Road Safety Guidelines Part-I...PIARC World Road Association RSA Road Safety Audit 7 ADB Project...

TA-8990PAK:EnablingEconomicCorridorsthroughSustainableTransportSector

Development–002RoadSafetyFirm(49063-001)

RoadSafetyEngineeringGuidelines

-PartI–

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InceptionReport

Aprojectimplementedby

MINISTRYOFCOMMUNICATIONS.

supportedbyNTUthroughADBandDFID

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ADBProjectTA-8990PAK:EnablingEconomicCorridorsthroughSustainableTransportSectorDevelopment-002RoadSafetyFirm(49063-001)

RoadSafetyEngineeringGuidelines|PartI

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DISCLAIMER

TheworkexplainedhereinfallsundertheCapacityDevelopmentTechnicalAssistance(CDTA)TA8990-PAK:EnablingEconomicCorridorsthroughSustainableTransportSectorDevelopmentfinancedby theUKDepartment for InternationalDevelopment (DfID), andadministeredbyADB(AsianDevelopmentBank).TheCDTAaimstodevelopacoordinated,efficient,safe,andsustainabletransportsysteminPakistaninsupportofrealizingPakistan’sVision2025.The views expressed in this document are those of the Consultants and do not necessarilyreflecttheviewsandpoliciesoftheAsianDevelopmentBankoritsBoardofGovernorsorthegovernments they represent. By making any designation of or reference to a particularterritoryorgeographicarea,orbyusingtheterm ‘country’ in thisdocument,ADBdoesnotintendtomakeanyjudgmentsastothelegalorotherstatusofanyterritoryorarea.

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INFORMATIONABOUTTHEPROJECT

ProjectContractName:

TA-8990 PAK: Enabling Economic Corridors through SustainableTransportSectorDevelopment–002RoadSafetyFirm(49063-001)

Contractnumber: 125179-S52864

Country: Pakistan

Contractor: NTUInternationalA/S

Address: VestreHavnepromenade5.4.Floor

DK-9000Aalborg

Denmark

Telephone:

Fax:

+4599300000

+4599300001

ContactPersons:

E-mail:

NikolayChavov

[email protected]

DateofReport:

Fax:

17May2018

+4599300001Authorsofreport: EdoardoMazzia,InternationalRoadSafetyEngineeringSpecialist

ManagementTeam

TeamLeader RosemaryRouse [email protected]

DeputyTL KhushalKhan [email protected]

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DOCUMENTCONTROL

ProjectContractName

TA-8990 PAK: Enabling Economic Corridors through SustainableTransport Sector Development – 002 Road Safety Firm (49063-001)

Country Pakistan

Date 17May2018

Version 01

VersionN° Date Preparedby

01 17May2018 EdoardoMazzia

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TABLEOFCONTENTS

Preamble................................................................................................................................................................................8 Introduction.......................................................................................................................................................................10

1 Referenceroadsafetyframework................................................................................................................11 1.1 Pakistaniroadnetwork............................................................................................................................11

1.2 Thecurrentroadsafetysituation........................................................................................................11 2 Reviewofexistingstandardsandguidelines..........................................................................................18

2.1 Roaddesignstandardscurrentlyused.............................................................................................18

2.2 Newgeometricdesignstandards........................................................................................................18 2.3 AsianHighwaydesignstandards........................................................................................................19

2.4 CARECRoadSafetyEngineeringManuals.......................................................................................20

2.5 NHARoadSafetyAuditguidelines......................................................................................................21 3 Sustainablesafetyprinciplesforroaddesign.........................................................................................22

3.1 SafeSystemprinciples..............................................................................................................................22 3.2 SustainableSafetyprinciples................................................................................................................23

3.3 Categorizationofroadsandnetworkdesign.................................................................................34

3.4 Speedmanagement....................................................................................................................................40 4 Roadinfrastructuresafetymanagement...................................................................................................50

4.1 Roadsafetystrategies...............................................................................................................................51

4.2 Roadsafetyimpactassessment............................................................................................................52 4.3 Roadsafetyaudits.......................................................................................................................................55

4.4 Roadsafetyinspections...........................................................................................................................58 4.5 Treatmentofcrashlocations.................................................................................................................62

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LISTOFABBREVIATIONSANDACRONYMS

AASHTO AmericanAssociationofStateHighwayandTransportationOfficials

AADT AverageAnnualDailyTraffic

ADB AsianDevelopmentBank

AfDB AfricanDevelopmentBank

AJK AzadJammuandKashmir

CAREC CentralAsiaRegionalEconomicCooperation

CDA CapitalDevelopmentAuthority

CMF CrashModificationFactor

EC EuropeanCommission

ECSP EngineeringConsultancyServicesPunjab

EN EuropeanNorm

EU EuropeanUnion

ESCAP EconomicandSocialCommissionforAsiaandthePacific

FYRR FirstYearRateofReturn

GB Gilgit-Baltistan

GDP GrossDomesticProduct

GoP GovernmentofPakistan

GPS GlobalPositioningSystem

iRAP InternationalRoadAssessmentProgramme

ITP IslamabadTrafficPolice

KP KhyberPakhtunkhwa

MASH ManualforAssessingSafetyHardware

MoC MinistryofCommunications

NHA NationalHighwayAuthority

NH&MP NationalHighwayandMotorwayPolice

NPV NetPresentValue

NTRC NationalTransportResearchCentre

NUST NationalUniversityofSciencesandTechnology

OECD OrganisationforEconomicCo-operationandDevelopment

PAK Pakistan

PKHA PakhtunkhwaHighwaysAuthority

PIARC WorldRoadAssociation

RSA RoadSafetyAudit

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RSI RoadSafetyInspection

RSIA RoadSafetyImpactAssessment

TA TechnicalAssistance

UN UnitedNations

US UnitedStates

WHO WorldHealthOrganisation

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Preamble

TheobjectiveoftheTA-8990PAK:EnablingEconomicCorridorsthroughSustainableTransportSector - Road Safety Component is to assist the Government of Pakistan (GoP) to establishsustainable national road safety institutions and to build the structures, processes andcapacityrequiredatalllevelstoachievelongtermreductionsinroadtrafficdeaths.

TheprojectstructureisalignedwiththeUNRoadSafetyPillarsandunderpinnedbytheSafeSystem Approach. Globally, Pillar 2 ‘Safe Roads’ is a key focus area. Currently road safety,particularly the safety of vulnerable road users, such as motorcycle riders, pedestrians,bicyclists and occupants of 3-wheeled vehicles is not sufficiently prioritised in roaddesign,construction,improvementandmaintenance.These Road Safety Engineering Guidelines aim to provide a suitable document forpractitionersbothbeingengineersinagencieswitharesponsibilityforroadconstructionandnetwork management and private consultants. The objective is therefore to provide apractical tool that will be used by managers and engineers responsible for designing,improving,andmaintainingallclassesofroadatallgovernmentlevelsinPakistan.ThedevelopmentofGuidelinescontentandformatisbeingcoordinatedwithtwoconcurrentNHA projects: development of Pakistan Road Design Guidelines and the introduction ofPakistan International Road Assessment Program to ensure that the three initiatives areintegrated.TheoverallobjectiveistosupportFederal,ProvincialandTerritoryroadagenciestodeliversaferroadsthroughoutPakistan.

