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Speeding Vehicles in Residential Areas
A Curriculum Developed by Rana Sampson
Companion training curriculum to the Speeding in Residential Areas Problem-Oriented Policing Guide
developed by Michael S. Scott
This project was supported by Cooperative Agreement #2001CKWXK051 by the U.S. Department of Justice Office of Community Oriented Policing Services.
Points of view or opinions contained in this document are those of the presenter and do not necessarily represent the official position or policies of
the U.S. Department of Justice.
Speeding Problems in Residential Areas
In communities across the country, one of the most common community complaints is of speeding vehicles in residential areas, even in areas where crime problems appear more serious.
Why do community residents care so much about speeding vehicles in their neighborhoods?
What Are The Actual Harms?
How Does it Increase the Risk of Crashes and Injuries?
The driver is more likely to lose control of the vehicle
The vehicle safety equipment is less effective at higher speeds
The distance it takes to stop the vehicle is greater
The vehicle travels farther during the time it takes the driver to react to the hazard
Crashes are more severe at higher speeds
Speeding – Force of Impact
Even modestly higher speeds can mean the difference between life and death for a pedestrian hit by a vehicle
The force of impact on the body is more than one-third greater at 35 mph than at 30 mph
Each 1-mph reduction in average speed translates roughly to a 5% reduction in vehicle crashes
Speeders and Crashes
Speeders are disproportionately involved in vehicle crashes
Speeding is a contributing factor in – 1/8 of all crashes, and – 1/3 of all fatal crashes
Where Do Most Crashes Occur?
Rural Suburban Urban
Why?
What contributes to speeding?
Popular culture?
Road design?
Driver beliefs?
Societal views of accidents?
Why Do Drivers Speed?
Many drivers admit to speeding.
What do drivers tell you about why they speed?
Drivers’ Perceptions
The most important factors in a driver’s choice to speed is the driver’s perception of the road environment and the speed that he or she thinks it is safe to drive
Drivers make calculated decisions to speed, creating opportunities for police to alter their calculations
Given that speeding is such a common community complaint, does the current police response to it reflect how serious it is to community members?
In your community, do citizens know how to report speeding problems? Whom to call, whom to speak to?
What kind of response do community members get when they call about speeding vehicles on their street?
Do the most common responses work? If so, for how long?
What training do officers receive in addressing speeding problems?
______________ ______________ ______________
What more would be useful? ______________________ ______________________
Generally, There Are Four Strategies Used To Address Speeding
Education
Enforcement
Regulatory
Engineering
The 85th Percentile
The common standard for a posted speed limit is the 85th percentile. It is the speed on a specific street at or below which 85 percent of vehicles travel.
Motorists adjust their speeds for what is reasonable on a street, so the 85th percentile sets the speed to that traveled by most motorists.
The 85th percentile legalizes the vast majority of motorists driving.
Lowering speed limits below the 85th percentile does not significantly affect speeds or accidents.
How Do Jurisdictions Determine the 85th Percentile?
