated primarily by growing public concern over the rising number
of traffic fatalities in the United States Between 1960 and 1965 the annual number
of traffic fatalities increased by nearly thirty percent As President Lyndon B
Johnson stated at the signing of the act on September 9 1966 we have tolerated
a raging epidemic of highway death which has killed more of our youth than all
other diseases combined Through the Highway Safety Act we are going to find out
more about highway diseasemdashand we aim to cure it
Nonetheless highways fatalities continued to increase until the Arab oil
embargo of 1973 led to the NMSL of 55 mph all across the USA Do we just
ignore this undeniable historical record and focus only on the declining fatality
rate as the NMA and other proponents of higher speed limits seem to argue
(see links above)
The misleading nature of using fatality rates (per 100 M VMT) alone is also
obvious if one considers fatality data for individual states Take for example
the state of Montana which seems to have experienced no increase in
fatalities after repeal of NMSL
httpwww-nrdnhtsadotgovdepartmentsnrd-
30ncsaSTSI30_MT200930_MT_2009htm
For the period 2005-2009 the absolute number of fatalities for Montana
varied between a high of 277 in 2007 to a low of 229 in 2009 The fatality
rates per 100 M VMT on the other hand varied from a high of 245 for 2007
to a low of 201 for 2009 The corresponding US fatality rates varied from
136 to 114 Is the higher number for the fatality rate for Montana compared
to USA good or bad Likewise fatality rate per 100000 of population was
much higher for Montana than the US as a whole
This again highlights the pitfalls of using simple ratios to assess fatality statistics
without a full analysis of the underlying trends We will discuss this point
separately
As shown already the continuous decline in the fatality rate is a mathematical
artifact and essentially overlooks the unmistakable positive correlation
between the variables x and y of the type y = hx + c which becomes obvious
Page 29 of 45
only when we prepare the x-y scatter graph The ratio yx = h + (cx) can
decrease with increasing x (VMT) and increasing y (fatalities) since the
intercept c has a positive value when we consider only data spanning a short
period (such as 1994-2009 of more relevance to the current situation)
The debate between fatality rates and absolute number of fatalities is an
unending one A few years ago the Wall Street Journal carried an article
which was entitled (or something close) ―Unemployments rate in Ohio are
going down but why is the number of unemployed increasing The reason is
the same The graph of the number of unemployed (y) versus the number in
the labor market (x) is linear with a positive slope h and a positive intercept c
So the unemployment rate computed using the ratio yx keeps going down
year after year although the number unemployed keeps increasing Is it a
good thing that the unemployment rate is going down when more people
seem to be unable to find gainful unemployment
Or consider the situation with cancer death rates This too has been going
down in recent years but the actual number of cancer-related deaths has not
declined in any significant way Is it good that cancer death rates are going
down In all these situations the researchers or the socio-econo-politico
analysts involved in analyzing the trends in the data have failed to consider
the underlying x-y relation describing each problem
Hence it appears that the debate on the effect of increased speed limits
should not be focused on only the fatality rates (which have been decreasing
and proponents of higher speed limits cite this in their arguments) or even the
absolute number of fatalities (which has been the focus here) but on the
relationship between speed and the number of fatal crashes and the number
of fatalities within each speed segment (see Table 3 and also Figure 4)
Unfortunately details of number of fatalities and the number of fatal crashes
at each speed limit are not available even from NHTSA for detailed study
When a crash does occur (it is immaterial how many miles were driven) the
speed of the driver and vehicle design and engineering including safety
devices in place (seat belts airbags other impact absorbing technologies)
Page 30 of 45
determine if the occupants(s) will be killed One cannot argue that speed
does NOT kill That would be an absolute denial of the laws of physics
Studies show that setting the speed limit at the 85th percentile in any given
zone (this is the speed at or below which 85 of drivers are observed to
travel in traffic engineering studies) is the safest speed limit The majority of
drivers try to obey the posted speed limit while a few choose to drive at a
speed they consider is safe and prudent These are also perhaps the most
vociferous advocates of higher speed limits It is this tension caused due to
differences in speeds that leads to tailgating improper passing reckless
driving weaving from lane to lane and ultimately crashes and deaths in some
unfortunate cases
httpblogmotoristsorgspeed-limits-slower-safer
MARK TAYLOR
ANOTHER LOST A man was killed when his 4WD drive hit a tree east of Morrinsville (in New
Zealand) on Monday May 30 2011 The driver lost control of the vehicle on a bend probably tried
to correct his mistake and put the car into a ―yaw causing it to leave the road and smash sideways
into a tree Alerts to slow down had been posted since this was a high accident area but the driver
probably did not pay attention
64 Other factors
Many other factors besides speed no doubt affect highway fatalities The
vehicles of the 21st century are very different from the vehicles of the mid 20th
Page 31 of 45
century Technological innovations such as improvements in vehicle design
and engineering have greatly increased crash worthiness of vehicles even at
high speeds Environmental factors such as the weather also contribute to
accidents but not necessarily to increased fatalities Drivers actually tend to
slow down instinctively during adverse weather conditions (rain snow storms
etc) and although such weather may contribute to increased accidents the
lower speeds actually reduce fatalities
Yes technology has changed fundamentally from 1966 Drivers today are
more distracted by their cellmobile phone conversations (and also built-in
phones in luxury models) and text messaging than the drivers of the pre-1966
era High end cars now have many multimedia and internet features Again a
careful observation (even personal experience by the author) suggests that
such distracted drivers actually tend to (instinctively) drive more slowly and
hold up the traffic Perhaps such behavior leads to an increase in the number
of accidents but it does not necessarily lead to an increase in the number of
accident-related fatalities
Much talked about technological innovations such as automatic collision
avoidance systems and sensors (on the sides of vehicles) can indeed detect
vehicles in the front and neighboring lanes Furthermore vehicle-to-vehicle
communication systems vehicle-to-infrastructure communication systems
can no doubt avoid collisions and accidents Again such collision avoidance
systems work and are effective entirely because they automatically reduce
vehicle speeds - even if one of the offending vehicles is being at a super
high speed Also it must be remembered that such futuristic systems have
not yet been implemented widely nor can they be implemented widely since
the large majority of vehicles on the road are NOT luxury models Advanced
safety features come with a price and not all drivers can afford to pay that
price and ―buy that ―additional safety
Ultimately it is the laws of physics that govern what will happen when two or
more vehicles collide or even when a single vehicle collides with a stationary
infrastructural object (a bridge a wall a building or some impediment on the
road) The lower the number of crashes the lower the number of fatalities as
revealed by the 1994-2009 data graphed in Figure 5 The higher the speed of
Page 32 of 45
the object or objects that are involved in a collision the higher the kinetic
energy K that must be absorbed andor dissipated Increasing the posted
speed limit only increases the energy that must be absorbed when a crash
does occur This ultimately is the most important criterion determining the
number of fatalities
The kinetic energy increases as the square of the speed being given by the
well-known formula K = frac12 mv2 where m is the mass of the vehicle (in
laypersonlsquos language m increases directly with vehicle weight) and v is the
speed For the same vehicle mass an increase in the speed from 55 mph to
85 mph increases the kinetic energy K by a factor of 239 or roughly a 250
increase in the kinetic energy that must be absorbed in a collision
Ideally speaking the kinetic energy of the colliding object(s) is absorbed by
the vehicle infrastructure (a sturdy space frame the engine other vehicle
components etc) andor the surroundings However in the unfortunate
cases where this kinetic energy must be absorbed by the vehicle occupant(s)
the result is severe life-altering injuries andor death An unequivocal
relationship between an increase in vehicle speeds and fatal accidents can
be demonstrated by a careful examination of available traffic fatality data
This is a more involved discussion and is not the purpose of this short
communication These topics are no doubt very politically charged with many
social legal and financial implications with each interest group favoring a
different conclusion Nonetheless we cannot escape the laws of physics as
they govern the fundamental need to absorb higher and higher values of the
kinetic energy K with increasing vehicle speeds This same point is also
emphasized by Dr Friedman of the University of Illinois Chicago (see earlier
discussion)
Speed kills because of these energy transfer considerations and there can be
no doubt about it
Innovative 21st century solutions to speed management on the highways
such as strict enforcement of speed limits minimizing speed dispersion
(difference between speeds at which different drivers travel) while using
cameras to track the 15 of drivers who willfully violate the speed limit and
Page 33 of 45
create hazardous driving conditions is certainly recommended (Recall that
the optimum recommended speed limit is at or below which 85 of all drivers
travel ndash a policy also supported by NMA) Even on this score however the
results are confounding if we consider the Australian experience
httpwwwthenewspapercomnews282840asp
Up until 2007 there was no speed limit in the Northern Territory of
Australia Imposing a speed limit 130 kmph (80 mph) on some areas and
110 kmph (68 mph) in some others actually increased the number of deaths
The death toll in 2006 when there was no speed limit in this region was 44
and went up to 75 in 2009 see data table in link below
httpwwwthenewspapercomrlcdocs2009au-ntroadtollpdf
Furthermore it appears that installation of cameras to enforce speed limits
has proved to be a hazardous distraction to drivers and deaths actually
began to skyrocket between 2005 and 2007 in all Australian roadways
The main purpose here is to sound a cautionary note amid renewed attempts
in many states across the US to increase the speed limits on our highways by
calling attention to the historical facts regarding the ―epidemic levels of
highway traffic fatalities that engaged our national attention in the fateful year
of 1966 The graphical representation of the traffic fatality data in Figures 1
to 5 tells its own story
Indeed it would be tragic if highway-accident-related fatalities were to start
increasing once again and reach the historically high level that was last seen
in 1972 the year before the Arab oil embargo of 1973
Page 34 of 45
Conclusions
1 The graphical representation of the highway fatality data and the brief
summary of the historical facts of traffic safety legislation suggest that
recent attempts to increase the speed limits by various states (notably
Texas) may be misguided The distinct peak in the highway fatalities
observed in these graphs is highly alarming This appears to be related to
the enactment of the National Maximum Speed Limit (NSML) in 1974
following the 1973 Arab oil embargo Although NSML was motivated by a
desire to reduce gasoline consumption an unintended benefit might have
been a dramatic reduction in fatalities The fundamental reasons for the
peak in the fatalities-VMT curve must be examined carefully without
political posturing
2 The widely used fatality rate fatalities per 100 M vehicle miles traveled
has been declining since 1921 the first year for which a fatality rate could
be computed and has now reached a historical low The absolute number
of fatalities on the other hand was increasing in the 1950s and 1960s at
an alarming rate and the public outcry that ensued led to the highly
publicized Congressional hearing of 1966 and the subsequent traffic safety
legislations The fatality rate has been decreasing even in the most recent
15-year period (1994-2009) again with increasing fatalities although less
dramatically Thus it appears that fatality rate calculation based on vehicle
miles traveled (VMT) might not be a reliable indicator of the underlying
dynamics in the fatality trends
3 More detailed compilation of number of fatalities and the number of fatal
crashes within each speed limit segment is required to better understand
the effect of increasing speed limits on highway fatalities (and also fatality
rates) Such data is already available and is being compiled at the local
city and county levels in all jurisdictions and only needs to be reorganized
to highlight the effect of (posted) speed limits on the number of crashes
and fatalities This will require some minor rewriting and revisions to the
chapters named ―Crashes and ―States in the annual NHTSA reports
Page 35 of 45
Analysis of the fatalities-crashes data for several years with various
speed limits will be more revealing and meaningful than the current
fatality rates analysis and will be discussed separately in a follow up
report
4 One should not be lulled by the fact that vehicles of the 21st century are
now equipped with advanced safety features not available in the 1950s
and the 1960s In spite of these safety features the laws of physics dictate
that the higher the speed the higher kinetic energy of the colliding objects
and hence the greater the risk indeed near certainty of fatalities in a
higher speed collision compared to a lower speed one
5 The higher the speed at which the vehicle that is involved in a crash is
traveling the higher the kinetic energy that must be absorbed andor
dissipated without affecting the occupant(s) to avoid serious injuries andor
death This was true in the 1950s and the 1960s and will continue to be
true in the 21st century as well
Speed Kills for this just reason
6 It appears that higher fuel economies and reduced
highway fatalities were the twin societal benefits of 55
mph adopted after 1973 If so the current attempts to
increase the speed limits appear to be in conflict with
other important societal objectives
Page 36 of 45
Table 1 Annual US Street amp Highway
Fatalities from 1957
Year
Fatalities
Vehicle Miles
(millions)
Rate100M Vehicle Miles
1957 38702 646915 598
1958 36981 664915 556
1959 37910 700478 541
1960 38137 718845 531
1961 38091 737535 516
1962 40804 766852 532
1963 43564 805423 541
1964 47700 846500 563
1965 49163 887640 554
1966 51524 927915 555
1967 51559 965132 534
1968 53831 1019726 528
1969 55032 1066108 516
1970 53672 1114098 482
1971 53761 1183524 454
1972 55704 1264614 440
1973 55113 1316207 419
1974 46078 1282790 359
1975 45500 1330074 342
1976 45523 1402380 325
1977 47878 1467027 326
1978 50331 1544704 326
1979 51103 1529133 334
1980 51091 1527295 335
1981 49301 1552803 317
1982 43945 1595010 276
1983 42589 1652788 258
1984 44257 1720269 257
1985 43795 1774179 247
Page 37 of 45
1986 46056 1835000 251
1987 46385 1921000 241
1988 47093 2026000 232
1989 45555 2107040 216
1990 44529 2147501 207
1991 41162 2172214 189
1992 39235 2239828 175
1993 40115 2296585 175
1994 40676 2359984 172
1995 41798 2422696 173
1996 41907 2485848 169
1997 41967 2560373 164
Data from Federal Highway Administration
Source httpwwwpublicpurposecomhwy-fatal57+htm
Telephone +16186328507 - Facsimile +16186328538
WENDELL COX CONSULTANCY P O Box 841 - Belleville IL 62269 USA
Page 38 of 45
Fatality data for 1921-1982 compiled by NHTSA
Year
VMT
(Millions)
VMT
(Billions)
Fatalities
Fatality rate
per 100 M VMT
1921 55027 5503 13253 241 1922 67697 6770 14859 219 1923 84995 8500 17870 210 1924 104838 10484 18400 176 1925 122346 12235 20771 170 1926 140735 14074 22194 158 1927 158453 15845 24470 154 1928 172856 17286 26557 154 1929 197720 19772 29592 150 1930 206320 20632 31204 151 1931 216151 21615 31963 148 1932 200517 20052 27979 140 1933 200642 20064 29746 148 1934 215563 21556 34240 159 1935 228568 22857 34494 151 1936 252128 25213 36126 143 1937 270110 27011 37819 140 1938 271177 27118 31083 115 1939 285402 28540 30895 108 1940 302188 30219 32914 109 1941 333612 33361 38142 114 1942 268224 26822 27007 101 1943 208192 20819 22727 109 1944 212713 21271 23165 109 1945 250173 25017 26785 107 1946 340880 34088 31874 94 1947 370894 37089 31193 84 1948 397957 39796 30775 77 1949 424461 42446 30246 71 1950 458246 45825 33186 72 1951 491093 49109 35309 72
1952 513581 51358 36088 70
Page 39 of 45
1953 544433 54443 36190 66 1954 561963 56196 33890 60 1955 605646 60565 36688 61 1956 627843 62784 37965 60 1957 647004 64700 36932 57 1958 664653 66465 35331 53 1959 700480 70048 36223 52 1960 718762 71876 36399 51 1961 737421 73742 36285 49 1962 766734 76673 38980 51 1963 805249 80525 41723 52 1964 846298 84630 45645 54 1965 887812 88781 47089 53 1966 925899 92590 50894 55 1967 964005 96401 50724 53 1968 1015869 101587 52725 52 1969 1061791 106179 53543 50 1970 1109724 110972 52627 47 1971 1178811 117881 52542 45 1972 1259786 125979 54589 43 1973 1313110 131311 54052 41 1974 1280544 128054 45196 35 1975 1327664 132766 44525 34 1976 1402380 140238 45523 32 1977 1467027 146703 47878 33 1978 1544704 154470 50331 33 1979 1529133 152913 51093 33 1980 1527295 152730 51091 33 1981 1555308 155531 49301 32 1982 1595010 159501 43945 28
Source Analysis of Significant Decline in Motor Vehicle Traffic Fatalities in
2008 httpwww-nrdnhtsadotgovPubs811346pdf see Table A1 page 31
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Page 40 of 45
Acknowledgements
The author is grateful for thoughtful comments provided by friends and colleagues
with whom this document was shared via email prior to it being uploaded as a
publicly available document for wider dissemination and study The comments
offered by Prof Subra Ganesan of Oakland University Electrical and Computer
Engineering Department are reproduced with permission in their entirety
About the author
The author obtained his Masterrsquos (S M) and Doctoral (Sc D) degrees in Materials Engineering
from the Massachusetts Institute of Technology Cambridge USA He then spent his entire
professional career at leading US research institutions (MIT NASA Case Western Reserve
University and General Motors R amp D Center in Warren MI) He holds four patents in advanced
materials processing has co-authored two books and has published several scientific papers in
leading peer-reviewed international journals His expertise includes developing simple
mathematical models to explain the behavior of complex systems He can be reached by email at
vlaxmananhotmailcom
Page 41 of 45
Please Buckle Up
httpwwwlakecountypublichealthorgindexphpbuckle-up-montana
Public Awareness
Respect the Cage Exhibit
The Department of Transportation hopes that showing the reality of the crash will reduce traffic
fatalities A crushed car crash dummies and a sobering message ndash all part of the ―Respect The
Cage exhibit that is traveling across Montana The exhibit sponsored by the Montana Department
of Transportation stopped in Ronan on November 6th and is aimed at raising awareness about the
importance of wearing seat belts
The car in the exhibit was in an actual wreck many years ago
the passenger in the vehicle died because he was not wearing a
seat belt the driver who was wearing his seat belt survived
Montanarsquos likeliest crash fatality scenario
A Pickup
A Rural road
And Seat belts that
arenrsquot used
Page 42 of 45
Occupants of pickups are less likely to wear seat belts and pickups are more likely to
roll over than passenger cars
Seat belts reduce the risk of death by 60 percent in pickups and SUVs
In Montana from 2006-2008 81 of those killed in a crash while riding in a pickup were not wearing seat belts
In Montana pickups make up 401 of the vehicle population
For more information on Respect the Cage click here
Page 43 of 45
Appendix 1
Lack of seat belts leading cause of Louisiana highway deaths
1251 AM May 28 2011 |
Written by Adam Duvernay
Crashes involving unbuckled motorists were the leading cause of highway fatalities
in Louisiana last year and cost $9888 million according to recent reports The
Louisiana Highway Safety Commission reported 59 percent of vehicle occupants
killed in Louisiana crashes last year mdash about one in four mdash werent wearing seat
belts
httpwwwshreveporttimescomarticle20110528NEWS01105280354Lack-seat-
belts-leading-cause-La-highway-deathsodyssey=tab|topnews|text|FRONTPAGE
Crash bull Stats Published by NHTSAlsquos National Center for Statistics and Analysis 1200 New Jersey Avenue SE Washington DC 20590
DOT HS 811 451
Early Estimate of Motor Vehicle Traffic Fatalities in 2010
httpwww-nrdnhtsadotgovPubs811451pdf
Summary
A statistical projection of traffic fatalities in 2010 shows that an estimated 32788
people died in motor vehicle traffic crashes This represents a decline of about 3
percent as compared to the 33808 fatalities in 2009 as shown in Table 1 If these
projections are realized fatalities will be lowest on record (since 1949)
Traffic Safety Facts Overview 2009 Data
httpwww-nrdnhtsadotgovPubs811392pdf
In 2009 33808 people were killed in the estimated 5505000 police-reported
motor vehicle traffic crashes 2217000 people were injured and 3957000
crashes involved property damage only Compared to 2008 this is a 10-
percent decrease in the number of fatalities and a 5-percent decrease in the
Page 44 of 45
number of police-reported motor vehicle traffic crashes people injured and
crashes involving property damage
An average of 93 people died each day in motor vehicle crashes in 2009 mdash
an average of one every 16 minutes
Traffic Safety Facts Overview 2008 Data
httpwww-nrdnhtsadotgovPubs811162pdf
In 2008 37261 people were killed in the estimated 5811000 police-reported
motor vehicle traffic crashes 2346000 people were injured and 4146000
crashes involved property damage only
Some comments and Feedback
The following comments were received from Prof Ganesan after his review of the
first draft of this document It was subsequently revised thanks to this input to
address some of the very important issues raised here
Dear Laxman
The write up is not enough
You are emphasizing that the speed limit reduces the fatal accidents (comparing 1966
to 2000 accident numbers)
Can you also add a few sentences why the number is decreasing from 1980 to 2000
values (May be due to better design of vehicles)
Can you say anything about the fuel consumption with the speed for any typical
vehicle in 2011 or 2010 (do not consider the fatalities issue)
Probably a speed between 55 and 60 mph gives a better mileage If so this is a
compelling reason to keep the speed limit low But cars probably can be tuned to
give better mileage at any high speed also
Page 45 of 45
Weather is also a major factor in fatal accidents Speed limit may be kept low during
winter and kept higher in summer Give your comments on this too
Driver distractions can cause more accidents Now cars have many multimedia and
internet features Automatic collision avoidance systems and sensors on the sides can
detect vehicles in the front and neighboring lanes and it can automatically decrease
speed even if the driver speeds at super high speeds
Give some comments on this too There is also Vehicle to Vehicle communications
vehicle to infrastructure communications and they can avoid collisions and accidents
Technology has changed from 1966 I cannot agree with you on the speed limit
without any discussion on the above and other factors
Have a great day
Subra Ganesan
Professor Subramaniam Ganesan
Director Real Time amp DSP Lab
Electrical and Computer Engineering Department
2200 Squirrel Road Dodge Hall Room 105
Oakland University Rochester MI 48309 USA
Phone 248 370 2206 Fax 248 370 4633
wwwsecsoaklandedu~ganesan
IEEE Distinguished Visiting Speaker (2005-2009) Coordinator
IEEE SEM CS chapter Chair Region 4 and CS Society Board member
SAE ASEE ACM member
Page 29 of 45
only when we prepare the x-y scatter graph The ratio yx = h + (cx) can
decrease with increasing x (VMT) and increasing y (fatalities) since the
intercept c has a positive value when we consider only data spanning a short
period (such as 1994-2009 of more relevance to the current situation)