TheGuidelinesconsistoftwomainpartsasfollows:

PartI- Generalrecommendationsforsaferroads

Methodological document inwhich, after a brief overview of themain road safetyissuesaffectingPakistan,asystemicroute isdefinedforsolvingproblems inacost-effectiveperspective.Referenceismadetointernationalbestpracticessuchas,forexample,theEuropeanDirective2008/96/EC,orroadsafetyengineeringmanualspublishedinthecountrieshistoricallymost reputable in the field of road safety (e.g. UK, Netherland, Ireland,Australia,etc.).

PartII-Catalogueofcountermeasuresfortypicalroadsafetyissues

Practical design guide consisting of a sample of forms describing typical cases ofinfrastructuraldeficienciesandpossiblecountermeasures.The catalogue gives brief information, including pictorial representations, of well-knowndesignerrorsinareadilyunderstoodway,willsuggestarangeofmethodstoovercometheseandwillgiveanindicationofthecountermeasurecostsandbenefitstofacilitateprioritisationofthework.

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Thecataloguecanbeusedbothasaproactivesafetytooltoensurethedesignfaultsdo not arise in the first place, or a reactive safety tool to assist in designing cost-effectivecountermeasureswhereproblemsalreadyexistontheroadnetwork.

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Introduction

InPakistan,WHOstatistics(WHO,2015)indicatethatmorethan25,000peoplewerekilledinroadcollisionsin20141.Accordingtotheinternationalstatistics2,wecanestimatethatthedeathofaboutonethirdofthemis–atleastpartially–relatedtotheroadenvironment.Infact,althoughreliablecrashdataarestillnotavailableinPakistan,thereisinformationaboutmanycollisionswheretheroadalignment,equipmentortrafficmanagementwereoneofthemainfactorsConsequently,itisproventhatagoodand‘safety-oriented’designmayreducetheprobabilityand severity of crashes, and measurable safety gains have been achieved in all countrieswherethisapproachhasbeenimplemented.On theotherhand, if thisnewapproach todesign isnotpartof amanagementsystem thatallows the entire cycle from planning to the construction and maintenance of theinfrastructuretobeeffectivelycontrolled,thereisariskofprovidingasteriletoolthatisnotsupportedbytheinstitutionalandprogrammingframework.

Currently,Pakistandoesnothavea shared system formanaging road infrastructure safety.Eachactivityrelatedtoroadinfrastructuresecurityismainlyduetooccasionalinitiativesofafew individual organisations (e.g. NHA, Punjab Road Safety Authority, etc.), without thembeing part of a broader national design. This is also in addition to a situation where thelimitedadherencetoaspecificsetofroaddesignguidelinesisstillanissue.This document, underpinned by the principles of the Safe System approach, is intended torespond to these needs. After a general description of the problem, it describes some keyprocesses,alreadywidelytestedinothercountries,which,ifimplemented,canconstitutethearchitectureonwhichtoimplantanew(safety-oriented)approachtodesign.

ThePartIoftheGuidelinesconsistsoffourmainsections:

1. Referenceroadsafetyframework2. Reviewofexistingstandardsandguidelines3. Sustainablesafetyprinciplesforroaddesign4. Roadinfrastructuresafetymanagement

1Tomakeacomparison,in2015,Pakistanlost3,682preciouslivesinterrorismandinsurgencyincidences(source:SouthAsiaTerrorismPortal),eventsthatalwaysevokeadramaticsocietalresponse;unfortunately,thesameresponsewasnottherefortheroadcarnage.2Cf.Treatetal.(1979)-Tri-levelstudyofthecausesoftrafficaccidents:Finalreport.USDoTNHTSAReportDOTHS-805-099,orAASHTO(2010)-HighwaySafetyManual.1stEdn.Washington,DC.

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1 Referenceroadsafetyframework1.1 PakistaniroadnetworkThePakistaninationalroadnetworkamountstomorethan263,000km.The lengthof the networkunder the administrationof theNHA is 12,131 km (4.6%of thetotal).Thisroadnetworkcomprises39nationalhighways,expresswaysandstrategicroads,andcarriesabout80%ofthecommercialtraffic.The restof the road network contains provincial highways and the roads under respectivelocal administration e.g. Cantonment Boards, Municipal Corporations, Local DevelopmentAuthorities,etc.

TotallengthoftheroadsmaybeseenfromtheTablebelow.Table1–EstimatedlengthofroadsinProvinces(km;2016)

Category Punjab Sindh KP Balochistan GB&AJK Total

Lowtype 30,901 23,415 12,320 8,460 453 75,549

Hightype 76,817 58,209 30,625 21,030 1,126 187,807

Total 107,718 81,624 42,945 29,490 1,579 263,356

(source:NTRC)

1.2 ThecurrentroadsafetysituationIn the followingparagraphs themain roadsafety issuesobservedacross thePakistani roadnetworkare summarized.Thisassessmentdoesnot intend tobeexhaustivebut is ratherabriefoverviewofthemostemblematictopicsofarathercriticalsituation.

1.2.1 HighwayhierarchyWith the exception of few cases (e.g. Islamabadurban area), the road categories are not easilyrecognizable. It results in a situationwhere roadusershardlyunderstandwhich typeofbehaviourisexpectedinaspecificroadsection,thusleadingtospeedingorotherdangerouspractices.Inaddition,ifthefunctionofaroadlinkisnotwelldefined or understood, a very dangerous mix oftraffic categories can be observed. The lesshomogeneous traffic is, the more dangerousconflictsare likely:differences inspeedandmassbetween road users using the same link orjunctionat the same timeshouldbe reduced toa

Figure1-Karachicitycentre:disorganizedmixoftrafficfunctions

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minimum.Onthecontrary,inPakistan,especiallyoninterurbanhighwaysormainurbanarterials,oftenwecanobserveverydifferentvehiclesusingthesamelinkatthesametime:heavytrucksandbusestogetherwithmotorcyclesandrickshaws,fastcarswithdonkeycartsorpedestrians.

1.2.2 RoadalignmentThe road alignment of the main road network,usuallydesignedaccordingtoAASHTOstandards,isgenerally satisfactory although there is a tendencytoutiliselongstraightsinterspersedwithfairlytightradii. This is now known to generate anunacceptablyhighnumberof crashes.Amixtureoflarge andmedium radii to give amore curvilinearalignmenthasbeenshowntoreducethecrashrate.Unfortunately,we cannot say the same formostofthe local roads, i.e. secondary, tertiary and accessroads,thatingeneralseemtobe justlaidfollowingthe terrain, without significant earthworks. Thisobviously leads to very dangerous alignments,especially in rolling environments. It is not rare toobserveverysharpbends,steepgradientsandsharpcrestverticalcurves,thusleadingtoverypoorsightdistances.

Poorharmonisationofthegeometricelementscanbealsoobserved.Thealignmentofsomerural provincial roads is composed of long straights, sections of very large radii and, verysudden,verytightbends(withoutpropersignagetoalertdrivers).

As regards the motorways and other trunk roads, somemajor departures from standardshavebeenobserved,i.e.sharpbendswithoutsuper-elevation,steepgradientsandsharpcrestverticalcurves.Thesedepartures,whicharejustifiedbecauseoftheincreaseofconstructioncosts inrollingormountainousenvironments, leadtounexpectedanddangeroussituations

suchas:-Poorsightdistances;

- Lack of proper transition or termination of theverticalalignment;

- Sudden bends, poorly signed, requiring suddendrasticreductioninspeed;-Presenceofheavytruckstravellingatavery lowspeed (less than 30 km/h), that on downhillsections,becauseoftheirpoorlymaintainedbrakesand state of overloading, contribute to manyseriouscrashesasaresultoflossofcontrol.

