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 .)

3-17

EM 1110-3-1309 Apr 84

EM 1110-3-1309 Apr 84

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 .