alldocuments.siteonestudio.com/uploads/mobilepw/1832.pdfavailable for resurfacing, restoration, and...
TRANSCRIPT
FO
OT
PR
INT
DE
SIG
N
MA
NU
AL
FOR
LO
CA
L
RO
AD
S
SPON
SOR
EI)
BY
The
Tran
sportatio
nand
Dev
elopm
ent
institu
te(T
&D
I)ol
theA
merican
Society
ofC
ivilE
ng
ineers
AU
TH
OR
ED
BY
The
Local
Roads
andS
treetsC
om
mittee
of
theT
ransp
ortatio
nand
Dev
elop
men
tInstitute
ofthe
Am
ericanS
ocietyof
Civil
Engineers
ASC
ETR
AN
SPOR
TATIO
N&
DEV
ELOPM
ENT
INSTITU
TE
Published
bthe
Am
ericanS
ocietyof
Civil
Engineers
Cataloging-in-P
ublicationD
ataon
filew
iththe
Librar
of
Congress.
Am
ericanS
ocietyof
Civil
Engineers
1801A
lexanderB
ellD
riveR
eston,V
irginia.20191-4400
ww
w.pubsasce.org
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statements
expressedin
thesem
aterialsare
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ddo
notnecessarily
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CE
,w
hichtakes
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herein.N
oreference
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orservice
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SC
E.
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egisteredin
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ISB
N978-0-7844-1091-2
Manufactured
inthe
United
States
ofA
merica.
Preface
Inresponse
tolim
iteddesign
guidanceavailable
forR
esurfacing,R
estoration,and
Rehabilitation
(RR
R)
projects,functionally
classifiedas
“Local
Roads”
ofthe
National
Highw
ayS
ystem,
thiscom
mittee
hasspecifically
undertakenthe
taskto
developsystem
aticm
ethodsthat
relateto
Resurfacing,
Restoration,
andR
ehabilitation(R
RR
)projects.
The
comm
ittee’scritical
reviews
andfindings,
frompublications
likeT
ransportationR
esearchB
oard,”S
pecialR
eport214
“,
1987(1,);
AA
SH
TO
,A
merican
Association
ofState
l-lighway
andT
ransportationO
fficials,“G
uidelinesfo
rG
eometric
Design
of
Very
Low
-Volum
eL
ocalR
oads(A
DT
400)“,
2001(‘2,),
AA
SH
TO
,A
ssociationof
StateH
ighway
andT
ransportationO
fficials“G
eometric
Design
,förR
esur/icing,R
estoration,and
Rehabilitation
(RR
R)
of
Streets
“,
1977(3,),
andm
anyother
localagency
internalpublications
were
usedto
make
judgments
aboutthe
relationshipbetw
eensafety
andkey
highway
features.F
orseveral
designfeatures,
thecom
mittee
foundsufficient
evidenceto
supportquantitative
relationshipsbetw
eensafety
anddesign
improvem
ents.H
owever,
therelationships
must
bereview
edas
approximate
innature.
Although
therelationships
arebased
onthe
bestavailable
data,they
couldbe
substantiallychanged
bethe
resultsof
futureresearch.
The
Code
oJF
ederalR
egister2007,
Title
23:highw
ays,P
art625
—D
esignS
iandardsfb
iH
ighways.
‘625.2
Policy
(b,Lstates
“Resurfacing,
restoration,and
rehabilitation(R
RR
)projects,
otherthan
thoseon
theInterstate
systemand
otherfreew
ays,shall
beconstructed
inaccordance
with
standardsw
hichpreserve
andextend
theservice
lifeof
highways
andenhance
highway
safety.R
esurfacing,restoration,
andrehabilitation
work
includesplacem
entof
additionalsurface
material
and/orother
work
necessaryto
returnan
existingroadw
ay.including
shoulders,bridges,
theroadside,
andappurtenances
toa
conditionof
structuralof
functionaladequacy.”
Inaddition
topublications
usedfor
(RR
R)
work,
otherresearch
anddocum
entsw
ereused
inthe
productionof
thisdocum
ent:A
AS
HT
O,
Association
ofState
Highw
ayand
Transportation
Officials,
“Roadside
Design
Guide”
(4),N
ationalC
ooperativeIlighw
ayR
esearchP
rogram,
“Report
350,R
ecomm
endedP
rocedures/hr
theS
afrtyP
erformance
Evaluation
of
hig
hw
ayF
eatures“,
Transportation
Research
Record
1599(5),
“Guardrail
A’eed:
Em
bankments
and
Culveris
“,
Transportation
Research
Board,
Washington,
DC
,1997
(6).
Draw
ingprim
arilyon
casestudies
ofcurrent
RR
Rpractices
andanalyses
ofsafety
cost-effectiveness,the
comm
itteehas
recomm
endedpractices
thatencom
passthe
entireR
RR
processbut
with
specialfocus
ondesign.
The
comm
ittee’srecom
mendations
inthis
document
areintended
toserve
asguidance.
Engineering
judgment
basedof
localconditions
isparam
ountin
fulfillingthe
tasksto
improve
anexisting
roadway
andto
improve
safety.
111
Acknow
ledgements
Special
appreciationis
expressedto
them
embers
ofthe
Local
Roads
andS
treetsC
omm
itteeof
theT
ransportationand
Developm
entInstitute
of
AS
CE
thatcontributed
tothe
development
ofthis
document.
JoeW
.R
uffer,P,E
.,F
.AS
CE
,C
o-Author
James
D.
Foster,
Co-A
uthorC
orneliusW
.A
ndres,P.E
.,A
.M.A
SC
EL
arryW
.E
rnig,P.E
.,F
.AS
CE
Andrew
E.R
arnisch,P.E
.,M
AS
CE
Eugene
R.
Russell,
Ph.D.,
P.E
.,F
.AS
CE
Roger
E.Sm
ith,P
h.D.,
P.E.,
F.A
SC
EJohn
C.
Vancor,
M.A
SC
E
iv
Contents
Intro
ductio
n.