Figure2-PooralignmentoftheroadtoMargallaHills,Islamabad

Figure3-PooralignmentontheM2motorway(KallarKaharsection):sharpbendsandsteep

gradients

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1.2.3 JunctionsThe vast majority of non-signalised junctionsidentified both in urban and rural locationsthroughout Pakistan have no clearly statedpriorityandaredevoidofbothroadmarkingsandsigningwhichcouldhavebeenusedtoconveyanyinstructions or advice to drivers. The practice oftrafficmanagementatintersectionsdoesnotseemto be practised to any great extent and traffic isinvariably left to drivers to sort out how tonegotiate the intersecting lines of travel withoutactuallyhittinganyothervehicles.

Even large complex intersections in large urbanareasarewithoutanyformoftrafficmanagementor control and drivers are left to find their wayacrossmany conflicting lines of traffic as best they can. As a result, even during relativelyquiet off-peak periods there aremassive queues atmajor junctions because of the need toproceedcautiouslyanduncertaintyshownbymanydrivers.

Roundabouts in Pakistan are not very common. Some examples have been observed inschemesrecentlyimplementedinurbanorsub-urbanareas.Unfortunately, in many cases, the junction layout contains very poor geometry, i.e. smallcentral islands, wide circulating roadway and, above all, minimal or no deflection oftrajectories. It can result in poor capacity (and therefore long queues), dangerous conflictsandinsufficientspeedreduction.Asregardsmotorwayinterchanges,ithasbeenobservedthatmostofthemarenotprovidedwiththe fullyrequiredlengthofaccelerationanddecelerationlanesandtapers. Inaddition,thesedonot includeaweavingsectionwheretheenteringvehiclescanattaintheoperatingspeedofthemotorwaylaneandmergeintotheflowinsafety.Incaseofheavytrafficvolume,itcouldbedifficulttocarryoutthismanoeuvreinsafety.

1.2.4 U-turnsThe need to provide a safe and efficient facility to accommodate U-turn movements isessentialformanydividedhighwaysinPakistan.Insomecases,especiallyinurbanareas,theyarealsousedtoavoidright-turnmovementsatjunctions3.

Unfortunately, in many cases the median width neither allows the complete manoeuvrewithin themedian (vehiclesare forced to cross theopposite carriagewayandmerge in thetrafficstreaminthetravellane)nortohostsafedecelerationandaccelerationlanes.Insomecases, in order to provide enough room to U-turning long trucks, the cross-section isnarrowed, and one or more lanes are devoted to this manoeuvre. It is clear that such

3 This is typified by one of the preferred solutions adopted by the Islamabad Traffic Police of closing theproblematicjunctionandtheprovisionofU-turnseitherside

Figure4-UrbanjunctioninIslamabadwithnomarkingsorsigns

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narrowing produces a dangerous bottleneck andprovidesfurtherpotentialforcrashestooccur.

Thesenarrowingsofcarriagewaywidthareusuallynot signed in advance so that vehiclemanoeuvresareinvariablyundertakenatthelastmoment.

1.2.5 Cross-sectionTheroadcross-sectionwillinevitablyhavequiteabearing on the relative safety of road usersinasmuchthatthecarriagewaytypeandwidth,thepresence or not of a hard shoulder and whethervehicle restraints are provided are factors whichwillpermitorregulateappropriatevehiclespeed.Generally,throughoutPakistanthemorestrategicroadsarewellequippedwith2-or3-lanecarriageways ineachdirection, separatedbyamedianandwithahard shoulder.However,even these strategic roadshavedeficient safetyaspects, themain concernbeing the lackofmediancrashbarriertopreventtheoccurrenceofcross-overcollisionsandthelackofcrashbarriertopreventerrantvehiclesfromleavingthecarriagewayandproceedingout-of-controldown an embankment or into a structure with obvious results of increased severity ofcasualties.

The provision not justof crash barrier but the correct installation of themost appropriatetype of barrier is equally important. Incorrectinstallationwillnegateany effect that the crash isintendedtohavewithregardtorestrainingerrantvehicles.Wheninstalled,thecrashbarriermustbethecorrectworkingdistanceawayfromtheobjectit is intended to protect from impact or from thepoint at which a vehicle would proceed down anembankment,i.e.thebackofverge.Again, the type of crash barrier is important.Different types of barriers have different restraintcapacity. Accordingly, for each type of road andtrafficmixaspecifictypeofbarriershouldbeused.Atthemoment,onthecontrary,wecansaythatthesametypeofbarrierisusedeverywhere.

1.2.6 TrafficsignsTrafficsigndesignisaveryextensivesubjectintermsofthelegibility,conspicuity,frequencyof use, siting and location. Irrespective of the standards currently in use for signing, thegeneralcommentwithregardtotrafficsigninginPakistaninbothruralandurbansituationsisthatitisconsiderablylackinginallthesecriteria.

Figure5–U-turnsalongN5highwaywithnodeceleration/accelerationlanes

Figure6-Unsafevehiclerestraintsystem

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Traffic signs are not noticeable as a means ofcommunication and are often mostly poorlydesigned, poorly fabricated and erected, badlylocated and mostly quite inappropriate for thepurposeforwhichtheyareintended.Secondonlytoroadmarkings, trafficsignsarethenext most effective method of guiding, warning,informing and directing traffic. However, they areonlyeffectiveifbasicguidelinesarefollowed.

The same criteria should apply to warning andregulatorysigns,buttheyareoftennotaccordingtoanyimposedstandard.

An additional feature that is seriously lacking from the current provision of signing inPakistan is compliance with the material specification. In many cases signs are made uplocally to no set standards. It results in a lack of retroreflectivity – so that signs cannot bediscernedduringnight-time–anduseof inappropriatesubstratesand/orsupports thatcanbehazardousincaseofcollisions.

1.2.7 RoadmarkingsWith the exception of the motorway network,pavement markings are often worn, notretroreflectiveorevenabsent.Intheseconditionsit is very difficult to have a precise spatialcognition of the roadsides and a vision at adistance of the road alignment, especially underpoor visibility conditions such as might beencounteredinnight,rainorfog.Evenincentralurbanareaswhereahighdegreeoftrafficmanagement is required to copewithhightraffic flow levels and at quite complex junctions,there is a conspicuous lack of information andguidance employed on the road surface. Globallytheuseoflanemarkingsanddirectionsisusedtoguidetrafficintothemostappropriatelanewhenapproachingmajorjunctions.Thispracticeisalmostnon-existentinPakistan.

1.2.8 TrafficsignalsTraffic signals, if they do not already suffer from a of lack of maintenance, are ofteninconspicuous incorrectly located, are insufficient for the number of lanes and volumes oftraffic, do not appear to have sufficiently illuminated aspects and are often precariouslymountedand installed.Particularlyon thearterialurban roads,where3ormore lanesarepresent,thesmallsizeandthelocationofthetrafficlightsareinadequateandasaresulttheyarenotvisibleatgreatdistance,especiallyinheavytraffic,whenvehiclesaheadmayobstructtheview.Theresultisthatdriversmaybeleadtoignorethesignsortobrakesuddenly.

Figure7-InconsistentsignsinKarachi

Figure8-Roadwithoutcentre,laneoredgelines

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The authorities in Pakistan do not appear to befollowing any standards or guidelines related tothe design or layout of signals with regard to i)locationoftrafficpoles,ii)mountingrequirements,iii)sizeofsignalheads,iv)sequenceofphasingandv) pavement marking required on the signalizedintersections.

Moreover, signal timing is also based uponanecdotal experience rather than any specificstudyormeasurementofactualtrafficdemand.