Some don’t, they may set some streets at artificially low speed limits, often because of community pressure
There are Different Types of Residential Streets
A Local Street – A street whose primary function is access to adjacent properties – these residential streets are often posted 25 mph
A Collector Street – A street for which vehicle movement and access are of equal importance – these residential streets may be posted 35 mph
An Arterial Street – A major street for which the primary function is to provide vehicle movement
Education
Enforcement Regulation Engineering
What We Know
Education Neighborhood Safety Campaigns
– Community Letters– Warnings– Community Meetings– Radar Speed Display Trailers– Neighborhood Speed Watch– Neighborhood Signage
A sample communityletter – its intent is to gain the public’s voluntary compliance in reducingresidential speeding
Neighborhood Safety Campaigns
It is the least coercive means of trying to gain compliance with neighborhood speed limits
However, there is little empirical evidence to support that compliance is gained beyond a short period of time
If highly targeted, it can have some impact
Highly Targeted Neighborhood Safety Campaign – Raleigh, NC
Examined prior year’s citations at The Drive -- they had issued 300 speeding tickets in this one 25 mph school zone
The average speed of citations was 38 mph
11% were for speeds exceeding 45 mph
The Police surveyed speeders and found that most were parents of school-aged children
Erected temporary speed signs to flash vehicle speeds
Placed speeding info in PTA newsletter
Distributed educational flyers to students’ parents
Measuring Effectiveness - Raleigh
Campaign resulted in immediate reduction in speeding -- average speeds fell to 31 mph from 38 mph
The proportion of drivers complying with the speed limit (including a 5 mph tolerance) more than doubled after the educational effort, although by the end of the first week some of the impact deteriorated
Three weeks after the educational campaign there remained about a 50% increase in compliance from the compliance rate calculated during the analysis phase of the project
Radar Speed Display Trailers
May slow speeds during the time the display is in place (mixed results). On low volume streets, repeated use of the trailer may reduce speeds on the street by about 5% for as long as 30 days after Photo Credit: Tony Mazzela
Traffic Calming: State of the Practice
Neighborhood Speed Watch Residents borrow radar guns from police, check
speeds and write down the make, model and license plates of speeders
Police send warning letters to these speeders reminding them of the speed limit and reasons to reduce their speed
Effectiveness
Near negligible effect More a “resident calming” approach as residents
tend to feel better after they do it
Neighborhood Yard Signs Anti-speeding campaigns developed at the grass-
roots level are potentially more effective than official campaigns.
Neighborhood yard signs, with different “slow down” anti-speeding messages can convey more heartfelt messages to speeders.
Slow Down!Protect our Kids
Brought to you by your neighbors
For more information call …
Slow DownFor our Children
Brought to you by the Kensington neighborhoodFor more information call …
Play video segment
Neighborhood Safety Campaign
video segment
Informing Complainants About Actual Speeds
Complainants often inaccurately estimate speeds
Speeds seem faster to a stationary pedestrian watching from a front yard
What’s the best way to deal with this?
Play video segment
Busy Residential Street
video segment
Simply Lowering Speed Limits
Some residents ask the police to lower the posted speed on their street
Lowering speed limits has the general effect of reducing speeds by one-quarter of the speed limit reduction
Reducing the posted speed limit from 25 mph to 20 mph will reduce average speeds by about 1 mph
Education
Enforcement Regulation Engineering
What Do We Know About How Well Enforcement Works?
Enforcement
It can have impact during enforcement
Speeds revert to previous levels soon after enforcement
Residential streets are more amenable to traffic calming (discussed later in this presentation)
Enforcement – Alerting the Public?
Discuss the pros and cons of each approach
Some police agencies alert the community
Some police agencies specifically name the streets they’ll be ticketing
Some agencies simply say it will be in a certain general area
Some agencies explain why they will be enforcing at certain locations (e.g., high number of crashes, high level of community complaints)
Some agencies do these alerts on the morning radio
Speed Enforcement Has the Greatest Effect …
1. If drivers believe it is likely to occur, and
2. It is meaningfully costly to offenders, and
3. Enforcement is associated with driving in general, rather than any specific time of day or roadways, and
4. If enforcement is not associated with any specific cues that signal the presence or absence of enforcement efforts.
Is There An Incentive System for Traffic Officers?
How are they evaluated in your jurisdiction?
What if their goal was to maintain reduced average speeds in a specific geographic area of responsibility, what would change?
What Do We Know About Photo Radar Speed Enforcement?
Method: Radar gun with camera attached. Camera catches the speeding vehicle and the vehicle’s license plate and vehicle owner is sent a ticket
Some states allow this, others do not
Can be expensive, may be about $4,000 a month to lease equipment but is effective in reducing speeds and collisions
Research says that it is best used on high volume streets with collision problems
Education Enforcement
Regulation Engineering
What Do We Know About Regulation?
What About Regulatory Measures to Reduce Speeding, Do They Work?
Common Regulatory Measures
– Stop Signs
– Speed Limit Signs
– Turn Limits
– One-Way Streets
What Do We Know About Stop Signs?
The consensus among traffic engineers is that stop signs should not be used as speed control measures
Research shows that on a stop-signed block, motorist do not slow to the speed limit at mid-block and they often do a rolling stop once they come to the stop sign
Research also shows that some drivers even speed up between stop signs to make up for lost time at the stop sign
Play video segment
Moraga Avenue
video segment
Speed Limit Signs
Speed limit signs should reflect the 85 percentile to be effective.