I
Ty
pes
of
Pro
jects
3
Preserv
ation
or
Main
tenan
ce3
Resu
rfacing
3
Resto
ration
3
Reh
abilitatio
n3
Reco
nstru
ction
4
Esta
blish
ing
Geom
etric
Gu
idelin
es
5
Traffic
Data
5
Speed
5
Desig
nC
riteria
Reco
mm
en
datio
ns
7
Reco
mm
endatio
nI:
Review
Curren
tC
onditio
ns
7
Reco
mm
endatio
n2:
Determ
ine
Pro
jectS
cope8
Reco
mm
endatio
n3:
Determ
ine
Lane
and
Should
erW
idth
11
Reco
mm
endatio
n4:
Determ
ine
Norm
alP
avement
Crow
n12
Reco
mm
endatio
n5:
Determ
ine
Horizo
ntal
Curv
ature
and
Superelev
ation
13
Reco
mm
endatio
n6:
Determ
ine
Vertical
Curv
ature
and
Sto
ppin
gS
ight1)istance
15
Reco
mm
endatio
n7:
I)etermin
eB
ridgeW
idth
16
Reco
mm
endatio
n8:
I)eterniin
eS
ideS
lopesan
dC
learZ
ones17
Reco
mm
endatio
n9:
Gu
ardrail
Need
forE
rnb
ank
men
tsan
dC
ulv
erts19
Reco
mm
endatio
n10:
Pav
emen
tE
dgeD
ropan
dS
ho
uld
erT
ype20
Reco
mm
endatio
n11:
Intersectio
nIm
pro
vem
ents
21
Reco
mm
endatio
n12:
I)ocu
men
tthe
i)esignP
rocess21
Refe
rences
22
V
I.In
troductio
n
Ithas
become
apparentever
sinceroad
constructionbegan
thatfunding
availablefor
resurfacing,restoration
andrehabilitation
(RR
R)
oflocal
roadsand
streetsw
illbe
insufficientto
improve
existingroadw
aysto
thegeom
etricstandards
desirablefor
major
reconstructionand
newconstruction
ata
rateequal
tothat
atw
hichpavem
entsare
deteriorating.A
vailablefunds
areexpected
torem
ainessentially
constantor
perhapseven
decreasew
hileat
thesam
etim
econstruction
costsare
increasing.
Inaddition
tocosts,
upgradinghighw
aysto
guidancelevels
recomm
endedfor
newconstruction
(AA
SHT
OA
Policy
onG
eometric
Design
of H
ighways
and
Streets),
impacts
theenvironm
entof
abuttingareas
andcom
munities
inthe
vicinity.T
hesocial
andeconom
iccosts
tothe
comm
unitym
ustbe
balancedagainst
improved
serviceto
thetraveling
public.M
anypublications
like“A
Guide
for
Achieving
Flexibility
inhighw
ayD
esign”(7),
“Roadside
Design
Guide”
(8,),“G
uidelinesfo
rG
eometric
Design
ofV
eryL
ow-
Volum
eL
ocalR
oads(A
DT
400)”(2),
hav
eshow
nth
atflexibility
hasto
bea
partof
thedesign
process.
Previously
statedreasons
providethe
backgroundand
needfor
newgeo
metric
guidelinesfor
resurfacing,restoration,
andrehabilitation
(RR
R)
projects.W
henthe
designerdeterm
inesthat
RR
Rdesign
criteriashould
beused,
thism
anualis
intendedto
provideguidelines
tofollow
inthe
designprocess.
The
designengineer
shouldconsider
eachproject
individuallyusing
engineeringjudgm
entto
determine
what
improvem
entsare
feasiblew
ithinavailable
fundingto
providea
facilitythat
will
servethe
publicat
areasonable
levelof
safetyand
comfort.
This
innovativeapproach
todesign
isessential
inorder
togive
designersoptions
tobe
usethe
limited
roadway
resourcesto
meet
thepressing
needsof
improving
functionand
safetycharacteristics
tothe
extentpossible
ofthe
roadway
systems
ina
costeffective
manner.
This
guidehas
beendeveloped
toprovide
thedesigner
flexibilityby
presentingm
inimum
valuesfor
designand
recognizingthat
engineeringjudgm
entshould
beused
toobtain
thetraffic
serviceand
safetybenefits
possiblew
ithinexisting
conditionsand
constraints.T
hisguide
isonly
applicableto
roadways
functionallyclassified
as“L
ocal”.For
higherfunctionally
classifiedroadw
aysother
publicationsshould
beused.
The
primary
purposesof
RR
Rprojects
areto
providea
betterriding
surface,preserve
pavement
structuralsection,
increasesafety,
andto
improve
operatingconditions,
tothe
most
feasibledegree
possible.In
additionto
theprim
aryobjectives,
itm
aybe
possiblein
some
casesto
considersecondary
objectivesappropriate
toa
projectto
anextent
thatis
financiallyand
environmentally
acceptable.
The
following
listof
objectives(not
inprio
rityorder,
orall
inclusive)m
aybe
considered.
1
2F
OO
TP
RT
NT
DE
SIG
NM
AN
UA
LF
OR
LO
CA
LR
OA
DS
Prim
aryO
bjectives:•
improve
surfacesm
oothness•
Extend
servicelife
•R
estorecross-slope
•Im
provesuperelevation
•Im
proveskid
resistance•
Restore
deterioratedbridge
decks•
Reconstruct
sectionsof
pavement
structure•
Widen
pavement
andshoulders
•F
lattenfront
slopes•
Improve
drainage•
improve
pipe-endstreatm
ents•
Extend
culverts•
Upgrading
trafficcontrol
devices•
Improve
sightdistance
•Im
provesite-specific
crashlocations
Secondary
Objectives:
•Increase
verticaland
horizontalclearance
toobstructions
•Intersection
improvem
entsand
channelization•
Provide
pavedshoulders
•P
rovidefor
controlof
erosion•
Installnew
typesof
trafficcontrol
devices•
Provide
curbing,sidew
alks,A
DA
ramps
(onlyin
built-upareas)
•P
rovidebikew
ays•
installstreet
lighting•
improved
landscaping•
Flatten
backslopes
•C
onstructclosed
drainagesystem
s
The
presentright-of-w
ay(R
OW
)m
aybe
adequateto
accomplish
theabove
improvem
ents.In
some
casesm
inorR
OW
acquisitionsor
easements
may
berequire.
Deficiencies
insom
eexisting
roadways
systems
areusually
identifiedby
sufficiencyratings,
crashdata,
skidtests,
maintenance
reports.road
safetyaudits,
andin
some
cases,suggestions
fromthe
public.
Often
attentionto
theoverall
appearanceof
thero
ad\ay
,as
itis
beingim
proved,w
illresult
ina
productthat
ism
orereadily
acceptedby
thecom
munity.