The debate between fatality rates and absolute number of fatalities is an
unending one A few years ago the Wall Street Journal carried an article
which was entitled (or something close) ―Unemployments rate in Ohio are
going down but why is the number of unemployed increasing The reason is
the same The graph of the number of unemployed (y) versus the number in
the labor market (x) is linear with a positive slope h and a positive intercept c
So the unemployment rate computed using the ratio yx keeps going down
year after year although the number unemployed keeps increasing Is it a
good thing that the unemployment rate is going down when more people
seem to be unable to find gainful unemployment
Or consider the situation with cancer death rates This too has been going
down in recent years but the actual number of cancer-related deaths has not
declined in any significant way Is it good that cancer death rates are going
down In all these situations the researchers or the socio-econo-politico
analysts involved in analyzing the trends in the data have failed to consider
the underlying x-y relation describing each problem
Hence it appears that the debate on the effect of increased speed limits
should not be focused on only the fatality rates (which have been decreasing
and proponents of higher speed limits cite this in their arguments) or even the
absolute number of fatalities (which has been the focus here) but on the
relationship between speed and the number of fatal crashes and the number
of fatalities within each speed segment (see Table 3 and also Figure 4)
Unfortunately details of number of fatalities and the number of fatal crashes
at each speed limit are not available even from NHTSA for detailed study
When a crash does occur (it is immaterial how many miles were driven) the
speed of the driver and vehicle design and engineering including safety
devices in place (seat belts airbags other impact absorbing technologies)
Page 30 of 45
determine if the occupants(s) will be killed One cannot argue that speed
does NOT kill That would be an absolute denial of the laws of physics
Studies show that setting the speed limit at the 85th percentile in any given
zone (this is the speed at or below which 85 of drivers are observed to
travel in traffic engineering studies) is the safest speed limit The majority of
drivers try to obey the posted speed limit while a few choose to drive at a
speed they consider is safe and prudent These are also perhaps the most
vociferous advocates of higher speed limits It is this tension caused due to
differences in speeds that leads to tailgating improper passing reckless
driving weaving from lane to lane and ultimately crashes and deaths in some
unfortunate cases
httpblogmotoristsorgspeed-limits-slower-safer
MARK TAYLOR
ANOTHER LOST A man was killed when his 4WD drive hit a tree east of Morrinsville (in New
Zealand) on Monday May 30 2011 The driver lost control of the vehicle on a bend probably tried
to correct his mistake and put the car into a ―yaw causing it to leave the road and smash sideways
into a tree Alerts to slow down had been posted since this was a high accident area but the driver
probably did not pay attention
64 Other factors
Many other factors besides speed no doubt affect highway fatalities The
vehicles of the 21st century are very different from the vehicles of the mid 20th
Page 31 of 45
century Technological innovations such as improvements in vehicle design
and engineering have greatly increased crash worthiness of vehicles even at
high speeds Environmental factors such as the weather also contribute to
accidents but not necessarily to increased fatalities Drivers actually tend to
slow down instinctively during adverse weather conditions (rain snow storms
etc) and although such weather may contribute to increased accidents the
lower speeds actually reduce fatalities
Yes technology has changed fundamentally from 1966 Drivers today are
more distracted by their cellmobile phone conversations (and also built-in
phones in luxury models) and text messaging than the drivers of the pre-1966
era High end cars now have many multimedia and internet features Again a
careful observation (even personal experience by the author) suggests that
such distracted drivers actually tend to (instinctively) drive more slowly and
hold up the traffic Perhaps such behavior leads to an increase in the number
of accidents but it does not necessarily lead to an increase in the number of
accident-related fatalities
Much talked about technological innovations such as automatic collision
avoidance systems and sensors (on the sides of vehicles) can indeed detect
vehicles in the front and neighboring lanes Furthermore vehicle-to-vehicle
communication systems vehicle-to-infrastructure communication systems
can no doubt avoid collisions and accidents Again such collision avoidance
systems work and are effective entirely because they automatically reduce
vehicle speeds - even if one of the offending vehicles is being at a super
high speed Also it must be remembered that such futuristic systems have
not yet been implemented widely nor can they be implemented widely since
the large majority of vehicles on the road are NOT luxury models Advanced
safety features come with a price and not all drivers can afford to pay that
price and ―buy that ―additional safety
Ultimately it is the laws of physics that govern what will happen when two or
more vehicles collide or even when a single vehicle collides with a stationary
infrastructural object (a bridge a wall a building or some impediment on the
road) The lower the number of crashes the lower the number of fatalities as
revealed by the 1994-2009 data graphed in Figure 5 The higher the speed of
Page 32 of 45
the object or objects that are involved in a collision the higher the kinetic
energy K that must be absorbed andor dissipated Increasing the posted
speed limit only increases the energy that must be absorbed when a crash
does occur This ultimately is the most important criterion determining the
number of fatalities
The kinetic energy increases as the square of the speed being given by the
well-known formula K = frac12 mv2 where m is the mass of the vehicle (in
laypersonlsquos language m increases directly with vehicle weight) and v is the
speed For the same vehicle mass an increase in the speed from 55 mph to
85 mph increases the kinetic energy K by a factor of 239 or roughly a 250
increase in the kinetic energy that must be absorbed in a collision
Ideally speaking the kinetic energy of the colliding object(s) is absorbed by
the vehicle infrastructure (a sturdy space frame the engine other vehicle
components etc) andor the surroundings However in the unfortunate
cases where this kinetic energy must be absorbed by the vehicle occupant(s)
the result is severe life-altering injuries andor death An unequivocal
relationship between an increase in vehicle speeds and fatal accidents can
be demonstrated by a careful examination of available traffic fatality data
This is a more involved discussion and is not the purpose of this short
communication These topics are no doubt very politically charged with many
social legal and financial implications with each interest group favoring a
different conclusion Nonetheless we cannot escape the laws of physics as
they govern the fundamental need to absorb higher and higher values of the
kinetic energy K with increasing vehicle speeds This same point is also
emphasized by Dr Friedman of the University of Illinois Chicago (see earlier
discussion)
Speed kills because of these energy transfer considerations and there can be
no doubt about it
Innovative 21st century solutions to speed management on the highways
such as strict enforcement of speed limits minimizing speed dispersion
(difference between speeds at which different drivers travel) while using
cameras to track the 15 of drivers who willfully violate the speed limit and
Page 33 of 45
create hazardous driving conditions is certainly recommended (Recall that
the optimum recommended speed limit is at or below which 85 of all drivers
travel ndash a policy also supported by NMA) Even on this score however the
results are confounding if we consider the Australian experience
httpwwwthenewspapercomnews282840asp
Up until 2007 there was no speed limit in the Northern Territory of
Australia Imposing a speed limit 130 kmph (80 mph) on some areas and
110 kmph (68 mph) in some others actually increased the number of deaths
The death toll in 2006 when there was no speed limit in this region was 44
and went up to 75 in 2009 see data table in link below
httpwwwthenewspapercomrlcdocs2009au-ntroadtollpdf
Furthermore it appears that installation of cameras to enforce speed limits
has proved to be a hazardous distraction to drivers and deaths actually
began to skyrocket between 2005 and 2007 in all Australian roadways
The main purpose here is to sound a cautionary note amid renewed attempts
in many states across the US to increase the speed limits on our highways by
calling attention to the historical facts regarding the ―epidemic levels of
highway traffic fatalities that engaged our national attention in the fateful year
of 1966 The graphical representation of the traffic fatality data in Figures 1
to 5 tells its own story
Indeed it would be tragic if highway-accident-related fatalities were to start
increasing once again and reach the historically high level that was last seen
in 1972 the year before the Arab oil embargo of 1973
Page 34 of 45
Conclusions
1 The graphical representation of the highway fatality data and the brief
summary of the historical facts of traffic safety legislation suggest that
recent attempts to increase the speed limits by various states (notably
Texas) may be misguided The distinct peak in the highway fatalities
observed in these graphs is highly alarming This appears to be related to
the enactment of the National Maximum Speed Limit (NSML) in 1974
following the 1973 Arab oil embargo Although NSML was motivated by a
desire to reduce gasoline consumption an unintended benefit might have
been a dramatic reduction in fatalities The fundamental reasons for the
peak in the fatalities-VMT curve must be examined carefully without
political posturing
2 The widely used fatality rate fatalities per 100 M vehicle miles traveled
has been declining since 1921 the first year for which a fatality rate could
be computed and has now reached a historical low The absolute number
of fatalities on the other hand was increasing in the 1950s and 1960s at
an alarming rate and the public outcry that ensued led to the highly
publicized Congressional hearing of 1966 and the subsequent traffic safety
legislations The fatality rate has been decreasing even in the most recent
15-year period (1994-2009) again with increasing fatalities although less
dramatically Thus it appears that fatality rate calculation based on vehicle
miles traveled (VMT) might not be a reliable indicator of the underlying
dynamics in the fatality trends
3 More detailed compilation of number of fatalities and the number of fatal
crashes within each speed limit segment is required to better understand
the effect of increasing speed limits on highway fatalities (and also fatality
rates) Such data is already available and is being compiled at the local
city and county levels in all jurisdictions and only needs to be reorganized
to highlight the effect of (posted) speed limits on the number of crashes
and fatalities This will require some minor rewriting and revisions to the
chapters named ―Crashes and ―States in the annual NHTSA reports
Page 35 of 45
Analysis of the fatalities-crashes data for several years with various
speed limits will be more revealing and meaningful than the current
fatality rates analysis and will be discussed separately in a follow up
report
4 One should not be lulled by the fact that vehicles of the 21st century are
now equipped with advanced safety features not available in the 1950s
and the 1960s In spite of these safety features the laws of physics dictate
that the higher the speed the higher kinetic energy of the colliding objects
and hence the greater the risk indeed near certainty of fatalities in a
higher speed collision compared to a lower speed one
5 The higher the speed at which the vehicle that is involved in a crash is
traveling the higher the kinetic energy that must be absorbed andor
dissipated without affecting the occupant(s) to avoid serious injuries andor
death This was true in the 1950s and the 1960s and will continue to be
true in the 21st century as well
Speed Kills for this just reason
6 It appears that higher fuel economies and reduced
highway fatalities were the twin societal benefits of 55
mph adopted after 1973 If so the current attempts to
increase the speed limits appear to be in conflict with
other important societal objectives
Page 36 of 45
Table 1 Annual US Street amp Highway
Fatalities from 1957
Year
Fatalities
Vehicle Miles
(millions)
Rate100M Vehicle Miles
1957 38702 646915 598
1958 36981 664915 556
1959 37910 700478 541
1960 38137 718845 531
1961 38091 737535 516
1962 40804 766852 532
1963 43564 805423 541
1964 47700 846500 563
1965 49163 887640 554
1966 51524 927915 555
1967 51559 965132 534
1968 53831 1019726 528
1969 55032 1066108 516
1970 53672 1114098 482
1971 53761 1183524 454
1972 55704 1264614 440
1973 55113 1316207 419
1974 46078 1282790 359
1975 45500 1330074 342
1976 45523 1402380 325
1977 47878 1467027 326
1978 50331 1544704 326
1979 51103 1529133 334
1980 51091 1527295 335
1981 49301 1552803 317
1982 43945 1595010 276
1983 42589 1652788 258
1984 44257 1720269 257
1985 43795 1774179 247
Page 37 of 45
1986 46056 1835000 251
1987 46385 1921000 241
1988 47093 2026000 232
1989 45555 2107040 216
1990 44529 2147501 207
1991 41162 2172214 189
1992 39235 2239828 175
1993 40115 2296585 175
1994 40676 2359984 172
1995 41798 2422696 173
1996 41907 2485848 169
1997 41967 2560373 164
Data from Federal Highway Administration
Source httpwwwpublicpurposecomhwy-fatal57+htm
Telephone +16186328507 - Facsimile +16186328538
WENDELL COX CONSULTANCY P O Box 841 - Belleville IL 62269 USA
Page 38 of 45
Fatality data for 1921-1982 compiled by NHTSA
Year
VMT
(Millions)
VMT
(Billions)
Fatalities
Fatality rate
per 100 M VMT
1921 55027 5503 13253 241 1922 67697 6770 14859 219 1923 84995 8500 17870 210 1924 104838 10484 18400 176 1925 122346 12235 20771 170 1926 140735 14074 22194 158 1927 158453 15845 24470 154 1928 172856 17286 26557 154 1929 197720 19772 29592 150 1930 206320 20632 31204 151 1931 216151 21615 31963 148 1932 200517 20052 27979 140 1933 200642 20064 29746 148 1934 215563 21556 34240 159 1935 228568 22857 34494 151 1936 252128 25213 36126 143 1937 270110 27011 37819 140 1938 271177 27118 31083 115 1939 285402 28540 30895 108 1940 302188 30219 32914 109 1941 333612 33361 38142 114 1942 268224 26822 27007 101 1943 208192 20819 22727 109 1944 212713 21271 23165 109 1945 250173 25017 26785 107 1946 340880 34088 31874 94 1947 370894 37089 31193 84 1948 397957 39796 30775 77 1949 424461 42446 30246 71 1950 458246 45825 33186 72 1951 491093 49109 35309 72
1952 513581 51358 36088 70
Page 39 of 45
1953 544433 54443 36190 66 1954 561963 56196 33890 60 1955 605646 60565 36688 61 1956 627843 62784 37965 60 1957 647004 64700 36932 57 1958 664653 66465 35331 53 1959 700480 70048 36223 52 1960 718762 71876 36399 51 1961 737421 73742 36285 49 1962 766734 76673 38980 51 1963 805249 80525 41723 52 1964 846298 84630 45645 54 1965 887812 88781 47089 53 1966 925899 92590 50894 55 1967 964005 96401 50724 53 1968 1015869 101587 52725 52 1969 1061791 106179 53543 50 1970 1109724 110972 52627 47 1971 1178811 117881 52542 45 1972 1259786 125979 54589 43 1973 1313110 131311 54052 41 1974 1280544 128054 45196 35 1975 1327664 132766 44525 34 1976 1402380 140238 45523 32 1977 1467027 146703 47878 33 1978 1544704 154470 50331 33 1979 1529133 152913 51093 33 1980 1527295 152730 51091 33 1981 1555308 155531 49301 32 1982 1595010 159501 43945 28
Source Analysis of Significant Decline in Motor Vehicle Traffic Fatalities in
2008 httpwww-nrdnhtsadotgovPubs811346pdf see Table A1 page 31
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Page 40 of 45
Acknowledgements
The author is grateful for thoughtful comments provided by friends and colleagues
with whom this document was shared via email prior to it being uploaded as a
publicly available document for wider dissemination and study The comments
offered by Prof Subra Ganesan of Oakland University Electrical and Computer
Engineering Department are reproduced with permission in their entirety
About the author
The author obtained his Masterrsquos (S M) and Doctoral (Sc D) degrees in Materials Engineering
from the Massachusetts Institute of Technology Cambridge USA He then spent his entire
professional career at leading US research institutions (MIT NASA Case Western Reserve
University and General Motors R amp D Center in Warren MI) He holds four patents in advanced
materials processing has co-authored two books and has published several scientific papers in
leading peer-reviewed international journals His expertise includes developing simple
mathematical models to explain the behavior of complex systems He can be reached by email at
vlaxmananhotmailcom
Page 41 of 45
Please Buckle Up
httpwwwlakecountypublichealthorgindexphpbuckle-up-montana
Public Awareness
Respect the Cage Exhibit
The Department of Transportation hopes that showing the reality of the crash will reduce traffic
fatalities A crushed car crash dummies and a sobering message ndash all part of the ―Respect The
Cage exhibit that is traveling across Montana The exhibit sponsored by the Montana Department
of Transportation stopped in Ronan on November 6th and is aimed at raising awareness about the
importance of wearing seat belts
The car in the exhibit was in an actual wreck many years ago
the passenger in the vehicle died because he was not wearing a
seat belt the driver who was wearing his seat belt survived
Montanarsquos likeliest crash fatality scenario
A Pickup
A Rural road
And Seat belts that
arenrsquot used
Page 42 of 45
Occupants of pickups are less likely to wear seat belts and pickups are more likely to
roll over than passenger cars
Seat belts reduce the risk of death by 60 percent in pickups and SUVs
In Montana from 2006-2008 81 of those killed in a crash while riding in a pickup were not wearing seat belts
In Montana pickups make up 401 of the vehicle population
For more information on Respect the Cage click here
Page 43 of 45
Appendix 1
Lack of seat belts leading cause of Louisiana highway deaths
1251 AM May 28 2011 |
Written by Adam Duvernay
Crashes involving unbuckled motorists were the leading cause of highway fatalities
in Louisiana last year and cost $9888 million according to recent reports The
Louisiana Highway Safety Commission reported 59 percent of vehicle occupants
killed in Louisiana crashes last year mdash about one in four mdash werent wearing seat
belts
httpwwwshreveporttimescomarticle20110528NEWS01105280354Lack-seat-
belts-leading-cause-La-highway-deathsodyssey=tab|topnews|text|FRONTPAGE
Crash bull Stats Published by NHTSAlsquos National Center for Statistics and Analysis 1200 New Jersey Avenue SE Washington DC 20590
DOT HS 811 451
Early Estimate of Motor Vehicle Traffic Fatalities in 2010
httpwww-nrdnhtsadotgovPubs811451pdf
Summary
A statistical projection of traffic fatalities in 2010 shows that an estimated 32788
people died in motor vehicle traffic crashes This represents a decline of about 3
percent as compared to the 33808 fatalities in 2009 as shown in Table 1 If these
projections are realized fatalities will be lowest on record (since 1949)
Traffic Safety Facts Overview 2009 Data
httpwww-nrdnhtsadotgovPubs811392pdf
In 2009 33808 people were killed in the estimated 5505000 police-reported
motor vehicle traffic crashes 2217000 people were injured and 3957000
crashes involved property damage only Compared to 2008 this is a 10-
percent decrease in the number of fatalities and a 5-percent decrease in the
Page 44 of 45
number of police-reported motor vehicle traffic crashes people injured and
crashes involving property damage
An average of 93 people died each day in motor vehicle crashes in 2009 mdash
an average of one every 16 minutes
Traffic Safety Facts Overview 2008 Data
httpwww-nrdnhtsadotgovPubs811162pdf
In 2008 37261 people were killed in the estimated 5811000 police-reported
motor vehicle traffic crashes 2346000 people were injured and 4146000
crashes involved property damage only
Some comments and Feedback
The following comments were received from Prof Ganesan after his review of the
first draft of this document It was subsequently revised thanks to this input to
address some of the very important issues raised here
Dear Laxman
The write up is not enough
You are emphasizing that the speed limit reduces the fatal accidents (comparing 1966
to 2000 accident numbers)
Can you also add a few sentences why the number is decreasing from 1980 to 2000
values (May be due to better design of vehicles)
Can you say anything about the fuel consumption with the speed for any typical
vehicle in 2011 or 2010 (do not consider the fatalities issue)
Probably a speed between 55 and 60 mph gives a better mileage If so this is a
compelling reason to keep the speed limit low But cars probably can be tuned to
give better mileage at any high speed also
Page 45 of 45
Weather is also a major factor in fatal accidents Speed limit may be kept low during
winter and kept higher in summer Give your comments on this too
Driver distractions can cause more accidents Now cars have many multimedia and
internet features Automatic collision avoidance systems and sensors on the sides can
detect vehicles in the front and neighboring lanes and it can automatically decrease
speed even if the driver speeds at super high speeds
Give some comments on this too There is also Vehicle to Vehicle communications
vehicle to infrastructure communications and they can avoid collisions and accidents
Technology has changed from 1966 I cannot agree with you on the speed limit
without any discussion on the above and other factors
Have a great day
Subra Ganesan
Professor Subramaniam Ganesan
Director Real Time amp DSP Lab
Electrical and Computer Engineering Department
2200 Squirrel Road Dodge Hall Room 105
Oakland University Rochester MI 48309 USA
Phone 248 370 2206 Fax 248 370 4633
wwwsecsoaklandedu~ganesan
IEEE Distinguished Visiting Speaker (2005-2009) Coordinator
IEEE SEM CS chapter Chair Region 4 and CS Society Board member
SAE ASEE ACM member
Page 30 of 45
determine if the occupants(s) will be killed One cannot argue that speed
does NOT kill That would be an absolute denial of the laws of physics
Studies show that setting the speed limit at the 85th percentile in any given
zone (this is the speed at or below which 85 of drivers are observed to
travel in traffic engineering studies) is the safest speed limit The majority of
drivers try to obey the posted speed limit while a few choose to drive at a
speed they consider is safe and prudent These are also perhaps the most
vociferous advocates of higher speed limits It is this tension caused due to
differences in speeds that leads to tailgating improper passing reckless
driving weaving from lane to lane and ultimately crashes and deaths in some
unfortunate cases
httpblogmotoristsorgspeed-limits-slower-safer
MARK TAYLOR
ANOTHER LOST A man was killed when his 4WD drive hit a tree east of Morrinsville (in New
Zealand) on Monday May 30 2011 The driver lost control of the vehicle on a bend probably tried
to correct his mistake and put the car into a ―yaw causing it to leave the road and smash sideways
into a tree Alerts to slow down had been posted since this was a high accident area but the driver
probably did not pay attention
64 Other factors
Many other factors besides speed no doubt affect highway fatalities The
vehicles of the 21st century are very different from the vehicles of the mid 20th
Page 31 of 45
century Technological innovations such as improvements in vehicle design
and engineering have greatly increased crash worthiness of vehicles even at
high speeds Environmental factors such as the weather also contribute to
accidents but not necessarily to increased fatalities Drivers actually tend to
slow down instinctively during adverse weather conditions (rain snow storms
etc) and although such weather may contribute to increased accidents the
lower speeds actually reduce fatalities
Yes technology has changed fundamentally from 1966 Drivers today are
more distracted by their cellmobile phone conversations (and also built-in
phones in luxury models) and text messaging than the drivers of the pre-1966
era High end cars now have many multimedia and internet features Again a
careful observation (even personal experience by the author) suggests that
such distracted drivers actually tend to (instinctively) drive more slowly and
hold up the traffic Perhaps such behavior leads to an increase in the number
of accidents but it does not necessarily lead to an increase in the number of
accident-related fatalities
Much talked about technological innovations such as automatic collision
