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PDHLibrary.com - you can take this course on our website by answering 20-40 questions. this course is available for any engineer looking to meet the pdh hours requirement. Engineering PDH - PDHLibrary.comEM 1110-3-130 - Geometrics for Roads, Streets, Walks, And Open Storage Areas - Mobilization Construction -Web
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ENGINEER MANUAL
ENGINEERING AND DESIGN
EM 1110-3-130April 1984
Geometrics forRoads, Streets, Walks, and Open
Storage Areas
Mobilization Construction
DEPARTMENT OF THE ARMYCORPS OF ENGINEERS
OFFICE OF THE CHIEF OF ENGINEERS
DEPARTMENT OF THE ARMY
EM 1110-3-130U .S . Army Corps of Engineers
DAEN-ECE-G
Washington, D .C . 20314
Engineer ManualNo . 1110-3-130 9 April 1984
1 . Purpose . This manual provides guidance for design and layout of roads,streets, walks, and open storage areas for U .S . Army mobilization facilities .
2 . Applicability . This manual is applicable to all field operatingactivities having mobilization construction responsibilities .
3 . Discussion . Criteria and standards presented herein apply to constructionconsidered crucial to a mobilization effort . These requirements may bealtered when necessary to satisfy special conditions on the basis of goodengineering practice consistent with the nature of the construction. Designand construction of mobilization facilities must be completed within 180 daysfrom the date notice to proceed is given with the projected life expectancy offive years . Hence, rapid construction of a facility should be reflected inits design . Time-consuming methods and procedures, normally preferred overquicker methods for better quality, should be de-emphasized . Lesser gradematerials should be substituted for higher grade materials when the lessergrade materials would provide satisfactory service and when use of highergrade materials would extend construction time. Work items not immediatelynecessary for the adequate functioning of the facility should be deferreduntil such time as they can be completed without delaying the mobilizationeffort .
FOR THE COMMANDER:
Engineering and DesignGEOMETRICS FOR ROADS, STREETS, WALKS,
AND OPEN STORAGE AREASMobilization Construction
VANAUGH`; Corps of Engineers
f of Staff
Engineer ManualNo . 1110-3-130
DEPARTMENT OF THE ARMY
EM 1110-3-130US Army Corps of Engineers
Washington, DC 20314
Engineering and DesignGEOMETRICS FOR ROADS, STREETS,
9 April 1984
WALKS, AND OPEN STORAGEAREAS
Mobilization Construction
Paragraph Page
CHAPTER 1 . GENERAL
Purpose and scope . . . . . . . . 1-1 1-1Definition of pertinent terms . . 1-2 1-1Highway planning . . . . . . . . 1-3 1-1Traffic . . . . . . . . . . . 1-4 1-2
CHAPTER 2 . DESIGN CONSIDERATIONS
General . . . . . . . . . . . 2-1 2-1Road and street types . . . . . . 2-2 2-1Design controls . . . . . . . . . 2-3 2-2Speed and capacity influence . . 2-4 2-4
CHAPTER 3 . GEOMETRIC DESIGN FOR ROADS AND STREETS
Cross-section elements . . . . . 3-1 3-1Curbs, combination curbs, and
gutters . . . . . . . . . . . . 3-2 3-1Road and street appendages . . . 3-3 3-2Sight distance . . . . . . . . . 3-4 3-6Horizontal alinement . . . . . . 3-5 3-7Vertical alinement . . . . . . . 3-6 3-8Cross section . . . . . . . . . . 3-7 3-13Intersection criteria . . . . . . 3-8 3-13Capacity of intersections . . . . 3-9 3-16Intersection curves . . . . . . . 3-10 3-17Miscellaneous . . . . . . . . . . 3-11 3-18
CHAPTER 4 . GEOMETRIC DESIGN FOR WALKS ANDOPEN STORAGE AREAS
Walks . . . . . . . . . . . . . . 4-1 4-1Open storage areas and parking . 4-2 4-2
EM 1110-3-1309 Apr 84
APPENDIX A .
REFERENCES
A-1,
LIST' OF' FIGURES:
Figure 3-1 .
Cross sections of general types of medians .3-2 .
Design criteria : guardrails, guideposts,: and earthslopes .
3-3 .
Method of layout of widening and superelevation ofspiral lanes .
3-4 .
Stopping sight distance on horizontal curves, openroad conditions .
3-5 .
Types of vertical curves .3-6 .
Typical road-type cross. sections . :3-7 .
Typical street-type cross sections .
Paragraph Page
CHAPTER 1
GENERAL
EM 1110-3-1309Apr84
1-1 . Purpose and scope . This manual establishes the geometric designcriteria for roads, streets, walks, and open storage areas . Thismanual sets forth . the approaches and traffic flow criteria for guidancein determining types and configurations best suited for mobilizationconstruction . This manual presents general criteria and is intendedfor use in conjunction with EM 1110-3-131, EM 1110-3-132, EM1110-3-136, and EM 1110-3-150 .
1-2 . Definitions of pertinent terms . The definitions of termsrelative to highway design are given in lists of definitionspresented in the manuals of AASHTO as a part of specific proceduresreferenced from this manual, D6 .1 and as described below .
a . Access highways . An access highway is an existing or proposedpublic highway which is needed to provide highway transportationservices from an Army reservation to suitable transportationfacilities . This will not include installation highways within theboundary of an Army reservation, but may include a highway through anArmy reservation that has been dedicated to public use if reasonableassurance can be given that future closure to public use will not berequired . The design and construction of access highways are normallythe responsibility of the state, county, or local authorities . Thedesign criteria of these authorities will be used for access roadconstruction but with due consideration given to the mobilizationeffort .
b . Installation highways . Installation highways include all roadsand streets within the site limits of Army installations which areconstructed and maintained by the Department of Defense . Allinstallation highways are classified in accordance with their relativeimportance to the installation as a whole and with respect to thecomposition, volume, and characteristics of the traffic using them .Design criteria for roads and streets within Army installations arepresented herein .
1-3 . Highway planning . The planning of the general road system is anintegral part of installation master planning . Major objectives ofmaster planning are the grouping of related functions reasonably closeto each other and the interrelating of land-use areas for maximumefficiency, speed of construction, and economy of operation . Theconnecting road system should be planned in keeping with theseobjectives to minimize on-post travel and permit the optimumcirculation of traffic originating both outside and within theinstallation . Traffic studies may not be available during amobilization situation, so good engineering judgment and assessment ofcurrent and/or near future needs must be made to determine traffic
EM 1110- 3-130g Apr 84
requirements . The geometric design of highway facilities shouldprovide for safe, smooth, and convenient traffic movement consistentwith time limitations, topographical conditions, and to the extentpossible, economical construction . Existing roads and streets at Armyinstallations can be classified in accordance with requirementspresented in tables l-1 and 1-2 . The elements to be given primaryconsideration in such classifications are pavement width, shoulderwidth, degree and length of slopes (grade), and passing sight distance .Values for these elements should be essentially equal to or greaterthan the minimum requirements for classification assigned . All of therequirements in table 1-1 or 1-2 should be considered, but requirementsother than those just listed can be given greater latitude .
1-4 . Traffic . The volume and composition of the traffic determinesthe geometric requirements for roads, streets, walks, and open storageareas . Type, volume, character, frequency, and composition of trafficat Army installations are related to size, type, and mission of theinstallation . The size, type, and mission of the installation provideinformation as to its functional requirements, indicating character andsize of vehicles . Types of vehicles, types of terrain, and frequencyof use establish the traffic classification in which roads and streetsfall . The system of highway classification outlined and defined aboveis believed sufficiently broad for the classification of all roads andstreets within an Army installation regardless of type and mission .Classification reflecting character of traffic is based upon thecharacteristics and dimensions of existing civilian and Army vehicles .Army vehicles include not only wheeled vehicles but also combined wheeland tracked vehicles . It is essential that the designer be aware ofthe vehicular traffic anticipated prior to selection of the type designto use on a particular project .
Desi
gnCo
ntro
lsand_
Elements
Flat
Roll
ing
Moun
tain
ous
Flat
Roll
ing
Mountainous
Flat
Roll
ing
Moun
tain
ou:
Desi
gnCo
ntro
ls:
Trafficcomposition
:)
T=0%
ADT2
%
DHV
T=
10%
ADT
DHV3
T=20
%AD
3DHV
500-750
380-
560
240-380
130-500
" 95-380
60-240
Unde
r13
0
Unde
r95
Unde
r60
T=30
%AD
T
3,00
0-4,
700
2,00
0-3,
200
1,200-2,100
.
770-3,000
570-2,100
330-1,200
Unde
r77
0
Unde
r570
Unde
r330
DHV3
450-700
310-480
180-310
115-450
85-310
50-180
Unde
r11
5
Unde
r85
Unde
r50
Desi
gnsp
eed,
mph
70
60
50
55
45
35
55
45
35
w
Average
running
speed,
mph
49
45
40
43
37
30
43
37
30
Cross-Section
Elements
:
Pavement
s:
Minimumw4dth
oftraffic
lanes,
ft
Table
1-1
.Geom
etri
cCriteria
forClassified
Road
sWi
thin
"Ope
n"Ar
easof
Army
Installations
(Rural
Areas)
Class
BRo
adaTwo-Lane
Road
Class
DRo
ada
Two-Lane
Road
ClassE
Roada
Two-Lane
Road
b
With
barrier
curbs
12
12
12
10
10
10
10
10
10Without
barrier
curbs
12
12
12
10
10
10
10
10
10
Minimum
distance
poetween
barrier
curb
s,ft
29
29
29
24
24
24
20
20
20
Desirable
lateral
clearance,
toobstructions,
ft
6
6
6
4
4
4
2
2
Norm
alcross
slop
e,in
./ft
1/8
to1/
4
3/16
to3/
8
1/4
to1/
2
Curb
s:6
Type
sSee
paragraph3-2.b
4,00
0-6,
000
600-900
4,00
0-6,
000
600-900
4,000-6,000
600-900
1,00
0-4,
000
150-600
1,000-4,000
150-
600
1,000-4,000
150-600
Unde
r1,000
Under
150
Unde
r1,000Un
der
1,0(
Unde
r15
0Under
150
3,60
0-5,
500
3,00
0-4,
600
2,400-3,500
950-3,600
770-3,000
600-
2,40
0Un
der950
Unde
r770
Under600
550-820
450-
690
360-
530
140-550
115-450
90-360
Unde
r14
0Un
der
115
Unde
r90
3,30
0-5,
000
2,50
0-3,
700
1,600-2,500
870-3,300
630-2,500
400-
1,60
0Un
der
870
Unde
r630
Unde
r40
0
Desi
gnCo
ntro
lsandElements
Flat
Roll
ing
Mountainous
Flat
Roll
ing
Mountainous
Flat
Roll
ing
MountainousK
Offs
etforbarrier
curbs
2.5
2.5
2.5
2.0
2.0
2.0
0
0
0
Medians?