Exam
plescould
bethe
inclusionof
curband
sidewalks
inurbanized
areas.the
relocationof
utilitypoles
away
fromthe
edgeof
pavement,
orthe
additionof
wider
shouldersand
flattenedfront
slopes.T
hecost
of
suchim
provements
muSt
becarefully
weighed
againstbenefits
availablefrom
anequivalent
projectelsew
here.
II.T
ypesof
Pro
jects
Preserv
ation
or
Main
tenan
ce
These
areprojects
where
itsprim
aryobjective
isto
preserveand
extendthe
servicelife
ofexisting
roads.T
hisis
anim
portantactivity
forthe
preservationof
aroadw
ay.T
histype
ofw
orkw
ouldtypically
nothave
anyadditional
items
ofw
orkthat
would
upgradeits
presentcondition.
This
guidew
ouldnot
beapplicable
forthis
typeof
activity.
Gen
eralR
RR
RR
Rprojects
aredivided
intothree
categories
Resurfacing
While
thiscategory
isprim
arilyfor
pavement
resurfacing,other
typesof
work
may
beincluded
suchas
shortsections
ofpavem
entreconstruction,
jackingconcrete
slabs,and
jointreplacem
entand/or
repair.it
might
alsoinclude
widening
ofnarrow
lanes,shoulders,
trafficcontrol
devices,channelization
work,
barriers,and
some
drainageim
provements.
Locations,
which
haveproven
tobe
hazardous,should
becorrected.
Usually
noadditional
rights-of-way
arerequired.
Resto
ration
This
typeof
work
would
returnroad
orstructures
tothe
conditionof
originalconstruction.
Some
intersectionsm
ayneed
additionalcapacity.
There
couldbe
some
needfor
curbing,sidew
alks,channelization,
drainageim
provements,
etc.R
esurfacingor
pavement
reconstructionto
improve
wet
weather
safetyis
includedthat
will
enableexisting
pavement
toperform
satisfactorilyfor
substantialtim
eperiods.
New
andupgraded
trafficcontrol
devicesare
comm
onlyneeded.
Some
additionalright-of-w
aym
aybe
necessary.C
onsiderationm
aybe
givento
improving
anisolated
grade,curve,
orsight
distanceby
constructionor
trafficcontrol
measures.
Reh
abilitatio
n
Traffic
serviceim
provements
andsom
ebetterm
entneeds
inthis
categorym
aybe
ofequal
orgreater
importance
thanthe
needto
improve
theriding
qualityof
thepavem
ent.T
heseroads
areusually
foundin
urbanareas
orsuburban
areasw
hereland
usealong
thefacility
hasintensified
overthe
years.T
hereis
agreat
needto
providecontinuous
throughor
auxiliarylanes
inorder
toreduce
trafficbottlenecks
andim
provetraffic
serviceand
safety.Safety
shouldbe
givenclose
attentionw
ithem
phasison
featureshaving
crashhistory
andthose
known
tohave
highpotential
forcrashes.
Often
aclosed
drainagesystem
may
beappropriate.
Curbing
andsidew
alks
3
4FO
OT
PRIN
TD
ESIG
NM
AN
UA
LFO
RL
OC
AL
RO
AD
S
may
bedesirable.
Resurfacing
ofthe
existingpavem
entis
usuallyincluded.
Insom
ecases.
complete
pavement
structurereplacem
entor
enhancements
thatextend
theservice
lifeand/or
improve
itsload
carryingcapability
forspecified
sectionsm
aybe
calledfor.
Retaining
walls
may
berequired.
Bridge
widening,
deckreplacem
ent,or
railingupgrading
may
benecessary.
New
andupgraded
trafficcontrol
devicesare
comm
onlyneeded.
Some
additionalright-of-w
aym
aybe
necessary.C
onsiderationm
aybe
givento
improving
isolatedgrade,
curve,or
sightdistance
byconstruction
ortraffic
controlm
easures.
Reco
nstru
ction
Work
thatw
ouldincrease
thefunctional
classificationof
theroadw
ay,im
provethe
level-of-service(L
OS
),increase
capacity,increase
designspeed.
and/orim
provehorizontal
andvertical
alignment
alonga
substantiallength
ofa
roadway
would
bereconstruction
activities.T
hispublication
isnot
intendedfor
thesetypes
ofim
provements.
Other
guidanceshould
beobtained.
III.E
stablish
ing
Geo
metric
Guidelines
Gen
eral
RR
Rprojects
shouldapply
designcriteria
thatw
illallow
some
flexibilityin
orderto
adjustto
actualfield
conditions.T
herefore,the
geometric
information
inthis
guideis
generallythe
minim
umconsidered
acceptable.It
isintended
thatengineering
judgment
beexercised
todeterm
inew
hereit
may
befeasible
todesign
abovethese
minim
ums
inorder
toinsure
thegreatest
trafficservice
andsafety
improvem
entspossible
within
existingconditions
andconstraints.
Traffic
Data
The
projectscovered
bythis
guidelineare
undertakenprim
arilyto
meet
specificcurrent
needsand
aredesigned
toim
provea
greaterportion
ofthe
roadway
systemw
ithinfunds
available.T
herefore,the
basicthrust
ofR
RR
projectsm
ustbe
tosatisfy
existingtraffic
conditions.T
hepresent
level-of-servicew
illbe
maintained
orim
provedif
foundto
becost
effective.
Current
datathat
shouldbe
availableduring
thedesign
isas
follows:
1.A
DT
and/orD
I1V2.
Crash
locationsand
descriptions3.
Turning
movem
entsat
major
trafficgenerators
4.A
nyknow
n“future
developments”
thatcould
impact
theroadw
ay
Because
ofthe
varyingdegree
ofprojects,
RR
Rim
provements
andcosts
shouldbe
developedon
thebasis
ofa
5or
10-yeartraffic
forecast.If
existingvolum
esare
highand
conditionsare
restricted,only
minim
alincrease
incapacity
may
berealized.
Speed11
iscom
mon
practicew
henfull
reconstructionis
beingconsidered
torelate
forecastedtraffic
volumes
tospecific
designcriteria
includingdesign
speed.H
igherforecasted
trafficvolum
esusually
requirehigher
guidelines.H
owever,
when
trafficvolum
esbecom
em
oderateto
heavy,it
isusually
becausethe
roadway
isapproaching
oris
within
anurban
area.T
hus,the
abilityto
applyhigher
guidelinesbecom
esincreasingly
difficultand
costlybecause
ofadjacent
landuses.