1.2.9 TemporarytrafficmanagementTrafficmanagementforroadworksisinvariablyverypoor,borderingonthenon-existent,inPakistan.Thework site ishardlyever signedorprotected (it isoften thatsiteswhereroadconstruction is taking place to find that traffic is permitted to travel into the constructionarea), advance warning is usually absent and the transition to the diversion is often verysharp.Ingeneral,standarddiversionroutesarenotadoptedandtrafficislefttofinditsownwayaroundtheconstructionsite.

Inaddition,roadworksandtemporarydiversionsarenotlitandcannotbeseenatnight-time,signing is not retro-reflective and cannot bediscerned in poor light and there is usuallyconfusion with respect to what constitutes therecommended carriageway and what constitutesthe work area. In every major project, a TrafficManagementPlanissupposedtobedevelopedandsubmitted to the client by the design consultant.However, during the implementation stage theapprovedTrafficManagementPlan,ifoneexists,isinvariablyignored.

Asa result,works sitesareverydangerousplacesfor both the traffic and those who have to workwithinthem.

1.2.10 Vulnerableroadusers

Pedestrians have a hard time in Pakistan in both urban and rural settingswith very littleattentiongiventotheprovisionofgoodfacilitiesforwalking.Itisalmostasifitistakenforgrantedthatpedestrianswillfindawaytotheirdestinationandthereforenospecialfacilitiesneedtobeprovided.Worsestilltheyareexpectedtofindawayacrosslanesoftrafficwhere,insomeplaces,thiscanbequiteaconsiderablehazard.

Figure9-DamagedtrafficsignalsinKarachi

Figure10–Roadworkspoorlysignalised

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Even in recently built towns, e.g. Islamabad, thepedestrians – and other VRUs – are not properlyconsidered in road planning and design, i.e.pedestrianpathsareinterrupted,noteffective(andtherefore not used), not contiuous or even notpresent.

1.2.11 Trafficcalming

TrafficcalmingtechniquescanbeobservedrarelyinPakistan.

The most common features are speed humps thatareoftenusedinaconfusedmanner,i.e.alongtrunkroads or as isolated measures, without any clearplanningorappliedstrategy.In addition, existing speed humps are often notsignalisedbymarkingsand/orwarning signs, thusbeingnotvisible,particularlyatnight.

Theirprofile isusuallycircular.Flat-toppedhumpsare also frequent, whereas very few sinusoidalprofiles have been observed. Again, there is nouniform standard on their application or to covertheirdesign.

Figure11-Noseparationbetweenroadvehiclesandpedestrians

Figure12-TypicalspeedhumpinPakistan

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2 Reviewofexistingstandardsandguidelines2.1 RoaddesignstandardscurrentlyusedInPakistan,thereisnotalegislationobligatingroaddesignerstoapplyspecificstandards.Currently themost designers use US standards (AASHTO, ‘A Policy on Geometric Design ofHighwaysandStreets’,6thEdition,2011,commonlyreferredtoasthe‘GreenBook’).Almostthetotalityofroadsrecentlybuiltfollowsthesestandards,evenatprovinciallevel.Moreover,itisobservedthatalsotherehabilitationofoldroads-builtintheperiodbetween60sand80s-iscarriedoutfollowingAASHTOstandards.RecentlyithasalsobeenobservedanincreaseintheuseofChinesestandards,especiallyforroad projects funded by the Chinese government (e.g. Pakistan Economic Corridor, mainarterialhighwayconnectingChinabordertoGwadarPort).However,thesestandardsderivemainlyfromAASHTOstandards.

ThereviewofToRsforthedesignofnewroadsorrehabilitationofexistingroadalignmentsconfirmstheuseofAASHTOstandards.Itisworthnoting,however,thataquickanalysisofasampleofdocumentsshowsthatsomeparametersareoftenmisinterpreted(ordeliberatelyaltered?)withrespecttotheAASHTOguidance.Theactualimplementationofthesestandardsisthereforeinsomecasesstillfarfromanacceptablelevel.

It has also to be underlined that AASHTO standards are complex and are developed for acompletelydifferentroadenvironment.TheirimplementationinPakistanisthereforeprettydifficultinmanycases.

2.2 NewgeometricdesignstandardsIn order to tackle the critical issues that have risen up in the use of AASHTO standards inPakistan, the NHA is developing an important project for the drafting of new ‘GeometricDesign Standards & Parameters for National Highway System of Pakistan’. A publictenderwaslaunchedattheendof2016andthenewguidelinesareexpectedtobereadybytheendof2018.Thepurposeoftheservicesis ‘toformulatecountry-specificGeometricDesignStandardsinpursuitofharmonizingtheroadnetworkinPakistanforalllocalandinternationalneeds’.Thenewstandards‘shouldaddressaspectrumofroadtypes,varyingfrommulti-lanemotorways...tosinglecarriagewayroads’.

Thescopeofwork iswelldetailed.Anewfunctionalclassificationofroads isexpectedand,besidesthemainGeometricDesignStandards, it isexpectedthat the followingmanualsarealsoproduced:

• Manualforroadsurvey• Manualforroadwaysignage• Manualforpavementmarking• Trainingmanuals

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ThisdocumentwillthereforebethemainreferenceforroaddesignersinPakistan,whowillfinallybeabletorelyonasetofstandardstailoredtothelocalsituation.

2.3 AsianHighwaydesignstandardsInorder toaddress the road safetyproblemalong theAsianHighwayNetwork4 theESCAPsecretariat,conductedastudyduring2015-2017onthedevelopmentoftechnicalstandardsonroadinfrastructuresafetyfacilities.Amongothers, theobjectivewastodevelopdetaileddesignguidelines for theselectedroadinfrastructure safety facilities for the Asian Highway Network. The outcome was acomprehensive document that addresses these facilities from both the road planning anddesignperspective.Thedesignstandardinvolvesbothactiveprovisionofroadinfrastructurefacilitiesandavoidanceofundesirablepracticesordesign.The design standard, as developed in the abovementioned study, consists of twocomponents5:

1. DesignStandards,containingmandatoryrequirements6;2. Detail Design Manual, consisting of recommendations pertaining to the design

standards.The approach followed in drafting the standards is really innovative and addresses roadsafety from a holistic perspective incorporating modern concepts such as ‘self-explainingroads’7and‘forgivingdesign’8.The purpose of the standards is basically to propose a series of road infrastructure safetyfacilities that, if implemented,wouldallowtherisktobereducedandthestarrating9 tobeincreasedcomparedtothebaselinescenario10.

Theguidelinesareorganisedinsevenpartsasfollows:1. Roadinfrastructure

4TheAsianHighwayNetworkconsistsofeightcoreroutesthatsubstantiallycrossmorethanonesub-regionandanumberofotherrouteswithinsub-regionsorESCAPmembercountries.ThenetworkwasformalizedthroughanIntergovernmentalAgreementthatenteredintoforceinJuly2005(UNESCAP,2004).5Adraftversionofbothdocumentsisavailablehere:http://www.unescap.org/events/expert-group-meeting-road-infrastructure-safety-facilities-asian-highway6InthestudyitisproposedthatthesewouldformAnnexIVoftheInternationalAgreementontheAsianHighwayNetwork7Theconceptofself-explainingroadsencouragesroaddesignsthatpromoteroad-userstoadoptappropriatespeedsandbehaviour.Thissubjecttouchesonconsistencyofalignmentdesignandawell-definedroadhierarchy,andshouldbeintroducedintothedesignstandardwhereverapplicable.8Forgivingdesignsaimatgivingroad-usersadequateroomsforerrorsandlimitingtheseverityofinjuriesincaseofacrash.9StarratingsaretheindexesusedbyiRAPtoassessthesafetyofroadusers.Theyarebasedonroadinspectiondataandprovideasimpleandobjectivemeasureofthelevelofsafetythatis‘built-in’totheroadforvehicleoccupants,motorcyclists,bicyclistsandpedestrians.10The‘baseline’scenarioistheonebasedontheexistingAsianHighwayStandardsasstipulatedintheAnnexIItotheIntergovernmentalAgreement(i.e.AsianHighwayclassificationanddesignstandards).Accordingtothestudy‘baseline’scenariosareinthehighrisk1-and2-starranges(inascale1to5).