See
figure
3-1
Shoulders
:8
Minimum
widt
h,shoulders
onro
adswithoutbarrier
curb
s,ft
10
8
8
8
6
4
6
6
4
Norm
alcr
oss
slop
e,in
./ft
3/8
to1/
2
1/2
to3/
4
3/4
toI
Type
Dustless
and
stable
forall-weatheruse
Stabilized
with
sele
ctmaterial
Compacted
soil
Guar
drai
ls,
guid
eposts,
andea
rth
slop
es
See
figure
3-2
Brid
geclearance
See
paragraph
3-3e
t-+
7De
sign
Elements
:
?;
Sigh
tdi
stan
ce:
Table
1-1
.Geometric
Criteria
for
Classified
Roads
Within
"Open"
Areasof
Army
Inst
alla
tion
s(Rural
Areas)
(Continued)
ClassB
Roada
Two-Lane
Road
Clas
sD
Roada
Two-Lane
Road
Clas
sERoad
aTwo-Lane
Roadb
Z
Minimum
stopdistance,ft
Minimumpassing
sight
dist
ance
,ft
Horizontal
alinement
:
Horizontal
curves,
maximumcurvature
Desirable
maximul
Absolute
maximum
Wher
esn
owan
dice
areno
tfactors
Wher
esnow
and
ice
are
factors
Pave
ment
wide
ning
See
table
3-1
and
figu
re3-
3
ping
sight
600
475
350
415
310
240
415
310
240
2,300
2,000
1,700
1,850
1,50
01,050
1,50
1,500
1,050
1°30'
2°00
'3°0
0'2°
30'
3°3
0'6°00
'2°
30'
3°3
0'6°00'
4°00
'5°3
0'8°
00'
7°00
'10°30'
18°00'
7°00
'10°30'
18° 00'
3°00'
4°30
'7°
00'
5°45'
9°00
'16°30'
-5°45'
9°00'
16°30'
Table
1-1
.Geometric
Criteria
forClassified
Road
sWithin
"Ope
n"Ar
eas
ofArmy
Installations
(Rural
Areas)
(Continued)
NOTE
S:
1Th
esymbol
"T,"
with
percentage
limitations,
represents
the
proportion
oftotal
traf
fic
composed
ofbuses,
truc
ks,
and
track-laying
vehicles
;theremainderarelight
delivery
trucks
andpassenger
cars
.2
TheDH
Vis
equalto
appr
oxim
atel
y15
percentof
theADT
.3
These
values
show
the
mixed
traf
fic
volu
mewhich
requires
the
same
operational
area
asthat
required
bytraffic
composed
oflight-
deli
very
trucks
andpassenger
cars
.These
D11V
'sar
eba
sedon
the
indicated
percentage
ofthe
daily
volume
andmay
beoverconservative
inso
mein
stan
ces
because
the
perc
enta
ges
oftr
ucks
,track-laying
vehicles,
etc.,
during
peak
hours
are
generally
considerably
lower
than
theaveragepercentage
during
allhours
.4
The.
traffic
lane
widths
indicated
are
for
use
onro
ads
where
the
traffic
will
consistprincipally
ofvehicles
with
maxi
mumov
eral
lwidths
of8
ft.jr
less
.Fo
rde
term
inin
gtr
affi
clane
widt
hfo
rex
cess
ive-
widt
hvehicles,
seeparagraph
3-1.b
.5
Distance
shown
isthe
minimum
distance
betw
een
face
ofcurbs
where
ClassB
road
sre
quir
emore
than
2-lanes,
addi
tion
allane
widths
are
tobe
addedto
minimumdi
stan
cebetwee
ncu
rbs
.6
Generally,
curbs
will
not
beprovid
edon
road
sin
open
areas
.Seepa
ragr
aph
3-2forexce
ptio
nson
provision
ofcurbswithin
open
area
sat
Army
inst
alla
tion
s.
The
curb
offset
ismeasured
from
the
edge
ofth
epavement
toth
evertical
face
ofthe
curb
onth
ecurb
portionof
acombined
curb
andgutter
.7
Where
traffic
volume
requ
ires
constr
uction
ofmultilane
road
s,opposing
traffic
shou
ldbe
sepa
rate
dby
medians
.Wi
dthand
location
ofme
dian
s,median
shoulders,
andme
dian
curbsarediscussed
inparagraph3-
3.b
.8
There
should
bea
color
ortextural
cont
rast
between
pavement
and
shoulder
surf
ace
sufficient
toclearly
define
the
pavement
and
4~,p
shou
lder
sin
alltypesof
weather
.
N rcp~ O
00W
ClassB
Roada
Two-Lane
Road
ClassD
Road
aTwo-Lane
Road
Class
ERoad
aTwo-Lane
Road
bDe
sign
Cont
rols
andElements
Vert
ical
alinement
:
Flat
Roll
ing
Mountainous
Flat
Rolling
Mountainous
Flat
Roll
ing
Mountainous
Grade;10
Desirablemaximum
Percent
33
44
56
56
7Cr
itic
allength,
ft11
1035
1035
720
720
550
450
550
450
375
Absolute
maximum
for
permanent
installations
Percent
115
66
78
98
910
Crit
ical
length,
ft10
00660
450
850
550
275
900
600
400
Absolute
maximum
for
temporary
installations
Percent
116
78
89
1010
1112
Crit
ical
length,
ft82
5550
325
750
500
250
700
525
375
Mini
mum,
percent
0.3
0.5
Vert
ical
12cu
rves
Kforde
term
inin
gsa
fele
ngth
Crest
vert
ical
curves
240
150
8011
565
40115
6440
Sagvertical
curves
140
100
7085
6045
8560
45
Minimum
length,
ft21
018
015
016
513
510
516
513
510
5
Table
1-1
.
Geomet
ric
Criteria
forClassified
Road
sWith'it"Open"
Area
sof
Army
Installations
(Rural
Areas)
(Continued)
NOTES
:(C
onti
nued
)9
Absolute
maximum
values
shownwe
recalculated
onth
ebasis
ofa
maxi
mumrate
ofsu
perelevation
o£0.10
:Absolute
valu
efor
hori
zont
alcurves
will
have
tobe
reca
lcul
ated
ifama
ximu
mrate
ofsuperelevation
otherth
an-0
.10
isused
.10
Seeparagraph3-6.a
.fo
rexce
ptio
nto
this
criteria
.11
The
term
"critical
length"
isused
toindicate
thema
ximu
mlength
ofa
designated
upgrade
upon
whicha
loaded
truc
kca
nop
erat
ewithout
anunreasonable
reduction
inspee
d.
Methodsforde
term
inat
ionof
critical
length
-are
discussed
inpa
ragr
aphs
3-6.a
- .(1)
.12
Theminimumlengthsof
vertical
curv
esaredetermined
bymu
ltip
lyin
g"R
"times
thealgebraicdi
ffer
ence
ofgrades
(inpercent)
.a
TheDH
Vis
intotalvehicles
perho
urforalllanes
inboth
directions
.b
For
single
lane
roadsus
ecriteria
ofClassEmo
unta
inou
s.
U.S
.Army
Corp
sof
Engi
neer
s
Class
BSt
reetaTwo-Lane
Street
ClassD_Sl
reeta
Two-Lane
Street
ClassE
Street
aTwo-Lane
Street
Desi
gnControls
and
Elements
Flat
Roll
ing
Flat
__
Roll
ing
Flat
Roll
ing
Desi
gnControls
Traffic
composition
1
T=
0%AD
T2DH
V
T=10
%AD
TDH
V3
T=20
%AD
T 3
Table
1-2
.
Geometri
cCriteria
for
Classified
Street
Within
"Bui
lt-u
p"Ar
easof
Army
Inst
alla
tion
s
Norm
alcross
slop
e,in
./ft
1/8
to1/
43/16
to3/8
DH
T=30
%ADT
DHV3
750-1,000
5,80
0-7,
700
700-920
550-760
4,20
0-5,
300
500-640
220-
750
1,600-5,800
190-
700
160-
550
1,100-4,200
130-
500
Unde
r220
Unde
r1,600
Unde
r190
Unde
r16
0
Unde
r1,100
Unde
r13
0
Desi
gnspeed,
mph
5040
4030
4030
Average
running
speed,
mph
36,
3232
2532
25
Cros
s-Se
ctio
nEl
emen
ts:
Pavements
:
4Minimumwidth
oflanes,
ftWi
thbarrier
curbs
Traffic
Parking
12None
12None
11 811 8
10 810 8
Withoutbarrier
curbs
Traffic
1212
.l1
1110
10
Minimumd4stgnce
betweenbarrier
3
curb
s,ft
With
parking
lane
s5
lanes?