Forthis
reason,m
anyprojects
oftencannot
beim
plemented
when
itis
necessaiyto
meet
theguidelines
ofnew
construction.
Itis
apparentfrom
theabove
discussionthat
ifexisting
roadways
areto
bem
aintainedand
improved
within
strictconstraints
andm
inimal
socialand
5
6FO
OT
PRIN
TD
ESIG
NM
AN
UA
LFO
RL
OC
AL
RO
AD
S
environmental
impact,
am
orecosteffective
approachis
essential.T
hedesirable
designshould
accomm
odatethe
currentrunning
speedbut
am
inimum
designspeed
shouldnot
beestablished.
Advisory
speedreduction
signsattached
tocurve
signsm
aybe
utilizedfor
horizontalcurvature
asis
thepresent
practiceand/or
anyother
trafficcontrol
devicesavailable,
with
thesam
efor
verticalcurves.
Transportation
Research
Board,
“Special
Report
214”,1987,
suggeststhat
when
thedifference
between
thecurrent
runningspeed
andcorresponding
designspeed
ofa
horizontalcurve
exceeds15
mph,
orvertical
curveexceeds
20m
ph,additional
considerationsshould
begiven
tocorrective
work
orto
provideadditional
warning
devicesin
orderto
avoidlaige
changesof
runningspeed.
Itis
important
when
consideringa
RR
Rproject
fora
sectionof
roadway
toconsider
thegeom
etricconditions
beyondthe
portionto
beim
proved.E
veryattem
ptshould
bem
adeto
maintain
auniform
lysafe
runningspeed
fora
significantsegm
entof
roadway.
Considerable
considerationshould
begiven
tothe
transitionpoint
between
portionsof
aroadw
ayhaving
differentdesign
speeds.T
hegreater
thechange
indesign
speedsthe
higherthe
demand
thatw
illbe
placedon
driverexpectancy.
Consistency
indesign
isparam
ountto
driverexpectation,
onew
ithoutabrupt
changesin
sectionor
alignment.
Ifconfronted
with
atransition
point,for
whatever
reason,attem
ptsshould
becarefully
plannedto
advisethe
driverw
ellin
advanceof
thischange
point.T
heM
anualon
Uniform
Traffic
Control
Devices
(‘MU
TC
D)
shouldbe
referencedand
implem
entedas
neededas
partof
theR
RR
project.
IV.
Design
Criteria
Recom
mendations
Significant
improvem
entsin
safetyshould
besystem
aticallydesigned
intoeach
roadway
RR
Rproject.
Designers
shouldseek
opportunitiesspecific
toeach
projectand
applysound
safetyand
trafficengineering
principles.A
ttentionto
safety,along
with
documentation
ofthe
designprocess
improves
designdecisions.
The
designpractice
shouldincorporate
thefollow
ingrecom
mendations.
Recom
mendation
1:R
eviewC
urren
tC
onditions
Designers
shouldreview
existingphysical
andoperational
conditionsaffecting
safety:
•C
onductand
document
athorough
siteinspection
ofall
physicalelem
entsand
geometry
within
theroadw
aylim
its.•
Analyze
existingroadw
ayusers,
functionalclassification,
AD
T,
andaverage
speeds.•
Analyze
crashdata,
toinclude
fieldinspection,
andconcerns
expressedby
thepublic.
•A
combination
ofdifferent
elements
may
contributeto
possiblereasons
fora
crashlocation.
7
8F
OO
TP
RIN
TD
ES
IGN
MA
NU
AL
FO
RL
OC
AL
RO
AD
S
Recom
mendation
2:D
etermin
eP
roject
Scope
Inaddition
topavem
entrepairs,
thedesigners
shouldconsider,
where
appropriate,to
incorporate;intersection,
roadside,and
trafficcontrol
improvem
entsthat
may
enhancesafety.
Based
onrecom
mendation
#1the
designershould:
•D
etermine
site-specificlocations
where
physicalelem
entsshould
bereplaced
orim
proved.T
hedesigner
shouldfield
reviewthe
roadway
for;drivew
ayshidden
becauseof
roadway
geometry,
especiallyif
thedrivew
ayis
usedby
largetrucks
orfarm
machinery,
intersectionsw
ithlim
itedsight
distance,sharp
horizontalor
verticalcurves,
narrowbridge,
drainageareas
closeto
thepavem
ent,headw
alls,obstructions
within
theright-of-w
ay,etc.
•Include
low-cost
improvem
ents,like
replacingroadw
aysign
thatm
eetM
.L
1.T.C
.Dcurrent
requirements
ina
project.can
vastlyenhance
theappearance
ofa
projectas
well
aidthe
driver’sdecision
making.
Signsshould
comm
andrespect
of
theaction
beingadvised
tothe
user.
Poorlym
aintainedsign
doesnthelpthe
driversaw
arenessofcurve
ahead
FO
OT
PR
INT
DE
SIG
NM
AN
UA
LF
OR
LO
CA
LR
OA
DS
9
•G
oodtravelw
aycross-section.
Additional
safetybenefits
includea
pavedshoulder
(reducingpavem
entedge
drop)and
gentlesloping
frontslope(helps
theerrant
driverto
recoverback
tothe
traveiway).
1-lowever,
thevertical
headwall
cancause
seriousinjuries
when
struck.•
Determ
inesite-specific
locationsw
herecrash
dataindicates
theneed
foradditional
improvem
ents.T
hedesigner
shouldreview
crashdata
infonnationand
may
developcollision
diagrams.
•It
isim
portantto
knowthe
functionalclassification
of
theroadw
ay.Som
eadjacent
elements
alongthe
roadsidem
aynot
beappropriate
ifan
errantvehicle
leavesthe
traveiway
athigh
speeds.
10F
OO
TP
RIN
TD
ES
IGN
MA
NU
AL
FOR
LO
CA
LR
OA
DS
•N
arrowing
of
thetraveiw
aycreates
apotential
dangerfor
ahead-on
collision,especially
atnight.
Os
Iad
ay
dtF
Hig
hspeed
arte
rial
roadw
ay
FO
OT
PR
II’41D
ES
IGN
MA
NU
AL
FO
RL
OC
AL
RO
AD
S11
•Y
oum
ustknow
theproper
devicesto
useand
where
touse.