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2. Intersections3. Roadsideareas4. Pedestrians,slowvehiclesandtrafficcalming5. Delineation,pavementmarkingsandlighting6. Roadsignage7. Tunnels

Thedocumentisthereforeanimportantsupplement(andsourceofvaluableinformation)tothedraftingPakistanigeometricdesignstandards.

2.4 CARECRoadSafetyEngineeringManualsThe Asian Development Bank (ADB) has recently financed a technical assistance forenhancing road safety for CAREC countries11. In the frame of this project three road safetyengineeringmanualshavebeenproduced:

1. RoadSafetyAudit(March2018)2. SaferRoadWorks(March2018)3. RoadsideHazardManagement(April2018)

These reports cover three key topics in the field of road safety and are therefore practicalpointsofreferenceforallpractitionersintheregion.

ThemanualsaremainlyaddressedtoCARECroadprojects12,butthisdoesnotmeanthattheirusecaneasilybeextendedtotheentireroadnetwork.

11TheCentralAsiaRegionalEconomicCooperation(CAREC)Programisapartnershipof11countriesanddevelopmentpartnersworkingtogethertopromotedevelopmentthroughcooperation,leadingtoaccelerateeconomicgrowthandpovertyreduction.MembercountriesofCARECare:Afghanistan,Azerbaijan,China,Georgia,Kazakhstan,KyrgyzRepublic,Mongolia,Pakistan,Tajikistan,TurkmenistanandUzbekistan.12CARECfocusesinvestmentandotheractivitiesonthedevelopmentofsixcompetitivetransportcorridorsthatlinknorth,south,east,andwestthroughthepivotofCentralAsia.Thecorridorsreflecttradeflowpatternsandwillspeedthemovementofpeopleandgoodsacrosstheregion.Critically,theyalsoconnectthemainlylandlockedCARECcountriestowiderregionalandglobalnetworks.PakistaniscrossedbyCorridors5a,band6c,bothofwhichfollowthePeshawar–Islamabad–Lahore-Karachiroute.

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Figure13–CARECRoadSafetyEngineeringManuals

2.5 NHARoadSafetyAuditguidelinesAtthedateofthisreport,NHAisfinalizingguidelinesforRoadSafetyAudits(RSA).TheNHAisinfactpromotingRSAatleastformainroadschemesanditisthereforetimetohaveclearandsharedprocedures.

These guidelines will therefore be the reference document for carrying out RSA on thePakistaninationalroadnetwork.Itisdesirable,however,thatthisgoodpracticeisextendedtothenetworksofProvincesandTerritories.

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3 Sustainablesafetyprinciplesforroaddesign3.1 SafeSystemprinciplesSafe System principles underpin these Guidelines and the road infrastructure safetymanagementstrategy.

The identificationand removalor treatmentof roadelements thatmaycontribute to crashoccurrenceorcrashseverityisakeycomponentoftheSafeSystemapproachtoroadsafety.Adopting a Safe System approach to road safety recognises that humans, as roadusers arefallible and will continue to make mistakes, and that the community should not penalisepeoplewithdeathorseriousinjurywhentheydomakemistakes.InaSafeSystem,therefore,roads(andvehicles)shouldbedesignedtoreducetheincidenceandseverityofcrasheswhentheyinevitablyoccur.TheSafeSystemapproachrequires,inpart13:

• Designing,constructingandmaintainingaroadsystem(roads,vehiclesandoperatingrequirements) so that forceson the humanbody generated in crashes are generallylessthanthoseresultinginfatalordebilitatinginjury.

• Improving roads and roadsides to reduce the risk of crashes and minimise harm:measures for higher speed roads including dividing traffic, designing ‘forgiving'roadsides, and providing clear driver guidance. In areas with large numbers ofvulnerable roadusersor substantial collisionrisk, speedmanagement supplementedbyroadandroadsidetreatmentsisakeystrategyforlimitingcrashes.

• Managingspeeds,takingintoaccounttherisksondifferentpartsoftheroadsystem.

Roadsafetyengineeringisthereforeacornerstoneofthisstrategy.Infrastructuretreatments,in fact, can primarily reduce the probability of a crash occurring and secondly to reduce acrash’sseverity should itoccur.Toa lesserextent road safetyengineering canevenensurethat rescue services can reach a crash site promptly (e.g. providing the motorways withemergencymedianopeningsandshoulders).

13Cf.AustralianTransportCouncil(2006)–NationalRoadSafetyActionPlan2007and2008

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Figure14–SafeSystemapproach(source:SaferRoads,SaferQueensland;2015)

3.2 SustainableSafetyprinciples‘In a sustainably safe road traffic system, infrastructure design inherently and drasticallyreduces crash risk. Should a crash occur, the process that determines crash severity isconditionedinsuchawaythatsevereinjuryisalmostexcluded.’

From:Naareenduurzaamveiligwegverkeer[Towardssustainablysaferoadtraffic],Koornstraetal.,1992.

TheconceptofSustainableSafetywaslaunchedintheearly1990sintheNetherlandswiththeambitionstatedabove. In2006thisconceptwasadoptedandrelaunchedbySWOV,aDutchInstitute forRoadSafetyResearch, inordertoadapt it,wherenecessary, tonewknowledgeanddevelopments(Wegman&Aarts,2006).

TheSustainableSafetyvision,whichisoneofthepillarsonwhichtheSafeSystemapproachisbuilt,aimstopreventcrashesand,ifthisisnotpossible,toreducecrashseverityinsuchawaythat (severe) injury risk is almost excluded. These objectives are aimed for bymeans of aproactiveapproachinformedbypriorstudyofthetrafficsituationsinwhichserious,injury-producing crashes canoccur.Thenextstage involves twooptions: either the circumstancesarechangedinsuchawaythatthecrashriskisalmosttotallyremoved,or,ifthisisinevitable,seriouscrashinjuryriskiseliminated.In the analysis of and approach to preventing crashes or reducing the severity ofconsequences of dangerous situations, human capacities and limitations are the guiding

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factors. The central issue is that people, even if they are highlymotivated to behave safelywhileusing the road,makeerrors thatmay result in crashes. Inaddition,man isphysicallyvulnerableandthishasconsequencesforinjuryseveritywhenacrashoccurs.Taking intoaccountthesehumancharacteristicsas thestartingpoint,sustainablysaferoadtrafficcanbeattainedbyan integralapproachtothecomponents ‘man’, ‘vehicle’and ‘road’.Focusingontheroadinfrastructure,thismeansthattheroadhastobedesignedsuchthatitmeetshumancapacitiesandlimitations.