None 29
None
41 2541
3636
lpO
Withoutparking
2925
2020
> 'T3W
Desirable
lateral
clearance
toFl
obstructions,
ft6
64
42
2poW
~O
7,500-10,000
7,500-10,000
2,100-7,500
2,100-7,500
Unde
r2,
100
Unde
r2,
100
900-1,200
900-1,200
250-
900
250-900
Unde
r250
Unde
r250
6,80
0-9,
100
5,70
0-7,
700
1,900-6,800
1,600-5,700
Unde
r1,900
ilnd
er1,600
810-1,090
680-920
230-
810
190-
680
Unde
r230
Unde
r19
0
6,20
0-8,
300
4,60
0-6,
300
1,800-6,200
1,300-4,600
Undec
1,800
Unde
r1,300
Shoulders
:10
Table
1-2
.Geometric
Criteria
forClassified
Stre
etsWi
thin
"Built-up"
Areasof
Army
Inst
alla
tion
s(Continued)
toC
ClassB
Street
aTwo-Lane
Street
ClassD
Street
aTwo-Lane
Street
Class
EStreet
aTwo-Lane
Street
>De
sign
Cont
rols
and
Elements
Flat
Roll
ing
Flat
Rolling
Flat
Rolling
FCu
rbs
:8
00C tr
Type
s
Seepa
ragr
aph
3-2.b
.
i
Offs
etforbarrier
curbs,
ft
2.5
2.5
1.5
1.5
1.5
1.5
CMedians9
See
figu
re3-
1
Minimum
width,
shoulders
onstreets
without
barrier
curbs,
ft
10
8
8
8
8
6
Norm
alcr
oss
slope,
in./
ft
3/8to
1/2
1/2
to3/4
Type
Dustless
and
stab
lefo
rallwe
athe
ruse
Guar
drai
ls,
guideposts,
andearth
slop
es
See
figu
re3-
2
Brid
gecl
eara
nce
Desi
gnEl
emen
ts
Sight
dist
ance
:
See,
paragraph
3-3e
Minimum
stop
ping
sight
distance,
ft350
275
275
200
275
200
Horizontal
alin
emen
t:
Horizont
alcurves
Abso
lute
maximum
fornormal
crown
section
'003
0'00
45'
0045'
1030
'0045'
1030
'Absolut7
maximum
for
superelevated
section
503
0'90
15'
9015'
1701
5'901
5'17015'
Pave
ment
widening
See
tabl
e3-
1and
figure
3-3
Vertical
alinement
:
Grad
eDesirablemaximum
Percent
33
44
56
Crit
ical
length,
ft12
900
550
750
475
400
200
Table
1-2
.Geometric
Criteria
for
Classified
ocreets
Within
"Built-up"
Areas
ofArmy
Installations
(Continued)
NOTES
:
Desi
gnCo
ntro
lsandElements
Absolute
maximumfo
rpermanent
Class
BStreet
aFl
atTwo-Lane
Roll
ingStreet ,
ClassD FlatSt
reet
aTwo-Lane
Street
Rolling
ClassE
Street
aFlat
Two-Lane
Street
Roll
ing
installations
Percent
124
56
77
8Critical
length,
ft675
200
500
200
450
175
Absolute
maximumfo
rtemporary
installations
Percent
126
67
88
9Critical
length,
ft500
275
450
200
200
150
Mini
mum,
percent
0.3
0.5
Vertical
13curves
Kfordetermining
safe
length
Crest
vertical
curves
8050
50_
2850
28Sa
gvertical
curves
7050
5035
5035
1.., I
Minimum
length,
ft.
150
120
120
90120
9010
1Th
esymbol
"T,"
with
percentage
limitations,
represents
the
proportion
ofto
tal
traf
fic
composed
ofbuses,
truc
ks,
and
track-laying
vehicles
;theremainderar
eli
ght-
deli
very
truc
ksandpassengercars
.2
TheDH
Vis
equalto
appr
oxim
atel
y12
percent
ofth
eADT
.3
These
values
show
themixe
dtraf
fic
volume
whic
hrequires
the
same
operational
area
asthat
required
bytraffic
composed
oflight-
delivery
trucks
andpassen
ger
cars
.These
DHV's
areba
sed
onth
eindicated
percenta
geof
theda
ilyvolume
andmay
beoverconserva-
tive
inso
meinstances
because
the
perc
enta
ges
oftrucks,
track-laying
vehicles,etc.,
during
peak
hours
are
generally
considerably
lowerthan
theaveragepe
rcentage
during
allho
urs
.4
The
traffic
and
parking
lane
widths
indicated
are
for
use
onst
reet
swh
ere
the
traffic
will
consist
principally
ofvehicles
with
maximum
overall
widths
of8
ftor
less
.For
dete
rmin
ing
traf
fic
lane
width
for
use
ofexcessive-width
vehicles,
see
para
grap
h3-
l.b
.Traffic
lanes
ofstreet
swi
thou
tcurbs
inwarehouse
areas
shou
ldno
tbe
less
than
12ft
rega
rdle
ssof
class
.The
tota
lwidth
ofstreets
with
curb
sadjacent
towarehouses
should
not
beless
than
:30
ftbetween
curbs
rega
rdle
ssof
class
.Thevalues
given
for
widthof
parking
lane
sis
the
distance
between
theoutside
edge
ofth
eadjacent
traffic
lane
and
the
face
ofth
ecurb
for
Type
IVcurbs
.Thewidth
ofgutt
erin
combined
curb
and
gutt
er(Types
Ian
dIII
curbs)
maybe
included
inth
ewidthof
park
ing
lane
provided
the
gutter
isas
stro
ngstructurally
asth
eadjoining
pavement
.,otherwis
eth
ewi
dth
ofpa
rkin
glane
show
nwill
bethe
distance
betweentheoutside
edge
ofth
eadjacent
traffic
lane
andth
ein
side
edKe
ofth
egutter
.5
Seeparagraph3-
2fo
rcr
iteria
relative
toprovision
ofpa
rkin
gfa
cili
ties
.Cr
l6
Distance
shownis
theminimumdist
ance
between
face
ofcurbs
.3
7Where
ClassEstreets
are
designed
with
barr
iercu
rbs,
curb
offsetsar
eno
tre
quir
edadjacent
totrafficlanes
.N
8Ge
nera
lly,
barrier
curbs
will
beprovided
onstreets
inbuilt-up
areas
.St
,t,paragraph
3-2
for
exceptions
onprovision
ofcurbs
within
built-up
areas
atArmy
inst
alla
tion
s.
Type
sI
and
IVcurbs
greater
tlia
n6
in.
inheight
andType
III
curbsgr
eate
rthan
18t0
~+
in.
inheight
are
cons
idered
tobe
lateral
obstructions
.The
curb
offset
ismeasured
from
the
edge
ofth
epavement
toth
evertical
vo
face
ofthe
curb
orthe
curb
port
ionof
acombined
curb
and
gutt
er.
''LfW
Hi
9Where
traffic
volume
requires
cons
truc
tion
ofmultilane
stre
ets,
0111
1-11
19Ir
alli
cshould
beseparated
bymedians
.Wi
dth
and
location
ofme
dian
s,median
shou
lder
s,an
dme
dian
curbs
are
discussed
in3, .
iragrall
h:3
-."3.
h.
Gene
rall
y,me
dian
sareprovided
with
00W
-P.O
barrier
curb
sin
built-up
areas
.
U.S
.Army
Corp
sof
Engi
neer
s
Table
1-2
.GeometricCr
itei
afor-Classified
StreetsWi
thin
"Bui
lt-u
p"Ar
eas
ofArmy
Inst
alla
tion
s(Continued)
NOTE
S:
(Con
tinu
ed)
10
There
should
bea
coloror
textural
contrast
between
pavement
and
shoulder
surf
ace
suff
icie
ntto
clea
rly
define
the
pavement
and
shoulders
inalltypesof
weat
her
.11
Absolute
maximum
values
show
nwe
recalculated
onth
ebasis
ofama
ximu
mrate
ofsupere
leva
tion
of0.02
.Su
pere
leva
tion
rate
of0.0
4or
0.0
6maybe
used
onstreets
inwh
ichcase
theabsolute
maximumva
lues
forho
rizo
ntal
curves
will
have
tobe
recalculated
.12
The
term
"cri
tica
llength"
isused
toindicate
the
maxi
mum
length
ofa
designated
upgrade
upon
which
aloaded
truc
kcan
operate
without
anunreasonable
reduction
inspeed.
Methods
fordetermination
ofcritical
leng
tharediscussed
inpa
ragr
aph3-
6.a
.(1)
.13
Theminimumlengths
ofvertical
curves
aredetermined
bymu
ltip
lyin
g"K
"timesth
ealgebraicdifference
ofgrades
(inpercent)
.14
On-streetparkingwi
llnot
beprov
ided
onnewClassB
orCstreets
.Dimension
givenis
appl
icab
leonly
toexisting
streets
.a
TheDB
Vis
givenin
totalvehicles
perho
urfo
ral
lla
nes
inboth
directions
.
2-1 . General . Geometric design deals with the dimensions of thevisible-features of a facility such as alinement, sight distances,widths, slopes, and grades . Geometric design critieria are set forthin tables 1-1 and 1-2 and discussed in subsequent paragraphs .
2-2 . Road and street types .
a . Designations of types . Highways are generally typed accordingto the number of traffic lanes as single-, two-, and three-lane, andundivided or divided multilane (four or more traffic lanes) highways .When information is available relative to volume and composition oftraffic and type of terrain for a proposed highway, the type requiredcan be readily determined by comparing the traffic volume expected onthe proposed road or street with the design hourly volume shown intables 1-1 and 1-2 .
b . Single-lane roads . Geometric design criteria for single-laneroads are shown in table l-1 under "Class E Roads - mountainous ." Whereshoulders are not sufficiently stable to permit all-weather use and thedistance between intersections is greater than 1/2 mile, turnouts willbe provided at 1/4-mile intervals for use by occasional passing ormeeting vehicles . Single-lane pavements may be provided for fire lanesand approach drives to buildings within built-up areas, in which casethe pavement will be at least 12 feet wide in all cases .
c . Two-lane roads and streets .
(1) Class B, Dat Army installationsand E roads and Class
CHAPTER 2
DESIGN CONSIDERATIONS
(2) Class A, C, and F roads . Road classifications A, C, and Fneed not be used for mobilization conditions . Class B roads will allowadequate traffic pattern considerations to provide criteria for roaddesign thicknesses commensurate with the 5-year life expectancy of themobilization program . The use of four lane roads is to be minimizedfor mobilization construction . Where four lane roads cannot beavoided, Class B criteria will be used . When the road classificationswere reviewed in light of mobilization requirements, it was determinedthat the requirements of Class B roads or Class D roads could be usedto satisfy the traffic range of Class C roads . The single lane roadsof Class F can readily be designed as minimum Class E roads . Byreducing the number of road classifications, the refinement and detailof traffic flow data is greatly reduced without seriously affecting thedevelopment of road systems for Army installations under mobilizationconditions .