Will
am
otorcycle,bicyclist,
ora
pedestrianbe
ableto
negotiatea
locationlike
this?
Reco
mm
end
ation
3:D
etermin
eL
ane
and
Shou
lder
Wid
th
The
lollowing
minim
umvalues
shouldbe
considered:
US
Cu
stom
ary
Design
Speedh
<10%
Tru
cks!
>10
%T
ruck
s!Y
earA
Dr
Machineryc
Machineryc
(Mp
h)
Lan
eC
Sh
ould
erd
Lane
eS
hould
erd
Width
Width
Width
Wid
th
1—750
<45
9ft
2ft
lOft
2ft
751—
2000<
4510
ft2
ft10
ft2
ft
2000>
<45
11ft
3ft
12ft
3ft
aD
esignY
earA
DT
shouldbe
basedon
a10-year
projectionh
Speedshould
bebased
onaverage
speedC
Some
typesof
vehiclesm
ayrequire
additionalroadw
ayw
idths.R
oadways
havingcurbing
may
have1.5
ftw
idthof
shouldere
Incontext
sensitiveenvironm
ents,engineering
judgment
shouldconsidered
theexisting
lanew
idthsto
remain,
evaluatingsite-specific
crashdata
andthe
possibleuse
oftraffic
controldevices
asan
alternative.
12FO
OT
PRIN
TD
ESIG
NM
AN
UA
LFO
RL
OC
AL
RO
AD
S
Design
Year
Speed
b<
10%T
ruck
s!>
10%T
ruck
s!A
DT
aM
achin
eryC
Mach
inery
(Mp
h)
Lan
ee
Should
erL
ane
eS
hou
lder
Wid
thW
idth
Wid
thW
idth
1—750
>45
lOft
2ft
lOft
2ft
751—2000
>45
lOft
3ft
lift
3ft
20
00
>>
45lift
4ft
12ft
4ft
Design
Year
AD
Tshould
bebased
ona
10-yearprojection
bSpeed
shouldbe
basedon
averagespeed
CSom
etypes
ofvehicles
may
requireadditional
roadway
widths.
eIn
contextsensitive
environments,
engineeringjudgm
entshould
consideredthe
existinglane
widths
torem
ain,evaluating
site-specificcrash
dataand
thepossible
useof
trafficcontrol
devicesas
analternative.
Reco
mm
endatio
n4:
Determ
ine
Norm
alP
avem
ent
Cro
wn
The
designershould
developconsistent
proceduresfor
evaluatingthe
existingpavem
entcrow
n,w
iththe
following
objectives:
•T
hepavem
entoverlay
shouldm
atchnew
constructionnorm
alcrow
npolicies.
Typically
2-
2.5%
crossslope.
•T
heshoulder
crossslope
shouldallow
rainfallto
drainthe
roadway.
Typically
4-
6%
crossslope.
c
FO
OT
PR
INT
DE
SIG
NM
AN
UA
LF
OR
LO
CA
LR
OA
DS
13
•T
hecom
binationof
grassshoulders,
higherthan
thetraveiw
ay,directs
water
down
thetraveiw
ayto
aflat
cross-slopearea.
The
poorcondition
ofthe
pavement
(cracks)allow
thisaccum
ulatedw
aterto
percolateinto
thebase
ofthe
roadbedcausing
severedam
age,w
hichis
costlyto
repair.
Recom
mendation
5:D
etermine
Horizo
ntal
Curv
ature
and
Superelevation
The
designershould
revieweach
horizontalcurve
todeterm
inethe
appropriateaction
thatm
aybe
required.R
eferto
AA
SH
TO
,A
Policy
onG
eometric
Design
ofH
ighways
andS
treets,2004
(9)for
thesuitable
superelevation(M
ethod2)
thatshould
beconsidered.
Use
ofa
Ball-B
ankindicator
andits
proceduresis
anadditional
toolin
determining
thecom
fortlevel
ofthe
vehiclebased
ondifferent
speedsaround
thecurve.
There
arevarious
typesof
ball-bankindicators
available.W
henm
ountingthis
devicein
avehicle
itis
veryim
portantto
havethe
vehicleon
alevel
surface.
•T
hedesigner
shouldadjust
theexisting
crosssection
with
increasedsuperelevation
tom
atchthe
averagespeed
ofvehicles.
•S
implified
curveform
ula:R11
=
15(0.01
Cln
ax/ax
)
•It
isacceptab]e
forthe
designer,w
henevaluating
curvesw
ithlow
averagevehicle
speeds,<
45m
ph,to
resurfacew
ithoutchanging
theexisting
curvegeom
etryand
crosssection
ifthe
nominal
designspeed
ofthe
curveis
within
15m
phof
theaverage
vehiclespeeds,
andif
thereis
noclear
evidenceof
asite-specific
safetyproblem
associatedw
iththe
curve.N
ote:A
speedstudy
will
aidin
understandingthe
prevailingspeeds
andcom
mon
characteristicsof
theusers.
•T
hedesigner,
when
evaluatingcurves
with
highaverage
vehiclespeeds,
45m
phand
hig
her,
shouldconsider
reconstructionw
henthe
nominal
designspeed
ofthe
existingcurve
ism
orethan
15m
phbelow
theaverage
vehiclespeeds.
andthe
projectedtraffic
volume
isgreater
than1000
AD
T,
14F
OO
TP
RIN
TD
ESIG
NM
AN
UA
LFO
RL
OC
AL
RO
AD
S
orifthere
isa
site-specificsafety
problemassociated
with
thecurve.
•If
curvereconstruction
isnot
feasible,additional
measures
shouldbe
consideredto
aidthe
driver.T
oreduce
speed;supplem
entalsigning,
pavement
markings,
rumble
strips,or
othertraffic
controldevices
shouldbe
applied.T
oim
provethe
roadside:clearing
slopes,flattening
steepside-
slopes,or
removing,
relocating,or
shieldingobstacles,
shouldbe
evaluatedif
thereis
anappreciable
site-specificsafety
problem.
To
improve
theroadw
ay:w
ideninglane
width,
widening
shoulderw
idth,or
pavingshoulders
may
improve
thedriving
operation.