Giventhefactthatpeoplemakeerrors,donotalwayscomplywithrulesand,moreover,thattheyarevulnerable, it isessential that ‘gaps’ in thetrafficsystemareprevented inordertoavoidabreedingground for crashes.According totheSustainableSafetyvision, inorder toprevent serious unintentional errors, the environment and the task demands that thisenvironmententailshave tobeadapted toa level that themajorityof roadusers can copewith. This produces, as it were, desirable behaviour almost automatically: the road userknowswhattoexpect(i.e. ‘self-explainingroad’),andpossibleerrorscanbeabsorbedbyaforgiving environment (i.e. ‘forgiving roads’). This also makes the breeding ground forintentionalorunintentionalviolations less fertile (e.g. speedingwouldbe less likely, as theroadenvironmentitselfsuggeststhemostappropriatespeed).

The vulnerable human has to be protected in traffic by the environment by means ofstructuresthatabsorbthekineticenergyreleasedinacrash.Tothisend,themassofvehiclessharingthesamespaceneedstobecompatible.Ifthisisnotpossible,thenspeedsneedtobelowered.Thissystemisembedded ina trafficplanningtaxonomyof fasttraffic flowsontheonehandandaccesstoresidencesontheother.Betweenthesetwoextremes,traffichastobeguided ingood, sustainably safeways.With this slightlyadaptedvisionon sustainably saferoadtraffic,SWOVfinallyarrivesatthefivecentralprinciples:

• Functionality• Homogeneity• Predictability• Forgivingness• Stateawareness

AshortdescriptionoftheseprinciplesisgivenintheTablebelow.

Thefirstfourprincipleshavestrictconnectionwithroadinfrastructureandroaddesignandaredetailedinthefollowingparagraphs.

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Table2–TheSustainableSafetyprinciples

SustainableSafetyprinciples Description

Functionalityofroads Monofunctionalityofroadsaseitherthroughroads,distributorroads,oraccessroads,inahierarchicallystructuredroadnetwork

Homogeneityofmassand/orspeedanddirection

Equalityinspeed,direction,andmassatmediumandhighspeeds

Predictabilityofroadcourseandroaduserbehaviourbyarecognizableroaddesign

Roadenvironmentandroaduserbehaviourthatsupportroaduserexpectationsthroughconsistencyandcontinuityinroaddesign

Forgivingnessoftheenvironmentandofroadusers

Injurylimitationthroughaforgivingroadenvironmentandanticipationofroaduserbehaviour

Stateawarenessbytheroaduser Abilitytoassessone’staskcapabilitytohandlethedrivingtask

(source:Wegman&Aarts,2006)

3.2.1 FunctionalityThe first approach to the functional categorization of roads dates back to 1963 when thereport Traffic in Towns was published (Buchanan, 1963). This report contained acomprehensive vision for the design of towns and villages in a highlymotorized society. Adistinctionwaspresentedbetweenroadshavingatrafficflowfunction(‘distributordesignedfor movement’), and roads that give access to destinations (‘access roads to serve thebuildings’).Elaborationoftheseideasresultedinaproposalforaroutehierarchy,builtupfromprimary,district and local distributors and access roads to destinations (Figure 15). All roads aregroupedintooneoftheseclasses,dependingonthecharacterofthetraffic(i.e. localorlongdistance)andthedegreeoflandaccessthattheyallow.

Typically,roadusersuseacombinationofarterial,collector,andlocalroadsfortheirtrips.Eachtypeofroadhasaspecificpurposeorfunction:someprovidelandaccesstoserveeachend of the trip; others provide travelmobility at varying levels, which is needed en route(Figure16).

Thereisabasicrelationshipbetweenfunctionallyclassifiedhighwaysystemsinservingtrafficmobility and land access. Arterials provide ahigh level ofmobility and agreater degree ofaccesscontrol,whilelocalfacilitiesprovideahighlevelofaccesstoadjacentpropertiesbutalowlevelofmobility.Collectorroadsprovideabalancebetweenmobilityandlandaccess.

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Figure15-Functionalcategorizationofroads

(Buchanan,1963)

Figure16-Relationshipoffunctionallyclassifiedroadsystems

inservingtrafficmobilityandlandaccess(adaptedfromAASHTO,2011)

TheSustainableSafetyvisionbuildsuponthehierarchyofroadsasdescribedabove.Basedonthefunctionalusage,roadshavetobeunequivocallydistinguishableinthefunctionthattheyperform(‘monofunctionality’).

Motorizedtrafficshouldbedirectedtoarterialroads(flowfunction),causingroadswithanaccess function to be burdenedminimallywithmotorized traffic. Roadswith a distributionfunction (collectors) should direct motorized traffic coming from roads with an accessfunctionasquicklyaspossibletoroadswithaflowfunctionandviceversa.Thisprincipleismeant to prevent unintended use of the infrastructure thus minimizing the number ofpotential conflicts with severe consequences. On the contrary mixing functions leads toconflicting road design requirements and, hence, to unclear road design for road users,resulting in higher risks. A road network functions properly if function, design and usage(behaviour)arewelltuned.

Thereisnoreasontodiscardthisprincipleofsustainablysaferoadtraffic:afunctionalroadnetworkcategorization isonewhereeach roadorstreet fulfilsonlyone function–eitheraflowfunction,oradistributionfunction,oranaccessfunction(e.g.theidealarterialroadisamotorway,whereasanidealaccessroadisa30km/hstreet).

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Figure17–ChaoticandunsafemixoffunctionalongN5highway

Figure18–TheflowfunctionoftheM2motorwayisclearandmakestrafficsafer

Thisframeworkis,generally,acceptedinmostofthecountriesandformspartofroaddesignhandbooksandcategorizationplans.In Pakistan, too, this is a well-known concept, but unfortunately it is not always put intopractice.However,examplesofgoodpracticearealsopresenthere.

At urban level, the road network of Islamabad is a typical example of hierarchic network,wherethethreefunctionsareprettywellrespected(seeFigure19).TheCapital'smasterplanis in facta forward-lookingand innovativeurbanexperimentdevelopedat thebeginningofthe1960s,wheretheroadnetworkalsobenefitsfromtheregularandwell-definedstructureofthecity.Bycontrast,inmanyareasofthecountry,theseprinciplesarenotobservedthusresultingindangerous function mix. Typical examples are housing schemes that are increasinglydeveloping along the main arterial roads. These areas, which can accommodate up tothousandsofpeople,oftenhavedirectaccesstothemainroad,thusmixingdifferentfunctionsandcreatingdangerouspointsofconflict(seeFigure20).

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Figure19–AerialviewoftheregularIslamabadroadnetwork

Figure20-AccesstoabighousingschemealongN5highway

3.2.2 HomogeneityThehomogeneoususageoftheroadaimstoavoidlargedifferencesinspeeds,directionsandmassesatmoderateandhighspeeds, thusreducingcrashseveritywhencrashescannotbeprevented.

Thecorrespondingideaisthatitisbeneficialfor road safetywhen there is little variationin the speeds of close-moving vehiclestravellinginthesamedirection.

Worldwide the safest roads are themotorways, based on the number ofcasualtiesperkilometredrivenas the safetyindicator. Although driving speeds are thehighest they are relatively uniform and islittle variation in direction (e.g. no crossingtraffic) and vehicle mass (no pedestrians,cyclists, mopeds or slow-moving vehicles).The30km/hzonesandresidentialareasarealso relatively safe despite considerablevariation in thedirectionandmassof traffic

Figure21–AnimaldrawnvehicleinatrunkroadinPakistan:differencesinspeedandmassposeseriousroadsafety

problems

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participants. In these cases, the increased safety is attributable to low driving speeds andsmallspeedvariationsbetweendifferentroadusers.