Painting speed limits or “SLOW” on the road surface, in combination with posting roadside signs, can help reduce speeds.
And remember, lowering speed limits below the 85th percentile for that street does not significantly reduce speeds or accidents.
Play video segment
800 Rutgers
video segment
What Do We Know AboutTurn Restrictions?
More a volume reducer than speed reducer
Best used at high volume hours
What Do We Know AboutThe Effect Of One-Way Streets?
Research suggests that one-way streets may in fact increase speeds
Two-way streets, on the other hand, tend to reduce speeds because drivers take into account on-coming traffic in their calculation of whether to speed
Education Enforcement Regulation
Engineering
What Do We Know About The Effect of Engineering on Speeding
Problems in Residential Areas?
Traffic Calming
Traffic calming is an approach to reducing vehicle speeds and vehicle volume on particular streets or in particular areas. Traffic calming describes a wide range of road and environmental design changes that either make it:
1. more difficult for a vehicle to speed, or 2. make drivers believe they should slow down
for safety.
Traffic calming measures are particularly effective at reducing speeds in residential areas.
What Traffic Calming is not …
Stop signs, signals, and speed limit signs are not traffic calming as they require enforcement.
Traffic calming is intended to be self-enforcing.
Traffic Calming History
Began in Europe in 1960s as a grass roots movement to slow traffic on residential streets
Design engineers picked it up in the 1970s and were able to design “slow streets”
Applied it also to some European highways and arterial streets in 1980s
Traffic Calming in U.S.
Some traffic calming as early as 1960s sprung up in several U.S. cities
Cities such as Berkeley, Seattle, and Portland had early versions of it
Many other cities now routinely use traffic calming
Traffic calming efforts now exist in each of the 50 states
Traffic Calming Results
Speeds reduced
In some cases accidents reduced
In many cases, severity of accidents reduced
In some cases traffic volume reduced
In area-wide traffic calming schemes traffic volume not displaced, and vehicle speeds reduced
Traffic Calming Now Used in … Denmark Sweden The Netherlands Germany Japan England Italy Switzerland Canada Australia U.S.A.
Traffic Calming 3 ways to reduce speed of vehicles
Vertical measures – discourages speeding with vertical traffic-slowers in the road such as speed humps
Horizontal measures – decreases speed through lateral impediments such as curves in the roadway
Narrowing – decreases speed by narrowing curb-to-curb distance so motorists slow down to adapt to changed roadway
Types of traffic calming
Speed humps Speed tables Chicanes Pinch points One-way streets converted to 2-way streets Roundabouts Small rounds Chokers
Table of Speed Reducing Measures
Vertical
Measures
Horizontal
Measures
Narrowing
Measures
Speed humps Chicanes Pinch-points
Speed tables Traffic Circles Chokers
RoundaboutsSmall center
islands or rounds
Vertical Speed Reducing Measures
Speed Humps
Speed Tables
Speed Humps
Speed humps are rounded raised areas placed across the roadway. They are generally 3 to 4 inches high and 12 to 14 feet long (in the direction of travel), making them distinct from the shorter "speed bumps” found in many parking lots. The profile of a speed hump can be circular, parabolic, or sinusoidal. They are often tapered as they reach the curb on each end to allow unimpeded drainage.
Speed Hump Profiles
Sinusoidal
Circular
Parabolic
Speed Hump (Portland, OR)
This speed hump is painted with chevron markings to make it more noticeable
Speed HumpsAdvantages
Speed humps are relatively inexpensive;
They are relatively easy for bicycles to cross if designed appropriately;
They are very effective in slowing travel speeds; and
Cost is approximately $2,000 (as per Portland (OR), Sarasota (FL), and Seattle (WA).
Disadvantages They cause a "rougher
ride" for all drivers, and in some cases, can cause pain for people with certain skeletal disabilities;
They force large vehicles, such as emergency vehicles and those with rigid suspensions, to travel at slower speeds; and
Some people do not find them aesthetically pleasing.