Pro
cedure
for
theuse
ofth
eB
all-Ban
kIn
dicato
rto
determ
ine
thesafe
speedof
acu
rve
The
ball-bankindicator
isused
tom
easurethe
overturningforce
(sidefriction),
measured
indegrees,
ona
vehiclenegotiating
ahorizontal
curve.T
heball-bank
canbe
easilym
ountedto
thedashboard
bym
eansof
rubbersuction
cupsor
otherstable
methods,
Itshould
bem
ountedin
sucha
positionas
toallow
theball
torest
freelyat
thezero
degreeposition
when
thevehicle
isstanding
level.T
hem
ovement
ofa
cararound
acurve
tothe
left,for
example,
causesthe
ballto
swing
tothe
rightof
thezero
degreeposition.
The
fasterthe
carm
ovesaround
thecurve,
orthe
sharperthe
curve,the
greaterdistance
theball
swings
away
fromthe
zerodegree
position.S
uperelevation,how
ever,tends
tobring
theball
backto
thezero
position.T
henet
resultis
theindicator
readingin
degreesof
deflection.
Beginning
well
inadvance
ofthe
curvebeing
checked,the
drivershould
enterthe
curveat
apredeterm
inedspeed,
drivethe
carparallel
with
thecenterline
ofthat
travellane,
andm
aintainthat
uniformspeed
throughoutthe
curve.T
hecurve
shouldbe
drivena
number
oftim
esuntil
atleast
two
identicalball-hank
readings(degrees)
foreach
directionof
travelare
obtained.E
achdirection
oftravel
shouldbe
consideredseparately.
The
maxim
umnegotiable
safespeed
forthe
curveis
thespeed
atw
hichthe
ball-bankindicator’s
readingis
10degrees
orless
for35
mph
orgreater.
The
llrsttrial
runis
made
ata
speedsom
ewhat
belowthe
anticipatedm
aximum
safespeed.
Subsequenttrial
runsare
conductedat
5m
phspeed
increments.
Readings
of14
degreesfor
speedsof
20m
phor
less,12
degreesfor
speedsof
25m
phthrough
30m
phand
10degrees
fOr
speedsof
35m
phthrough
50m
phare
theusually
acceptedlim
itsbeyond
which
ridingdiscom
fortw
illhe
excessiveand
lossof
vehiclecontrol
may
occur.
The
recomm
endedadvisory
speedshould
beto
thenearest
5m
phless
thanthe
maxim
umnegotiable
safespeed
determined
separatelyfor
eachdirection
oftravel.
Considerations
ofsign
distance,intersections,
crashrecords,
andother
conditionsm
ayresult
ina
recomm
endedspeed
lower
thanthat
derivedby
theball-bank
indicatorm
ethod.
FO
OT
PR
INT
DE
SIG
NM
AN
UA
LF
OR
LO
CA
LR
OA
DS
15
Advisory
speedplates
shouldbe
usedin
conjunctionw
ithcurve
andturn
signsw
henthe
safeoperating
speedis
belowthe
postedor
prevailingspeed
onthe
roadway.
When
platesare
usedw
ithcurve
andturn
signs,the
miles-per-hour
valueshow
non
eachplate
shouldbe
determined
bythe
useof
theball-bank
indicator.T
helow
estspeed
(tothe
nearest5
mph)
obtainedduring
trialruns
thatcreates
areading
of10
degreesor
more
onthe
ball-bankindicator
shallbe
used(degrees
andm
ph
arestated
above).E
achdirection
shouldbe
checkedindependently
andm
aybe
postedw
ithdifferent
speeds.
The
Manual
onU
niformT
rafficC
ontrolD
evices,M
UT
CD
,recom
mends
theuse
of’a
Turn
(WI-I)
signfor
alocation
where
testruns
at30
mph
orless
hasbeen
determined
forthe
curve.T
heuse
ofa
Curve
(Wl-2)
signis
recomm
endedfor
alocation
where
testruns
atspeeds
greaterthan
30m
phhas
beendeterm
inedfor
thecurve.
Reco
mm
end
ation
6:D
etermin
eV
erticalC
urv
ature
and
Sto
ppin
gS
ightD
istance
The
designershould
revieweach
verticalcurve
todeterm
inethe
appropriateaction
thatm
aybe
required.
•It
isacceptable
forthe
designer,w
henevaluating
curvesw
ithlow
averagevehicle
speeds,<
45m
ph,
toresurface
without
changingthe
exislingcurve
geometry
ifthe
nominal
designspeed
ofthe
curveis
within
20m
phof
theaverage
vehiclespeeds,
andif
thereis
noclear
evidenceof
asite-specific
safelyproblem
associatedw
iththe
curve.•
The
designer,w
henevaluating
curvesw
ithhigh
averagevehicle
speeds,45
mph
andhigher,
shouldconsider
reconstructionw
henthe
designspeed
ofthe
existingcurve
ism
orethan
20m
phbelow
theaverage
vehiclespeeds,
andthe
projectedtram
cvolum
eis
greaterthan
1000A
DT
,or
thereis
asite-specific
safetyproblem
associatedw
iththe
curve.•
Ifcurve
reconstructionis
notfeasible,
additionalm
easuresshould
beconsidered
toaid
thedriver.
To
reducespeed;
signingor
othertraffic
controldevices
shouldbe
applied.T
oim
provethe
roadside;rem
oving,relocating,
orshielding
locationof
driveways
orintersecting
roadsshould
beevaluated
ifthere
isan
appreciablesite-specific
safetyproblem
.T
oim
provethe
roadway:
lengtheningsharp
horizontalcurves,
widening
anarrow
bridge,or
improving
othergeom
etricfeatures
adjoiningthe
verticalcurve
proximity
may
improve
thedriving
operation.•
Sagvertical
curvestypically
donot
createsight
restrictionsand
donot
haveto
hereconstructed,
unlessthere
isa
site-specificsafety
problem.