avoidance systems and sensors (on the sides of vehicles) can indeed detect
vehicles in the front and neighboring lanes Furthermore vehicle-to-vehicle
communication systems vehicle-to-infrastructure communication systems
can no doubt avoid collisions and accidents Again such collision avoidance
systems work and are effective entirely because they automatically reduce
vehicle speeds - even if one of the offending vehicles is being at a super
high speed Also it must be remembered that such futuristic systems have
not yet been implemented widely nor can they be implemented widely since
the large majority of vehicles on the road are NOT luxury models Advanced
safety features come with a price and not all drivers can afford to pay that
price and ―buy that ―additional safety
Ultimately it is the laws of physics that govern what will happen when two or
more vehicles collide or even when a single vehicle collides with a stationary
infrastructural object (a bridge a wall a building or some impediment on the
road) The lower the number of crashes the lower the number of fatalities as
revealed by the 1994-2009 data graphed in Figure 5 The higher the speed of
Page 32 of 45
the object or objects that are involved in a collision the higher the kinetic
energy K that must be absorbed andor dissipated Increasing the posted
speed limit only increases the energy that must be absorbed when a crash
does occur This ultimately is the most important criterion determining the
number of fatalities
The kinetic energy increases as the square of the speed being given by the
well-known formula K = frac12 mv2 where m is the mass of the vehicle (in
laypersonlsquos language m increases directly with vehicle weight) and v is the
speed For the same vehicle mass an increase in the speed from 55 mph to
85 mph increases the kinetic energy K by a factor of 239 or roughly a 250
increase in the kinetic energy that must be absorbed in a collision
Ideally speaking the kinetic energy of the colliding object(s) is absorbed by
the vehicle infrastructure (a sturdy space frame the engine other vehicle
components etc) andor the surroundings However in the unfortunate
cases where this kinetic energy must be absorbed by the vehicle occupant(s)
the result is severe life-altering injuries andor death An unequivocal
relationship between an increase in vehicle speeds and fatal accidents can
be demonstrated by a careful examination of available traffic fatality data
This is a more involved discussion and is not the purpose of this short
communication These topics are no doubt very politically charged with many
social legal and financial implications with each interest group favoring a
different conclusion Nonetheless we cannot escape the laws of physics as
they govern the fundamental need to absorb higher and higher values of the
kinetic energy K with increasing vehicle speeds This same point is also
emphasized by Dr Friedman of the University of Illinois Chicago (see earlier
discussion)
Speed kills because of these energy transfer considerations and there can be
no doubt about it
Innovative 21st century solutions to speed management on the highways
such as strict enforcement of speed limits minimizing speed dispersion
(difference between speeds at which different drivers travel) while using
cameras to track the 15 of drivers who willfully violate the speed limit and
Page 33 of 45
create hazardous driving conditions is certainly recommended (Recall that
the optimum recommended speed limit is at or below which 85 of all drivers
travel ndash a policy also supported by NMA) Even on this score however the
results are confounding if we consider the Australian experience
httpwwwthenewspapercomnews282840asp
Up until 2007 there was no speed limit in the Northern Territory of
Australia Imposing a speed limit 130 kmph (80 mph) on some areas and
110 kmph (68 mph) in some others actually increased the number of deaths
The death toll in 2006 when there was no speed limit in this region was 44
and went up to 75 in 2009 see data table in link below
httpwwwthenewspapercomrlcdocs2009au-ntroadtollpdf
Furthermore it appears that installation of cameras to enforce speed limits
has proved to be a hazardous distraction to drivers and deaths actually
began to skyrocket between 2005 and 2007 in all Australian roadways
The main purpose here is to sound a cautionary note amid renewed attempts
in many states across the US to increase the speed limits on our highways by
calling attention to the historical facts regarding the ―epidemic levels of
highway traffic fatalities that engaged our national attention in the fateful year
of 1966 The graphical representation of the traffic fatality data in Figures 1
to 5 tells its own story
Indeed it would be tragic if highway-accident-related fatalities were to start
increasing once again and reach the historically high level that was last seen
in 1972 the year before the Arab oil embargo of 1973
Page 34 of 45
Conclusions
1 The graphical representation of the highway fatality data and the brief
summary of the historical facts of traffic safety legislation suggest that
recent attempts to increase the speed limits by various states (notably
Texas) may be misguided The distinct peak in the highway fatalities
observed in these graphs is highly alarming This appears to be related to
the enactment of the National Maximum Speed Limit (NSML) in 1974
following the 1973 Arab oil embargo Although NSML was motivated by a
desire to reduce gasoline consumption an unintended benefit might have
been a dramatic reduction in fatalities The fundamental reasons for the
peak in the fatalities-VMT curve must be examined carefully without
political posturing
2 The widely used fatality rate fatalities per 100 M vehicle miles traveled
has been declining since 1921 the first year for which a fatality rate could
be computed and has now reached a historical low The absolute number
of fatalities on the other hand was increasing in the 1950s and 1960s at
an alarming rate and the public outcry that ensued led to the highly
publicized Congressional hearing of 1966 and the subsequent traffic safety
legislations The fatality rate has been decreasing even in the most recent
15-year period (1994-2009) again with increasing fatalities although less
dramatically Thus it appears that fatality rate calculation based on vehicle
miles traveled (VMT) might not be a reliable indicator of the underlying
dynamics in the fatality trends
3 More detailed compilation of number of fatalities and the number of fatal
crashes within each speed limit segment is required to better understand
the effect of increasing speed limits on highway fatalities (and also fatality
rates) Such data is already available and is being compiled at the local
city and county levels in all jurisdictions and only needs to be reorganized
to highlight the effect of (posted) speed limits on the number of crashes
and fatalities This will require some minor rewriting and revisions to the
chapters named ―Crashes and ―States in the annual NHTSA reports
Page 35 of 45
Analysis of the fatalities-crashes data for several years with various
speed limits will be more revealing and meaningful than the current
fatality rates analysis and will be discussed separately in a follow up
report
4 One should not be lulled by the fact that vehicles of the 21st century are
now equipped with advanced safety features not available in the 1950s
and the 1960s In spite of these safety features the laws of physics dictate
that the higher the speed the higher kinetic energy of the colliding objects
and hence the greater the risk indeed near certainty of fatalities in a
higher speed collision compared to a lower speed one
5 The higher the speed at which the vehicle that is involved in a crash is
traveling the higher the kinetic energy that must be absorbed andor
dissipated without affecting the occupant(s) to avoid serious injuries andor
death This was true in the 1950s and the 1960s and will continue to be
true in the 21st century as well
Speed Kills for this just reason
6 It appears that higher fuel economies and reduced
highway fatalities were the twin societal benefits of 55
mph adopted after 1973 If so the current attempts to
increase the speed limits appear to be in conflict with
other important societal objectives
Page 36 of 45
Table 1 Annual US Street amp Highway
Fatalities from 1957
Year
Fatalities
Vehicle Miles
(millions)
Rate100M Vehicle Miles
1957 38702 646915 598
1958 36981 664915 556
1959 37910 700478 541
1960 38137 718845 531
1961 38091 737535 516
1962 40804 766852 532
1963 43564 805423 541
1964 47700 846500 563
1965 49163 887640 554
1966 51524 927915 555
1967 51559 965132 534
1968 53831 1019726 528
1969 55032 1066108 516
1970 53672 1114098 482
1971 53761 1183524 454
1972 55704 1264614 440
1973 55113 1316207 419
1974 46078 1282790 359
1975 45500 1330074 342
1976 45523 1402380 325
1977 47878 1467027 326
1978 50331 1544704 326
1979 51103 1529133 334
1980 51091 1527295 335
1981 49301 1552803 317
1982 43945 1595010 276
1983 42589 1652788 258
1984 44257 1720269 257
1985 43795 1774179 247
Page 37 of 45
1986 46056 1835000 251
1987 46385 1921000 241
1988 47093 2026000 232
1989 45555 2107040 216
1990 44529 2147501 207
1991 41162 2172214 189
1992 39235 2239828 175
1993 40115 2296585 175
1994 40676 2359984 172
1995 41798 2422696 173
1996 41907 2485848 169
1997 41967 2560373 164
Data from Federal Highway Administration
Source httpwwwpublicpurposecomhwy-fatal57+htm
Telephone +16186328507 - Facsimile +16186328538
WENDELL COX CONSULTANCY P O Box 841 - Belleville IL 62269 USA
Page 38 of 45
Fatality data for 1921-1982 compiled by NHTSA
Year
VMT
(Millions)
VMT
(Billions)
Fatalities
Fatality rate
per 100 M VMT
1921 55027 5503 13253 241 1922 67697 6770 14859 219 1923 84995 8500 17870 210 1924 104838 10484 18400 176 1925 122346 12235 20771 170 1926 140735 14074 22194 158 1927 158453 15845 24470 154 1928 172856 17286 26557 154 1929 197720 19772 29592 150 1930 206320 20632 31204 151 1931 216151 21615 31963 148 1932 200517 20052 27979 140 1933 200642 20064 29746 148 1934 215563 21556 34240 159 1935 228568 22857 34494 151 1936 252128 25213 36126 143 1937 270110 27011 37819 140 1938 271177 27118 31083 115 1939 285402 28540 30895 108 1940 302188 30219 32914 109 1941 333612 33361 38142 114 1942 268224 26822 27007 101 1943 208192 20819 22727 109 1944 212713 21271 23165 109 1945 250173 25017 26785 107 1946 340880 34088 31874 94 1947 370894 37089 31193 84 1948 397957 39796 30775 77 1949 424461 42446 30246 71 1950 458246 45825 33186 72 1951 491093 49109 35309 72
1952 513581 51358 36088 70
Page 39 of 45
1953 544433 54443 36190 66 1954 561963 56196 33890 60 1955 605646 60565 36688 61 1956 627843 62784 37965 60 1957 647004 64700 36932 57 1958 664653 66465 35331 53 1959 700480 70048 36223 52 1960 718762 71876 36399 51 1961 737421 73742 36285 49 1962 766734 76673 38980 51 1963 805249 80525 41723 52 1964 846298 84630 45645 54 1965 887812 88781 47089 53 1966 925899 92590 50894 55 1967 964005 96401 50724 53 1968 1015869 101587 52725 52 1969 1061791 106179 53543 50 1970 1109724 110972 52627 47 1971 1178811 117881 52542 45 1972 1259786 125979 54589 43 1973 1313110 131311 54052 41 1974 1280544 128054 45196 35 1975 1327664 132766 44525 34 1976 1402380 140238 45523 32 1977 1467027 146703 47878 33 1978 1544704 154470 50331 33 1979 1529133 152913 51093 33 1980 1527295 152730 51091 33 1981 1555308 155531 49301 32 1982 1595010 159501 43945 28
Source Analysis of Significant Decline in Motor Vehicle Traffic Fatalities in
2008 httpwww-nrdnhtsadotgovPubs811346pdf see Table A1 page 31
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Page 40 of 45
Acknowledgements
The author is grateful for thoughtful comments provided by friends and colleagues
with whom this document was shared via email prior to it being uploaded as a
publicly available document for wider dissemination and study The comments
offered by Prof Subra Ganesan of Oakland University Electrical and Computer
Engineering Department are reproduced with permission in their entirety
About the author
The author obtained his Masterrsquos (S M) and Doctoral (Sc D) degrees in Materials Engineering
from the Massachusetts Institute of Technology Cambridge USA He then spent his entire
professional career at leading US research institutions (MIT NASA Case Western Reserve
University and General Motors R amp D Center in Warren MI) He holds four patents in advanced
materials processing has co-authored two books and has published several scientific papers in
leading peer-reviewed international journals His expertise includes developing simple
mathematical models to explain the behavior of complex systems He can be reached by email at
vlaxmananhotmailcom
Page 41 of 45
Please Buckle Up
httpwwwlakecountypublichealthorgindexphpbuckle-up-montana
Public Awareness
Respect the Cage Exhibit
The Department of Transportation hopes that showing the reality of the crash will reduce traffic
fatalities A crushed car crash dummies and a sobering message ndash all part of the ―Respect The
Cage exhibit that is traveling across Montana The exhibit sponsored by the Montana Department
of Transportation stopped in Ronan on November 6th and is aimed at raising awareness about the
importance of wearing seat belts
The car in the exhibit was in an actual wreck many years ago
the passenger in the vehicle died because he was not wearing a
seat belt the driver who was wearing his seat belt survived
Montanarsquos likeliest crash fatality scenario
A Pickup
A Rural road
And Seat belts that
arenrsquot used
Page 42 of 45
Occupants of pickups are less likely to wear seat belts and pickups are more likely to
roll over than passenger cars
Seat belts reduce the risk of death by 60 percent in pickups and SUVs
In Montana from 2006-2008 81 of those killed in a crash while riding in a pickup were not wearing seat belts
In Montana pickups make up 401 of the vehicle population
For more information on Respect the Cage click here
Page 43 of 45
Appendix 1
Lack of seat belts leading cause of Louisiana highway deaths
1251 AM May 28 2011 |
Written by Adam Duvernay
Crashes involving unbuckled motorists were the leading cause of highway fatalities
in Louisiana last year and cost $9888 million according to recent reports The
Louisiana Highway Safety Commission reported 59 percent of vehicle occupants
killed in Louisiana crashes last year mdash about one in four mdash werent wearing seat
belts
httpwwwshreveporttimescomarticle20110528NEWS01105280354Lack-seat-
belts-leading-cause-La-highway-deathsodyssey=tab|topnews|text|FRONTPAGE
Crash bull Stats Published by NHTSAlsquos National Center for Statistics and Analysis 1200 New Jersey Avenue SE Washington DC 20590
DOT HS 811 451
Early Estimate of Motor Vehicle Traffic Fatalities in 2010
httpwww-nrdnhtsadotgovPubs811451pdf
Summary
A statistical projection of traffic fatalities in 2010 shows that an estimated 32788
people died in motor vehicle traffic crashes This represents a decline of about 3
percent as compared to the 33808 fatalities in 2009 as shown in Table 1 If these
projections are realized fatalities will be lowest on record (since 1949)
Traffic Safety Facts Overview 2009 Data
httpwww-nrdnhtsadotgovPubs811392pdf
In 2009 33808 people were killed in the estimated 5505000 police-reported
motor vehicle traffic crashes 2217000 people were injured and 3957000
crashes involved property damage only Compared to 2008 this is a 10-
percent decrease in the number of fatalities and a 5-percent decrease in the
Page 44 of 45
number of police-reported motor vehicle traffic crashes people injured and
crashes involving property damage
An average of 93 people died each day in motor vehicle crashes in 2009 mdash
an average of one every 16 minutes
Traffic Safety Facts Overview 2008 Data
httpwww-nrdnhtsadotgovPubs811162pdf
In 2008 37261 people were killed in the estimated 5811000 police-reported
motor vehicle traffic crashes 2346000 people were injured and 4146000
crashes involved property damage only
Some comments and Feedback
The following comments were received from Prof Ganesan after his review of the
first draft of this document It was subsequently revised thanks to this input to
address some of the very important issues raised here
Dear Laxman
The write up is not enough
You are emphasizing that the speed limit reduces the fatal accidents (comparing 1966
to 2000 accident numbers)
Can you also add a few sentences why the number is decreasing from 1980 to 2000
values (May be due to better design of vehicles)
Can you say anything about the fuel consumption with the speed for any typical
vehicle in 2011 or 2010 (do not consider the fatalities issue)
Probably a speed between 55 and 60 mph gives a better mileage If so this is a
compelling reason to keep the speed limit low But cars probably can be tuned to
give better mileage at any high speed also
Page 45 of 45
Weather is also a major factor in fatal accidents Speed limit may be kept low during
winter and kept higher in summer Give your comments on this too
Driver distractions can cause more accidents Now cars have many multimedia and
internet features Automatic collision avoidance systems and sensors on the sides can
detect vehicles in the front and neighboring lanes and it can automatically decrease
speed even if the driver speeds at super high speeds
Give some comments on this too There is also Vehicle to Vehicle communications
vehicle to infrastructure communications and they can avoid collisions and accidents
Technology has changed from 1966 I cannot agree with you on the speed limit
without any discussion on the above and other factors
Have a great day
Subra Ganesan
Professor Subramaniam Ganesan
Director Real Time amp DSP Lab
Electrical and Computer Engineering Department
2200 Squirrel Road Dodge Hall Room 105
Oakland University Rochester MI 48309 USA
Phone 248 370 2206 Fax 248 370 4633
wwwsecsoaklandedu~ganesan
IEEE Distinguished Visiting Speaker (2005-2009) Coordinator
IEEE SEM CS chapter Chair Region 4 and CS Society Board member
SAE ASEE ACM member
Page 31 of 45
century Technological innovations such as improvements in vehicle design
and engineering have greatly increased crash worthiness of vehicles even at
high speeds Environmental factors such as the weather also contribute to
accidents but not necessarily to increased fatalities Drivers actually tend to
slow down instinctively during adverse weather conditions (rain snow storms
etc) and although such weather may contribute to increased accidents the
lower speeds actually reduce fatalities
Yes technology has changed fundamentally from 1966 Drivers today are
more distracted by their cellmobile phone conversations (and also built-in
phones in luxury models) and text messaging than the drivers of the pre-1966
era High end cars now have many multimedia and internet features Again a
careful observation (even personal experience by the author) suggests that
such distracted drivers actually tend to (instinctively) drive more slowly and
hold up the traffic Perhaps such behavior leads to an increase in the number
of accidents but it does not necessarily lead to an increase in the number of
accident-related fatalities
Much talked about technological innovations such as automatic collision
avoidance systems and sensors (on the sides of vehicles) can indeed detect
vehicles in the front and neighboring lanes Furthermore vehicle-to-vehicle
communication systems vehicle-to-infrastructure communication systems
can no doubt avoid collisions and accidents Again such collision avoidance
systems work and are effective entirely because they automatically reduce
vehicle speeds - even if one of the offending vehicles is being at a super
high speed Also it must be remembered that such futuristic systems have
not yet been implemented widely nor can they be implemented widely since
the large majority of vehicles on the road are NOT luxury models Advanced
safety features come with a price and not all drivers can afford to pay that
price and ―buy that ―additional safety
Ultimately it is the laws of physics that govern what will happen when two or
more vehicles collide or even when a single vehicle collides with a stationary
infrastructural object (a bridge a wall a building or some impediment on the
road) The lower the number of crashes the lower the number of fatalities as
revealed by the 1994-2009 data graphed in Figure 5 The higher the speed of
Page 32 of 45
the object or objects that are involved in a collision the higher the kinetic
energy K that must be absorbed andor dissipated Increasing the posted
speed limit only increases the energy that must be absorbed when a crash
does occur This ultimately is the most important criterion determining the
number of fatalities
The kinetic energy increases as the square of the speed being given by the
well-known formula K = frac12 mv2 where m is the mass of the vehicle (in
laypersonlsquos language m increases directly with vehicle weight) and v is the
speed For the same vehicle mass an increase in the speed from 55 mph to
85 mph increases the kinetic energy K by a factor of 239 or roughly a 250
increase in the kinetic energy that must be absorbed in a collision
Ideally speaking the kinetic energy of the colliding object(s) is absorbed by
the vehicle infrastructure (a sturdy space frame the engine other vehicle
components etc) andor the surroundings However in the unfortunate
cases where this kinetic energy must be absorbed by the vehicle occupant(s)
the result is severe life-altering injuries andor death An unequivocal
relationship between an increase in vehicle speeds and fatal accidents can
be demonstrated by a careful examination of available traffic fatality data
This is a more involved discussion and is not the purpose of this short
communication These topics are no doubt very politically charged with many
social legal and financial implications with each interest group favoring a
different conclusion Nonetheless we cannot escape the laws of physics as
they govern the fundamental need to absorb higher and higher values of the
kinetic energy K with increasing vehicle speeds This same point is also
emphasized by Dr Friedman of the University of Illinois Chicago (see earlier
discussion)
Speed kills because of these energy transfer considerations and there can be
no doubt about it
Innovative 21st century solutions to speed management on the highways
such as strict enforcement of speed limits minimizing speed dispersion
(difference between speeds at which different drivers travel) while using
cameras to track the 15 of drivers who willfully violate the speed limit and
Page 33 of 45
create hazardous driving conditions is certainly recommended (Recall that
the optimum recommended speed limit is at or below which 85 of all drivers
travel ndash a policy also supported by NMA) Even on this score however the
results are confounding if we consider the Australian experience
httpwwwthenewspapercomnews282840asp
Up until 2007 there was no speed limit in the Northern Territory of
Australia Imposing a speed limit 130 kmph (80 mph) on some areas and
110 kmph (68 mph) in some others actually increased the number of deaths
The death toll in 2006 when there was no speed limit in this region was 44
and went up to 75 in 2009 see data table in link below
httpwwwthenewspapercomrlcdocs2009au-ntroadtollpdf
Furthermore it appears that installation of cameras to enforce speed limits
has proved to be a hazardous distraction to drivers and deaths actually
began to skyrocket between 2005 and 2007 in all Australian roadways
The main purpose here is to sound a cautionary note amid renewed attempts
in many states across the US to increase the speed limits on our highways by
calling attention to the historical facts regarding the ―epidemic levels of
highway traffic fatalities that engaged our national attention in the fateful year
of 1966 The graphical representation of the traffic fatality data in Figures 1
to 5 tells its own story
Indeed it would be tragic if highway-accident-related fatalities were to start
increasing once again and reach the historically high level that was last seen
in 1972 the year before the Arab oil embargo of 1973
Page 34 of 45
Conclusions
1 The graphical representation of the highway fatality data and the brief
summary of the historical facts of traffic safety legislation suggest that
recent attempts to increase the speed limits by various states (notably
Texas) may be misguided The distinct peak in the highway fatalities
observed in these graphs is highly alarming This appears to be related to
the enactment of the National Maximum Speed Limit (NSML) in 1974
following the 1973 Arab oil embargo Although NSML was motivated by a
desire to reduce gasoline consumption an unintended benefit might have
been a dramatic reduction in fatalities The fundamental reasons for the
peak in the fatalities-VMT curve must be examined carefully without
political posturing
2 The widely used fatality rate fatalities per 100 M vehicle miles traveled
has been declining since 1921 the first year for which a fatality rate could
be computed and has now reached a historical low The absolute number
of fatalities on the other hand was increasing in the 1950s and 1960s at
an alarming rate and the public outcry that ensued led to the highly