Speed Humps - Effectiveness
For a 12-foot hump– Average of 22% decrease in
the 85th percentile travel speeds; or
– Average decrease of 35.0 to 27.4 miles per hour (from a sample of 179 sites).
– Average of 11% decrease in accidents; or
– Average decrease of 2.7 to 2.4 accidents per year (from a sample of 49 sites).
For a 14-foot hump– Average of 23% decrease in
the 85th percentile travel speeds; or
– Average decrease of 33.3 to 25.6 miles per hour (from a sample of 15 sites).
– Average of 41% decrease in accidents; or
– Average decrease of 4.4 to 2.6 accidents per year (from a sample of 5 sites).
Similar Measures:By lengthening the hump with a flat section in the middle, you have a Speed Table. By turning an entire crosswalk into a speed hump, you have a Raised Crosswalk.By raising the level of an entire intersection, you have a Raised Intersection.
Speed Hump (West Palm Beach, FL)
This 12-foot hump is combined with textured pavement to increase visibility and its speed-reducing effect
Signage is importantto alert motorists toreduce speeds
Speed Tables a.k.a. trapezoidal humps, speed platforms
Speed tables are flat-topped speed humps.
Often constructed with brick or other textured materials on the flat section.
Speed tables usually let the entire wheelbase of a passenger car rest on the flat section.
Brick or other textured materials improve the appearance of speed tables, draw attention to them, enhancing safety and speed-reduction.
Speed Table Naples, FL
Concrete speed table with textured pavement to increase visibility and reduce speeds
Speed Tables
Advantages:
They are smoother on large vehicles (such as fire trucks) than Speed Humps.
They are effective in reducing speeds, though not to the extent of Speed Humps.
Disadvantages:
Without textured materials they are less aesthetically pleasing.
Textured materials, if used, can be expensive.
Cost: Approximately $2,000 – Sarasota, FL; Portland OR; Seattle, WA
Speed Tables
Effectiveness:
22-foot speed table– Average of 18% decrease in
the 85th percentile travel speeds; or
– Average decrease of 36.7 to 30.1 miles per hour; (from a sample of 58 sites).
– Average of 45% decrease in accidents; or
– Average decrease of 6.7 to 3.7 accidents per year (from a sample of 8 sites).
Similar Measures:
By removing the flat section in the middle, you have a Speed Hump
By placing a crosswalk on the flat section, you have a Raised Crosswalk; and
By raising the level of an entire intersection, you have a Raised Intersection
Horizontal Speed Reducing Measures
Chicanes
Traffic CirclesRoundabouts
Chicanes a.k.a. deviations, serpentines, reversing curves, and twists
Chicanes are curb extensions that alternate from one side of the street to the other, forming S-shaped curves.
Chicanes can be created by alternating on-street parking, either diagonal or parallel, between one side of the street and the other. Parking bays can be created by re-striping the roadway or installing raised, landscaping islands at the ends of each parking bay.
Good for locations where speeds are a problem but noise from Speed Humps would be unacceptable.
Chicane – Tallahassee, FL
This chicane uses a series of staggered jutting angles to slow traffic. By placing edged islands opposite each other (without staggering) you can create a Choker, which also slows speeds
Angled in
Angled out
Chicanes – Advantages and Disadvantages
Advantages
Chicanes discourage high speeds by strategic road narrowing through forced deflection; and
They are easily negotiable by large vehicles (such as fire trucks) except under heavy traffic conditions.
Disadvantages They must be designed
carefully to discourage drivers from deviating out of the appropriate lane;
Curb realignment and landscaping can be costly, particularly if there are drainage issues; and
They may require the elimination of some on-street parking.
Can cost as much as $14,000
Traffic Circles a.k.a. rotaries, intersection islands
Traffic circles are raised islands, placed in intersections, around which traffic circulates.
Good for calming intersections, especially within neighborhoods, where speeds, volumes, and safety are problems but larger vehicles (e.g., trucks) are not as prevalent.
Traffic Circle – Boulder, CO
This traffic circle uses low maintenance landscaping and is combined with a raised crosswalk. The circle narrows the traffic lane to slow speeding vehicles.