16F
OO
TP
RIN
TD
ES
IGN
MA
NU
AL
FO
RL
OC
AL
RO
AD
S
Recom
mendatio
n7:
Dete
rmin
eB
ridge
Wid
th
The
designershould
evaluatebridge
replacement
orw
ideningif
thebridge
isless
than100
ft.long
andthe
usablew
idthof
thebridge
isless
than:
US
Cu
stom
ary
Design
Year
Speed
Usable
Bridge
AD
Ta
(Mph)
Width
b,c
,d
I-
1000A
llS
peedsW
idthof
app
roach
lanes
1001—
40004
5W
idthof
appro
achlanes
plus2
ft
1001-
4000>
45W
idthof
appro
achlanes
plus3
ft
4000>
45W
idthof
appro
achlanes
plus3
ft
4000>
>45
Width
ofap
pro
achlanes
plus4
ft
aDesign
Year
AD
Tshould
bebased
ona
10-yearprojection
Ifthe
roadway
width
(laneplus
shoulder)is
paved,the
bridgeshould
beequal
inw
idthC
Bridge
usageby
trucks,farm
machinery,
orrecreational
vehiclesshould
beconsidered
indeterm
iningthe
appropriatew
idth
Existing
bridgesm
ayrem
ainin
placew
ithoutw
ideningunless
thereis
evidenceof
asite-specific
safetyproblem
Iso
c12
sectionof
gu
ardrail
enough
tohelp
ina
crash?
How
abo
ut
the
end-treatm
ent?
FO
OT
PR
INT
DE
SIG
NM
AN
UA
LF
OR
LO
CA
LR
OA
DS
17
•If
bridgereplacem
entis
notfeasible,
thedesigner
shouldevaluate
theapproaches
tothe
bridgeand
toim
plement
additionalm
easuresthat
may
aidthe
driver.Installing
transitionguardrails,
advancew
arningsigns,
and/orother
trafficcontrol
devicesshould
beconsidered.
Reco
mm
end
ation
8:D
etermin
eS
ideS
lopesand
Clear
Zones
The
designershould
developconsistent
proceduresfor
evaluatingand
improving
roadsidefeatures
with
thefollow
ingobjectives:
•A
clearzone
of
anyw
idthshould
providesom
econtribution
tosafety.
Thus,
where
clearzones
canbe
providedat
littleor
noadditional
cost,their
incorporationin
designshould
beconsidered.
A2
-3
ft.shoulder
isrecom
mended
forspeeds
<45,
and2
—4
ftfor
speedsgreater
than45.
•R
etaincurrent
slopes(w
ithoutincreasing
frontslopes)
when
widening
laneand
shoulders,unless
warranted
byspecial
circumstances.
•Flatten
sideslopes
steeperthan
3:1at
site-specificlocations
where
thereis
evidenceof
acrash
oravailable
crashdata.
•R
emove,
relocate,or
shieldisolated
roadsideobstacles.
•C
rossdrainpipes
andculverts
shouldonly
beextended
asrequired
toprovide
thew
idthfor
thepavem
ent,shoulder,
andconform
tothe
existingside-slope
where
possible.1-leadw
allsm
aybe
retainedon
existingcrossdrain
structuresw
herethere
areno
adjustments
requiredfor
thepavem
entand
shoulderw
idths.S
ite-specificcrash
locationsshould
beevaluated.
•S
idedrainpipe
shouldbe
relocatedas
requiredto
obtainthe
width
forthe
pavement,
shoulder,and
tom
atchexisting
side-slopesalong
theroadw
ayas
possible.S
lope-pavedheadw
allsof
othersloped-end
treatments
shouldbe
provided.1-leadw
allsm
aynot
bereplaced
onexisting
sidedrainpipe
thatw
illrem
ainin
placeif
noadjustm
entsare
requiredfor
thepavem
entor
shoulderw
idths.C
onsiderationshould
begiven
toreplacing
largevertical
headwalls
thatare
closeto
thepavem
entand
area
potentialhazard.
Site-specific
crashlocal ions
shouldbe
evaluated.•
When
itis
notfeasible
tom
akeim
provements
tothe
clearzone,
becauseof:
terrain,right-of-w
ay,potential
social/
environmental
impacts
and/orcost,
theprovision
fora
clearrecovery
aream
aybe
impractical
toachieve.
Clear
recoveryareas
ofa
width
thatis
lessthan
desiredm
aybe
used.E
ngineeringjudgm
entshould
beused
toim
plement
theuse
oftraffic
controldevices,
ifw
arranted,to
assistand
warn
thedriver
where
therem
aybe
anappreciable
site-specificsafety
problem.
18F
OO
TP
RIN
TD
ESIG
NM
AN
UA
LF
OR
LO
CA
LR
OA
DS
•D
othe
headwalls
needto
bethis
tall?If
so,should
areflector
ofsom
etype
beinstalled
toindicate
itspresence?
Shouldthe
pipeunder
thedrivew
aybe
thissize?
Adrainage
studym
aydeterm
inea
smaller
diameter.
•D
oesthe
driverhave
anyidea
thata
major
highway
isat
thetop
of’the
incline?Just
howdifficult
would
itbe
atnight?
Alocal
driverm
ayknow
this,but
afirst
time
user?
Fla
tter
slope
and
veg
eta
tion
rem
ov
al
needed
FO
OT
PR
iNT
DE
SIG
NM
AN
UA
LF
OR
LO
CA
LR
OA
DS
19
Recom
mendation
9:G
uard
railN
eedfor
Em
ban
km
ents
andC
ulverts
The
designershould
developconsistent
proceduresfor
evaluatingthe
needfor
guardrail,w
iththe
following
considerations:•
Exam
iningthe
shoulderslopes
andculvert
sizes.•
Identifvingsite-specific
safetylocations.
•C
learzone
encroachments
The
following
chartsare
guidelinesfrom
Transportation
Research
Record
1599,“G
uardrailN
eed:E
nibankmenis
and
Culverts”,
Transportation
Research
Board,
Washington,
DC
,1997
(6)and
isintended
tobe
usedas
toolsto
aidthe
designerin
thedecision
making
process.T
hesecurves
areintended
toelim
inatethe
needfor
conductingbenefit-cost
analysis.T
hesecharts
may
beused
ifthe
slopeor
culvertis
within
theclear
zone,or
ifthere
isa
site-specificsafety
problem.
-F
se=
Diam
eterof
Culvert
40an
=D
istance
measu
redp
arallel
E35
toth
etrav
elway
2R
T=
Eig
eofT
ravelw
ay
303
0.
C-)
.25
25
.
0
202
0.
151
5.
0
1010
.C
00
0
Traffic
Volum
e,A
DT
(vehicles’day)
Wam
Gu
ardrail
Need
forC
ulv
ertsu
rte
:G
uardrailN
eed,
nbankrn
entsa
nd
Culv
ertT
anorta
tbn
Farch
cord
1599,1997
The
previouschart
illustratesthe
lateraloffset
fromthe
travelway
tothe
faceof
theculvert.