publicized Congressional hearing of 1966 and the subsequent traffic safety
legislations The fatality rate has been decreasing even in the most recent
15-year period (1994-2009) again with increasing fatalities although less
dramatically Thus it appears that fatality rate calculation based on vehicle
miles traveled (VMT) might not be a reliable indicator of the underlying
dynamics in the fatality trends
3 More detailed compilation of number of fatalities and the number of fatal
crashes within each speed limit segment is required to better understand
the effect of increasing speed limits on highway fatalities (and also fatality
rates) Such data is already available and is being compiled at the local
city and county levels in all jurisdictions and only needs to be reorganized
to highlight the effect of (posted) speed limits on the number of crashes
and fatalities This will require some minor rewriting and revisions to the
chapters named ―Crashes and ―States in the annual NHTSA reports
Page 35 of 45
Analysis of the fatalities-crashes data for several years with various
speed limits will be more revealing and meaningful than the current
fatality rates analysis and will be discussed separately in a follow up
report
4 One should not be lulled by the fact that vehicles of the 21st century are
now equipped with advanced safety features not available in the 1950s
and the 1960s In spite of these safety features the laws of physics dictate
that the higher the speed the higher kinetic energy of the colliding objects
and hence the greater the risk indeed near certainty of fatalities in a
higher speed collision compared to a lower speed one
5 The higher the speed at which the vehicle that is involved in a crash is
traveling the higher the kinetic energy that must be absorbed andor
dissipated without affecting the occupant(s) to avoid serious injuries andor
death This was true in the 1950s and the 1960s and will continue to be
true in the 21st century as well
Speed Kills for this just reason
6 It appears that higher fuel economies and reduced
highway fatalities were the twin societal benefits of 55
mph adopted after 1973 If so the current attempts to
increase the speed limits appear to be in conflict with
other important societal objectives
Page 36 of 45
Table 1 Annual US Street amp Highway
Fatalities from 1957
Year
Fatalities
Vehicle Miles
(millions)
Rate100M Vehicle Miles
1957 38702 646915 598
1958 36981 664915 556
1959 37910 700478 541
1960 38137 718845 531
1961 38091 737535 516
1962 40804 766852 532
1963 43564 805423 541
1964 47700 846500 563
1965 49163 887640 554
1966 51524 927915 555
1967 51559 965132 534
1968 53831 1019726 528
1969 55032 1066108 516
1970 53672 1114098 482
1971 53761 1183524 454
1972 55704 1264614 440
1973 55113 1316207 419
1974 46078 1282790 359
1975 45500 1330074 342
1976 45523 1402380 325
1977 47878 1467027 326
1978 50331 1544704 326
1979 51103 1529133 334
1980 51091 1527295 335
1981 49301 1552803 317
1982 43945 1595010 276
1983 42589 1652788 258
1984 44257 1720269 257
1985 43795 1774179 247
Page 37 of 45
1986 46056 1835000 251
1987 46385 1921000 241
1988 47093 2026000 232
1989 45555 2107040 216
1990 44529 2147501 207
1991 41162 2172214 189
1992 39235 2239828 175
1993 40115 2296585 175
1994 40676 2359984 172
1995 41798 2422696 173
1996 41907 2485848 169
1997 41967 2560373 164
Data from Federal Highway Administration
Source httpwwwpublicpurposecomhwy-fatal57+htm
Telephone +16186328507 - Facsimile +16186328538
WENDELL COX CONSULTANCY P O Box 841 - Belleville IL 62269 USA
Page 38 of 45
Fatality data for 1921-1982 compiled by NHTSA
Year
VMT
(Millions)
VMT
(Billions)
Fatalities
Fatality rate
per 100 M VMT
1921 55027 5503 13253 241 1922 67697 6770 14859 219 1923 84995 8500 17870 210 1924 104838 10484 18400 176 1925 122346 12235 20771 170 1926 140735 14074 22194 158 1927 158453 15845 24470 154 1928 172856 17286 26557 154 1929 197720 19772 29592 150 1930 206320 20632 31204 151 1931 216151 21615 31963 148 1932 200517 20052 27979 140 1933 200642 20064 29746 148 1934 215563 21556 34240 159 1935 228568 22857 34494 151 1936 252128 25213 36126 143 1937 270110 27011 37819 140 1938 271177 27118 31083 115 1939 285402 28540 30895 108 1940 302188 30219 32914 109 1941 333612 33361 38142 114 1942 268224 26822 27007 101 1943 208192 20819 22727 109 1944 212713 21271 23165 109 1945 250173 25017 26785 107 1946 340880 34088 31874 94 1947 370894 37089 31193 84 1948 397957 39796 30775 77 1949 424461 42446 30246 71 1950 458246 45825 33186 72 1951 491093 49109 35309 72
1952 513581 51358 36088 70
Page 39 of 45
1953 544433 54443 36190 66 1954 561963 56196 33890 60 1955 605646 60565 36688 61 1956 627843 62784 37965 60 1957 647004 64700 36932 57 1958 664653 66465 35331 53 1959 700480 70048 36223 52 1960 718762 71876 36399 51 1961 737421 73742 36285 49 1962 766734 76673 38980 51 1963 805249 80525 41723 52 1964 846298 84630 45645 54 1965 887812 88781 47089 53 1966 925899 92590 50894 55 1967 964005 96401 50724 53 1968 1015869 101587 52725 52 1969 1061791 106179 53543 50 1970 1109724 110972 52627 47 1971 1178811 117881 52542 45 1972 1259786 125979 54589 43 1973 1313110 131311 54052 41 1974 1280544 128054 45196 35 1975 1327664 132766 44525 34 1976 1402380 140238 45523 32 1977 1467027 146703 47878 33 1978 1544704 154470 50331 33 1979 1529133 152913 51093 33 1980 1527295 152730 51091 33 1981 1555308 155531 49301 32 1982 1595010 159501 43945 28
Source Analysis of Significant Decline in Motor Vehicle Traffic Fatalities in
2008 httpwww-nrdnhtsadotgovPubs811346pdf see Table A1 page 31
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Page 40 of 45
Acknowledgements
The author is grateful for thoughtful comments provided by friends and colleagues
with whom this document was shared via email prior to it being uploaded as a
publicly available document for wider dissemination and study The comments
offered by Prof Subra Ganesan of Oakland University Electrical and Computer
Engineering Department are reproduced with permission in their entirety
About the author
The author obtained his Masterrsquos (S M) and Doctoral (Sc D) degrees in Materials Engineering
from the Massachusetts Institute of Technology Cambridge USA He then spent his entire
professional career at leading US research institutions (MIT NASA Case Western Reserve
University and General Motors R amp D Center in Warren MI) He holds four patents in advanced
materials processing has co-authored two books and has published several scientific papers in
leading peer-reviewed international journals His expertise includes developing simple
mathematical models to explain the behavior of complex systems He can be reached by email at
vlaxmananhotmailcom
Page 41 of 45
Please Buckle Up
httpwwwlakecountypublichealthorgindexphpbuckle-up-montana
Public Awareness
Respect the Cage Exhibit
The Department of Transportation hopes that showing the reality of the crash will reduce traffic
fatalities A crushed car crash dummies and a sobering message ndash all part of the ―Respect The
Cage exhibit that is traveling across Montana The exhibit sponsored by the Montana Department
of Transportation stopped in Ronan on November 6th and is aimed at raising awareness about the
importance of wearing seat belts
The car in the exhibit was in an actual wreck many years ago
the passenger in the vehicle died because he was not wearing a
seat belt the driver who was wearing his seat belt survived
Montanarsquos likeliest crash fatality scenario
A Pickup
A Rural road
And Seat belts that
arenrsquot used
Page 42 of 45
Occupants of pickups are less likely to wear seat belts and pickups are more likely to
roll over than passenger cars
Seat belts reduce the risk of death by 60 percent in pickups and SUVs
In Montana from 2006-2008 81 of those killed in a crash while riding in a pickup were not wearing seat belts
In Montana pickups make up 401 of the vehicle population
For more information on Respect the Cage click here
Page 43 of 45
Appendix 1
Lack of seat belts leading cause of Louisiana highway deaths
1251 AM May 28 2011 |
Written by Adam Duvernay
Crashes involving unbuckled motorists were the leading cause of highway fatalities
in Louisiana last year and cost $9888 million according to recent reports The
Louisiana Highway Safety Commission reported 59 percent of vehicle occupants
killed in Louisiana crashes last year mdash about one in four mdash werent wearing seat
belts
httpwwwshreveporttimescomarticle20110528NEWS01105280354Lack-seat-
belts-leading-cause-La-highway-deathsodyssey=tab|topnews|text|FRONTPAGE
Crash bull Stats Published by NHTSAlsquos National Center for Statistics and Analysis 1200 New Jersey Avenue SE Washington DC 20590
DOT HS 811 451
Early Estimate of Motor Vehicle Traffic Fatalities in 2010
httpwww-nrdnhtsadotgovPubs811451pdf
Summary
A statistical projection of traffic fatalities in 2010 shows that an estimated 32788
people died in motor vehicle traffic crashes This represents a decline of about 3
percent as compared to the 33808 fatalities in 2009 as shown in Table 1 If these
projections are realized fatalities will be lowest on record (since 1949)
Traffic Safety Facts Overview 2009 Data
httpwww-nrdnhtsadotgovPubs811392pdf
In 2009 33808 people were killed in the estimated 5505000 police-reported
motor vehicle traffic crashes 2217000 people were injured and 3957000
crashes involved property damage only Compared to 2008 this is a 10-
percent decrease in the number of fatalities and a 5-percent decrease in the
Page 44 of 45
number of police-reported motor vehicle traffic crashes people injured and
crashes involving property damage
An average of 93 people died each day in motor vehicle crashes in 2009 mdash
an average of one every 16 minutes
Traffic Safety Facts Overview 2008 Data
httpwww-nrdnhtsadotgovPubs811162pdf
In 2008 37261 people were killed in the estimated 5811000 police-reported
motor vehicle traffic crashes 2346000 people were injured and 4146000
crashes involved property damage only
Some comments and Feedback
The following comments were received from Prof Ganesan after his review of the
first draft of this document It was subsequently revised thanks to this input to
address some of the very important issues raised here
Dear Laxman
The write up is not enough
You are emphasizing that the speed limit reduces the fatal accidents (comparing 1966
to 2000 accident numbers)
Can you also add a few sentences why the number is decreasing from 1980 to 2000
values (May be due to better design of vehicles)
Can you say anything about the fuel consumption with the speed for any typical
vehicle in 2011 or 2010 (do not consider the fatalities issue)
Probably a speed between 55 and 60 mph gives a better mileage If so this is a
compelling reason to keep the speed limit low But cars probably can be tuned to
give better mileage at any high speed also
Page 45 of 45
Weather is also a major factor in fatal accidents Speed limit may be kept low during
winter and kept higher in summer Give your comments on this too
Driver distractions can cause more accidents Now cars have many multimedia and
internet features Automatic collision avoidance systems and sensors on the sides can
detect vehicles in the front and neighboring lanes and it can automatically decrease
speed even if the driver speeds at super high speeds
Give some comments on this too There is also Vehicle to Vehicle communications
vehicle to infrastructure communications and they can avoid collisions and accidents
Technology has changed from 1966 I cannot agree with you on the speed limit
without any discussion on the above and other factors
Have a great day
Subra Ganesan
Professor Subramaniam Ganesan
Director Real Time amp DSP Lab
Electrical and Computer Engineering Department
2200 Squirrel Road Dodge Hall Room 105
Oakland University Rochester MI 48309 USA
Phone 248 370 2206 Fax 248 370 4633
wwwsecsoaklandedu~ganesan
IEEE Distinguished Visiting Speaker (2005-2009) Coordinator
IEEE SEM CS chapter Chair Region 4 and CS Society Board member
SAE ASEE ACM member
Page 32 of 45
the object or objects that are involved in a collision the higher the kinetic
energy K that must be absorbed andor dissipated Increasing the posted
speed limit only increases the energy that must be absorbed when a crash
does occur This ultimately is the most important criterion determining the
number of fatalities
The kinetic energy increases as the square of the speed being given by the
well-known formula K = frac12 mv2 where m is the mass of the vehicle (in
laypersonlsquos language m increases directly with vehicle weight) and v is the
speed For the same vehicle mass an increase in the speed from 55 mph to
85 mph increases the kinetic energy K by a factor of 239 or roughly a 250
increase in the kinetic energy that must be absorbed in a collision
Ideally speaking the kinetic energy of the colliding object(s) is absorbed by
the vehicle infrastructure (a sturdy space frame the engine other vehicle
components etc) andor the surroundings However in the unfortunate
cases where this kinetic energy must be absorbed by the vehicle occupant(s)
the result is severe life-altering injuries andor death An unequivocal
relationship between an increase in vehicle speeds and fatal accidents can
be demonstrated by a careful examination of available traffic fatality data
This is a more involved discussion and is not the purpose of this short
communication These topics are no doubt very politically charged with many
social legal and financial implications with each interest group favoring a
different conclusion Nonetheless we cannot escape the laws of physics as
they govern the fundamental need to absorb higher and higher values of the
kinetic energy K with increasing vehicle speeds This same point is also
emphasized by Dr Friedman of the University of Illinois Chicago (see earlier
discussion)
Speed kills because of these energy transfer considerations and there can be
no doubt about it
Innovative 21st century solutions to speed management on the highways
such as strict enforcement of speed limits minimizing speed dispersion
(difference between speeds at which different drivers travel) while using
cameras to track the 15 of drivers who willfully violate the speed limit and
Page 33 of 45
create hazardous driving conditions is certainly recommended (Recall that
the optimum recommended speed limit is at or below which 85 of all drivers
travel ndash a policy also supported by NMA) Even on this score however the
results are confounding if we consider the Australian experience
httpwwwthenewspapercomnews282840asp
Up until 2007 there was no speed limit in the Northern Territory of
Australia Imposing a speed limit 130 kmph (80 mph) on some areas and
110 kmph (68 mph) in some others actually increased the number of deaths
The death toll in 2006 when there was no speed limit in this region was 44
and went up to 75 in 2009 see data table in link below
httpwwwthenewspapercomrlcdocs2009au-ntroadtollpdf
Furthermore it appears that installation of cameras to enforce speed limits
has proved to be a hazardous distraction to drivers and deaths actually
began to skyrocket between 2005 and 2007 in all Australian roadways
The main purpose here is to sound a cautionary note amid renewed attempts
in many states across the US to increase the speed limits on our highways by
calling attention to the historical facts regarding the ―epidemic levels of
highway traffic fatalities that engaged our national attention in the fateful year
of 1966 The graphical representation of the traffic fatality data in Figures 1
to 5 tells its own story
Indeed it would be tragic if highway-accident-related fatalities were to start
increasing once again and reach the historically high level that was last seen
in 1972 the year before the Arab oil embargo of 1973
Page 34 of 45
Conclusions
1 The graphical representation of the highway fatality data and the brief
summary of the historical facts of traffic safety legislation suggest that
recent attempts to increase the speed limits by various states (notably
Texas) may be misguided The distinct peak in the highway fatalities
observed in these graphs is highly alarming This appears to be related to
the enactment of the National Maximum Speed Limit (NSML) in 1974
following the 1973 Arab oil embargo Although NSML was motivated by a
desire to reduce gasoline consumption an unintended benefit might have
been a dramatic reduction in fatalities The fundamental reasons for the
peak in the fatalities-VMT curve must be examined carefully without
political posturing
2 The widely used fatality rate fatalities per 100 M vehicle miles traveled
has been declining since 1921 the first year for which a fatality rate could
be computed and has now reached a historical low The absolute number
of fatalities on the other hand was increasing in the 1950s and 1960s at
an alarming rate and the public outcry that ensued led to the highly
publicized Congressional hearing of 1966 and the subsequent traffic safety
legislations The fatality rate has been decreasing even in the most recent
15-year period (1994-2009) again with increasing fatalities although less
dramatically Thus it appears that fatality rate calculation based on vehicle
miles traveled (VMT) might not be a reliable indicator of the underlying
dynamics in the fatality trends
3 More detailed compilation of number of fatalities and the number of fatal
crashes within each speed limit segment is required to better understand
the effect of increasing speed limits on highway fatalities (and also fatality
rates) Such data is already available and is being compiled at the local
city and county levels in all jurisdictions and only needs to be reorganized
to highlight the effect of (posted) speed limits on the number of crashes
and fatalities This will require some minor rewriting and revisions to the
chapters named ―Crashes and ―States in the annual NHTSA reports
Page 35 of 45
Analysis of the fatalities-crashes data for several years with various
speed limits will be more revealing and meaningful than the current
fatality rates analysis and will be discussed separately in a follow up
report
4 One should not be lulled by the fact that vehicles of the 21st century are
now equipped with advanced safety features not available in the 1950s
and the 1960s In spite of these safety features the laws of physics dictate
that the higher the speed the higher kinetic energy of the colliding objects
and hence the greater the risk indeed near certainty of fatalities in a
higher speed collision compared to a lower speed one
5 The higher the speed at which the vehicle that is involved in a crash is
traveling the higher the kinetic energy that must be absorbed andor
dissipated without affecting the occupant(s) to avoid serious injuries andor
death This was true in the 1950s and the 1960s and will continue to be
true in the 21st century as well
Speed Kills for this just reason
6 It appears that higher fuel economies and reduced
highway fatalities were the twin societal benefits of 55
mph adopted after 1973 If so the current attempts to
increase the speed limits appear to be in conflict with
other important societal objectives
Page 36 of 45
Table 1 Annual US Street amp Highway
Fatalities from 1957
Year
Fatalities
Vehicle Miles
(millions)
Rate100M Vehicle Miles
1957 38702 646915 598
1958 36981 664915 556
1959 37910 700478 541
1960 38137 718845 531
1961 38091 737535 516
1962 40804 766852 532
1963 43564 805423 541
1964 47700 846500 563
1965 49163 887640 554
1966 51524 927915 555
1967 51559 965132 534
1968 53831 1019726 528
1969 55032 1066108 516
1970 53672 1114098 482
1971 53761 1183524 454
1972 55704 1264614 440
1973 55113 1316207 419
1974 46078 1282790 359
1975 45500 1330074 342
1976 45523 1402380 325
1977 47878 1467027 326
1978 50331 1544704 326
1979 51103 1529133 334
1980 51091 1527295 335
1981 49301 1552803 317
1982 43945 1595010 276
1983 42589 1652788 258
1984 44257 1720269 257
1985 43795 1774179 247
Page 37 of 45
1986 46056 1835000 251
1987 46385 1921000 241
1988 47093 2026000 232
1989 45555 2107040 216
1990 44529 2147501 207
1991 41162 2172214 189
1992 39235 2239828 175
1993 40115 2296585 175
1994 40676 2359984 172
1995 41798 2422696 173
1996 41907 2485848 169
1997 41967 2560373 164
Data from Federal Highway Administration
Source httpwwwpublicpurposecomhwy-fatal57+htm
Telephone +16186328507 - Facsimile +16186328538
WENDELL COX CONSULTANCY P O Box 841 - Belleville IL 62269 USA
Page 38 of 45
Fatality data for 1921-1982 compiled by NHTSA
Year
VMT
(Millions)
VMT
(Billions)
Fatalities
Fatality rate
per 100 M VMT
1921 55027 5503 13253 241 1922 67697 6770 14859 219 1923 84995 8500 17870 210 1924 104838 10484 18400 176 1925 122346 12235 20771 170 1926 140735 14074 22194 158 1927 158453 15845 24470 154 1928 172856 17286 26557 154 1929 197720 19772 29592 150 1930 206320 20632 31204 151 1931 216151 21615 31963 148 1932 200517 20052 27979 140 1933 200642 20064 29746 148 1934 215563 21556 34240 159 1935 228568 22857 34494 151 1936 252128 25213 36126 143 1937 270110 27011 37819 140 1938 271177 27118 31083 115 1939 285402 28540 30895 108 1940 302188 30219 32914 109 1941 333612 33361 38142 114 1942 268224 26822 27007 101 1943 208192 20819 22727 109 1944 212713 21271 23165 109 1945 250173 25017 26785 107 1946 340880 34088 31874 94 1947 370894 37089 31193 84 1948 397957 39796 30775 77 1949 424461 42446 30246 71 1950 458246 45825 33186 72 1951 491093 49109 35309 72
1952 513581 51358 36088 70
Page 39 of 45
1953 544433 54443 36190 66 1954 561963 56196 33890 60 1955 605646 60565 36688 61 1956 627843 62784 37965 60 1957 647004 64700 36932 57 1958 664653 66465 35331 53 1959 700480 70048 36223 52 1960 718762 71876 36399 51 1961 737421 73742 36285 49 1962 766734 76673 38980 51 1963 805249 80525 41723 52 1964 846298 84630 45645 54 1965 887812 88781 47089 53 1966 925899 92590 50894 55 1967 964005 96401 50724 53 1968 1015869 101587 52725 52 1969 1061791 106179 53543 50 1970 1109724 110972 52627 47 1971 1178811 117881 52542 45 1972 1259786 125979 54589 43 1973 1313110 131311 54052 41 1974 1280544 128054 45196 35 1975 1327664 132766 44525 34 1976 1402380 140238 45523 32 1977 1467027 146703 47878 33 1978 1544704 154470 50331 33 1979 1529133 152913 51093 33 1980 1527295 152730 51091 33 1981 1555308 155531 49301 32 1982 1595010 159501 43945 28
Source Analysis of Significant Decline in Motor Vehicle Traffic Fatalities in
2008 httpwww-nrdnhtsadotgovPubs811346pdf see Table A1 page 31
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Page 40 of 45
Acknowledgements
The author is grateful for thoughtful comments provided by friends and colleagues
with whom this document was shared via email prior to it being uploaded as a
publicly available document for wider dissemination and study The comments
offered by Prof Subra Ganesan of Oakland University Electrical and Computer
Engineering Department are reproduced with permission in their entirety
About the author
The author obtained his Masterrsquos (S M) and Doctoral (Sc D) degrees in Materials Engineering
from the Massachusetts Institute of Technology Cambridge USA He then spent his entire
professional career at leading US research institutions (MIT NASA Case Western Reserve
University and General Motors R amp D Center in Warren MI) He holds four patents in advanced
materials processing has co-authored two books and has published several scientific papers in
leading peer-reviewed international journals His expertise includes developing simple
mathematical models to explain the behavior of complex systems He can be reached by email at
vlaxmananhotmailcom
Page 41 of 45
Please Buckle Up
httpwwwlakecountypublichealthorgindexphpbuckle-up-montana
Public Awareness
Respect the Cage Exhibit
The Department of Transportation hopes that showing the reality of the crash will reduce traffic
fatalities A crushed car crash dummies and a sobering message ndash all part of the ―Respect The
Cage exhibit that is traveling across Montana The exhibit sponsored by the Montana Department
of Transportation stopped in Ronan on November 6th and is aimed at raising awareness about the
importance of wearing seat belts
The car in the exhibit was in an actual wreck many years ago
the passenger in the vehicle died because he was not wearing a
seat belt the driver who was wearing his seat belt survived
Montanarsquos likeliest crash fatality scenario
A Pickup
A Rural road
And Seat belts that
arenrsquot used
Page 42 of 45
Occupants of pickups are less likely to wear seat belts and pickups are more likely to
roll over than passenger cars
Seat belts reduce the risk of death by 60 percent in pickups and SUVs
In Montana from 2006-2008 81 of those killed in a crash while riding in a pickup were not wearing seat belts
In Montana pickups make up 401 of the vehicle population
For more information on Respect the Cage click here
Page 43 of 45
Appendix 1
Lack of seat belts leading cause of Louisiana highway deaths
1251 AM May 28 2011 |
Written by Adam Duvernay
Crashes involving unbuckled motorists were the leading cause of highway fatalities
in Louisiana last year and cost $9888 million according to recent reports The
Louisiana Highway Safety Commission reported 59 percent of vehicle occupants
killed in Louisiana crashes last year mdash about one in four mdash werent wearing seat
belts