Traffic can exit or go around the circle
Traffic CirclesAdvantages
Traffic Circles are effective in reducing speeds and improving safety.
When designed well, they can be aesthetically pleasing.
When placed at an intersection, they can calm two streets at once.
Disadvantages They can be difficult for
large vehicles (such as fire trucks) to navigate.
They must be designed so that the circulating lane does not encroach on the crosswalks.
They may require the elimination of some on-street parking, and
Landscaping must be maintained, either by the residents or by the municipality.
Traffic Circles -- Effectiveness
Effectiveness Average of 11% decrease in the
85th percentile travel speeds, or from an average of 34.1 to 30.2 mph (from a sample of 45 sites).
An average of 73% decrease in accidents, or from an average of 2.2 to 0.6 accidents per year (from a sample of 130 sites).
Similar Measures By placing a raised island in a
mid-block location, you have a Center Narrowing Island.
By enlarging the intersection and the center island, inserting splitter islands at each approach, setting back the crosswalks away from the circulating lane, and implementing yield control at all approaches, you have a Roundabout.
Cost varies based on materials and size of circle.
Traffic Circle – Dayton, OH
This small traffic circle slows vehicles speeds, eventhat of city busses, through this residential street. Circles slow speeds of two streets at once.
Circles don’t
need to circulate traffic in all cases
Landscaping
These traffic islands in two residential areas of Eugene, ORillustrate differences between landscaped and unlandscapedmid-street measures.
Narrowing as a Speed Reducing Measure
Pinch-points, Chokers, and
Small Center Islands or Rounds
Choker - Australia
This Choker narrows the road from both sides of the car reducing speeds of vehicles on this residential street.
Psycho Perception Controlsanother form of traffic calming
Attempts at altering ingrained driver responses using certain stimuli to induce or trick drivers to slow down
– Centerline striping– Edgeline striping
Centerline and Edgeline Striping Goal is to visually narrow the street Mixed results Bicycle lanes might have more effect than
just centerlines or edgelines (painted lines several feet in from curb)
Bike lanestriped
Centerlinestriped
Play video segment
Murray Ridge Road
video segment
Play video segment
Foothill Blvd and Loring
video segment
2-way southbound
2-way northbound
Foothill & Loring - Before
Foothill & Loring - After
1-way southboundBike lane
1-way northboundStop Sign
Turn lane
Deflectors
Lor
ing
A hillL
orin
g
Foothill
Play video segment
Melrose Avenue
video segment
Melrose Avenue
6,500 cars per day on this residential street
Cars speed as they wind downhill
40 mph average speeds
Citizen in conflict over 4-way stop sign
Parking lane can be added as was done at the top of the hill
Comparison of Costs
Measure Initial Cost
Annual Cost
Revenues
Photo-Radar (ownership option)
Photo-Radar (leased option)
Targeted Police Enforcement
Speed Humps
$85,000
0
$70,000
$300,000 ($2,000 per speed hump)
$145,000
$214,000
$194,000
$30,000
$40,000
$40,000
$40,000
0
Designing out Speeding in New Developments
Some growing communities require developers to design new residential areas to prevent traffic problems
Some features might include narrower streets, roundabouts for high volume areas, and sharp bends and other “slow points” at regular intervals
Some cities are designing residential streets as narrow as 18 feet
Play video segment
Oceans Hills Neighborhood
video segment
Ocean Hills Neighborhood Residents surveyed, speeding was top of the list of
community complaints
Officer Snarponis and his lieutenant conducted follow-up interviews with residents
Entrance street to neighborhood more than 100 feet wide. Downhill slope as residents exit exacerbates the speeding problem
Police should review plans for new developments
What could be done to slow speeds of residents exiting this neighborhood?
Play video segment
Corral Canyon
video segment
Play video segment
Otay Ranch
video segment
Play video segment
Residential Street
video segment
Reducing speeding…
1. Interview complaints to determine: if there is really a speeding problem, the times of day, and days of week, it occurs, and if there are certain people who are the worst offenders?