EM 1110-3-1309 Apr 84
and E roads . The bulk of the roads and streetsare two-lane highways . These include Class B, D,B, D, and E streets .
EM 1110-3-1309 Apr 84
d . Multilane (four traffic lanes or more) highways . . The designcriteria presented herein for highways are generally applicable tomultilane highways also, except that passing sight distance is notrequired . Where multilane highways are designed for relatively highspeeds, opposing traffic should be separated by properly designedmedians .
2-3 . Design controls .
a . Topography and land use . Tables 1-1 and 1-2 set forthappropriate design standards for roads and streets traversing flat,rolling, or mountainous terrain in built-up or open areas .
b . Vehicle characteristics . Table 2-1 shows dimensions of designvehicles on which the geometric design criteria presented herein arebased . Some of these vehicles are wider than 8 .5 feet, which is themaximum width shown in table 2-1 for any of the design vehicles . Theturning radii and dimensions of special vehicles will be obtained fromthe Facilities Engineer . Methods for modification of these criteriafor use on roads and streets subject to vehicles greater in overallwidth than 8 .5 feet are presented later in this manual .
c . . Traffic . The geometric design criteria presented in tables 1-1and 1-2 have been developed on the basis of horizontal arearequirements for various combinations of number and kind of vehiclesexpected in the traffic stream. The general unit for measurement oftraffic is average daily traffic (ADT) ; the basic fundamental unit ofmeasurement of traffic is design hourly volume (DHV) .
'
(1) Volume . Traffic volumes are expressed as ADT and DHV intables 1-1 and 1-2 . The ADT represents the total traffic volume forthe year divided by 365 . It is a value needed to determine totalservice and economic justification for highways but is inadequate forgeometric design because it does not indicate the significant variationin the traffic during seasons, days, or hours . If a road or street isto be designed so that traffic will be properly served, considerationmust be given to the rush-hour periods . The rush hour volumerepresented as an average daily peak hour is the basis of the DHV . TheDHV is to be used for geometric design . Limited studies made oftraffic flows at Army installations indicate that because of the highfrequency with which peak hourly traffic occurs, the average daily peakcan be economically and efficiently used as the DHV.
The DHV intables 1-1 and 1-2 are shown as 15 and 12 percent, respectively, of theADT . These are median values selected for Army installations .
(2) Composition . Traffic on installation roads and streets mayconsist of a combination of passenger cars, light-delivery trucks ;single-unit trucks, truck combinations, buses, and half-or full-tracktactical vehicles . Trucks, buses, and tracked vehicles have moresevere operating characteristics, occupy more roadway space, and
2-2
aLength
oftr
acto
rplus
length
oftr
aile
r.
bDistance
between
rear
wheels
offront
trailer
and
fron
twheels
ofrear
trailer
..c
Minimum
turn
ing
radius
outs
ide
fron
twheel
.
U.S
.Army
Corp
sof
Engineers
w
NOTE
:In
designs
forno
rmal
operations,
the
larg
est
vehi
cle
representing
asignificant
percentage
ofthe
traf
fic
shou
ldbe
used
.In
desi
gnin
gro
ads
orst
reet
sto
accommod
ate
truck
traffic,
one
ofthe
semitrailer
comb
inat
ions
should
beused
.A
design
chec
kshould
bemade
toin
sure
that
the
larg
est
vehi
cle
expe
cted
touse
the
road
orstreet
can
negotiate
all
turns,
particularly
ifpavements
are,
curb
ed.Vehi
cle
Type
Symbol
Tabl
e
Wheel
2-1
.Design
Base
Vehi
cle
Overhang
Fron
t
Dimensions
RearDi
mensions in
Feet
Over
all
Length
Over
all
Width
Height
Turning
Radi
usc'
Passenger
P11
35
197
--24
Sing
le-u
nit
truc
kSU
204
630
8.5
13.5
42
Sing
le-u
nit
bus
BUS
257
840
8.5
13.5
42
Semi
trai
ler
comb
ination
Inte
rmediate
WB40
13+
27=
40a
46
508.5
13.5
40
Large
WB50
20+
30=
50a
32
558.5
13.5
45
Full
trai
ler
WB60
9.7
+20
+9.4b
23
658.5
13.5
45co
mbination
+20
.9=
60
EM 1110-3-1309 Apr 84
2-4 . Speed and capacity influence .
a . Speed .
b . Capacity .
2-4
consequently impose a greater traffic load on highways than dopassenger cars and light-delivery trucks . ADT and DHV for variouscombinations of vehicular traffic are shown in tables 1-1 and 1-2 . Thelarger the proportions of buses, trucks, and tracked vehicles presentin the traffic stream during the selected design hour, the greater thetraffic load and highway capacity required . The DHV of tables 1-1 and1-2 diminish for each highway class as the percentage of buses, trucks,and tracked vehicles in the traffic stream increase . The tablesprovide design data for traffic containing 0, 10, 20, and 30 percentbuses, trucks, and tracked vehicles .
(1) Influence on geometric design . Vehicular speed variesaccording to the physical characteristics of the vehicle andhighway, weather conditions, volume of traffic, and the type ofshoulders and other roadside features . On streets, the speedgenerally will depend on traffic control devices when weather andtraffic conditions are favorable . On roads, the physical featuresof the roadway usually control speed if other conditions arefavorable . Therefore, speed is a positive control for geometricdesign . Consideration must be given to the selected design speedand average running speed if adequate designs are to bedeveloped .
(2) Design speed . The speed selected for design is the majorcontrol in designing physical features of highways . Practically allfeatures of a highway will be affected to some extent by the designspeed . Maximum curvature, superelevation, and minimum sight distanceare automatically determined by the selected design speed . Otherfeatures such as pavement and shoulder width, and lateral clearance toobstructions are not directly affected by design speed but do affectvehicle speed . The design speed should be selected primarily on thebasis of terrain characteristics, land use, and economicconsiderations . The geometric design criteria presented herein arebased on the design speeds shown under "Design Controls" in tables 1-1and 1-2 .
(3) Average running speed . The average running speeds on whichthe geometric design criteria are based are shown under "DesignControls" in tables 1-1 and 1-2 .
(1) Conditions affecting capacity . The capacity of a road orstreet will vary with lane width, distance to lateral obstructions,condition and width of shoulders, profile and alinement, and with thecomposition and speed of traffic . These factors are referred to
collectively as prevailing conditions . Those factors depending onphysical features of the highway are called prevailing roadwayconditions, and those depending on the character of the using trafficare called prevailing traffic conditions . The term capacity in itselfhas no significance unless the prevailing roadway and trafficconditions are stated .
(2) Capacity analysis . Capacities under ideal conditions arepresented in the TRB Highway Capacity Manual . Uninterrupted flowcapacities under ideal traffic and roadway conditions for 2-lane,2-way, highway, (total for both lanes) and for multilane highway(average per lane for direction of heavier flow), will be 2,000passenger cars per hour .
(3) Capacity for uninterrupted flow . The DHV shown intables 1-1 and 1-2 are equal,to the capacity for uninterrupted flow foreach class of road and street on the basis of the geometric designcriteria presented . Highway capacity is directly related to theaverage running speed . Maximum capacity occurs when average runningspeed is between 30 and 45 mph . Any factors which reduce or increasethe average running speed will also reduce capacity . The capacities(DHV) shown in tables 1-1 and 1-2 for Class B roads, and Class B and Dstreets will be reduced in accordance with the following tabulation inall cases where it is anticipated that the average running speed on asubstantial length of a road or street will be appreciably less than 30mph .
Capacity (DHV)Average Running
in Percentage of ValuesSpeed, mph_
Shown in Tables 1-1 and 1-2
EM 1110-3-1309 Apr 84
30 10025 9520 8715 72
3-1 . Cross-section elements .
a . Pavement .
CHAPTER 3
GEOMETRIC DESIGN FOR ROADS AND STREETS
EM 1110-3-1309 Apr 84
(1) Type surface . Pavement type is seldom an important factorin geometric design ; however, the ability of a pavement surface toretain its shape and dimensions, its cross-section, and the possibleeffect of pavement surface on driver behavior should be considered ingeometric design .
(2) Normal cross slope . Selection of proper cross slope dependsupon speed-curvature relations, vehicle characteristics, curbrequirements, and general weather conditions . Cross slope for sharpcurves (superelevation) is discussed in AASHTO GD-2 . Cross slope ontangents and flat curves are shown in tables 1-1 and 1-2 . Where two ormore lanes are inclined in the same direction on Class B roads andstreets, each successive lane outward from the crown line should havean increased cross slope . The lane adjacent to the crown line shouldhave the minimum cross slope shown in tables 1-1 and 1-2 and the crossslope of each successive lane should be increased 1/16 in/ft . Wherepavements are designed with barrier curbs, it is recommended that aminimum cross slope of 3/16 in/ft be used on Class B roads and streetsand that a minimum cross slope of 1/4 in/ft be used on Class D and Eroads and streets .
b . Lane width . The number and width of traffic lanes shown intables 1-1 and 1-2 are the minimum considered adequate to accommodatethe indicated design hourly volume when the traffic is composedprincipally of wheeled vehicles whose overall widths are 8 .5 feet orless . Wider traffic lanes are required when the traffic is composed ofa significant percentage of vehicles whose overall widths are greaterthan 8 .5 feet . In general, the lane width will be increased by theexcess width of the largest over-sized vehicle (vehicle width minus 8 .5feet to the nearest higher even foot) where such traffic isanticipated .