httpwwwshreveporttimescomarticle20110528NEWS01105280354Lack-seat-
belts-leading-cause-La-highway-deathsodyssey=tab|topnews|text|FRONTPAGE
Crash bull Stats Published by NHTSAlsquos National Center for Statistics and Analysis 1200 New Jersey Avenue SE Washington DC 20590
DOT HS 811 451
Early Estimate of Motor Vehicle Traffic Fatalities in 2010
httpwww-nrdnhtsadotgovPubs811451pdf
Summary
A statistical projection of traffic fatalities in 2010 shows that an estimated 32788
people died in motor vehicle traffic crashes This represents a decline of about 3
percent as compared to the 33808 fatalities in 2009 as shown in Table 1 If these
projections are realized fatalities will be lowest on record (since 1949)
Traffic Safety Facts Overview 2009 Data
httpwww-nrdnhtsadotgovPubs811392pdf
In 2009 33808 people were killed in the estimated 5505000 police-reported
motor vehicle traffic crashes 2217000 people were injured and 3957000
crashes involved property damage only Compared to 2008 this is a 10-
percent decrease in the number of fatalities and a 5-percent decrease in the
Page 44 of 45
number of police-reported motor vehicle traffic crashes people injured and
crashes involving property damage
An average of 93 people died each day in motor vehicle crashes in 2009 mdash
an average of one every 16 minutes
Traffic Safety Facts Overview 2008 Data
httpwww-nrdnhtsadotgovPubs811162pdf
In 2008 37261 people were killed in the estimated 5811000 police-reported
motor vehicle traffic crashes 2346000 people were injured and 4146000
crashes involved property damage only
Some comments and Feedback
The following comments were received from Prof Ganesan after his review of the
first draft of this document It was subsequently revised thanks to this input to
address some of the very important issues raised here
Dear Laxman
The write up is not enough
You are emphasizing that the speed limit reduces the fatal accidents (comparing 1966
to 2000 accident numbers)
Can you also add a few sentences why the number is decreasing from 1980 to 2000
values (May be due to better design of vehicles)
Can you say anything about the fuel consumption with the speed for any typical
vehicle in 2011 or 2010 (do not consider the fatalities issue)
Probably a speed between 55 and 60 mph gives a better mileage If so this is a
compelling reason to keep the speed limit low But cars probably can be tuned to
give better mileage at any high speed also
Page 45 of 45
Weather is also a major factor in fatal accidents Speed limit may be kept low during
winter and kept higher in summer Give your comments on this too
Driver distractions can cause more accidents Now cars have many multimedia and
internet features Automatic collision avoidance systems and sensors on the sides can
detect vehicles in the front and neighboring lanes and it can automatically decrease
speed even if the driver speeds at super high speeds
Give some comments on this too There is also Vehicle to Vehicle communications
vehicle to infrastructure communications and they can avoid collisions and accidents
Technology has changed from 1966 I cannot agree with you on the speed limit
without any discussion on the above and other factors
Have a great day
Subra Ganesan
Professor Subramaniam Ganesan
Director Real Time amp DSP Lab
Electrical and Computer Engineering Department
2200 Squirrel Road Dodge Hall Room 105
Oakland University Rochester MI 48309 USA
Phone 248 370 2206 Fax 248 370 4633
wwwsecsoaklandedu~ganesan
IEEE Distinguished Visiting Speaker (2005-2009) Coordinator
IEEE SEM CS chapter Chair Region 4 and CS Society Board member
SAE ASEE ACM member
Page 33 of 45
create hazardous driving conditions is certainly recommended (Recall that
the optimum recommended speed limit is at or below which 85 of all drivers
travel ndash a policy also supported by NMA) Even on this score however the
results are confounding if we consider the Australian experience
httpwwwthenewspapercomnews282840asp
Up until 2007 there was no speed limit in the Northern Territory of
Australia Imposing a speed limit 130 kmph (80 mph) on some areas and
110 kmph (68 mph) in some others actually increased the number of deaths
The death toll in 2006 when there was no speed limit in this region was 44
and went up to 75 in 2009 see data table in link below
httpwwwthenewspapercomrlcdocs2009au-ntroadtollpdf
Furthermore it appears that installation of cameras to enforce speed limits
has proved to be a hazardous distraction to drivers and deaths actually
began to skyrocket between 2005 and 2007 in all Australian roadways
The main purpose here is to sound a cautionary note amid renewed attempts
in many states across the US to increase the speed limits on our highways by
calling attention to the historical facts regarding the ―epidemic levels of
highway traffic fatalities that engaged our national attention in the fateful year
of 1966 The graphical representation of the traffic fatality data in Figures 1
to 5 tells its own story
Indeed it would be tragic if highway-accident-related fatalities were to start
increasing once again and reach the historically high level that was last seen
in 1972 the year before the Arab oil embargo of 1973
Page 34 of 45
Conclusions
1 The graphical representation of the highway fatality data and the brief
summary of the historical facts of traffic safety legislation suggest that
recent attempts to increase the speed limits by various states (notably
Texas) may be misguided The distinct peak in the highway fatalities
observed in these graphs is highly alarming This appears to be related to
the enactment of the National Maximum Speed Limit (NSML) in 1974
following the 1973 Arab oil embargo Although NSML was motivated by a
desire to reduce gasoline consumption an unintended benefit might have
been a dramatic reduction in fatalities The fundamental reasons for the
peak in the fatalities-VMT curve must be examined carefully without
political posturing
2 The widely used fatality rate fatalities per 100 M vehicle miles traveled
has been declining since 1921 the first year for which a fatality rate could
be computed and has now reached a historical low The absolute number
of fatalities on the other hand was increasing in the 1950s and 1960s at
an alarming rate and the public outcry that ensued led to the highly
publicized Congressional hearing of 1966 and the subsequent traffic safety
legislations The fatality rate has been decreasing even in the most recent
15-year period (1994-2009) again with increasing fatalities although less
dramatically Thus it appears that fatality rate calculation based on vehicle
miles traveled (VMT) might not be a reliable indicator of the underlying
dynamics in the fatality trends
3 More detailed compilation of number of fatalities and the number of fatal
crashes within each speed limit segment is required to better understand
the effect of increasing speed limits on highway fatalities (and also fatality
rates) Such data is already available and is being compiled at the local
city and county levels in all jurisdictions and only needs to be reorganized
to highlight the effect of (posted) speed limits on the number of crashes
and fatalities This will require some minor rewriting and revisions to the
chapters named ―Crashes and ―States in the annual NHTSA reports
Page 35 of 45
Analysis of the fatalities-crashes data for several years with various
speed limits will be more revealing and meaningful than the current
fatality rates analysis and will be discussed separately in a follow up
report
4 One should not be lulled by the fact that vehicles of the 21st century are
now equipped with advanced safety features not available in the 1950s
and the 1960s In spite of these safety features the laws of physics dictate
that the higher the speed the higher kinetic energy of the colliding objects
and hence the greater the risk indeed near certainty of fatalities in a
higher speed collision compared to a lower speed one
5 The higher the speed at which the vehicle that is involved in a crash is
traveling the higher the kinetic energy that must be absorbed andor
dissipated without affecting the occupant(s) to avoid serious injuries andor
death This was true in the 1950s and the 1960s and will continue to be
true in the 21st century as well
Speed Kills for this just reason
6 It appears that higher fuel economies and reduced
highway fatalities were the twin societal benefits of 55
mph adopted after 1973 If so the current attempts to
increase the speed limits appear to be in conflict with
other important societal objectives
Page 36 of 45
Table 1 Annual US Street amp Highway
Fatalities from 1957
Year
Fatalities
Vehicle Miles
(millions)
Rate100M Vehicle Miles
1957 38702 646915 598
1958 36981 664915 556
1959 37910 700478 541
1960 38137 718845 531
1961 38091 737535 516
1962 40804 766852 532
1963 43564 805423 541
1964 47700 846500 563
1965 49163 887640 554
1966 51524 927915 555
1967 51559 965132 534
1968 53831 1019726 528
1969 55032 1066108 516
1970 53672 1114098 482
1971 53761 1183524 454
1972 55704 1264614 440
1973 55113 1316207 419
1974 46078 1282790 359
1975 45500 1330074 342
1976 45523 1402380 325
1977 47878 1467027 326
1978 50331 1544704 326
1979 51103 1529133 334
1980 51091 1527295 335
1981 49301 1552803 317
1982 43945 1595010 276
1983 42589 1652788 258
1984 44257 1720269 257
1985 43795 1774179 247
Page 37 of 45
1986 46056 1835000 251
1987 46385 1921000 241
1988 47093 2026000 232
1989 45555 2107040 216
1990 44529 2147501 207
1991 41162 2172214 189
1992 39235 2239828 175
1993 40115 2296585 175
1994 40676 2359984 172
1995 41798 2422696 173
1996 41907 2485848 169
1997 41967 2560373 164
Data from Federal Highway Administration
Source httpwwwpublicpurposecomhwy-fatal57+htm
Telephone +16186328507 - Facsimile +16186328538
WENDELL COX CONSULTANCY P O Box 841 - Belleville IL 62269 USA
Page 38 of 45
Fatality data for 1921-1982 compiled by NHTSA
Year
VMT
(Millions)
VMT
(Billions)
Fatalities
Fatality rate
per 100 M VMT
1921 55027 5503 13253 241 1922 67697 6770 14859 219 1923 84995 8500 17870 210 1924 104838 10484 18400 176 1925 122346 12235 20771 170 1926 140735 14074 22194 158 1927 158453 15845 24470 154 1928 172856 17286 26557 154 1929 197720 19772 29592 150 1930 206320 20632 31204 151 1931 216151 21615 31963 148 1932 200517 20052 27979 140 1933 200642 20064 29746 148 1934 215563 21556 34240 159 1935 228568 22857 34494 151 1936 252128 25213 36126 143 1937 270110 27011 37819 140 1938 271177 27118 31083 115 1939 285402 28540 30895 108 1940 302188 30219 32914 109 1941 333612 33361 38142 114 1942 268224 26822 27007 101 1943 208192 20819 22727 109 1944 212713 21271 23165 109 1945 250173 25017 26785 107 1946 340880 34088 31874 94 1947 370894 37089 31193 84 1948 397957 39796 30775 77 1949 424461 42446 30246 71 1950 458246 45825 33186 72 1951 491093 49109 35309 72
1952 513581 51358 36088 70
Page 39 of 45
1953 544433 54443 36190 66 1954 561963 56196 33890 60 1955 605646 60565 36688 61 1956 627843 62784 37965 60 1957 647004 64700 36932 57 1958 664653 66465 35331 53 1959 700480 70048 36223 52 1960 718762 71876 36399 51 1961 737421 73742 36285 49 1962 766734 76673 38980 51 1963 805249 80525 41723 52 1964 846298 84630 45645 54 1965 887812 88781 47089 53 1966 925899 92590 50894 55 1967 964005 96401 50724 53 1968 1015869 101587 52725 52 1969 1061791 106179 53543 50 1970 1109724 110972 52627 47 1971 1178811 117881 52542 45 1972 1259786 125979 54589 43 1973 1313110 131311 54052 41 1974 1280544 128054 45196 35 1975 1327664 132766 44525 34 1976 1402380 140238 45523 32 1977 1467027 146703 47878 33 1978 1544704 154470 50331 33 1979 1529133 152913 51093 33 1980 1527295 152730 51091 33 1981 1555308 155531 49301 32 1982 1595010 159501 43945 28
Source Analysis of Significant Decline in Motor Vehicle Traffic Fatalities in
2008 httpwww-nrdnhtsadotgovPubs811346pdf see Table A1 page 31
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Page 40 of 45
Acknowledgements
The author is grateful for thoughtful comments provided by friends and colleagues
with whom this document was shared via email prior to it being uploaded as a
publicly available document for wider dissemination and study The comments
offered by Prof Subra Ganesan of Oakland University Electrical and Computer
Engineering Department are reproduced with permission in their entirety
About the author
The author obtained his Masterrsquos (S M) and Doctoral (Sc D) degrees in Materials Engineering
from the Massachusetts Institute of Technology Cambridge USA He then spent his entire
professional career at leading US research institutions (MIT NASA Case Western Reserve
University and General Motors R amp D Center in Warren MI) He holds four patents in advanced
materials processing has co-authored two books and has published several scientific papers in
leading peer-reviewed international journals His expertise includes developing simple
mathematical models to explain the behavior of complex systems He can be reached by email at
vlaxmananhotmailcom
Page 41 of 45
Please Buckle Up
httpwwwlakecountypublichealthorgindexphpbuckle-up-montana
Public Awareness
Respect the Cage Exhibit
The Department of Transportation hopes that showing the reality of the crash will reduce traffic
fatalities A crushed car crash dummies and a sobering message ndash all part of the ―Respect The
Cage exhibit that is traveling across Montana The exhibit sponsored by the Montana Department
of Transportation stopped in Ronan on November 6th and is aimed at raising awareness about the
importance of wearing seat belts
The car in the exhibit was in an actual wreck many years ago
the passenger in the vehicle died because he was not wearing a
seat belt the driver who was wearing his seat belt survived
Montanarsquos likeliest crash fatality scenario
A Pickup
A Rural road
And Seat belts that
arenrsquot used
Page 42 of 45
Occupants of pickups are less likely to wear seat belts and pickups are more likely to
roll over than passenger cars
Seat belts reduce the risk of death by 60 percent in pickups and SUVs
In Montana from 2006-2008 81 of those killed in a crash while riding in a pickup were not wearing seat belts
In Montana pickups make up 401 of the vehicle population
For more information on Respect the Cage click here
Page 43 of 45
Appendix 1
Lack of seat belts leading cause of Louisiana highway deaths
1251 AM May 28 2011 |
Written by Adam Duvernay
Crashes involving unbuckled motorists were the leading cause of highway fatalities
in Louisiana last year and cost $9888 million according to recent reports The
Louisiana Highway Safety Commission reported 59 percent of vehicle occupants
killed in Louisiana crashes last year mdash about one in four mdash werent wearing seat
belts
httpwwwshreveporttimescomarticle20110528NEWS01105280354Lack-seat-
belts-leading-cause-La-highway-deathsodyssey=tab|topnews|text|FRONTPAGE
Crash bull Stats Published by NHTSAlsquos National Center for Statistics and Analysis 1200 New Jersey Avenue SE Washington DC 20590
DOT HS 811 451
Early Estimate of Motor Vehicle Traffic Fatalities in 2010
httpwww-nrdnhtsadotgovPubs811451pdf
Summary
A statistical projection of traffic fatalities in 2010 shows that an estimated 32788
people died in motor vehicle traffic crashes This represents a decline of about 3
percent as compared to the 33808 fatalities in 2009 as shown in Table 1 If these
projections are realized fatalities will be lowest on record (since 1949)
Traffic Safety Facts Overview 2009 Data
httpwww-nrdnhtsadotgovPubs811392pdf
In 2009 33808 people were killed in the estimated 5505000 police-reported
motor vehicle traffic crashes 2217000 people were injured and 3957000
crashes involved property damage only Compared to 2008 this is a 10-
percent decrease in the number of fatalities and a 5-percent decrease in the
Page 44 of 45
number of police-reported motor vehicle traffic crashes people injured and
crashes involving property damage
An average of 93 people died each day in motor vehicle crashes in 2009 mdash
an average of one every 16 minutes
Traffic Safety Facts Overview 2008 Data
httpwww-nrdnhtsadotgovPubs811162pdf
In 2008 37261 people were killed in the estimated 5811000 police-reported
motor vehicle traffic crashes 2346000 people were injured and 4146000
crashes involved property damage only
Some comments and Feedback
The following comments were received from Prof Ganesan after his review of the
first draft of this document It was subsequently revised thanks to this input to
address some of the very important issues raised here
Dear Laxman
The write up is not enough
You are emphasizing that the speed limit reduces the fatal accidents (comparing 1966
to 2000 accident numbers)
Can you also add a few sentences why the number is decreasing from 1980 to 2000
values (May be due to better design of vehicles)
Can you say anything about the fuel consumption with the speed for any typical
vehicle in 2011 or 2010 (do not consider the fatalities issue)
Probably a speed between 55 and 60 mph gives a better mileage If so this is a
compelling reason to keep the speed limit low But cars probably can be tuned to
give better mileage at any high speed also
Page 45 of 45
Weather is also a major factor in fatal accidents Speed limit may be kept low during
winter and kept higher in summer Give your comments on this too
Driver distractions can cause more accidents Now cars have many multimedia and
internet features Automatic collision avoidance systems and sensors on the sides can
detect vehicles in the front and neighboring lanes and it can automatically decrease
speed even if the driver speeds at super high speeds
Give some comments on this too There is also Vehicle to Vehicle communications
vehicle to infrastructure communications and they can avoid collisions and accidents
Technology has changed from 1966 I cannot agree with you on the speed limit
without any discussion on the above and other factors
Have a great day
Subra Ganesan
Professor Subramaniam Ganesan
Director Real Time amp DSP Lab
Electrical and Computer Engineering Department
2200 Squirrel Road Dodge Hall Room 105
Oakland University Rochester MI 48309 USA
Phone 248 370 2206 Fax 248 370 4633
wwwsecsoaklandedu~ganesan
IEEE Distinguished Visiting Speaker (2005-2009) Coordinator
IEEE SEM CS chapter Chair Region 4 and CS Society Board member
SAE ASEE ACM member
Page 34 of 45
Conclusions
1 The graphical representation of the highway fatality data and the brief
summary of the historical facts of traffic safety legislation suggest that
recent attempts to increase the speed limits by various states (notably
Texas) may be misguided The distinct peak in the highway fatalities
observed in these graphs is highly alarming This appears to be related to
the enactment of the National Maximum Speed Limit (NSML) in 1974
following the 1973 Arab oil embargo Although NSML was motivated by a
desire to reduce gasoline consumption an unintended benefit might have
been a dramatic reduction in fatalities The fundamental reasons for the
peak in the fatalities-VMT curve must be examined carefully without
political posturing
2 The widely used fatality rate fatalities per 100 M vehicle miles traveled
has been declining since 1921 the first year for which a fatality rate could
be computed and has now reached a historical low The absolute number
of fatalities on the other hand was increasing in the 1950s and 1960s at
an alarming rate and the public outcry that ensued led to the highly
publicized Congressional hearing of 1966 and the subsequent traffic safety
legislations The fatality rate has been decreasing even in the most recent
15-year period (1994-2009) again with increasing fatalities although less
dramatically Thus it appears that fatality rate calculation based on vehicle
miles traveled (VMT) might not be a reliable indicator of the underlying
dynamics in the fatality trends
3 More detailed compilation of number of fatalities and the number of fatal
crashes within each speed limit segment is required to better understand
the effect of increasing speed limits on highway fatalities (and also fatality
rates) Such data is already available and is being compiled at the local
city and county levels in all jurisdictions and only needs to be reorganized
to highlight the effect of (posted) speed limits on the number of crashes
and fatalities This will require some minor rewriting and revisions to the
chapters named ―Crashes and ―States in the annual NHTSA reports
Page 35 of 45
Analysis of the fatalities-crashes data for several years with various
speed limits will be more revealing and meaningful than the current
fatality rates analysis and will be discussed separately in a follow up
report
4 One should not be lulled by the fact that vehicles of the 21st century are
now equipped with advanced safety features not available in the 1950s
and the 1960s In spite of these safety features the laws of physics dictate
that the higher the speed the higher kinetic energy of the colliding objects
and hence the greater the risk indeed near certainty of fatalities in a
higher speed collision compared to a lower speed one
5 The higher the speed at which the vehicle that is involved in a crash is
traveling the higher the kinetic energy that must be absorbed andor
dissipated without affecting the occupant(s) to avoid serious injuries andor
death This was true in the 1950s and the 1960s and will continue to be
true in the 21st century as well
Speed Kills for this just reason
6 It appears that higher fuel economies and reduced
highway fatalities were the twin societal benefits of 55
mph adopted after 1973 If so the current attempts to
increase the speed limits appear to be in conflict with
other important societal objectives
Page 36 of 45
Table 1 Annual US Street amp Highway
Fatalities from 1957
Year
Fatalities
Vehicle Miles
(millions)
Rate100M Vehicle Miles
1957 38702 646915 598
1958 36981 664915 556
1959 37910 700478 541
1960 38137 718845 531
1961 38091 737535 516
1962 40804 766852 532
1963 43564 805423 541
1964 47700 846500 563
1965 49163 887640 554
1966 51524 927915 555
1967 51559 965132 534
1968 53831 1019726 528
1969 55032 1066108 516
1970 53672 1114098 482
1971 53761 1183524 454
1972 55704 1264614 440
1973 55113 1316207 419
1974 46078 1282790 359
1975 45500 1330074 342
1976 45523 1402380 325
1977 47878 1467027 326
1978 50331 1544704 326
1979 51103 1529133 334
1980 51091 1527295 335
1981 49301 1552803 317
1982 43945 1595010 276
1983 42589 1652788 258
1984 44257 1720269 257
1985 43795 1774179 247
Page 37 of 45
1986 46056 1835000 251
1987 46385 1921000 241
1988 47093 2026000 232
1989 45555 2107040 216
1990 44529 2147501 207
1991 41162 2172214 189
1992 39235 2239828 175
1993 40115 2296585 175
1994 40676 2359984 172
1995 41798 2422696 173
1996 41907 2485848 169
1997 41967 2560373 164
Data from Federal Highway Administration
Source httpwwwpublicpurposecomhwy-fatal57+htm
Telephone +16186328507 - Facsimile +16186328538
WENDELL COX CONSULTANCY P O Box 841 - Belleville IL 62269 USA
Page 38 of 45
Fatality data for 1921-1982 compiled by NHTSA
Year
VMT
(Millions)
VMT
(Billions)
Fatalities
Fatality rate
per 100 M VMT
1921 55027 5503 13253 241 1922 67697 6770 14859 219 1923 84995 8500 17870 210 1924 104838 10484 18400 176 1925 122346 12235 20771 170 1926 140735 14074 22194 158 1927 158453 15845 24470 154 1928 172856 17286 26557 154 1929 197720 19772 29592 150 1930 206320 20632 31204 151 1931 216151 21615 31963 148 1932 200517 20052 27979 140 1933 200642 20064 29746 148 1934 215563 21556 34240 159 1935 228568 22857 34494 151 1936 252128 25213 36126 143 1937 270110 27011 37819 140 1938 271177 27118 31083 115 1939 285402 28540 30895 108 1940 302188 30219 32914 109 1941 333612 33361 38142 114 1942 268224 26822 27007 101 1943 208192 20819 22727 109 1944 212713 21271 23165 109 1945 250173 25017 26785 107 1946 340880 34088 31874 94 1947 370894 37089 31193 84 1948 397957 39796 30775 77 1949 424461 42446 30246 71 1950 458246 45825 33186 72 1951 491093 49109 35309 72
1952 513581 51358 36088 70
Page 39 of 45
1953 544433 54443 36190 66 1954 561963 56196 33890 60 1955 605646 60565 36688 61 1956 627843 62784 37965 60 1957 647004 64700 36932 57 1958 664653 66465 35331 53 1959 700480 70048 36223 52 1960 718762 71876 36399 51 1961 737421 73742 36285 49 1962 766734 76673 38980 51 1963 805249 80525 41723 52 1964 846298 84630 45645 54 1965 887812 88781 47089 53 1966 925899 92590 50894 55 1967 964005 96401 50724 53 1968 1015869 101587 52725 52 1969 1061791 106179 53543 50 1970 1109724 110972 52627 47 1971 1178811 117881 52542 45 1972 1259786 125979 54589 43 1973 1313110 131311 54052 41 1974 1280544 128054 45196 35 1975 1327664 132766 44525 34 1976 1402380 140238 45523 32 1977 1467027 146703 47878 33 1978 1544704 154470 50331 33 1979 1529133 152913 51093 33 1980 1527295 152730 51091 33 1981 1555308 155531 49301 32 1982 1595010 159501 43945 28
Source Analysis of Significant Decline in Motor Vehicle Traffic Fatalities in
2008 httpwww-nrdnhtsadotgovPubs811346pdf see Table A1 page 31
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Page 40 of 45
Acknowledgements
The author is grateful for thoughtful comments provided by friends and colleagues
with whom this document was shared via email prior to it being uploaded as a
publicly available document for wider dissemination and study The comments