Itshow
sthe
correlationbetw
eenvarious
AD
T(vehicles
perday)
volumes
andthe
variousculvert
sizes,depth
(rise)of
theculvert
andits
minim
umlength
(span)along
thetravelw
ay.If
theculvert
beingevaluated
fallsbelow
thevarious
curvedlines
shown
inthe
chart,a
guardrailshould
beconsidered
tobe
installed.
10002000
30004000
50006000
70008000
900010000
I’t)
0EL
0-
00
10002000
30004000
50006000
70008000
900010000
Traffic
‘4um
e,
AD
T(vehicleslday)
Warn
Gu
ardia
iiN
eedfor
Grib
ankm
ents
urc
e:
Guardrai’
Need
,E
rnb
ank
rnen
tsan
dC
uIv
ertT
ransportatlDn
Research
Record
1599,1997
This
chartillustrates
theem
bankment
depthfrom
theouter
edgeof
theroadw
ayshoulder
(elevation),dow
nvarious
sloperates
(frontslope),to
thelow
erelevation
ofthe
adjacentterrain.
Itshow
sthe
correlationbetw
eenvarious
AD
T(vehicles
perday)
volumes
andthe
variousdepths
basedon
thefrontslope
rates.if
thedepth
beingevaluated
fallsabove
thevarious
curvedlines
shown
inthe
chart,a
guardrailshould
beconsidered
tobe
installed.
Reco
mm
end
ation
10:P
avem
ent
Edge
Drop
and
Sh
ould
erT
ype
The
designershould
developconsistent
proceduresfor
evaluatingpavem
entedge
dropconditions
andthe
typeof
shoulderconstruction,
with
thefollow
ingobjective:
•A
llshoulders
shouldbe
re-establishedand
gradedto
aconsistent
slope.•
Edge
ofpavem
entdrops
shouldbe
repairedand
shouldm
atchthe
shoulderslope.
•S
electivelypave
shouldersat
pointsw
herethere
areSite-specific
safetyproblem
s(outside
orinside
ofhorizontal
curves,across
fromintersecting
roads,etc.).
20F
OO
TP
RIN
TD
ESIG
NM
AN
UA
LFO
RL
OC
AL
RO
AD
S
14121086.
4.
histaHW
-am
Gu
aira
ll
ope=
2.5:1
So
pe=
2.0:1
14.
12-
10-
864-
2.
2.
Sope
1.5.1
FO
OT
PR
INT
DE
SIG
NM
AN
UA
LFO
RL
OC
AL
RO
AD
S21
Reco
mm
endatio
n11:
Intersectio
nIm
pro
vem
ents
The
designershould
developconsistent
proceduresfor
evaluatingintersection
improvem
ents,w
iththe
following:
•C
ollisiondiagram
sshow
ingvehicle
paths,tim
eof
occurrence,and
weather
conditions.•
Condition
diagrams
showing
important
physicalfeatures
thataffect
trafficm
ovements.
•F
ieldreview
ofthe
intersectionto
detecthazards
notapparent
fromcollision
andcondition
diagrams.
•D
esignershould
considerintersection
improvem
entsto
site-specificsafety
problemareas.
•Im
provements
may
beorganized
onthree
primary
designobjectives:
reductionof
potentialconflicts
(trafficsignals,
turnlanes,
etc.),im
provesdriver
decision-m
aking(longer
linesof
sight,lane
markings,
etc.),and
improves
thebraking
capabilityof
thevehicle
(warning
signs,increased
pavement
skidresistance.
etc.).
Reco
mm
end
ation
12:D
ocu
men
tthe
Design
Pro
cess
Before
developingconstruction
plansand
specifications,designers
shouldprepare
asafety
anddesign
reportbased
theabove
11recom
mendations.
Additional
information
regardingspecific
elements,
notm
entionedabove,
may
beincluded
inthis
report.
For
some
RR
Rprojects,
itm
aybe
necessaryto
havethis
document
submitted
toan
appropriateagency
thatis
responsiblefor
theproject
areafor
reviewand
approval.T
heform
atof
theproject
filew
illbe
establishedby
thesam
eagency.
Any
waivers
ofthe
designcriteria
shallbe
submitted
toand
approvedby
thesam
eagency
ortheir
governingauthority
havingproject
approval.It
isunderstood
thatdesign
waivers
may
notbe
neededfor
RR
Rprojects
ifthe
projectis
internalto
thesam
eagency
fundingthe
project.H
owever,
fullydocum
entedproject
information
shouldbe
compiled
andfiled.
References
1.T
ransportationR
esearchB
oard,“S
pecial Report
214“,
1987.2.
AA
ST-ITO,
Am
ericanA
ssociationof
StateH
ighway
andT
ransportationO
fficials,“G
uidelinesfb
rG
eometric
Design
ofJ7en
.;L
ow-V
olume
Local
Roads
(AD
T40O
,J”,2001.
3.A
ASI-IT
O,
Association
ofState
Highw
ayand
Transportation
Officials
“Geom
etricD
esignfb
iR
esiujbcing,R
estoration,and
Rehabilitation
(RR
R)
ofS
treets“,
1977.4.
AA
SFITO
,A
ssociationof
StateH
ighway
andT
ransportationO
fficials,“R
oadsideD
esignG
uid
e”,2002.
5.N
ationalC
ooperativeH
ighway
Research
Program
,“R
eport350,
Recom
mended
Procedures
for
theS
afrtyP
eifbrmance
Evaluation
ofH
ighway
Features”,
1993.6.
Wolford,
D.,
andD
.L.
Sicking,“G
uardrailN
eed.E
mbankm
entsand
Culverts,”
InT
ransportationR
esearchR
ecord1599,
Transportation
Research
Board,
National
Research
Council,
Washington
D.C
.,D
ecember,
1997.F
igure6,
p.54
andFigure
8,p.
55.R
eproducedw
ithperm
issionof
TR
B.
7.A
AS
HT
O,
Association
ofState
Highw
ayand
Transportation
Officials
“AG
uidefor
Achieving
Flexibility
inH
ighway
Design
“,
2004.8.
AA
SH
TO
,A
ssociationof
StateH
ighway
andT
ransportationO
fficials“R
oadsideD
esignG
uide“,
2006.9.
AA
SH
TO
,A
merican
Association
ofState
Highw
ayand
Transportation
Officials,
AP
olicyon
Geom
etricD
esigno
fHighw
aysand
Streets,
2004.
22