3-2 . Curbs, combination curbs, and gutters . Curbs, combination curbsand gutters, and paved gutters with attendant storm drainage facilitieswill not be considered during a mobilization situation unless they aredetermined to be absolutely necessary or conditions would allow theirconstruction . The road or street design will account for the "no curb"feature and provide for drainage and erosion control accordingly .
a . Curb construction. In built-up areas, curbs, combination curbsand gutters, and paved gutters with attendant underground stormdrainage systems will be provided when necessary along streets and in
EM 1110-3-1309 Apr 84
open storage areas as required to aid in the collection, and disposal ofsurface runoff including snowmelt, to control erosion, to confinetraffic, or as required in the extension of existing similarfacilities . In open areas, combination curbs and gutters will not beprovided along roads except where necessary on steep grades to controldrainage and prevent erosion of shoulders and fill slopes . Where suchfacilities are required, they should be located outside the edges oftraffic lanes and should be either of the mountable type with suitableoutlets and attendant drainpipes or paved gutters with shallow channelsextending across the road shoulders and down the fill slopes .
b . Classification and types . Curbs are classified as barrier ormountable according to their intended use . Barrier curbs are designedto prevent or at least discourage vehicles from running off thepavement and therefore have a steeply sloping face at least 6 incheshigh . Mountable curbs are designed to allow a vehicle to pass over thecurb without damage to the vehicle, and have a flat sloping face 3 to 4inches high . For construction purposes, curbs are usually designatedas "combined curb and gutter" and "integral curb and gutter ." For Armyinstallations curbs are divided into four types for convenience ofreference : Type I is a combined gutter section and barrier curb ; TypeII is a combined gutter section and mountable curb ; Type III is acombined gutter section and offset barrier curb ; and Type IV is abarrier curb integral with pavement slab . Curbs should be placed onundisturbed subgrade or subgrade compacted to the same density assubgrade of adjacent road .
c . Location in regard to lane width .
(1) Type I, III, or IV (barrier curbs) . It is necessary tooffset barrier curbs a sufficient distance from the edge of the nearesttraffic lane to prevent reduction in capacity .
Curb offset andtraffic lane width for classified roads and streets designed withbarrier curbs are shown in tables 1-1 and 1-2 .
(2) Type II curbs . Mountable curbs cause very little, if any,lateral displacement of traffic adjacent to these curbs ; therefore, itis acceptable to locate Type II curbs at the edge of a traffic orparking lane .
3-3 . Road and street appendages .
a . Shoulders .
(1) Width . Shoulder widths should be as stated in tables 1-1and 1-2 .
(2) Shoulders for roads . Roads in rural areas are normallydesigned without curbs and require full width shoulders to accommodate
3-2
high traffic volumes . Geometric design criteria for-shoulders on roadsare presented in table 1-1 .
(3) Shoulders for streets. As a general rule, streets in citiesare designed .with some type of barrier curb and do not requireshoulders except where needed for lateral support of the pavement andcurb structure . Where lateral support is required, the shoulder shouldbe at least 4 feet in width where feasible . In other sections withinbuilt-up areas, where desirable to design streets without barriercurbs, geometric design criteria are presented in table 1-2 .
b . Medians .
(1) Uses . Where traffic volume requires construction ofmultilane highways, opposing traffic should be separated by medians .Medians should be highly visible both day and night, and there shouldbe a definite color contrast between median and traffic lane paving .The absolute minimum width for a median is 4 feet with a desirableminimum width of 14 feet .
(2) Types . Cross sections of medians are illustrated infigure 3-1 .
It is not necessary that medians be of uniform widththroughout the length of divided highways .
(3) Curbs . All design criteria relative to curbs presentedherein are applicable to median curbs .
c . Guardrails and guideposts .
(1) Uses . For safety and guidance of traffic, guideposts shouldbe provided at all locations along roadways where drivers may becomeconfused, particularly at night, as to the direction of the roadway ;along roadways subject to periodic flooding ; along roadways where fogexists for long periods of time ; and where driving off the roadway isprohibited for reasons other than safety . Guardrails are normallyrequired at locations where vehicles accidentally leaving the roadwaymight be damaged, resulting in injury to occupants . Guardrails orguideposts should conform to local highway department criteria .
(2) Design criteria . Guardrails or guideposts are not normallyrequired where the front side slopes are 4 :1 or flatter . Designcriteria for determining where guardrails or guideposts are required isshown by figure 3-2 . The ordinate of this figure, designated "Heightof Cut or Fill in Feet," is used in this manual to refer to thevertical distance between the outside (intersection of shoulder andfront slope planes) edge of the shoulder and the toe of the front slopein cuts and on fills, or between the toe and top of back slope incuts .
3-3
EM 1110-3-1309 Apr 84
EM 1110-3-1309 Apr 84
NOTE 3
1 . CURBED AND CROWNED : PAVED
6' TO 15'
3-4
B
~iioeiiie®eiri:
2_ CURBED AND CROWNED; TURF COVER
MINIMUM 10', 25' TO 40' DESIRABLE
3. CURBED AND DEPRESSED . TURF COVER
MINIMUM 16', 40' OR MORE DESIRABLE
SHOULDER STRIP
SHOULDER STRIP
4 . FLUSHED AND DEPRESSED; TURF COVER
NOTE 3
NOTES : 1 . Curbs and paved median may be monolithic as in l-B ormay be surface-mounted on monolithic pavement as in 1-C :If surface-mounted, the curb-and-median slab must be anchoredor bonded to the pavement (1-C) .
2 . All medians less than 10 feet wide should be designed withbarrier curbs . If vegetation is to be maintained on median,or if snow removal will be required, the minimum width ofmedian should be 10 feet .
Separating guardrails will beinstalled in medians if justified by traffic conditions .
3 . Where depressed medians are used for 4-lane highways, opposinglanes are to utilize standard Class B 2-lane roads design .
U . S . Army Corps of EngineersFIGURE 3-1 . CROSS SECTIONS OF GENERAL TYPES OF MEDIANS
tv M w (7) C a z tz~
H r G7 C H tz~ b O H w 9 z t7 th a H x r O ro
c 0 f-h
F- W W u_ z J _J W n: 0 t- U O 1- x 12 W x
17 16 15 14 13 12 11 10 9 e 7 6 5 4 3 2
USE
GUID
EPOS
TSON
LYIF
TOE
OFSLOPE
ISNOT~/~lJ
INUNDATEDAND
GUAR
DRAI
LSIFINUNDATE
MinimumSlope
for
Class
B,Roads
and
Streets
~2
:1,
fron
tslopes
incuts
15ft
orless
inheight
;1-1/2:1
,fr
ont
slop
esin
cuts
jover
15ft
inhe
ight
;1-
1/2:1
,ba
ckslopes
incuts
;2:1
,front
slop
eson
fills
20ft
orle
ssin
heig
ht;1-
1/2:1
,front
slopes
onfills
over
20ft
inhe
ight
.
Minimum
Slop
esfo
rRoads
and
Streets
1-1/2:1
,front
and
back
slop
es1-1/2-1Lfront
slop
eson
fills
NOTES
:1
.Minimum
Slopes_fo
rClass
4:1,
4ft
5ft
2.
Clas
sD
andE
TANGENT
B,Roads
and
_Streets
front
slop
esin
cuts
;4:1
,ba
cksl
opes
orle
ssin
heig
ht;3:
1,ba
cksl
opes
toin
heig
ht;
4:1,
fron
tsl
opes
onfi
lls
.
NOGU
ARDR
AILS
1-1/
2:1
,front
1-1/
2:1
,front
incuts
cuts
overMi
nimu
mSl
opes
for
Clas
sB,
Roads
and
Streets
3:1
,front
slop
esin
cuts
;2:1
,back
slop
esin
cuts
;front
slop
eson
fill
s
OR
GUID
EPOS
TSREQUIRED
Mini
mum
Slop
es
5
10
USEGUARDRAILS
ONLY
Mini
mum_
Slopes_fo
r_Cl
ass
B,Roads
and_
Stre
ets
3:1
,front
slop
esin
cuts
10ft
orless
inheight
;2:1
,fr
ont
slop
esin
cuts
betw
een
10an
d20
ftin
height
;1-
1/2:1
,fr
ont
slop
esin
cuts
over
20ft
inhe
ight
;1-
1/2:1,
back
slop
esin
cuts
;3 :
1,front
slop
eson
fill
s10
ftor
lass
inheight
;2-
1/2:1
,front
slop
eson
fill
sbe
twee
n10
and
20ft
inhe
ight
;2:1
,front
slop
eson
fill
sover
20ft
inheight
.
and
back
slopes
incuts
;sl
opes
onfi
lls
.
USEGUIDEPOSTS
ONLY
DEGREE
OFCURVE
Gene
rall
yth
edepth
ofcu
t(see
Hin
figu
re3-6)
adjacent
toro
ads
and
stre
etssh
all
notbe
grea
ter
than
6belowthesrade
line
oftheoutslde
edge
oftheshoulder
.Greater
depths
maybe
used
when
spec
ific
ally
approved
.Cuts
insolidrock
orloessshoul4
have
vertical
side
walls;
ther
efor
e,no
back
slop
ewill
berequired
inthesematerials
.
ft.
2:1,
fron
tan
dback
slop
esin
cuts
;2:1,
fron
tslopes
onfi
lls
.
11111
11
1i
1,
IL
II
II
I15
2025
90
'dw
K 00w
-pO
EM 1110-3-1309 Apr 84
(3) Location with respect to edge of pavement . Guardrails orguideposts should be located at a constant offset from the edge of apavement outside the limits of the usable shoulder and with anelevation of the base between 4 inches and 9 inches below the edge ofthe lane pavement . Shoulder widths shown in tables 1-1 and 1-2 will bewidened 2 feet to provide space for installation of guardrails orguideposts . Guardrails or alinement of guideposts should be flaredoutward and, if required, buried on the traffic approach end andtapered in at narrow structures to meet curb lines .
(4) Marking . Guardrails and guideposts must be highly visible,particularly at night . All guardrails and guideposts should be markedor painted in accordance with AASHTO safety requirements .
d . Earth slopes . In determining inclination of side slopes, properconsideration should be given to drainage, maintenance, erosion, andstability . It may be difficult to control erosion of some soils onsteep slopes (4 :1 or steeper), and it may be impossible to controlerosion or maintain vegetation cover on slopes steeper than 2 :1 . Ifmaintenance is to be accomplished without special equipment, sideslopes should not be steeper than 3 :1 . It is essential that sideslopes along highways be flat enough to assure stability under allnormal conditions . Design criteria for selecting earth slopes ispresented in combination with design policy for establishing need forguardrails and guideposts in figure 3-2 .
e . Bridge clearance . Requirements affecting highway safety arefound in AASHTO HB-12 .