Conduct speed survey to determine the 85th percentile train police volunteers to conduct speed survey review the survey data to determine if there is a
speeding problem
Reducing speeding - continued If there is not a speeding problem:
show the survey data to community members have community members watch you conduct radar
to show them that speeding is not occurring
4. If a speeding problem exists, do a visual assessment of the street to look for contributing factors: street width? downward slope? is the street being used as a cut-through? is signage appropriate to the street?
Speeding on a street - continued
5. Hold a community meeting to discuss results of the speed survey and discuss alternatives and the effectiveness of each alternative
► education
►enforcement
► regulation
►engineering
Speeding Approaches – Summary
Speeding Complaint
Education Enforcement Regulation Engineering
NeighborhoodSafety
Campaigns
Traffic Calming
Radar and Photo Radar
Stop Signsand Speed
Limit Signs
ChicanesSpeed Humps
Engineering
Narrowingtechniques
Traffic Calming
Vertical Horizontal
Self-enforcing
Traffic Circles
Roundabouts
Psycho Motor Pinch-points
ChokersParking Lanes Speed Tables
Bike Lanes
Play video segment
Palm Avenue
video segment
Tracking Speeding Complaints
Some policing agencies keep a database of speeding complaints, others do not.
What is the value of keeping one?
Value Of Tracking Speeding Complaints
You know what streets might be the most problematic
You can learn if certain days of the week are problematic
You can learn if certain times of the day are problematic for that street
You know if you’ve had one caller who constantly complains or multiple callers from the same block
You know whether your agency has tried to reduce the problem before on the same street
You can phone the caller back and tell the caller what you have done to reduce the problem and what the caller can do if the problem still persists (closing the loop)
Tracking Responses
Some policing agencies, in their traffic database, also include information about the types of responses tried on the street to reduce the speeding.
What is the value of keeping this?
Value Of Tracking Responses
You know what you’ve already tried and how often you’ve tried it
You know whether you have to try something else
You can begin to assess costs of responses
It gives you ammunition in discussions with traffic engineering if it is the appropriate response
Tracking Warnings
Some policing agencies keep in their database the number of warnings they issue on a street with speeding along with a record of the name of the person who was issued the warning.
What is the value of keeping these?
Value Of Tracking Warnings & Names of Violators Given Warnings
Other officers know whether to give the person a ticket the next time
If the speeding problem persists after warnings then you know you need to do something else to reduce the problem
Why Find Out the Actual Speeds on a Street that a Citizen Has
Complained About?
Why not just do a visual assessment or some radar or just start issuing tickets?
Class discussion
Should You Do a Visual Assessment of the Street?
What would you look for?
Other Things to Track Tracking the amount of time associated with
enforcement and education for specific speeding problems.
Why? It adds up pretty quickly when you have to go back to the place frequently. Sometimes, the amount of time expended, if significant, can be used to justify an engineering response if is a problem that will continue absent consistent enforcement.
Measuring whether what you did worked
What is the value of measuring impact when working on a speeding problem on residential streets?
What are some different ways you can measure impact?
Measuring Impact 1. The average speeds of vehicles (taken in mid-
blocks)
2. The percentage of vehicles speeding
3. The percentage of vehicles exceeding the speed limit by various amounts
4. The number of vehicle crashes
5. The number of injuries caused by vehicle crashes
6. The volume of citizen complaints about speeding
Measures should be taken before deciding countermeasures, and then after to see if there is an impact
Cautions in Measuring Impact
1. The number of citations issued is not an appropriate measure of the impact of your responses; it merely provides information about police enforcement levels.
2. Officers should also pay attention to the possible displacement effects of their efforts; drivers may divert to adjoining areas for roads, with positive or negative results.
Summary
Residential speeding, it’s a common problem.
It’s important to know the specifics of the street you want to affect.
It’s important to know what approaches work and for how long.
You have options in affecting it.
Measure whether what you did worked. Did it reduce the speeding problem? If so, by how much?
Q & A
Center for Problem-Oriented Policingwww.popcenter.org
This project was supported by Cooperative Agreement #2001CKWXK051 by the U.S. Department of Justice Office of Community Oriented Policing Services. Points of view or opinions contained in this document are those of the presenter and do not necessarily represent the official position or policies of the U.S. Department of Justice."