The principle of homogeneous use leads, for example, to operational requirements fordirectional separation on arterial and collector roads. For intersections, operationalrequirementsarederivedfromthestartingprinciple toeliminatecollisionswithhighspeedandmassdifferences.Pedestrians,cyclesandmopedsshouldnotbepresentatthepointsofaccessofarterialroads.Speeddifferencesshouldbereducedtoacceptablelevelsatcollectorroadswheremassdifferencesareallowedfunctionally.InthisframeSWOVsuggestsasystemof ‘safespeeds’(seeTable3)takingintoaccountthatspeedlimitsandtravelspeedsshouldnotbehigherthansafecrashspeedsandthatisusefultodistinguishbetweenurbanandruralareas(althoughthedifferenceisnotalwaysclearforroadusers).Table3–Safe-speedsystem

Location Safetravelspeed(km/h)

Ruralroadsections

Arterialroad 120

Collectorroad

withphysicalseparationofdrivingdirections 80

withoutphysicalseparationofdrivingdirections 70

Localroad 40/60

Ruralintersections

Collectorroadandlocalroad

withoutvulnerableroadusers 50

withvulnerableroadusers 30

Urbanroadsections

Arterialroad 70

Collectorroad 50

Localroad 30

Urbanintersections

Collectorroad 50

Localroad 30(source:adaptedfromWegman&Aarts,2006)

Speedisthereforeaveryimportantfactortobetakenintoaccount.

Atlowerspeedsadriverwillhavegreateropportunitytoreactandavoidacrash.Speedalsoaffects the severity of crashes. Higher speed crashes involve more kinetic energy (kinetic

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energyisproportionaltothespeedsquared)andthemoreenergythatisdispersedinacrash,themoresevereittendstobe.

TheFigure22showstheexpectedconsequencesforthreeofthemaincrashtypesatdifferentspeed.Asspeedincreases,thefatalityriskincreasesverysharplyforeachofthecrashtypes.Thisleadstoseveralguidingprinciplesforsurvivability:

• Whereconflictsbetweenpedestriansandcarsarepossible, the speedatwhichmostwillsurviveis30km/h(redline)

• Wheresideimpactsarepossibleatintersections(e.g.crossroadsandT-intersections),thespeedatwhichmostwillsurviveis50km/h(greenline)

• Where head-on crashes are possible (e.g.where there is nomedian separation), thespeedatwhichmostwillsurviveis70km/h(blueline)

Thepreviousonesarethereforethealreadymentionedsafecrashspeeds.On this basis potential frontal impacts with crash speeds exceeding 70 km/h have to beexcluded.Thismeansthatthedirectionoftravelonroadswithspeedsof80km/horhigherwillneedtobeseparatedinsuchawaythatvehiclescannothiteachotherheadon.

Figure22-Crashtypesandindicativefatalityriskatspeeds(source:Wramborg,ascitedbyAfDB,2014)

3.2.3 PredictabilityThepredictableusageisaimedatpreventinghumanerrorbyofferingaroadenvironmenttothe road user that is recognizable and predictable (i.e. ‘self-explaining’). This indicatespermissible road user behaviour and makes the behaviour of other road users morepredictable. Accordingly, within a given road category, the road and traffic characteristicshave to be as uniform as possible and designed homogeneously because, from a road userperspective,aconsiderableamountofuniformityisdesirable.

Thisprincipleaimsinpracticetoensurethattheroadusercanrecognizetheroadtypebyitsroad characteristics (recognisability), which makes the road course and the behaviour of

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otherroadusersmorepredictable(predictability).Unexpectedtrafficsituationsinfactsimplycostmoretimeforroadusers todetect, toperceive, to interpret, toassess,andtoelicit thecorrect behaviour or response. This alsomeans that transitions fromone road category toanotherrequirethenecessaryprecisionandtimefromroaduserstoadapttheirbehaviour.

Inshort,wecanstatethatfortherecognisabilityofroadsitisimportantthatthey:

• aredistinguishable,and• evokeandsupportcorrectexpectations.

According to some research (Van Schagen et al., 1999), only a limited number ofcharacteristicscanbeusedfordistinguishingroadcategories.Thesecharacteristicsmustbe:

i. continuouslyperceivableii. practicaliii. notdisadvantageousforroadsafety

Inpractice, to facilitaterecognisability, thenumberofroadclassesshouldberestrictedandtheirdesignandlayoutasuniformaspossiblewithineachcategory.Roaduserswillthenhavea better idea of what sort of driving behaviour is expected of them and be better able toanticipatethedrivingbehaviourofotherroadusers.With‘self-explaining’roads,roaduserswill know atwhich speed to drive,whether to expect traffic from side roads, andwhethervulnerableusersarelikelytobeontheroad.Inpracticetheaimof‘self-explaining’roadsistolower theworkload (ormental load) of drivers. Thiswill have a positive influence on theperformanceofthedrivingtask.Therequirementsforrecognitionandpredictabilityare:

• avoidunpredictablebehaviourbycleardesigning,markingandsigning• makeroadcategoriesrecognizable• limitthenumberofdesignelementseachcategoryandmakethemuniform

ForSustainableSafety, the limitationof thenumberofroadcategoriesproducesthe largestcontributiontotherecognition.Thisassumesthatthedifferencesbetweenthecategoriesarelarge,andwithineachcategoryaresmall.

A small set of the operational requirements should ensure the predictability of the trafficsituations:

• speedlimits• longitudinallane/directionroadmarkings• separationofdirections• pavement,irregularityofthesurface• presenceofhardshouldersandobstacle-freezones(emergencylaneonmotorways)• typesofintersections/accessesallowed• expectedroadusertypes

Theabovesetofitemsmustbeclearforeachroadcategory.

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Figure23–PrivateaccessesalongamotorwayinAlbania:

manoeuvresassociatedwiththeirpresencearenot‘predictable’forusers

Figure24–Howtomakearoad‘self-explaining’usingmarkingandsigning(source:IRF)

3.2.4 ForgivingnessThe starting principle is that road usersmake errors and that the environment should besufficientlyforgivingforroaduserstoavoidthesevereconsequencesoftheseerrors.

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Thefirststeptowardsmakingtheroaduserenvironmentforgivingistomakeroadshoulderssustainablysafe.Thisactivitymainlytakesplaceonruralroads(arterialandcollector)wherethespeedissupposedtobehigher.Aforgivingroadhasacrosssectionthatissufficientlywide,hassufficientbearingcapacityandobstacle-freeshoulders,andisadaptedtoacceptablerisks14tothirdpartiesorriskstocaroccupants.Ifthisisnotfeasibleandifthedangerzonecannotberemovedinanotherway,itisrecommendedtheuseofaprotectivefeature(i.e.vehiclerestraintsystems).

Itisimportanttounderlinethattheuseofrestraintsystemsisjustthelastsolutiontoprotectroadusersfromroadsidehazards.Designersshouldthereforepreliminarilycheckalternativesolutions,namely:

• removethehazards;• make the hazard safe (e.g. by changing the design of themedian and verges of the

road);• replacethehazardswithapassivesafestructure(e.g.postsandcolumns).

Vehiclerestraintsystemsrepresentinfactahazardinthemselvesandshouldthereforeonlybeinstalledifitismoredangeroustodriveofftheroadthantodriveintothevehiclerestraintsystems.Restraintsystemsshallbethereforeinstalledwherethereareoneormorehazardswithinthe‘safetyzone’(or‘clearzone’).

A‘safetyzone’isanobstacle-freeareawithflatandgentlygradedground,thusprovidingroaduserswith sufficient space and the right conditions to regain controlover their vehicles incaseofarun-off15.