(1) Horizontal . The minimum horizontal distance between curbson bridges should be equal to the width of the approaching roadwayincluding traffic lanes, parking lanes, full width of shoulders, andmedians (on divided highways) . When the cost of parapets and railingsis less than the cost of decking the median area, traffic lanes fortraffic in opposing directions will be on separate structures . It isusually more economical to pave over the median area on .bridges with amedian width less than about 15 feet .
(2) Vertical . The minimum vertical clearance will be at least14 feet over all traffic lanes, parking lanes, and shoulders .
3-4 . Sight distance . The length of roadway visible ahead of a vehiclealong a highway is termed "sight distance ." Sight distance is dividedinto two categories : stopping sight distance and passing sightdistance . Minimum stopping and passing sight distances are shown intables 1-1 and 1-2 . Effort should be made to provide sight distancesgreater than those shown .
a . Stopping sight distance . On single-lane roads, the stoppingsight distance must be adequate to permit approaching vehicles each to
3-6
stop . Horizontal curve sight distance will be critical and will betwice that required for a two or more, lane highway .
b . Passing sight distance . Passing sight distance should beprovided as frequently as possible along two-lane, two-way roads, and alength equal to or greater than the minimum values shown in table 1-1should be provided . The minimum passing sight distances in table 1-1provide safe distances for a single isolated vehicle traveling atdesign speed to pass a vehicle going 10 mph less than design speed .Sight distances and safe passing sections should be shown on allconstruction and improvement plans to aid in proper marking and signplacement .
3-5 . Horizontal alinement .
a . General . Where changes in horizontal alinement are necessary,horizontal curves should be used to affect gradual change betweentangents . In all cases ; consideration should be given to the use ofthe flattest curvature practicable under existing conditions . Adequatedesign of horizontal curves depends upon establishment of the properrelations between design speed and maximum degree of curvature (orminimum radius) and their relation to superelevation . The maximumdegree of curvature is a limiting value for a given design speed andvaries with the rate of superelevation and side friction factors .
b . Maximum curvature .
(1) Roads . Desirable and absolute values for use in design ofhorizontal curves on superelevated roads are shown in table 1-1 . Theabsolute maximum curvature for roads without superelevation is the sameas shown for streets with normal crown sections in table 1-2 .
(2) Streets . Absolute maximum values for degree of curvature onstreets in built-up areas are shown in table 1-2 . Absolute maximumvalues are given for streets with normal crown sections (nosuperelevation) and with superelevated sections .
c . Superelevation . A practical superelevation rate togetherwith a safe side friction factor determines maximum curvature .Superelevation rate and side friction factors depend upon speed,frequency and amount of precipitation and type of area, i .e .,built-up or open . Superelevation rates will be determined inaccordance with AASHTO GD-2 .
d . Widening of roads and streets .
(1) Pavements on roads and streets will be widened to provideoperating conditions on curves comparable to those on tangents .Widening is necessary on certain highway curves because long vehiclesoccupy greater width and the rear wheels generally track inside the
3-7
EM 1110-3-1309 Apr 84
EM 1110-3-130g Apr 84
front wheels . The added width of pavement necessary can be computed bygeometry for any combination of curvature and wheelbase . Generally,widening is not required on modern highways with 12-foot lanes andhightype alinement, but for some combinations of speed, curvature, andwidth, it may be necessary to widen these highways also . The amount ofwidening required on horizontal curves on roads is shown in table 3-1 .
(2) This is the widening normally required for off-tracking andmay not provide clearance where sight is restricted . The additionalwidth should be added to the inside of the curve, starting with zero atthe TS (tangent-spiral), attain the maximum at the SC (spiral-curve),and diminishing from the maximum at the CS (curve spiral) to zero atthe ST (spiral-tangent) as shown in figure 3-3 . Increased sightdistance may be provided by additional widening or by removal of sightobstructions . The latter is normally recommended because it isgenerally more economical . Figure 3-4 shows the relation between sightdistance along the center line of the inside lane on horizontal curvesand the distance to sight obstructions located inside these curves .The clear sight distance along the center line of the inside lane onhorizontal curves should equal the minimum stopping sight distanceshown in table 1-1 for the design speed .
3-6 . Vertical alinement .
a . Grade . Design of vertical alinement involves the establishmentof longitudinal grade or slope for roads, streets, and highways . Thekey considerations for determining grades are speed reduction formaximum grade and drainage for minimum grade .
(1) Determining maximum grade . The maximum allowable grade isdependent . on the length the grade is sustained . The critical length ofgrade is the distance a design vehicle with a 40,000 pound gross weightand a 100-hp engine can travel up a designated grade before speed isreduced below an acceptable value (usually 30 mph) . Critical lengthsfor grades are shown in tables 1-1 and 1-2 . If a grade exceedscritical length, highway capacity is reduced unless a climbing lane isadded for heavy vehicles .
(2) Determining minimum grade . Tables 1-1 and 1-2 give minimumgrades which are adequate for proper drainage .
b . Curves . Generally, vertical curves should be provided at allpoints on roads or streets where there is a change in longitudinalgrade . The major control for safe vehicle operation on vertical curvesis sight distance, and the sight distance should be as long as possibleor economically feasible . Minimum sight distance required for safetymust be provided in all cases . Vertical curves may be any one of thetypes of simple parabolic curves shown in figure 3-5 . There are threelength categories for vertical curves : maximum, length required forsafety, and minimum . All vertical curves should be as long as
3-8
Tabl
e3-
1.
Calculat
edand
Design
Values
for
Pave
ment
Widening
onRo
ads
and
Stre
ets
Within
Army
Installations
2-Lane
Pave
ment
s,On
e-Wa
yor
Two-
Way
Widening,
inFe
et,
for
2-Lane
Pavements
Degr
eeof Curve
1 2 3 4 5 6 7 8 9 10-1
112-14.5
15-1
8
19-2
122
-25
26-26.5
NOTES
:
Values
less
than
2.0
may
bedi
sreg
arde
d.
3-lane
pavements
:multip
lyab
ove
values
by1.5
.4-lane
pavements
:multip
lyab
ove
values
by2
.Wh
ere
semitrailers
are
significant,
increase
tabular
values
ofwidening
by0.5
for
curves
of10
to16
degr
ees,
and
by1.0
for
curves
17de
gree
san
dsharper
.
onCurves
forWidth
ofPa
veme
nton
Tangentof
:
24fe
t22
feet
20feet
_Design
spee
d,mph
Design
speed,
mph
Desi
gnspeed,
mph
3040
5060
7080
3040
5060
7030
40.
5060
0.0
0.0
0.0
0.0
0.0
0.0
0.5
0.5
0.5
1.0
1.0
1.5
1.5
1.5
2.0
0.0
6.0
0.0
0.5
0.5
0.5
1.0
1.0
1 .0
1.5
1.5
2.0
2.0
2.0
2.5
0.0
0.0
0.5
0.5
1.0
1.0
1.0
1.0
1.5
1.5
2.0
2.0
2.0
2.5
2.5
0.0
0.5
0.5
1.0
1.0
1.0
1.5
1.5
2.0
2.0
2.0
2.5
2.5
3.0
0.5
0.5
1.0
1.0
1.5
1.5
2.0
2.0
2.5
2.5
3.0
3.0
0.5
1.0
1.0
1.5
1.5
2.0
2.0
2.5
2.5
3.0
3.0
3.5
0.5
1.0
1.5
1.5
2.0
2.5
2.5
3.0
3.5
1.0
1.0
1.5
2.0
2.0
2.5
3.0
-3.0
3.5
1.0
1.5
2.0
2.0
2 .5
3.0
3.0
3.5
4.0
1.0
1 .5
2.0
2.5
3.0
3.5
1.5
2.0
2.5
3.0
3.5
4.0
2.0
3.0
4.0
2.5
_3.5
4.5
3.0
4.0
5.0
3.5
4.5
5.5
HORIZONTAL CURVES WITH TRANSITION SPIRALS - BOTH ENDS
L.C . -Straight Line Chord distance T .S . to S .C .
OsK -Distance from T.S . to point on tangent
opposite the P .C . of the circular curveproduced .
W
U . S . Army Corps of Engineers
3- 10
-Intersection angle between the tangent of thecomplete curve and the tangent at the S .C ., Thespiral angle.
-Widening
CONSTANT SUPERELEVATION
°NAND WIDENING
To locate spiral transition, use tables as givenin Transition Curves for Highways, (See appendixA, Government Depository Libraries)
FIGURE'S-3 . METHOD OF LAYOUT OF WIDENING ANDSUPERELEVATION OF SPIRAL LANES
TRANSITION SYMBOLS
P .I . -Point of intersection of main tangents . Es -External distance P .I . to center of circularT.S . -Common point of tangent and spiral . curve portion.
6S .T . Spiral and tangent . L .T . -Long tangent distance of spiral only .S.C . -Spiral curve, common point of spiral and S .T . -Short tangent distance of spiral only .
circular curve of near transition . P -Offset distance from the tangent of P .C . ofC.S . -Curve spiral, common point of circular circular curve produced .
curve and spiral of far transition . 0 -Intersection angle between tangents ofRc -Radius of circular curve. entire curve.Ls -Length of spiral between T .S . and S .C . c -Intersection angle between tangents at S .C . andTs -Tangent distance P .I . to T .S . or S .T, or Tangent at the C.S . or the central angle of the circular
distance of the complete curve . curve portion of the curve .
m-
_57730VERS
50200
Also m = RIVERS2865SR ),
And S = 2865COS 1
~Rm/
WZaJWGz
OWzJW .z 15WUWOW
UOWWW00
20
10
5
00
U . S . Army Corps of Engineers
EM 1110-3-1309 Apr 84
200
250
300
400
500
700800
108815002 0030005000
5 10 15 20 25 30 - 35
m= MIDDLE ORDINATE CENTER LINE INSIDE LANE TO SIGHT OBSTRUCTION IN FEET
W
zWzaJWCcoz
OWZJW
600 HzWUOW0a
z
FIGURE 3-4 . STOPPING SIGHT DISTANCE ON HORIZONTAL CURVES, OPEN ROAD CONDITIONS
.LEGEND
O = Maximum D when e = Q10 ~V = Design spe " .
v.