offered by Prof Subra Ganesan of Oakland University Electrical and Computer
Engineering Department are reproduced with permission in their entirety
About the author
The author obtained his Masterrsquos (S M) and Doctoral (Sc D) degrees in Materials Engineering
from the Massachusetts Institute of Technology Cambridge USA He then spent his entire
professional career at leading US research institutions (MIT NASA Case Western Reserve
University and General Motors R amp D Center in Warren MI) He holds four patents in advanced
materials processing has co-authored two books and has published several scientific papers in
leading peer-reviewed international journals His expertise includes developing simple
mathematical models to explain the behavior of complex systems He can be reached by email at
vlaxmananhotmailcom
Page 41 of 45
Please Buckle Up
httpwwwlakecountypublichealthorgindexphpbuckle-up-montana
Public Awareness
Respect the Cage Exhibit
The Department of Transportation hopes that showing the reality of the crash will reduce traffic
fatalities A crushed car crash dummies and a sobering message ndash all part of the ―Respect The
Cage exhibit that is traveling across Montana The exhibit sponsored by the Montana Department
of Transportation stopped in Ronan on November 6th and is aimed at raising awareness about the
importance of wearing seat belts
The car in the exhibit was in an actual wreck many years ago
the passenger in the vehicle died because he was not wearing a
seat belt the driver who was wearing his seat belt survived
Montanarsquos likeliest crash fatality scenario
A Pickup
A Rural road
And Seat belts that
arenrsquot used
Page 42 of 45
Occupants of pickups are less likely to wear seat belts and pickups are more likely to
roll over than passenger cars
Seat belts reduce the risk of death by 60 percent in pickups and SUVs
In Montana from 2006-2008 81 of those killed in a crash while riding in a pickup were not wearing seat belts
In Montana pickups make up 401 of the vehicle population
For more information on Respect the Cage click here
Page 43 of 45
Appendix 1
Lack of seat belts leading cause of Louisiana highway deaths
1251 AM May 28 2011 |
Written by Adam Duvernay
Crashes involving unbuckled motorists were the leading cause of highway fatalities
in Louisiana last year and cost $9888 million according to recent reports The
Louisiana Highway Safety Commission reported 59 percent of vehicle occupants
killed in Louisiana crashes last year mdash about one in four mdash werent wearing seat
belts
httpwwwshreveporttimescomarticle20110528NEWS01105280354Lack-seat-
belts-leading-cause-La-highway-deathsodyssey=tab|topnews|text|FRONTPAGE
Crash bull Stats Published by NHTSAlsquos National Center for Statistics and Analysis 1200 New Jersey Avenue SE Washington DC 20590
DOT HS 811 451
Early Estimate of Motor Vehicle Traffic Fatalities in 2010
httpwww-nrdnhtsadotgovPubs811451pdf
Summary
A statistical projection of traffic fatalities in 2010 shows that an estimated 32788
people died in motor vehicle traffic crashes This represents a decline of about 3
percent as compared to the 33808 fatalities in 2009 as shown in Table 1 If these
projections are realized fatalities will be lowest on record (since 1949)
Traffic Safety Facts Overview 2009 Data
httpwww-nrdnhtsadotgovPubs811392pdf
In 2009 33808 people were killed in the estimated 5505000 police-reported
motor vehicle traffic crashes 2217000 people were injured and 3957000
crashes involved property damage only Compared to 2008 this is a 10-
percent decrease in the number of fatalities and a 5-percent decrease in the
Page 44 of 45
number of police-reported motor vehicle traffic crashes people injured and
crashes involving property damage
An average of 93 people died each day in motor vehicle crashes in 2009 mdash
an average of one every 16 minutes
Traffic Safety Facts Overview 2008 Data
httpwww-nrdnhtsadotgovPubs811162pdf
In 2008 37261 people were killed in the estimated 5811000 police-reported
motor vehicle traffic crashes 2346000 people were injured and 4146000
crashes involved property damage only
Some comments and Feedback
The following comments were received from Prof Ganesan after his review of the
first draft of this document It was subsequently revised thanks to this input to
address some of the very important issues raised here
Dear Laxman
The write up is not enough
You are emphasizing that the speed limit reduces the fatal accidents (comparing 1966
to 2000 accident numbers)
Can you also add a few sentences why the number is decreasing from 1980 to 2000
values (May be due to better design of vehicles)
Can you say anything about the fuel consumption with the speed for any typical
vehicle in 2011 or 2010 (do not consider the fatalities issue)
Probably a speed between 55 and 60 mph gives a better mileage If so this is a
compelling reason to keep the speed limit low But cars probably can be tuned to
give better mileage at any high speed also
Page 45 of 45
Weather is also a major factor in fatal accidents Speed limit may be kept low during
winter and kept higher in summer Give your comments on this too
Driver distractions can cause more accidents Now cars have many multimedia and
internet features Automatic collision avoidance systems and sensors on the sides can
detect vehicles in the front and neighboring lanes and it can automatically decrease
speed even if the driver speeds at super high speeds
Give some comments on this too There is also Vehicle to Vehicle communications
vehicle to infrastructure communications and they can avoid collisions and accidents
Technology has changed from 1966 I cannot agree with you on the speed limit
without any discussion on the above and other factors
Have a great day
Subra Ganesan
Professor Subramaniam Ganesan
Director Real Time amp DSP Lab
Electrical and Computer Engineering Department
2200 Squirrel Road Dodge Hall Room 105
Oakland University Rochester MI 48309 USA
Phone 248 370 2206 Fax 248 370 4633
wwwsecsoaklandedu~ganesan
IEEE Distinguished Visiting Speaker (2005-2009) Coordinator
IEEE SEM CS chapter Chair Region 4 and CS Society Board member
SAE ASEE ACM member
Page 35 of 45
Analysis of the fatalities-crashes data for several years with various
speed limits will be more revealing and meaningful than the current
fatality rates analysis and will be discussed separately in a follow up
report
4 One should not be lulled by the fact that vehicles of the 21st century are
now equipped with advanced safety features not available in the 1950s
and the 1960s In spite of these safety features the laws of physics dictate
that the higher the speed the higher kinetic energy of the colliding objects
and hence the greater the risk indeed near certainty of fatalities in a
higher speed collision compared to a lower speed one
5 The higher the speed at which the vehicle that is involved in a crash is
traveling the higher the kinetic energy that must be absorbed andor
dissipated without affecting the occupant(s) to avoid serious injuries andor
death This was true in the 1950s and the 1960s and will continue to be
true in the 21st century as well
Speed Kills for this just reason
6 It appears that higher fuel economies and reduced
highway fatalities were the twin societal benefits of 55
mph adopted after 1973 If so the current attempts to
increase the speed limits appear to be in conflict with
other important societal objectives
Page 36 of 45
Table 1 Annual US Street amp Highway
Fatalities from 1957
Year
Fatalities
Vehicle Miles
(millions)
Rate100M Vehicle Miles
1957 38702 646915 598
1958 36981 664915 556
1959 37910 700478 541
1960 38137 718845 531
1961 38091 737535 516
1962 40804 766852 532
1963 43564 805423 541
1964 47700 846500 563
1965 49163 887640 554
1966 51524 927915 555
1967 51559 965132 534
1968 53831 1019726 528
1969 55032 1066108 516
1970 53672 1114098 482
1971 53761 1183524 454
1972 55704 1264614 440
1973 55113 1316207 419
1974 46078 1282790 359
1975 45500 1330074 342
1976 45523 1402380 325
1977 47878 1467027 326
1978 50331 1544704 326
1979 51103 1529133 334
1980 51091 1527295 335
1981 49301 1552803 317
1982 43945 1595010 276
1983 42589 1652788 258
1984 44257 1720269 257
1985 43795 1774179 247
Page 37 of 45
1986 46056 1835000 251
1987 46385 1921000 241
1988 47093 2026000 232
1989 45555 2107040 216
1990 44529 2147501 207
1991 41162 2172214 189
1992 39235 2239828 175
1993 40115 2296585 175
1994 40676 2359984 172
1995 41798 2422696 173
1996 41907 2485848 169
1997 41967 2560373 164
Data from Federal Highway Administration
Source httpwwwpublicpurposecomhwy-fatal57+htm
Telephone +16186328507 - Facsimile +16186328538
WENDELL COX CONSULTANCY P O Box 841 - Belleville IL 62269 USA
Page 38 of 45
Fatality data for 1921-1982 compiled by NHTSA
Year
VMT
(Millions)
VMT
(Billions)
Fatalities
Fatality rate
per 100 M VMT
1921 55027 5503 13253 241 1922 67697 6770 14859 219 1923 84995 8500 17870 210 1924 104838 10484 18400 176 1925 122346 12235 20771 170 1926 140735 14074 22194 158 1927 158453 15845 24470 154 1928 172856 17286 26557 154 1929 197720 19772 29592 150 1930 206320 20632 31204 151 1931 216151 21615 31963 148 1932 200517 20052 27979 140 1933 200642 20064 29746 148 1934 215563 21556 34240 159 1935 228568 22857 34494 151 1936 252128 25213 36126 143 1937 270110 27011 37819 140 1938 271177 27118 31083 115 1939 285402 28540 30895 108 1940 302188 30219 32914 109 1941 333612 33361 38142 114 1942 268224 26822 27007 101 1943 208192 20819 22727 109 1944 212713 21271 23165 109 1945 250173 25017 26785 107 1946 340880 34088 31874 94 1947 370894 37089 31193 84 1948 397957 39796 30775 77 1949 424461 42446 30246 71 1950 458246 45825 33186 72 1951 491093 49109 35309 72
1952 513581 51358 36088 70
Page 39 of 45
1953 544433 54443 36190 66 1954 561963 56196 33890 60 1955 605646 60565 36688 61 1956 627843 62784 37965 60 1957 647004 64700 36932 57 1958 664653 66465 35331 53 1959 700480 70048 36223 52 1960 718762 71876 36399 51 1961 737421 73742 36285 49 1962 766734 76673 38980 51 1963 805249 80525 41723 52 1964 846298 84630 45645 54 1965 887812 88781 47089 53 1966 925899 92590 50894 55 1967 964005 96401 50724 53 1968 1015869 101587 52725 52 1969 1061791 106179 53543 50 1970 1109724 110972 52627 47 1971 1178811 117881 52542 45 1972 1259786 125979 54589 43 1973 1313110 131311 54052 41 1974 1280544 128054 45196 35 1975 1327664 132766 44525 34 1976 1402380 140238 45523 32 1977 1467027 146703 47878 33 1978 1544704 154470 50331 33 1979 1529133 152913 51093 33 1980 1527295 152730 51091 33 1981 1555308 155531 49301 32 1982 1595010 159501 43945 28
Source Analysis of Significant Decline in Motor Vehicle Traffic Fatalities in
2008 httpwww-nrdnhtsadotgovPubs811346pdf see Table A1 page 31
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Page 40 of 45
Acknowledgements
The author is grateful for thoughtful comments provided by friends and colleagues
with whom this document was shared via email prior to it being uploaded as a
publicly available document for wider dissemination and study The comments
offered by Prof Subra Ganesan of Oakland University Electrical and Computer
Engineering Department are reproduced with permission in their entirety
About the author
The author obtained his Masterrsquos (S M) and Doctoral (Sc D) degrees in Materials Engineering
from the Massachusetts Institute of Technology Cambridge USA He then spent his entire
professional career at leading US research institutions (MIT NASA Case Western Reserve
University and General Motors R amp D Center in Warren MI) He holds four patents in advanced
materials processing has co-authored two books and has published several scientific papers in
leading peer-reviewed international journals His expertise includes developing simple
mathematical models to explain the behavior of complex systems He can be reached by email at
vlaxmananhotmailcom
Page 41 of 45
Please Buckle Up
httpwwwlakecountypublichealthorgindexphpbuckle-up-montana
Public Awareness
Respect the Cage Exhibit
The Department of Transportation hopes that showing the reality of the crash will reduce traffic
fatalities A crushed car crash dummies and a sobering message ndash all part of the ―Respect The
Cage exhibit that is traveling across Montana The exhibit sponsored by the Montana Department
of Transportation stopped in Ronan on November 6th and is aimed at raising awareness about the
importance of wearing seat belts
The car in the exhibit was in an actual wreck many years ago
the passenger in the vehicle died because he was not wearing a
seat belt the driver who was wearing his seat belt survived
Montanarsquos likeliest crash fatality scenario
A Pickup
A Rural road
And Seat belts that
arenrsquot used
Page 42 of 45
Occupants of pickups are less likely to wear seat belts and pickups are more likely to
roll over than passenger cars
Seat belts reduce the risk of death by 60 percent in pickups and SUVs
In Montana from 2006-2008 81 of those killed in a crash while riding in a pickup were not wearing seat belts
In Montana pickups make up 401 of the vehicle population
For more information on Respect the Cage click here
Page 43 of 45
Appendix 1
Lack of seat belts leading cause of Louisiana highway deaths
1251 AM May 28 2011 |
Written by Adam Duvernay
Crashes involving unbuckled motorists were the leading cause of highway fatalities
in Louisiana last year and cost $9888 million according to recent reports The
Louisiana Highway Safety Commission reported 59 percent of vehicle occupants
killed in Louisiana crashes last year mdash about one in four mdash werent wearing seat
belts
httpwwwshreveporttimescomarticle20110528NEWS01105280354Lack-seat-
belts-leading-cause-La-highway-deathsodyssey=tab|topnews|text|FRONTPAGE
Crash bull Stats Published by NHTSAlsquos National Center for Statistics and Analysis 1200 New Jersey Avenue SE Washington DC 20590
DOT HS 811 451
Early Estimate of Motor Vehicle Traffic Fatalities in 2010
httpwww-nrdnhtsadotgovPubs811451pdf
Summary
A statistical projection of traffic fatalities in 2010 shows that an estimated 32788
people died in motor vehicle traffic crashes This represents a decline of about 3
percent as compared to the 33808 fatalities in 2009 as shown in Table 1 If these
projections are realized fatalities will be lowest on record (since 1949)
Traffic Safety Facts Overview 2009 Data
httpwww-nrdnhtsadotgovPubs811392pdf
In 2009 33808 people were killed in the estimated 5505000 police-reported
motor vehicle traffic crashes 2217000 people were injured and 3957000
crashes involved property damage only Compared to 2008 this is a 10-
percent decrease in the number of fatalities and a 5-percent decrease in the
Page 44 of 45
number of police-reported motor vehicle traffic crashes people injured and
crashes involving property damage
An average of 93 people died each day in motor vehicle crashes in 2009 mdash
an average of one every 16 minutes
Traffic Safety Facts Overview 2008 Data
httpwww-nrdnhtsadotgovPubs811162pdf
In 2008 37261 people were killed in the estimated 5811000 police-reported
motor vehicle traffic crashes 2346000 people were injured and 4146000
crashes involved property damage only
Some comments and Feedback
The following comments were received from Prof Ganesan after his review of the
first draft of this document It was subsequently revised thanks to this input to
address some of the very important issues raised here
Dear Laxman
The write up is not enough
You are emphasizing that the speed limit reduces the fatal accidents (comparing 1966
to 2000 accident numbers)
Can you also add a few sentences why the number is decreasing from 1980 to 2000
values (May be due to better design of vehicles)
Can you say anything about the fuel consumption with the speed for any typical
vehicle in 2011 or 2010 (do not consider the fatalities issue)
Probably a speed between 55 and 60 mph gives a better mileage If so this is a
compelling reason to keep the speed limit low But cars probably can be tuned to
give better mileage at any high speed also
Page 45 of 45
Weather is also a major factor in fatal accidents Speed limit may be kept low during
winter and kept higher in summer Give your comments on this too
Driver distractions can cause more accidents Now cars have many multimedia and
internet features Automatic collision avoidance systems and sensors on the sides can
detect vehicles in the front and neighboring lanes and it can automatically decrease
speed even if the driver speeds at super high speeds
Give some comments on this too There is also Vehicle to Vehicle communications
vehicle to infrastructure communications and they can avoid collisions and accidents
Technology has changed from 1966 I cannot agree with you on the speed limit
without any discussion on the above and other factors
Have a great day
Subra Ganesan
Professor Subramaniam Ganesan
Director Real Time amp DSP Lab
Electrical and Computer Engineering Department
2200 Squirrel Road Dodge Hall Room 105
Oakland University Rochester MI 48309 USA
Phone 248 370 2206 Fax 248 370 4633
wwwsecsoaklandedu~ganesan
IEEE Distinguished Visiting Speaker (2005-2009) Coordinator
IEEE SEM CS chapter Chair Region 4 and CS Society Board member
SAE ASEE ACM member
Page 36 of 45
Table 1 Annual US Street amp Highway
Fatalities from 1957
Year
Fatalities
Vehicle Miles
(millions)
Rate100M Vehicle Miles
1957 38702 646915 598
1958 36981 664915 556
1959 37910 700478 541
1960 38137 718845 531
1961 38091 737535 516
1962 40804 766852 532
1963 43564 805423 541
1964 47700 846500 563
1965 49163 887640 554
1966 51524 927915 555
1967 51559 965132 534
1968 53831 1019726 528
1969 55032 1066108 516
1970 53672 1114098 482
1971 53761 1183524 454
1972 55704 1264614 440
1973 55113 1316207 419
1974 46078 1282790 359
1975 45500 1330074 342
1976 45523 1402380 325
1977 47878 1467027 326
1978 50331 1544704 326
1979 51103 1529133 334
1980 51091 1527295 335
1981 49301 1552803 317
1982 43945 1595010 276
1983 42589 1652788 258
1984 44257 1720269 257
1985 43795 1774179 247
Page 37 of 45
1986 46056 1835000 251
1987 46385 1921000 241
1988 47093 2026000 232
1989 45555 2107040 216
1990 44529 2147501 207
1991 41162 2172214 189
1992 39235 2239828 175
1993 40115 2296585 175
1994 40676 2359984 172
1995 41798 2422696 173
1996 41907 2485848 169
1997 41967 2560373 164
Data from Federal Highway Administration
Source httpwwwpublicpurposecomhwy-fatal57+htm
Telephone +16186328507 - Facsimile +16186328538
WENDELL COX CONSULTANCY P O Box 841 - Belleville IL 62269 USA
Page 38 of 45
Fatality data for 1921-1982 compiled by NHTSA
Year
VMT
(Millions)
VMT
(Billions)
Fatalities
Fatality rate
per 100 M VMT
1921 55027 5503 13253 241 1922 67697 6770 14859 219 1923 84995 8500 17870 210 1924 104838 10484 18400 176 1925 122346 12235 20771 170 1926 140735 14074 22194 158 1927 158453 15845 24470 154 1928 172856 17286 26557 154 1929 197720 19772 29592 150 1930 206320 20632 31204 151 1931 216151 21615 31963 148 1932 200517 20052 27979 140 1933 200642 20064 29746 148 1934 215563 21556 34240 159 1935 228568 22857 34494 151 1936 252128 25213 36126 143 1937 270110 27011 37819 140 1938 271177 27118 31083 115 1939 285402 28540 30895 108 1940 302188 30219 32914 109 1941 333612 33361 38142 114 1942 268224 26822 27007 101 1943 208192 20819 22727 109 1944 212713 21271 23165 109 1945 250173 25017 26785 107 1946 340880 34088 31874 94 1947 370894 37089 31193 84 1948 397957 39796 30775 77 1949 424461 42446 30246 71 1950 458246 45825 33186 72 1951 491093 49109 35309 72
1952 513581 51358 36088 70
Page 39 of 45
1953 544433 54443 36190 66 1954 561963 56196 33890 60 1955 605646 60565 36688 61 1956 627843 62784 37965 60 1957 647004 64700 36932 57 1958 664653 66465 35331 53 1959 700480 70048 36223 52 1960 718762 71876 36399 51 1961 737421 73742 36285 49 1962 766734 76673 38980 51 1963 805249 80525 41723 52 1964 846298 84630 45645 54 1965 887812 88781 47089 53 1966 925899 92590 50894 55 1967 964005 96401 50724 53 1968 1015869 101587 52725 52 1969 1061791 106179 53543 50 1970 1109724 110972 52627 47 1971 1178811 117881 52542 45 1972 1259786 125979 54589 43 1973 1313110 131311 54052 41 1974 1280544 128054 45196 35 1975 1327664 132766 44525 34 1976 1402380 140238 45523 32 1977 1467027 146703 47878 33 1978 1544704 154470 50331 33 1979 1529133 152913 51093 33 1980 1527295 152730 51091 33 1981 1555308 155531 49301 32 1982 1595010 159501 43945 28
Source Analysis of Significant Decline in Motor Vehicle Traffic Fatalities in
2008 httpwww-nrdnhtsadotgovPubs811346pdf see Table A1 page 31
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Page 40 of 45
Acknowledgements
The author is grateful for thoughtful comments provided by friends and colleagues
with whom this document was shared via email prior to it being uploaded as a
publicly available document for wider dissemination and study The comments
offered by Prof Subra Ganesan of Oakland University Electrical and Computer
Engineering Department are reproduced with permission in their entirety
About the author
The author obtained his Masterrsquos (S M) and Doctoral (Sc D) degrees in Materials Engineering
from the Massachusetts Institute of Technology Cambridge USA He then spent his entire
professional career at leading US research institutions (MIT NASA Case Western Reserve
University and General Motors R amp D Center in Warren MI) He holds four patents in advanced
materials processing has co-authored two books and has published several scientific papers in
leading peer-reviewed international journals His expertise includes developing simple
mathematical models to explain the behavior of complex systems He can be reached by email at
vlaxmananhotmailcom
Page 41 of 45
Please Buckle Up
httpwwwlakecountypublichealthorgindexphpbuckle-up-montana
Public Awareness
Respect the Cage Exhibit
The Department of Transportation hopes that showing the reality of the crash will reduce traffic
fatalities A crushed car crash dummies and a sobering message ndash all part of the ―Respect The
Cage exhibit that is traveling across Montana The exhibit sponsored by the Montana Department
of Transportation stopped in Ronan on November 6th and is aimed at raising awareness about the
importance of wearing seat belts
The car in the exhibit was in an actual wreck many years ago
the passenger in the vehicle died because he was not wearing a
seat belt the driver who was wearing his seat belt survived
Montanarsquos likeliest crash fatality scenario
A Pickup
A Rural road
And Seat belts that
arenrsquot used
Page 42 of 45
Occupants of pickups are less likely to wear seat belts and pickups are more likely to
roll over than passenger cars
Seat belts reduce the risk of death by 60 percent in pickups and SUVs
In Montana from 2006-2008 81 of those killed in a crash while riding in a pickup were not wearing seat belts
In Montana pickups make up 401 of the vehicle population
For more information on Respect the Cage click here
Page 43 of 45
Appendix 1
Lack of seat belts leading cause of Louisiana highway deaths
1251 AM May 28 2011 |
Written by Adam Duvernay
Crashes involving unbuckled motorists were the leading cause of highway fatalities
in Louisiana last year and cost $9888 million according to recent reports The
Louisiana Highway Safety Commission reported 59 percent of vehicle occupants
killed in Louisiana crashes last year mdash about one in four mdash werent wearing seat
belts
httpwwwshreveporttimescomarticle20110528NEWS01105280354Lack-seat-
belts-leading-cause-La-highway-deathsodyssey=tab|topnews|text|FRONTPAGE
Crash bull Stats Published by NHTSAlsquos National Center for Statistics and Analysis 1200 New Jersey Avenue SE Washington DC 20590
DOT HS 811 451
Early Estimate of Motor Vehicle Traffic Fatalities in 2010
httpwww-nrdnhtsadotgovPubs811451pdf
Summary
A statistical projection of traffic fatalities in 2010 shows that an estimated 32788
people died in motor vehicle traffic crashes This represents a decline of about 3
percent as compared to the 33808 fatalities in 2009 as shown in Table 1 If these
projections are realized fatalities will be lowest on record (since 1949)
Traffic Safety Facts Overview 2009 Data
httpwww-nrdnhtsadotgovPubs811392pdf
In 2009 33808 people were killed in the estimated 5505000 police-reported
motor vehicle traffic crashes 2217000 people were injured and 3957000
crashes involved property damage only Compared to 2008 this is a 10-
percent decrease in the number of fatalities and a 5-percent decrease in the
Page 44 of 45
number of police-reported motor vehicle traffic crashes people injured and
crashes involving property damage
An average of 93 people died each day in motor vehicle crashes in 2009 mdash
an average of one every 16 minutes
Traffic Safety Facts Overview 2008 Data
httpwww-nrdnhtsadotgovPubs811162pdf
In 2008 37261 people were killed in the estimated 5811000 police-reported
motor vehicle traffic crashes 2346000 people were injured and 4146000
crashes involved property damage only
Some comments and Feedback
The following comments were received from Prof Ganesan after his review of the
first draft of this document It was subsequently revised thanks to this input to
address some of the very important issues raised here
Dear Laxman
The write up is not enough
You are emphasizing that the speed limit reduces the fatal accidents (comparing 1966
to 2000 accident numbers)