~̀QQ~C1 1
-owol
/S.350
J 0
V'60 8:60070
GIV1 IIIU-S-1309 Apr 84
TYPE I
TYPE II
CREST VERTICAL CURVES
3- 12
TYPE IV
SAG VERTICAL CURVES
U . S . Army Corps of Engineers
FIGURE 3-5 . TYPES OF VERTICAL CURVES
economically feasible .
The minimum length of vertical curves is alsoshown in tables 1-1 and 1-2 .
a . Roads .
EM 1110-3-1309 Apr 84
3-7 . Cross section . Figures 3-6 and 3-7 illustrate typicalcombinations of cross-section elements for which geometric designcriteria are outlined in tables 1-1 and 1-2 . Other combinations ofthese cross-section elements are illustrated in AASHTO GU-2 .
(1) Normal-crown section . The typical road-type, normal-crowncross section shown in figure 3-6 comprises the so-called "streamlined"cross section . Shoulder edges, channel bottoms, and the intersectionof side slopes with original groundare rounded for simplification ofmaintenance and appearance . On roads in open areas rounding ofshoulder edges will be restricted to a strip 3 to 4 feet wide at theintersection of slopes steeper than 2-1/2 :1, and only slight roundingwill be used at intersections of slopes flatter than 2-1/2 :1 .
(2) Superelevated section . Figure 3-6 shows the preferablesuperelevated cross sections for roads at Army installations . The lowside of this cross section is similar to a normal-crown section exceptthat the shoulder slope on the low side of the section is the same asthe pavement superelevation, except where normal slope is greater . Onthe high side of a superelevated section the algebraic difference incross slopes at the pavement edge should not exceed about 0 .07 .
Thevertical curve should be at least 4 feet long, and at least the inside2 feet of the shoulder should be held on the superelevated slope .
b . Streets . Typical street-type cross sections with and withoutparking are shown in figure 3-7 . Geometric design for the variouscross-section elements shown are presented in table 1-2 .
3-8 . Intersection criteria .
a . General . Practically all highways within Army installationswill intersect at grade, and normally the designer will need toconsider only plain unsignalized or signalized intersections .Intersections are normally closely spaced at regular intervals alongstreets in built-up areas, and the capacity of these streets will inmost cases be controlled by intersection capacity .
b . Design criteria . Geometric design criteria for intersectionsare presented in AASHTO GD-3, GU-2, SR-2 and the TRB Highway CapacityManual .
c . Army installation areas equivalent to design criteria .areas .Variations in average intersection capacities on one-way and two-waystreets subject to fixed time signal control are shown for generaltypes of areas within cities in the TRB Highway Capacity Manual . Thecurves used at a particular location on Army installations should be
3- 1 3
'TJH C',
tr1
W H ~-Cb H C7 a ,n7O a t7 I H FC b ty n O tr1
C) H H 0 z
MINIMUM
=20
FT
3TO
4-FTROUNDING
FOR
2:1
FS
SLIGHTROUNDINGFOR
FLATTER
E'S
MINIMUM
=20
FT
3TO
4-FT
ROUNDING
FOR2
:1FS
SLIGHT
ROUNDING
FOR
FLATTER
Fh
ROUNDING
FS
NORMALCROSSSLOPE
SEENOTE51
.."
...".
NATURALGROUND
MIN
2FT
PARABOLICCURVE-MINIMUM
LENGTH
=4
FT
ROUNDING
NOTES
:1.
Variations
incross
sect
ion
and
righ
t-of-way
are
shown
inAA
SHTO
GD-2
2.
The
widt
hof
usable
shou
lder
srequired
varies
with
road
clas
sifi
cati
on,
steepness
offront
slop
esand
guar
drai
lor
guid
epos
tlocations,
see
tabl
e1-1
.
3.St
eepn
ess
offront
and
back
slop
esvaries
with
Has
shown
infi
gure
3-2
.U
.S
.Army
Corp
sof
Engi
neer
s
MINIMUM
RIGHT-OF-WAY
VARIES
FROM
APPROXIMATELY
60
FT
FOR
SINGLE
LANECLASS
EROADS
TO
APPROXIMATELY
210FT
F()R
CLASS
8MULTI-LANE
Rd10S(SEE
NOTE
1)
VARIABLE
SEE
NOTE
4
SUPERELEVATED
S
4.
Tva
ries
with
road
classification
.Traffic
composition
and
type
curb
used
inde
sign
see
tabl
e1-
1.
5.Us
esuperelevation
rate
ewh
ere
greater
than
norm
alcr
oss
slop
e.
6.Se
enote
l,fi
gure
3-2
for
maxi
mum
value
ofH
.
MINIMUM
LEGEND
Pavement
Shoulder20
FT
ROUNDING
Base
Cour
seFS
Fron
tSlope
BS
Back
Slope
H
Heig
htof
cut
brfill
S
Width
ofshoulder
T
Tota
lwidth
oftr
affi
cla
nes
e
Superelevation
rate
NORMALCROWN
ST
SVARIABLE
VARIABLE
SEE
NOTE
4VARIABLE
SEE
NOTE
2SEE
NOTE
2
n ',L1 O
n 0
MINIMUM
RIGHT-OF-WAY
VARI
ESFROM
APPR
OXIM
ATEL
Y40
FTFORCLASSE
STREETS
TOAPPROXIMATELYTO
FTFO
RCL
ASS8ST
REET
AND
NOTE
I
INDU
STRI
ALFR
ONTA
GE
~+
to
CURBED
;NO
PARK
ING
n a rB
P
TMIN=
8FT
VARIABLE
VARI
ABLE
SEENOTE
2CURB_
SEETA
BLE
1-2
.H I H b trl
NORMAL
CROSSSL
OPE-
1/4"
TOI"
PERFT
W.'LK
c
INDU
STRI
ALFRONTAGE
GUTT
ER
NOTES
:1
.Dimens
ions
ofel
emen
tsof
cros
ssections
nowsh
ownon
this
figure
are
shown
inta
ble1-2
.
2.
Tvaries
with
stre
etcl
assi
fica
tion
traffic
composition,
and
type
curb
used
indesign
.
rCURB
G
MIN=8FT 11
NORMAL
CROSS
SLOPE-
1/4.
.TO
I"PERFTr
CURB
ED;WIT
HPARKINGLANES
(- V
ARIABLE
SEETA
BLE
1-2
n
MINIMUMRIGHT-OF-WAY
VARI
ESFROM
APPROXIMATELY54
FTFO
RCLASSE
STRE
ETS
TOAP
PROX
IMAT
ELY
88FT
FOR
CLAS
SBST
REET
SH H O
GUTTER
8 WALK
ADMINISTRATIVE
AND
RESIDENTIAL
FRONTAGE
BMIN=8
FT
NORMAL
CROS
SSL
OPE-
1/4"TO
I"PE
RFTC_
WALK
ADMI
NIST
RATI
VEAN
D'
RESIDENTIAL
FRONTAGE
LEGEND
Traf
ficLane
Pavement
Curb
Walk
Base
Course
111111
111111
1Pa
rkin
gLane
Pavement
TTo
talWi
dthof
Traf
ficLa
nes
tpf' .
'
ao
BBorder
wG
Turfed
Area
(Grassed
Area)
00
Crd
PPa
rkin
gLane
4~-O
EM 1110-3-1309 Apr 84
selected on the basis of similarity with the type of area indicated inthe TRB Highway Capacity Manual . The following tabulation indicatesareas in which the intersection curves should normally be used .
Area DesignationUsed in HighwayCapacity Manual
Equivalent Area at Army Installations
Downtown
Central portion of built-up areas at majorinstallations
Fringe, business
Central portion of built-up areas at alldistrict
but major installations . Industrial,service, and warehouse areas at majorinstallations.
Outlying business
Residential portion of built-up areas atdistrict and
major installations . Industrial, service,intermediate
warehouse, and residential portions ofresidential
built-up areas at intermediate installations .All built-up areas at small installations,isolated shopping centers, community centers,and similar areas of public assembly in openareas . Isolated road intersections in openareas .
Rural
TRB Highway Capacity Manual .
3-9 . Capacity of intersections . The capacity (DHV) shown intables 1-1 and 1-2 is for free-flowing highways without intersectionsat grade or with few crossroads and minor traffic . These highways haveno traffic control signals at intersections (plain unsignalizedintersections), and capacity is affected very little and uninterruptedflow is assumed . The AASHTO procedure is suggested as a guide indesign of intersections .
AASHTO Suggested Design Hourly Volume Combinations forWhich Signal Control Should be Assumed in Geometric
Design of Intersections .
Type of Intersection Minimum Two-Way DHV
2-lane through highway 400 500 650Crossroad 250 200 100
4-lane through highway 1,000 1,500 2,000Crossroad 100 50 25
This . tabulation may serve as a general guide for design of at-gradeintersections in the following manner . If the DHV of traffic at agiven intersection ~is approximately equal to or less than that shown inthe tabulation, capacity of the through highway is based on the DHVshown in tables. 1-1 and 1-2, and no intersection capacity analysis isrequired . If the DHV of traffic is greater than that shown in thistabulation, the intersection should be designed as if it were undersignal control . The geometric layout should be made in conjunctionwith an intersection capacity analysis, as in the Highway CapacityManual . The volumes shown in this tabulation have no relation towarrants for signalization, nor are they indicative of whether or notsignalization should be used . Warrants for traffic control'signals aregiven in ANSI D6 .1 .