Can you also add a few sentences why the number is decreasing from 1980 to 2000
values (May be due to better design of vehicles)
Can you say anything about the fuel consumption with the speed for any typical
vehicle in 2011 or 2010 (do not consider the fatalities issue)
Probably a speed between 55 and 60 mph gives a better mileage If so this is a
compelling reason to keep the speed limit low But cars probably can be tuned to
give better mileage at any high speed also
Page 45 of 45
Weather is also a major factor in fatal accidents Speed limit may be kept low during
winter and kept higher in summer Give your comments on this too
Driver distractions can cause more accidents Now cars have many multimedia and
internet features Automatic collision avoidance systems and sensors on the sides can
detect vehicles in the front and neighboring lanes and it can automatically decrease
speed even if the driver speeds at super high speeds
Give some comments on this too There is also Vehicle to Vehicle communications
vehicle to infrastructure communications and they can avoid collisions and accidents
Technology has changed from 1966 I cannot agree with you on the speed limit
without any discussion on the above and other factors
Have a great day
Subra Ganesan
Professor Subramaniam Ganesan
Director Real Time amp DSP Lab
Electrical and Computer Engineering Department
2200 Squirrel Road Dodge Hall Room 105
Oakland University Rochester MI 48309 USA
Phone 248 370 2206 Fax 248 370 4633
wwwsecsoaklandedu~ganesan
IEEE Distinguished Visiting Speaker (2005-2009) Coordinator
IEEE SEM CS chapter Chair Region 4 and CS Society Board member
SAE ASEE ACM member
Page 37 of 45
1986 46056 1835000 251
1987 46385 1921000 241
1988 47093 2026000 232
1989 45555 2107040 216
1990 44529 2147501 207
1991 41162 2172214 189
1992 39235 2239828 175
1993 40115 2296585 175
1994 40676 2359984 172
1995 41798 2422696 173
1996 41907 2485848 169
1997 41967 2560373 164
Data from Federal Highway Administration
Source httpwwwpublicpurposecomhwy-fatal57+htm
Telephone +16186328507 - Facsimile +16186328538
WENDELL COX CONSULTANCY P O Box 841 - Belleville IL 62269 USA
Page 38 of 45
Fatality data for 1921-1982 compiled by NHTSA
Year
VMT
(Millions)
VMT
(Billions)
Fatalities
Fatality rate
per 100 M VMT
1921 55027 5503 13253 241 1922 67697 6770 14859 219 1923 84995 8500 17870 210 1924 104838 10484 18400 176 1925 122346 12235 20771 170 1926 140735 14074 22194 158 1927 158453 15845 24470 154 1928 172856 17286 26557 154 1929 197720 19772 29592 150 1930 206320 20632 31204 151 1931 216151 21615 31963 148 1932 200517 20052 27979 140 1933 200642 20064 29746 148 1934 215563 21556 34240 159 1935 228568 22857 34494 151 1936 252128 25213 36126 143 1937 270110 27011 37819 140 1938 271177 27118 31083 115 1939 285402 28540 30895 108 1940 302188 30219 32914 109 1941 333612 33361 38142 114 1942 268224 26822 27007 101 1943 208192 20819 22727 109 1944 212713 21271 23165 109 1945 250173 25017 26785 107 1946 340880 34088 31874 94 1947 370894 37089 31193 84 1948 397957 39796 30775 77 1949 424461 42446 30246 71 1950 458246 45825 33186 72 1951 491093 49109 35309 72
1952 513581 51358 36088 70
Page 39 of 45
1953 544433 54443 36190 66 1954 561963 56196 33890 60 1955 605646 60565 36688 61 1956 627843 62784 37965 60 1957 647004 64700 36932 57 1958 664653 66465 35331 53 1959 700480 70048 36223 52 1960 718762 71876 36399 51 1961 737421 73742 36285 49 1962 766734 76673 38980 51 1963 805249 80525 41723 52 1964 846298 84630 45645 54 1965 887812 88781 47089 53 1966 925899 92590 50894 55 1967 964005 96401 50724 53 1968 1015869 101587 52725 52 1969 1061791 106179 53543 50 1970 1109724 110972 52627 47 1971 1178811 117881 52542 45 1972 1259786 125979 54589 43 1973 1313110 131311 54052 41 1974 1280544 128054 45196 35 1975 1327664 132766 44525 34 1976 1402380 140238 45523 32 1977 1467027 146703 47878 33 1978 1544704 154470 50331 33 1979 1529133 152913 51093 33 1980 1527295 152730 51091 33 1981 1555308 155531 49301 32 1982 1595010 159501 43945 28
Source Analysis of Significant Decline in Motor Vehicle Traffic Fatalities in
2008 httpwww-nrdnhtsadotgovPubs811346pdf see Table A1 page 31
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Page 40 of 45
Acknowledgements
The author is grateful for thoughtful comments provided by friends and colleagues
with whom this document was shared via email prior to it being uploaded as a
publicly available document for wider dissemination and study The comments
offered by Prof Subra Ganesan of Oakland University Electrical and Computer
Engineering Department are reproduced with permission in their entirety
About the author
The author obtained his Masterrsquos (S M) and Doctoral (Sc D) degrees in Materials Engineering
from the Massachusetts Institute of Technology Cambridge USA He then spent his entire
professional career at leading US research institutions (MIT NASA Case Western Reserve
University and General Motors R amp D Center in Warren MI) He holds four patents in advanced
materials processing has co-authored two books and has published several scientific papers in
leading peer-reviewed international journals His expertise includes developing simple
mathematical models to explain the behavior of complex systems He can be reached by email at
vlaxmananhotmailcom
Page 41 of 45
Please Buckle Up
httpwwwlakecountypublichealthorgindexphpbuckle-up-montana
Public Awareness
Respect the Cage Exhibit
The Department of Transportation hopes that showing the reality of the crash will reduce traffic
fatalities A crushed car crash dummies and a sobering message ndash all part of the ―Respect The
Cage exhibit that is traveling across Montana The exhibit sponsored by the Montana Department
of Transportation stopped in Ronan on November 6th and is aimed at raising awareness about the
importance of wearing seat belts
The car in the exhibit was in an actual wreck many years ago
the passenger in the vehicle died because he was not wearing a
seat belt the driver who was wearing his seat belt survived
Montanarsquos likeliest crash fatality scenario
A Pickup
A Rural road
And Seat belts that
arenrsquot used
Page 42 of 45
Occupants of pickups are less likely to wear seat belts and pickups are more likely to
roll over than passenger cars
Seat belts reduce the risk of death by 60 percent in pickups and SUVs
In Montana from 2006-2008 81 of those killed in a crash while riding in a pickup were not wearing seat belts
In Montana pickups make up 401 of the vehicle population
For more information on Respect the Cage click here
Page 43 of 45
Appendix 1
Lack of seat belts leading cause of Louisiana highway deaths
1251 AM May 28 2011 |
Written by Adam Duvernay
Crashes involving unbuckled motorists were the leading cause of highway fatalities
in Louisiana last year and cost $9888 million according to recent reports The
Louisiana Highway Safety Commission reported 59 percent of vehicle occupants
killed in Louisiana crashes last year mdash about one in four mdash werent wearing seat
belts
httpwwwshreveporttimescomarticle20110528NEWS01105280354Lack-seat-
belts-leading-cause-La-highway-deathsodyssey=tab|topnews|text|FRONTPAGE
Crash bull Stats Published by NHTSAlsquos National Center for Statistics and Analysis 1200 New Jersey Avenue SE Washington DC 20590
DOT HS 811 451
Early Estimate of Motor Vehicle Traffic Fatalities in 2010
httpwww-nrdnhtsadotgovPubs811451pdf
Summary
A statistical projection of traffic fatalities in 2010 shows that an estimated 32788
people died in motor vehicle traffic crashes This represents a decline of about 3
percent as compared to the 33808 fatalities in 2009 as shown in Table 1 If these
projections are realized fatalities will be lowest on record (since 1949)
Traffic Safety Facts Overview 2009 Data
httpwww-nrdnhtsadotgovPubs811392pdf
In 2009 33808 people were killed in the estimated 5505000 police-reported
motor vehicle traffic crashes 2217000 people were injured and 3957000
crashes involved property damage only Compared to 2008 this is a 10-
percent decrease in the number of fatalities and a 5-percent decrease in the
Page 44 of 45
number of police-reported motor vehicle traffic crashes people injured and
crashes involving property damage
An average of 93 people died each day in motor vehicle crashes in 2009 mdash
an average of one every 16 minutes
Traffic Safety Facts Overview 2008 Data
httpwww-nrdnhtsadotgovPubs811162pdf
In 2008 37261 people were killed in the estimated 5811000 police-reported
motor vehicle traffic crashes 2346000 people were injured and 4146000
crashes involved property damage only
Some comments and Feedback
The following comments were received from Prof Ganesan after his review of the
first draft of this document It was subsequently revised thanks to this input to
address some of the very important issues raised here
Dear Laxman
The write up is not enough
You are emphasizing that the speed limit reduces the fatal accidents (comparing 1966
to 2000 accident numbers)
Can you also add a few sentences why the number is decreasing from 1980 to 2000
values (May be due to better design of vehicles)
Can you say anything about the fuel consumption with the speed for any typical
vehicle in 2011 or 2010 (do not consider the fatalities issue)
Probably a speed between 55 and 60 mph gives a better mileage If so this is a
compelling reason to keep the speed limit low But cars probably can be tuned to
give better mileage at any high speed also
Page 45 of 45
Weather is also a major factor in fatal accidents Speed limit may be kept low during
winter and kept higher in summer Give your comments on this too
Driver distractions can cause more accidents Now cars have many multimedia and
internet features Automatic collision avoidance systems and sensors on the sides can
detect vehicles in the front and neighboring lanes and it can automatically decrease
speed even if the driver speeds at super high speeds
Give some comments on this too There is also Vehicle to Vehicle communications
vehicle to infrastructure communications and they can avoid collisions and accidents
Technology has changed from 1966 I cannot agree with you on the speed limit
without any discussion on the above and other factors
Have a great day
Subra Ganesan
Professor Subramaniam Ganesan
Director Real Time amp DSP Lab
Electrical and Computer Engineering Department
2200 Squirrel Road Dodge Hall Room 105
Oakland University Rochester MI 48309 USA
Phone 248 370 2206 Fax 248 370 4633
wwwsecsoaklandedu~ganesan
IEEE Distinguished Visiting Speaker (2005-2009) Coordinator
IEEE SEM CS chapter Chair Region 4 and CS Society Board member
SAE ASEE ACM member
Page 38 of 45
Fatality data for 1921-1982 compiled by NHTSA
Year
VMT
(Millions)
VMT
(Billions)
Fatalities
Fatality rate
per 100 M VMT
1921 55027 5503 13253 241 1922 67697 6770 14859 219 1923 84995 8500 17870 210 1924 104838 10484 18400 176 1925 122346 12235 20771 170 1926 140735 14074 22194 158 1927 158453 15845 24470 154 1928 172856 17286 26557 154 1929 197720 19772 29592 150 1930 206320 20632 31204 151 1931 216151 21615 31963 148 1932 200517 20052 27979 140 1933 200642 20064 29746 148 1934 215563 21556 34240 159 1935 228568 22857 34494 151 1936 252128 25213 36126 143 1937 270110 27011 37819 140 1938 271177 27118 31083 115 1939 285402 28540 30895 108 1940 302188 30219 32914 109 1941 333612 33361 38142 114 1942 268224 26822 27007 101 1943 208192 20819 22727 109 1944 212713 21271 23165 109 1945 250173 25017 26785 107 1946 340880 34088 31874 94 1947 370894 37089 31193 84 1948 397957 39796 30775 77 1949 424461 42446 30246 71 1950 458246 45825 33186 72 1951 491093 49109 35309 72
1952 513581 51358 36088 70
Page 39 of 45
1953 544433 54443 36190 66 1954 561963 56196 33890 60 1955 605646 60565 36688 61 1956 627843 62784 37965 60 1957 647004 64700 36932 57 1958 664653 66465 35331 53 1959 700480 70048 36223 52 1960 718762 71876 36399 51 1961 737421 73742 36285 49 1962 766734 76673 38980 51 1963 805249 80525 41723 52 1964 846298 84630 45645 54 1965 887812 88781 47089 53 1966 925899 92590 50894 55 1967 964005 96401 50724 53 1968 1015869 101587 52725 52 1969 1061791 106179 53543 50 1970 1109724 110972 52627 47 1971 1178811 117881 52542 45 1972 1259786 125979 54589 43 1973 1313110 131311 54052 41 1974 1280544 128054 45196 35 1975 1327664 132766 44525 34 1976 1402380 140238 45523 32 1977 1467027 146703 47878 33 1978 1544704 154470 50331 33 1979 1529133 152913 51093 33 1980 1527295 152730 51091 33 1981 1555308 155531 49301 32 1982 1595010 159501 43945 28
Source Analysis of Significant Decline in Motor Vehicle Traffic Fatalities in
2008 httpwww-nrdnhtsadotgovPubs811346pdf see Table A1 page 31
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Page 40 of 45
Acknowledgements
The author is grateful for thoughtful comments provided by friends and colleagues
with whom this document was shared via email prior to it being uploaded as a
publicly available document for wider dissemination and study The comments
offered by Prof Subra Ganesan of Oakland University Electrical and Computer
Engineering Department are reproduced with permission in their entirety
About the author
The author obtained his Masterrsquos (S M) and Doctoral (Sc D) degrees in Materials Engineering
from the Massachusetts Institute of Technology Cambridge USA He then spent his entire
professional career at leading US research institutions (MIT NASA Case Western Reserve
University and General Motors R amp D Center in Warren MI) He holds four patents in advanced
materials processing has co-authored two books and has published several scientific papers in
leading peer-reviewed international journals His expertise includes developing simple
mathematical models to explain the behavior of complex systems He can be reached by email at
vlaxmananhotmailcom
Page 41 of 45
Please Buckle Up
httpwwwlakecountypublichealthorgindexphpbuckle-up-montana
Public Awareness
Respect the Cage Exhibit
The Department of Transportation hopes that showing the reality of the crash will reduce traffic
fatalities A crushed car crash dummies and a sobering message ndash all part of the ―Respect The
Cage exhibit that is traveling across Montana The exhibit sponsored by the Montana Department
of Transportation stopped in Ronan on November 6th and is aimed at raising awareness about the
importance of wearing seat belts
The car in the exhibit was in an actual wreck many years ago
the passenger in the vehicle died because he was not wearing a
seat belt the driver who was wearing his seat belt survived
Montanarsquos likeliest crash fatality scenario
A Pickup
A Rural road
And Seat belts that
arenrsquot used
Page 42 of 45
Occupants of pickups are less likely to wear seat belts and pickups are more likely to
roll over than passenger cars
Seat belts reduce the risk of death by 60 percent in pickups and SUVs
In Montana from 2006-2008 81 of those killed in a crash while riding in a pickup were not wearing seat belts
In Montana pickups make up 401 of the vehicle population
For more information on Respect the Cage click here
Page 43 of 45
Appendix 1
Lack of seat belts leading cause of Louisiana highway deaths
1251 AM May 28 2011 |
Written by Adam Duvernay
Crashes involving unbuckled motorists were the leading cause of highway fatalities
in Louisiana last year and cost $9888 million according to recent reports The
Louisiana Highway Safety Commission reported 59 percent of vehicle occupants
killed in Louisiana crashes last year mdash about one in four mdash werent wearing seat
belts
httpwwwshreveporttimescomarticle20110528NEWS01105280354Lack-seat-
belts-leading-cause-La-highway-deathsodyssey=tab|topnews|text|FRONTPAGE
Crash bull Stats Published by NHTSAlsquos National Center for Statistics and Analysis 1200 New Jersey Avenue SE Washington DC 20590
DOT HS 811 451
Early Estimate of Motor Vehicle Traffic Fatalities in 2010
httpwww-nrdnhtsadotgovPubs811451pdf
Summary
A statistical projection of traffic fatalities in 2010 shows that an estimated 32788
people died in motor vehicle traffic crashes This represents a decline of about 3
percent as compared to the 33808 fatalities in 2009 as shown in Table 1 If these
projections are realized fatalities will be lowest on record (since 1949)
Traffic Safety Facts Overview 2009 Data
httpwww-nrdnhtsadotgovPubs811392pdf
In 2009 33808 people were killed in the estimated 5505000 police-reported
motor vehicle traffic crashes 2217000 people were injured and 3957000
crashes involved property damage only Compared to 2008 this is a 10-
percent decrease in the number of fatalities and a 5-percent decrease in the
Page 44 of 45
number of police-reported motor vehicle traffic crashes people injured and
crashes involving property damage
An average of 93 people died each day in motor vehicle crashes in 2009 mdash
an average of one every 16 minutes
Traffic Safety Facts Overview 2008 Data
httpwww-nrdnhtsadotgovPubs811162pdf
In 2008 37261 people were killed in the estimated 5811000 police-reported
motor vehicle traffic crashes 2346000 people were injured and 4146000
crashes involved property damage only
Some comments and Feedback
The following comments were received from Prof Ganesan after his review of the
first draft of this document It was subsequently revised thanks to this input to
address some of the very important issues raised here
Dear Laxman
The write up is not enough
You are emphasizing that the speed limit reduces the fatal accidents (comparing 1966
to 2000 accident numbers)
Can you also add a few sentences why the number is decreasing from 1980 to 2000
values (May be due to better design of vehicles)
Can you say anything about the fuel consumption with the speed for any typical
vehicle in 2011 or 2010 (do not consider the fatalities issue)
Probably a speed between 55 and 60 mph gives a better mileage If so this is a
compelling reason to keep the speed limit low But cars probably can be tuned to
give better mileage at any high speed also
Page 45 of 45
Weather is also a major factor in fatal accidents Speed limit may be kept low during
winter and kept higher in summer Give your comments on this too
Driver distractions can cause more accidents Now cars have many multimedia and
internet features Automatic collision avoidance systems and sensors on the sides can
detect vehicles in the front and neighboring lanes and it can automatically decrease
speed even if the driver speeds at super high speeds
Give some comments on this too There is also Vehicle to Vehicle communications
vehicle to infrastructure communications and they can avoid collisions and accidents
Technology has changed from 1966 I cannot agree with you on the speed limit
without any discussion on the above and other factors
Have a great day
Subra Ganesan
Professor Subramaniam Ganesan
Director Real Time amp DSP Lab
Electrical and Computer Engineering Department
2200 Squirrel Road Dodge Hall Room 105
Oakland University Rochester MI 48309 USA
Phone 248 370 2206 Fax 248 370 4633
wwwsecsoaklandedu~ganesan
IEEE Distinguished Visiting Speaker (2005-2009) Coordinator
IEEE SEM CS chapter Chair Region 4 and CS Society Board member
SAE ASEE ACM member
Page 39 of 45
1953 544433 54443 36190 66 1954 561963 56196 33890 60 1955 605646 60565 36688 61 1956 627843 62784 37965 60 1957 647004 64700 36932 57 1958 664653 66465 35331 53 1959 700480 70048 36223 52 1960 718762 71876 36399 51 1961 737421 73742 36285 49 1962 766734 76673 38980 51 1963 805249 80525 41723 52 1964 846298 84630 45645 54 1965 887812 88781 47089 53 1966 925899 92590 50894 55 1967 964005 96401 50724 53 1968 1015869 101587 52725 52 1969 1061791 106179 53543 50 1970 1109724 110972 52627 47 1971 1178811 117881 52542 45 1972 1259786 125979 54589 43 1973 1313110 131311 54052 41 1974 1280544 128054 45196 35 1975 1327664 132766 44525 34 1976 1402380 140238 45523 32 1977 1467027 146703 47878 33 1978 1544704 154470 50331 33 1979 1529133 152913 51093 33 1980 1527295 152730 51091 33 1981 1555308 155531 49301 32 1982 1595010 159501 43945 28
Source Analysis of Significant Decline in Motor Vehicle Traffic Fatalities in
2008 httpwww-nrdnhtsadotgovPubs811346pdf see Table A1 page 31
httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R
elated20Fatal20Motor20Vehicle20Traffic20Crashespdf
Page 40 of 45
Acknowledgements
The author is grateful for thoughtful comments provided by friends and colleagues
with whom this document was shared via email prior to it being uploaded as a
publicly available document for wider dissemination and study The comments
offered by Prof Subra Ganesan of Oakland University Electrical and Computer
Engineering Department are reproduced with permission in their entirety
About the author
The author obtained his Masterrsquos (S M) and Doctoral (Sc D) degrees in Materials Engineering
from the Massachusetts Institute of Technology Cambridge USA He then spent his entire
professional career at leading US research institutions (MIT NASA Case Western Reserve
University and General Motors R amp D Center in Warren MI) He holds four patents in advanced
materials processing has co-authored two books and has published several scientific papers in
leading peer-reviewed international journals His expertise includes developing simple
mathematical models to explain the behavior of complex systems He can be reached by email at
vlaxmananhotmailcom
Page 41 of 45
Please Buckle Up
httpwwwlakecountypublichealthorgindexphpbuckle-up-montana
Public Awareness
Respect the Cage Exhibit
The Department of Transportation hopes that showing the reality of the crash will reduce traffic
fatalities A crushed car crash dummies and a sobering message ndash all part of the ―Respect The
Cage exhibit that is traveling across Montana The exhibit sponsored by the Montana Department
of Transportation stopped in Ronan on November 6th and is aimed at raising awareness about the
importance of wearing seat belts
The car in the exhibit was in an actual wreck many years ago
the passenger in the vehicle died because he was not wearing a
seat belt the driver who was wearing his seat belt survived
Montanarsquos likeliest crash fatality scenario
A Pickup
A Rural road
And Seat belts that
arenrsquot used
Page 42 of 45
Occupants of pickups are less likely to wear seat belts and pickups are more likely to
roll over than passenger cars
Seat belts reduce the risk of death by 60 percent in pickups and SUVs
In Montana from 2006-2008 81 of those killed in a crash while riding in a pickup were not wearing seat belts
In Montana pickups make up 401 of the vehicle population
For more information on Respect the Cage click here
Page 43 of 45
Appendix 1
Lack of seat belts leading cause of Louisiana highway deaths
1251 AM May 28 2011 |
Written by Adam Duvernay
Crashes involving unbuckled motorists were the leading cause of highway fatalities
in Louisiana last year and cost $9888 million according to recent reports The
Louisiana Highway Safety Commission reported 59 percent of vehicle occupants
killed in Louisiana crashes last year mdash about one in four mdash werent wearing seat
belts
httpwwwshreveporttimescomarticle20110528NEWS01105280354Lack-seat-
belts-leading-cause-La-highway-deathsodyssey=tab|topnews|text|FRONTPAGE
Crash bull Stats Published by NHTSAlsquos National Center for Statistics and Analysis 1200 New Jersey Avenue SE Washington DC 20590
DOT HS 811 451
Early Estimate of Motor Vehicle Traffic Fatalities in 2010
httpwww-nrdnhtsadotgovPubs811451pdf
Summary
A statistical projection of traffic fatalities in 2010 shows that an estimated 32788
people died in motor vehicle traffic crashes This represents a decline of about 3
percent as compared to the 33808 fatalities in 2009 as shown in Table 1 If these
projections are realized fatalities will be lowest on record (since 1949)
Traffic Safety Facts Overview 2009 Data
httpwww-nrdnhtsadotgovPubs811392pdf
In 2009 33808 people were killed in the estimated 5505000 police-reported
motor vehicle traffic crashes 2217000 people were injured and 3957000
crashes involved property damage only Compared to 2008 this is a 10-
percent decrease in the number of fatalities and a 5-percent decrease in the
Page 44 of 45
number of police-reported motor vehicle traffic crashes people injured and
crashes involving property damage
An average of 93 people died each day in motor vehicle crashes in 2009 mdash
an average of one every 16 minutes
Traffic Safety Facts Overview 2008 Data
httpwww-nrdnhtsadotgovPubs811162pdf
In 2008 37261 people were killed in the estimated 5811000 police-reported
motor vehicle traffic crashes 2346000 people were injured and 4146000
crashes involved property damage only
Some comments and Feedback
The following comments were received from Prof Ganesan after his review of the
first draft of this document It was subsequently revised thanks to this input to
address some of the very important issues raised here
Dear Laxman
The write up is not enough
You are emphasizing that the speed limit reduces the fatal accidents (comparing 1966
to 2000 accident numbers)
Can you also add a few sentences why the number is decreasing from 1980 to 2000
values (May be due to better design of vehicles)
Can you say anything about the fuel consumption with the speed for any typical
vehicle in 2011 or 2010 (do not consider the fatalities issue)
Probably a speed between 55 and 60 mph gives a better mileage If so this is a