3-10 . Intersection curves .
a . Minimum edge of pavement design . Where it is necessary toprovide minimum space for turning vehicles at unsignalized at-gradeintersections, the AASHTO design criteria presented in GU-2 and SR-2should be used . The minimum radius for edge of pavement design onstreet intersections is 30 feet, which is required for passenger (P)cars on 90-degree turns . A larger radius should be used if any trucktraffic is expected or turning speeds greater than 10 mph areanticipated . The minimum radius on road intersections is 50 feet .
b . Minimum curb radii . Minimum curb radii are normally used atplain unsignalized intersections to reduce intersection area andminimize conflict between pedestrians and vehicles . The curb designshould fit the minimum turning path of the critical design vehicleexpected in the traffic . Generally, the minimum curb radii to be usedon intersection curves maybe determined on the basis of the followinginformation .
(1) Curb radii of 15 to 25 feet are adequate for P designvehicles and should be used on Classes D and E cross streets wherepractically no single unit (SU) truck, WB40, WB50, and WB60(semitrailer combination trucks) design vehicles are expected or atmajor intersections where parking is permitted on both intersectingstreets . Radii of 25 feet should be provided on all new constructionand on reconstruction where space is available .
(2) Curb radii of 30 feet or more should be provided at allmajor highway intersections to accommodate an occasional truck in thetraffic . (See table 2-1 for minimum turning radius .)
(3) Radii of 40 feet or more, preferably three-centered compoundcurves, to fit the path of the critical design vehicle expected in thetraffic, should be provided where SU, WB40, WB50, and WB60 designvehicles turn repeatedly .
(See table 2-1 for minimum turning radius .)
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3-11 . Miscellaneous .
a .
Signing .
Signs should conform with ANSI D6 .1 standards .
b . Pavement markings . Marking should be provided on paved surfacesas a safety measure and to increase orderly traffic flow . Markingsshould conform to local highway practice criteria . Standardrequirements are provided in ANSI D6 .1 on uniform traffic controldevices .
4-1 . Walks .
GEOMETRIC DESIGN FOR WALKS AND OPEN STORAGE AREAS
a . , Need . Walks and walkways could be non-essential items during anemergency situation and hence, should not be considered unless deemednecessary or circumstances allow for their construction .
b . Criteria . Smooth, hard-surface walks should be provided' toaccommodate pedestrian traffic . However, gravel, stone slab, wood orother type walk materials could be utilized if they are readilyavailable .
c . Geometric design . Safety and volume of pedestrian traffic arethe primary controls for geometric design of walks . A designpedestrian traffic volume (pedestrians per hour) must be estimated onthe basis of available data, engineering judgment, and pedestriantraffic at existing similar installations .
d . Width .
The minimum width for walks at Army installations willbe 3 feet . Walks will normally be in increments of 2 feet (width ofpedestrian traffic lane) as required to accommodate the anticipatedvolume of pedestrian traffic . An extra foot of width should be addedto walks adjacent to curbs or where obstacles encroach on the walk .Width of walks will be determined on the basis of the capacities(pedestrians per hour) shown in the following tabulation :
Capacity of Walks inPedestrians per Hour
Less than 10Up to 100100 to 750100 to 1,000Greater than 750Greater than 1,000
e . Grade . The grade of walks should follow the natural grade ofthe ground as nearly as possible . The transverse grade will not beless than 1/4 in/ft . The longitudinal grade should not be greater than
will be used where the maximum longitudinaltoo great . Steps should be grouped together,
steps, and located so that they willnight lights . The sum of the depth ofnot be less than 18 inches and risersor greater than 7 inches on any
about 15 percent . Stepsslope would otherwise berather than spaced as individualbe lighted by adjacent street ortread and height of riser shouldshould not be less than 5 inchessteps .
CHAPTER 4
Minimum Width, ft
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4-2 . Open storage areas and parking .
a . General . This section deals with geometric design criteria forparking lots, motor pools, organizational motor parks, material storageareas, utility yards, and miscellaneous repair yards . Storage ofexplosives or fuels require special conditions and are not included inopen storage .
b . Parking lots, motor pools, and repair areas . Traffic volume andmix are the primary considerations in the selection of type ofsurfacing . It is essential to determine the number of vehicle passesand the traffic patterns of the various types of vehicles underconsideration . Special consideration should be given to pavementssubject to repeated traffic of track-type vehicles or where fuel andlubricant spillage may occur . The minimum traffic volumes consideredfor parking lots, motor pools, or repair areas should be equivalent toClass E streets (See table 1-2) . Where applicable, design criteria ofstate or local regulatory agencies may be utilized . Where massiveparking is necessary, cross traffic connections should be provided atabout 360 foot (40 stalls) intervals . Islands or medians may not bepractical under mobilization conditions, however wooden barriers (powerpoles), railroad ties, or precast concrete bumpers can be used toorganize and control traffic and to protect adjoining areas at edge ofpavements . Minimum grades should be provided to allow drainage of theareas . Natural drainage to the perimeter of the paved area ispreferred ; inlets for drainage within the paved area will be avoided tothe greatest extent possible . A maximum slope of 5 percent may be usedin parking lots, motor pools, and repair areas without restriction oftraffic direction or parking angle .
c . Material storage areas . Suitable areas for the storage of goodsand materials that do not require extensive protection from theelements will be required at nearly all types of Army installations .In general, these areas will be of an improved type with the areagraded to allow good drainage, the subgrade and base course prepared,and a hard surface provided . Semi-improved areas where no hard surfaceis included may be used under special conditions ; however, reducedbearing capacity and potential material handling equipment problemswill restrict the use of this type of area . Unimproved areas where nograding for drainage or hard surfaces are provided may be acceptablefor materials during construction but should not be considered as Armyinstallation open storage .
(1) Shipping and receiving . A space for loading and unloading
will be provided the extent of which will be a function of volume ofmaterials handled and the method of delivery . Minimum provisions will
be space for a tractor-trailer to be unloaded by a fork lift truck .
Where a railroad siding is included or where high volumes of truck
deliveries are anticipated, rail siding platforms will be provided .
4-2
(2) Arrangement of storage . Detailed arrangement of storageareas will be a function of type and volume of material, storage timeper item, material handling equipment used, and storage inventoryprocedures . In general though, efficient layouts provide forstraight-line flow of material from loading/unloading areas to storage,ready access to each material storage location and efficient use ofaisles . Aisles will essentially be roads and should be designed assuch for dimensions and traffic flow .
(3) Lines and grades . Storage areas will have minimum slopesconsistent with good drainage . Area drains and inlets within thelimits of the pavement will be avoided to the greatest extent possible .Surface smoothness on hard surface pavements, will not exceed 3/8 inchdeviation from a straightedge laid diagonally across the space of asingle storage element (pallet, drum, packing crate, etc .) . Wheresemi-improved storage areas are provided, the deviation from astraightedge should not exceed 5/8 inch . The difference in elevationof the highest and the lowest point of any single storage space (basedon a 4 foot square pallet) should not exceed 1-1/2 inches whenmaterials are stacked 15 feet or higher, nor should the slope of theoverall storage area exceed 3 percent grade . Where material is stackedless than 15 feet high, a single space differential of 2-1/2 inches andan overall slope of 5 percent grade may be permitted . The use ofcontainerized storage for Army installations other than ports or depotsis expected to be limited . See EM 1110-3-150 for special requirementsof container handling and storage if required .
(4) Selection of hard surface pavements . The factors thataffect the surfacing requirements of improved open storage areasinclude vehicle characteristics, traffic volume and flow patterns,material accessibility, and weight requirements of the stored material .There are two types of surfaces that are frequently used on improvedstorage areas : flexible pavements (EM 1110-3-131) and rigid pavements(EM 1110-3-132) . Rigid pavement applications are better suited inareas where temperature fluctuations are extreme ; however they arelabor intensive with longer construction times and are generally moreexpensive . Flexible pavements are more commonly used but may belimited by material availability . Steel mat may be selected for shortterm use as an expedient surfacing method . Minimum designconsiderations should be based on traffic flows for Class E streets(see table 1-2) and/or a minimum static load from material of 1,500psf . The use of both rigid and flexible pavements may be considered,such as flexible pavement for storage and concrete for aisles andspecial areas ; however, design and construction time constraints aswell as material availability must be considered .
(5) Lighting . General area lighting of 1/2 foot-candle atground level uniformly distributed over the entire storage area shouldbe considered the minimum lighting level . Additional lighting must beconsidered where night operations are anticipated .
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(6) Fire protection . While open storage areas are not normallyconsidered as high a risk as conventional warehousing, proper fireprotection is still a major consideration .
(7) Outdoor sports and recreation areas . Sports fields andrecreation areas requiring hard surfaces will follow the minimumcriteria indicated for open storage . Slopes of pavement and lightingof areas will be in keeping with the requirement of the sportinvolved .
Government Publications .
Department of the Army .
APPENDIX A
REFERENCES
EM 1110-3-131
Flexible Pavements for Roads,Streets, Walks, and OpenStorage Areas .
EM 1110-3-132
Rigid Pavements for Roads,Streets, Walks, and OpenStorage Areas .
EM 1110-3-136
Drainage and. Erosion Control .
EM 1110-3-150
Storage Depots .
Gove rnment Depository Libraries
Transition Curves for Highways (1958), Catalog No . A22 .2 :H53/7*
Nongovernment Publications .
EM 1110-3-1309 Apr 84
American Association of State Highway and Transportation Officials(AASHTO), 444 North Capital, N .W ., Suite 225 Washington, D .C .20001
GD-2
Policy on Geometric Design of RuralHighways (1965) .
GU-2
Policy on Design of Urban HighwaysArterial Streets (1973) .
HB-12
Standard Specifications for HighwayBridges . (Including ISB-78, ISB-79,ISB-80, and ISB-81) (1977) .
*No longer in print . Originally published by U.S . Department ofAgriculture, Bureau of Public Highways . Now available for examinationat selected Government Depository Libraries .
EM 1110-3-1309 Apr 84
SR-2 (1974)
Highway Design and OperationalPractices Related Highway Safety .
American National Standards Institute (ANSI), 1430 Broadway,New York, NY 10018
D6 .1-1978
Uniform Traffic Control Devices forStreets and Highways
Transportation Research Board (TR8), 2101 Constitution AvenueN .W ., Vashington, D .C . 20418
Highway Capacity Manual .