compelling reason to keep the speed limit low But cars probably can be tuned to
give better mileage at any high speed also
Page 45 of 45
Weather is also a major factor in fatal accidents Speed limit may be kept low during
winter and kept higher in summer Give your comments on this too
Driver distractions can cause more accidents Now cars have many multimedia and
internet features Automatic collision avoidance systems and sensors on the sides can
detect vehicles in the front and neighboring lanes and it can automatically decrease
speed even if the driver speeds at super high speeds
Give some comments on this too There is also Vehicle to Vehicle communications
vehicle to infrastructure communications and they can avoid collisions and accidents
Technology has changed from 1966 I cannot agree with you on the speed limit
without any discussion on the above and other factors
Have a great day
Subra Ganesan
Professor Subramaniam Ganesan
Director Real Time amp DSP Lab
Electrical and Computer Engineering Department
2200 Squirrel Road Dodge Hall Room 105
Oakland University Rochester MI 48309 USA
Phone 248 370 2206 Fax 248 370 4633
wwwsecsoaklandedu~ganesan
IEEE Distinguished Visiting Speaker (2005-2009) Coordinator
IEEE SEM CS chapter Chair Region 4 and CS Society Board member
SAE ASEE ACM member
Page 40 of 45
Acknowledgements
The author is grateful for thoughtful comments provided by friends and colleagues
with whom this document was shared via email prior to it being uploaded as a
publicly available document for wider dissemination and study The comments
offered by Prof Subra Ganesan of Oakland University Electrical and Computer
Engineering Department are reproduced with permission in their entirety
About the author
The author obtained his Masterrsquos (S M) and Doctoral (Sc D) degrees in Materials Engineering
from the Massachusetts Institute of Technology Cambridge USA He then spent his entire
professional career at leading US research institutions (MIT NASA Case Western Reserve
University and General Motors R amp D Center in Warren MI) He holds four patents in advanced
materials processing has co-authored two books and has published several scientific papers in
leading peer-reviewed international journals His expertise includes developing simple
mathematical models to explain the behavior of complex systems He can be reached by email at
vlaxmananhotmailcom
Page 41 of 45
Please Buckle Up
httpwwwlakecountypublichealthorgindexphpbuckle-up-montana
Public Awareness
Respect the Cage Exhibit
The Department of Transportation hopes that showing the reality of the crash will reduce traffic
fatalities A crushed car crash dummies and a sobering message ndash all part of the ―Respect The
Cage exhibit that is traveling across Montana The exhibit sponsored by the Montana Department
of Transportation stopped in Ronan on November 6th and is aimed at raising awareness about the
importance of wearing seat belts
The car in the exhibit was in an actual wreck many years ago
the passenger in the vehicle died because he was not wearing a
seat belt the driver who was wearing his seat belt survived
Montanarsquos likeliest crash fatality scenario
A Pickup
A Rural road
And Seat belts that
arenrsquot used
Page 42 of 45
Occupants of pickups are less likely to wear seat belts and pickups are more likely to
roll over than passenger cars
Seat belts reduce the risk of death by 60 percent in pickups and SUVs
In Montana from 2006-2008 81 of those killed in a crash while riding in a pickup were not wearing seat belts
In Montana pickups make up 401 of the vehicle population
For more information on Respect the Cage click here
Page 43 of 45
Appendix 1
Lack of seat belts leading cause of Louisiana highway deaths
1251 AM May 28 2011 |
Written by Adam Duvernay
Crashes involving unbuckled motorists were the leading cause of highway fatalities
in Louisiana last year and cost $9888 million according to recent reports The
Louisiana Highway Safety Commission reported 59 percent of vehicle occupants
killed in Louisiana crashes last year mdash about one in four mdash werent wearing seat
belts
httpwwwshreveporttimescomarticle20110528NEWS01105280354Lack-seat-
belts-leading-cause-La-highway-deathsodyssey=tab|topnews|text|FRONTPAGE
Crash bull Stats Published by NHTSAlsquos National Center for Statistics and Analysis 1200 New Jersey Avenue SE Washington DC 20590
DOT HS 811 451
Early Estimate of Motor Vehicle Traffic Fatalities in 2010
httpwww-nrdnhtsadotgovPubs811451pdf
Summary
A statistical projection of traffic fatalities in 2010 shows that an estimated 32788
people died in motor vehicle traffic crashes This represents a decline of about 3
percent as compared to the 33808 fatalities in 2009 as shown in Table 1 If these
projections are realized fatalities will be lowest on record (since 1949)
Traffic Safety Facts Overview 2009 Data
httpwww-nrdnhtsadotgovPubs811392pdf
In 2009 33808 people were killed in the estimated 5505000 police-reported
motor vehicle traffic crashes 2217000 people were injured and 3957000
crashes involved property damage only Compared to 2008 this is a 10-
percent decrease in the number of fatalities and a 5-percent decrease in the
Page 44 of 45
number of police-reported motor vehicle traffic crashes people injured and
crashes involving property damage
An average of 93 people died each day in motor vehicle crashes in 2009 mdash
an average of one every 16 minutes
Traffic Safety Facts Overview 2008 Data
httpwww-nrdnhtsadotgovPubs811162pdf
In 2008 37261 people were killed in the estimated 5811000 police-reported
motor vehicle traffic crashes 2346000 people were injured and 4146000
crashes involved property damage only
Some comments and Feedback
The following comments were received from Prof Ganesan after his review of the
first draft of this document It was subsequently revised thanks to this input to
address some of the very important issues raised here
Dear Laxman
The write up is not enough
You are emphasizing that the speed limit reduces the fatal accidents (comparing 1966
to 2000 accident numbers)
Can you also add a few sentences why the number is decreasing from 1980 to 2000
values (May be due to better design of vehicles)
Can you say anything about the fuel consumption with the speed for any typical
vehicle in 2011 or 2010 (do not consider the fatalities issue)
Probably a speed between 55 and 60 mph gives a better mileage If so this is a
compelling reason to keep the speed limit low But cars probably can be tuned to
give better mileage at any high speed also
Page 45 of 45
Weather is also a major factor in fatal accidents Speed limit may be kept low during
winter and kept higher in summer Give your comments on this too
Driver distractions can cause more accidents Now cars have many multimedia and
internet features Automatic collision avoidance systems and sensors on the sides can
detect vehicles in the front and neighboring lanes and it can automatically decrease
speed even if the driver speeds at super high speeds
Give some comments on this too There is also Vehicle to Vehicle communications
vehicle to infrastructure communications and they can avoid collisions and accidents
Technology has changed from 1966 I cannot agree with you on the speed limit
without any discussion on the above and other factors
Have a great day
Subra Ganesan
Professor Subramaniam Ganesan
Director Real Time amp DSP Lab
Electrical and Computer Engineering Department
2200 Squirrel Road Dodge Hall Room 105
Oakland University Rochester MI 48309 USA
Phone 248 370 2206 Fax 248 370 4633
wwwsecsoaklandedu~ganesan
IEEE Distinguished Visiting Speaker (2005-2009) Coordinator
IEEE SEM CS chapter Chair Region 4 and CS Society Board member
SAE ASEE ACM member
Page 41 of 45
Please Buckle Up
httpwwwlakecountypublichealthorgindexphpbuckle-up-montana
Public Awareness
Respect the Cage Exhibit
The Department of Transportation hopes that showing the reality of the crash will reduce traffic
fatalities A crushed car crash dummies and a sobering message ndash all part of the ―Respect The
Cage exhibit that is traveling across Montana The exhibit sponsored by the Montana Department
of Transportation stopped in Ronan on November 6th and is aimed at raising awareness about the
importance of wearing seat belts
The car in the exhibit was in an actual wreck many years ago
the passenger in the vehicle died because he was not wearing a
seat belt the driver who was wearing his seat belt survived
Montanarsquos likeliest crash fatality scenario
A Pickup
A Rural road
And Seat belts that
arenrsquot used
Page 42 of 45
Occupants of pickups are less likely to wear seat belts and pickups are more likely to
roll over than passenger cars
Seat belts reduce the risk of death by 60 percent in pickups and SUVs
In Montana from 2006-2008 81 of those killed in a crash while riding in a pickup were not wearing seat belts
In Montana pickups make up 401 of the vehicle population
For more information on Respect the Cage click here
Page 43 of 45
Appendix 1
Lack of seat belts leading cause of Louisiana highway deaths
1251 AM May 28 2011 |
Written by Adam Duvernay
Crashes involving unbuckled motorists were the leading cause of highway fatalities
in Louisiana last year and cost $9888 million according to recent reports The
Louisiana Highway Safety Commission reported 59 percent of vehicle occupants
killed in Louisiana crashes last year mdash about one in four mdash werent wearing seat
belts
httpwwwshreveporttimescomarticle20110528NEWS01105280354Lack-seat-
belts-leading-cause-La-highway-deathsodyssey=tab|topnews|text|FRONTPAGE
Crash bull Stats Published by NHTSAlsquos National Center for Statistics and Analysis 1200 New Jersey Avenue SE Washington DC 20590
DOT HS 811 451
Early Estimate of Motor Vehicle Traffic Fatalities in 2010
httpwww-nrdnhtsadotgovPubs811451pdf
Summary
A statistical projection of traffic fatalities in 2010 shows that an estimated 32788
people died in motor vehicle traffic crashes This represents a decline of about 3
percent as compared to the 33808 fatalities in 2009 as shown in Table 1 If these
projections are realized fatalities will be lowest on record (since 1949)
Traffic Safety Facts Overview 2009 Data
httpwww-nrdnhtsadotgovPubs811392pdf
In 2009 33808 people were killed in the estimated 5505000 police-reported
motor vehicle traffic crashes 2217000 people were injured and 3957000
crashes involved property damage only Compared to 2008 this is a 10-
percent decrease in the number of fatalities and a 5-percent decrease in the
Page 44 of 45
number of police-reported motor vehicle traffic crashes people injured and
crashes involving property damage
An average of 93 people died each day in motor vehicle crashes in 2009 mdash
an average of one every 16 minutes
Traffic Safety Facts Overview 2008 Data
httpwww-nrdnhtsadotgovPubs811162pdf
In 2008 37261 people were killed in the estimated 5811000 police-reported
motor vehicle traffic crashes 2346000 people were injured and 4146000
crashes involved property damage only
Some comments and Feedback
The following comments were received from Prof Ganesan after his review of the
first draft of this document It was subsequently revised thanks to this input to
address some of the very important issues raised here
Dear Laxman
The write up is not enough
You are emphasizing that the speed limit reduces the fatal accidents (comparing 1966
to 2000 accident numbers)
Can you also add a few sentences why the number is decreasing from 1980 to 2000
values (May be due to better design of vehicles)
Can you say anything about the fuel consumption with the speed for any typical
vehicle in 2011 or 2010 (do not consider the fatalities issue)
Probably a speed between 55 and 60 mph gives a better mileage If so this is a
compelling reason to keep the speed limit low But cars probably can be tuned to
give better mileage at any high speed also
Page 45 of 45
Weather is also a major factor in fatal accidents Speed limit may be kept low during
winter and kept higher in summer Give your comments on this too
Driver distractions can cause more accidents Now cars have many multimedia and
internet features Automatic collision avoidance systems and sensors on the sides can
detect vehicles in the front and neighboring lanes and it can automatically decrease
speed even if the driver speeds at super high speeds
Give some comments on this too There is also Vehicle to Vehicle communications
vehicle to infrastructure communications and they can avoid collisions and accidents
Technology has changed from 1966 I cannot agree with you on the speed limit
without any discussion on the above and other factors
Have a great day
Subra Ganesan
Professor Subramaniam Ganesan
Director Real Time amp DSP Lab
Electrical and Computer Engineering Department
2200 Squirrel Road Dodge Hall Room 105
Oakland University Rochester MI 48309 USA
Phone 248 370 2206 Fax 248 370 4633
wwwsecsoaklandedu~ganesan
IEEE Distinguished Visiting Speaker (2005-2009) Coordinator
IEEE SEM CS chapter Chair Region 4 and CS Society Board member
SAE ASEE ACM member
Page 42 of 45
Occupants of pickups are less likely to wear seat belts and pickups are more likely to
roll over than passenger cars
Seat belts reduce the risk of death by 60 percent in pickups and SUVs
In Montana from 2006-2008 81 of those killed in a crash while riding in a pickup were not wearing seat belts
In Montana pickups make up 401 of the vehicle population
For more information on Respect the Cage click here
Page 43 of 45
Appendix 1
Lack of seat belts leading cause of Louisiana highway deaths
1251 AM May 28 2011 |
Written by Adam Duvernay
Crashes involving unbuckled motorists were the leading cause of highway fatalities
in Louisiana last year and cost $9888 million according to recent reports The
Louisiana Highway Safety Commission reported 59 percent of vehicle occupants
killed in Louisiana crashes last year mdash about one in four mdash werent wearing seat
belts
httpwwwshreveporttimescomarticle20110528NEWS01105280354Lack-seat-
belts-leading-cause-La-highway-deathsodyssey=tab|topnews|text|FRONTPAGE
Crash bull Stats Published by NHTSAlsquos National Center for Statistics and Analysis 1200 New Jersey Avenue SE Washington DC 20590
DOT HS 811 451
Early Estimate of Motor Vehicle Traffic Fatalities in 2010
httpwww-nrdnhtsadotgovPubs811451pdf
Summary
A statistical projection of traffic fatalities in 2010 shows that an estimated 32788
people died in motor vehicle traffic crashes This represents a decline of about 3
percent as compared to the 33808 fatalities in 2009 as shown in Table 1 If these
projections are realized fatalities will be lowest on record (since 1949)
Traffic Safety Facts Overview 2009 Data
httpwww-nrdnhtsadotgovPubs811392pdf
In 2009 33808 people were killed in the estimated 5505000 police-reported
motor vehicle traffic crashes 2217000 people were injured and 3957000
crashes involved property damage only Compared to 2008 this is a 10-
percent decrease in the number of fatalities and a 5-percent decrease in the
Page 44 of 45
number of police-reported motor vehicle traffic crashes people injured and
crashes involving property damage
An average of 93 people died each day in motor vehicle crashes in 2009 mdash
an average of one every 16 minutes
Traffic Safety Facts Overview 2008 Data
httpwww-nrdnhtsadotgovPubs811162pdf
In 2008 37261 people were killed in the estimated 5811000 police-reported
motor vehicle traffic crashes 2346000 people were injured and 4146000
crashes involved property damage only
Some comments and Feedback
The following comments were received from Prof Ganesan after his review of the
first draft of this document It was subsequently revised thanks to this input to
address some of the very important issues raised here
Dear Laxman
The write up is not enough
You are emphasizing that the speed limit reduces the fatal accidents (comparing 1966
to 2000 accident numbers)
Can you also add a few sentences why the number is decreasing from 1980 to 2000
values (May be due to better design of vehicles)
Can you say anything about the fuel consumption with the speed for any typical
vehicle in 2011 or 2010 (do not consider the fatalities issue)
Probably a speed between 55 and 60 mph gives a better mileage If so this is a
compelling reason to keep the speed limit low But cars probably can be tuned to
give better mileage at any high speed also
Page 45 of 45
Weather is also a major factor in fatal accidents Speed limit may be kept low during
winter and kept higher in summer Give your comments on this too
Driver distractions can cause more accidents Now cars have many multimedia and
internet features Automatic collision avoidance systems and sensors on the sides can
detect vehicles in the front and neighboring lanes and it can automatically decrease
speed even if the driver speeds at super high speeds
Give some comments on this too There is also Vehicle to Vehicle communications
vehicle to infrastructure communications and they can avoid collisions and accidents
Technology has changed from 1966 I cannot agree with you on the speed limit
without any discussion on the above and other factors
Have a great day
Subra Ganesan
Professor Subramaniam Ganesan
Director Real Time amp DSP Lab
Electrical and Computer Engineering Department
2200 Squirrel Road Dodge Hall Room 105
Oakland University Rochester MI 48309 USA
Phone 248 370 2206 Fax 248 370 4633
wwwsecsoaklandedu~ganesan
IEEE Distinguished Visiting Speaker (2005-2009) Coordinator
IEEE SEM CS chapter Chair Region 4 and CS Society Board member
SAE ASEE ACM member
Page 43 of 45
Appendix 1
Lack of seat belts leading cause of Louisiana highway deaths
1251 AM May 28 2011 |
Written by Adam Duvernay
Crashes involving unbuckled motorists were the leading cause of highway fatalities
in Louisiana last year and cost $9888 million according to recent reports The
Louisiana Highway Safety Commission reported 59 percent of vehicle occupants
killed in Louisiana crashes last year mdash about one in four mdash werent wearing seat
belts
httpwwwshreveporttimescomarticle20110528NEWS01105280354Lack-seat-
belts-leading-cause-La-highway-deathsodyssey=tab|topnews|text|FRONTPAGE
Crash bull Stats Published by NHTSAlsquos National Center for Statistics and Analysis 1200 New Jersey Avenue SE Washington DC 20590
DOT HS 811 451
Early Estimate of Motor Vehicle Traffic Fatalities in 2010
httpwww-nrdnhtsadotgovPubs811451pdf
Summary
A statistical projection of traffic fatalities in 2010 shows that an estimated 32788
people died in motor vehicle traffic crashes This represents a decline of about 3
percent as compared to the 33808 fatalities in 2009 as shown in Table 1 If these
projections are realized fatalities will be lowest on record (since 1949)
Traffic Safety Facts Overview 2009 Data
httpwww-nrdnhtsadotgovPubs811392pdf
In 2009 33808 people were killed in the estimated 5505000 police-reported
motor vehicle traffic crashes 2217000 people were injured and 3957000
crashes involved property damage only Compared to 2008 this is a 10-
percent decrease in the number of fatalities and a 5-percent decrease in the
Page 44 of 45
number of police-reported motor vehicle traffic crashes people injured and
crashes involving property damage
An average of 93 people died each day in motor vehicle crashes in 2009 mdash
an average of one every 16 minutes
Traffic Safety Facts Overview 2008 Data
httpwww-nrdnhtsadotgovPubs811162pdf
In 2008 37261 people were killed in the estimated 5811000 police-reported
motor vehicle traffic crashes 2346000 people were injured and 4146000
crashes involved property damage only
Some comments and Feedback
The following comments were received from Prof Ganesan after his review of the
first draft of this document It was subsequently revised thanks to this input to
address some of the very important issues raised here
Dear Laxman
The write up is not enough
You are emphasizing that the speed limit reduces the fatal accidents (comparing 1966
to 2000 accident numbers)
Can you also add a few sentences why the number is decreasing from 1980 to 2000
values (May be due to better design of vehicles)
Can you say anything about the fuel consumption with the speed for any typical
vehicle in 2011 or 2010 (do not consider the fatalities issue)
Probably a speed between 55 and 60 mph gives a better mileage If so this is a
compelling reason to keep the speed limit low But cars probably can be tuned to
give better mileage at any high speed also
Page 45 of 45
Weather is also a major factor in fatal accidents Speed limit may be kept low during
winter and kept higher in summer Give your comments on this too
Driver distractions can cause more accidents Now cars have many multimedia and
internet features Automatic collision avoidance systems and sensors on the sides can
detect vehicles in the front and neighboring lanes and it can automatically decrease
speed even if the driver speeds at super high speeds
Give some comments on this too There is also Vehicle to Vehicle communications
vehicle to infrastructure communications and they can avoid collisions and accidents
Technology has changed from 1966 I cannot agree with you on the speed limit
without any discussion on the above and other factors
Have a great day
Subra Ganesan
Professor Subramaniam Ganesan
Director Real Time amp DSP Lab
Electrical and Computer Engineering Department
2200 Squirrel Road Dodge Hall Room 105
Oakland University Rochester MI 48309 USA
Phone 248 370 2206 Fax 248 370 4633
wwwsecsoaklandedu~ganesan
IEEE Distinguished Visiting Speaker (2005-2009) Coordinator
IEEE SEM CS chapter Chair Region 4 and CS Society Board member
SAE ASEE ACM member
Page 44 of 45
number of police-reported motor vehicle traffic crashes people injured and
crashes involving property damage
An average of 93 people died each day in motor vehicle crashes in 2009 mdash
an average of one every 16 minutes
Traffic Safety Facts Overview 2008 Data
httpwww-nrdnhtsadotgovPubs811162pdf
In 2008 37261 people were killed in the estimated 5811000 police-reported
motor vehicle traffic crashes 2346000 people were injured and 4146000
crashes involved property damage only
Some comments and Feedback
The following comments were received from Prof Ganesan after his review of the
first draft of this document It was subsequently revised thanks to this input to
address some of the very important issues raised here
Dear Laxman
The write up is not enough
You are emphasizing that the speed limit reduces the fatal accidents (comparing 1966
to 2000 accident numbers)
Can you also add a few sentences why the number is decreasing from 1980 to 2000
values (May be due to better design of vehicles)
Can you say anything about the fuel consumption with the speed for any typical
vehicle in 2011 or 2010 (do not consider the fatalities issue)
Probably a speed between 55 and 60 mph gives a better mileage If so this is a
compelling reason to keep the speed limit low But cars probably can be tuned to
give better mileage at any high speed also
Page 45 of 45
Weather is also a major factor in fatal accidents Speed limit may be kept low during
winter and kept higher in summer Give your comments on this too
Driver distractions can cause more accidents Now cars have many multimedia and
internet features Automatic collision avoidance systems and sensors on the sides can
detect vehicles in the front and neighboring lanes and it can automatically decrease
speed even if the driver speeds at super high speeds
Give some comments on this too There is also Vehicle to Vehicle communications
vehicle to infrastructure communications and they can avoid collisions and accidents
Technology has changed from 1966 I cannot agree with you on the speed limit
without any discussion on the above and other factors
Have a great day
Subra Ganesan
Professor Subramaniam Ganesan
Director Real Time amp DSP Lab
Electrical and Computer Engineering Department
2200 Squirrel Road Dodge Hall Room 105
Oakland University Rochester MI 48309 USA
Phone 248 370 2206 Fax 248 370 4633
wwwsecsoaklandedu~ganesan
IEEE Distinguished Visiting Speaker (2005-2009) Coordinator
IEEE SEM CS chapter Chair Region 4 and CS Society Board member
SAE ASEE ACM member
Page 45 of 45
Weather is also a major factor in fatal accidents Speed limit may be kept low during
winter and kept higher in summer Give your comments on this too
Driver distractions can cause more accidents Now cars have many multimedia and
internet features Automatic collision avoidance systems and sensors on the sides can
detect vehicles in the front and neighboring lanes and it can automatically decrease
speed even if the driver speeds at super high speeds
Give some comments on this too There is also Vehicle to Vehicle communications
vehicle to infrastructure communications and they can avoid collisions and accidents
Technology has changed from 1966 I cannot agree with you on the speed limit
without any discussion on the above and other factors
Have a great day
Subra Ganesan
Professor Subramaniam Ganesan
Director Real Time amp DSP Lab
Electrical and Computer Engineering Department
2200 Squirrel Road Dodge Hall Room 105
Oakland University Rochester MI 48309 USA
Phone 248 370 2206 Fax 248 370 4633
wwwsecsoaklandedu~ganesan
IEEE Distinguished Visiting Speaker (2005-2009) Coordinator
IEEE SEM CS chapter Chair Region 4 and CS Society Board member
SAE ASEE ACM member