Figure25–Safety(clear)zonedefinition

14Asregardswhatconstitutesacceptablerisk,generallyitistranslatedforshouldersonthebasisthatifavehicleleavestheroaditshouldnothitanyobstaclescausingsevereinjury.15Furtherdetailsonthe‘clearzone’conceptand,moreingeneral,ontheroadsidehazardmanagement,areavailableintheCARECRoadSafetyEngineeringManual3(CAREC,2018c)

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Figure26–Exampleofa‘safetyzone’

According to these principles fixed roadsideobjectsshouldbedesignedsuchthatcrashesat high speeds cannot result in severeinjuries. Here, international criteria forvehicle restraint systems (‘performanceclasses’) have been established (e.g.European Standards EN 1317-1 to 7, USMASH,etc.).Thefactthattherearestillmanyroad crash victims following impact withprotective devices, raises questions as towhether the currently used criteria requirerevision, or in turn, the decision toimplement a protective device in certaincircumstances.

Safe shoulders along collector roads arehowever a difficult subject. Often, the freespace is not sufficiently wide, nor has itsufficientbearingcapacity,norisitobstacle-freeforprotectivedevicestoworkinasafeway.Inaddition,itisnotyetgeneralpracticeinPakistan-likeinmanyothercountries-toprotectroadsideobstaclesonruralcollectorroads.

3.3 CategorizationofroadsandnetworkdesignCategorizingroadsisacoreactivityforsustainablysafeinfrastructure.

Theinitialthreecategories(seesection3.2.1)aregenerallydetailedinmoreclassesinorderto take into account local circumstances (e.g. distinction can be made between inside andoutsideurbanareas).As stated in the section 3.2.3, the influence of the design and the environment on driveranticipationiscrucial.Forthisreason,accordingtothefunction,toeachcategoryofroadmust

Figure27–Crashagainstapoorlyinstalledbarrier(N5highway,Taxila,15/11/2017-2fatalities)

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be associated, not only a typical cross-section and a design speed, but also a mode ofoperation,definingthe‘rules’tousethespecificinfrastructure.

The layout of a road should therefore be appropriate to its function and ‘automatically’enforcethedesiredspeed.InPakistanthisispresentlyexplicitlythecaseformotorways,butnotforallotherroadcategories.TheTablesbelowsummarizestheessentialcharacteristicsofthemainroadcategories,bothinruralandurbanareas.

Table4–Characteristicsofmainroadcategoriesinruralenvironment

Roadcategory Characteristics Example

ArterialroadMotorway

- speedlimit120km/h- grade-separatedinterchanges- U-turnsnotallowed- physicalseparation- atleast2x2lanes- emergencylane- lightingonlyatinterchangesand

otherpeculiarpoints

ArterialroadTrunkroad

- speedlimit90/100km/h- grade-separatedinterchanges- U-turnsnotallowed- physicalseparation- 2x2lanes- emergencybaysand/orsemihard

shoulder- lightingonlyatinterchangesand

otherpeculiarpoints

CollectorroadDualcarriageway

- speedlimit80km/h- physicalcarriagewayseparation- priorityroad,2x2lanes- closedto(light-)mopedsand

bicycles- junctionsdesignedasroundabouts

orprioritycrossroadwithtrafficlights

- limitednumberofU-turns- limitednumberofconnectionsto

accessroads- emergencybaysorsemi-surfaced

shoulder

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CollectorroadSinglecarriageway

- speedlimit70km/h- non-physicaldrivingdirection

separation- priorityroad,1x2lanes- closedto(light-)mopedsand

bicycles- junctionsequippedwithspeed

reducingprovisionsordesignedasroundabout

- limitednumberofconnectionstolocalroads

- emergencybaysandsemi-surfacedshoulder

Localroad - speedlimit40/60km/h- non-physicaldrivingdirection

separation- 1x2lanes- atgradeintersectionsintheformof

aroundaboutorathreeorfour-armcrossroads

- presenceofprivateaccesses

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Table5–Characteristicsofmainroadcategoriesinurbanareas


ArterialroadUrbanMotorway

- speedlimit90/100km/h- grade-separatedinterchanges- U-turnsnotallowed- physicalseparation- atleast2x2lanes- emergencylane- serviceroads(optional)- lighting

ArterialroadTransitcorridor

- speedlimit70km/h- junctionsdesignedasroundabouts


- U-turnsnotallowed- physicalseparation- atleast2x2lanes- serviceroads(optional)- lighting

CollectorstreetDualcarriageway

- speedlimit50km/h- physicalcarriagewayseparation- priorityroad,2x2lanes- junctionsdesignedasroundabouts


- limitednumberofU-turns- limitednumberofconnectionsto

accessstreets- presenceofparkingareas,preferably

outsidethecarriageway- presenceoffootpaths- lighting

CollectorstreetSinglecarriageway

- speedlimit50km/h- non-physicaldrivingdirection

separation- 1x2lanes- junctionsdesignedaspriority

crossroadwithorwithouttrafficlights

- presenceofparkingareas,preferablyoutsidethecarriageway

- presenceoffootpaths- lighting

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Localstreet - speedlimit30/40km/h- non-physicaldrivingdirection

separation- 1x2lanes- atgradeintersectionsintheformof

athreeorfour-armcrossroads- presenceofprivateaccesses- presenceofparkingslots- presenceoftrafficcalmingmeasures- presenceoffootpaths(butincaseof

30km/hareas,thespacecanbesharedbypedestriansandmotorists)

- lighting

Oncethecharacteristicsofeachroadcategoryhavebeendefined,itisparticularlyimportantto define the principles for designing the network and, in particular, the interconnectionnodes.

Thematrixbelowdistinguishesbetweenhomogeneousnodes connecting roadsof the sametype and non-homogeneous nodes connecting roads of different types. While in the first(‘homogeneous’nodes)connectionsarealwaysallowedthattransferflowsfromoneroadtoanother,inthesecond(‘non-homogeneous’),forsafetyandfunctionalreasons,therealizationoftrafficflowconnectionmaynotalwaysbeallowed.Therefore,somenodes,wherethereisalargedifferencebetweenthehierarchicallevelsoftheconfluentroads,shouldbeconsideredineligible.Table6–Matrixofpossibleintersectionnodes

Homogeneousnodes

Permittednodes

Notpermittednodes

Type1:Systeminterchange(e.g.cloverleaf)

Type2:Serviceinterchange(e.g.halfcloverleaf)

Type3:At-gradeintersection

Arterial Collector Local

Arterial

1 2 -

Collector

2 3 3

Local

- 3 3

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Whereconnectionisallowed,itispossibletodistinguishdifferenttypesofnodeaccordingtowhetherornot intersection conflictpointsmayoccurat thenode. In the caseof a junctionwhere the roads are all with separate carriageways, intersection conflict points are notallowedandtheconnectionwillbesolvedwithaninterchange(type1junction).Whereoneofthe roads converging on the node has a single carriageway, at-grade manoeuvres may bepermittedonthatroad,whilethecrossingofthemaincurrentsmustbesolvedbyseparatingthe levels (type2node).Where the two roads considered tobelong to types forwhich theintendedcross-sectionisasinglecarriageway,theintersectionmaybesolvedat-grade(type3node).

Theconceptsillustratedaregenerallypresentinthemostwidelyusedroaddesignstandards.InTable4,asanexample,issummarizedthemodeofoperationofthehighwaysaccordingtotheAsianHighwayDesignStandards.

As regards Pakistan, the classification currently in use divides roads into very specificcategories,eventhoughthemodesofoperationarenotwelldefinedand,aboveall,notalwayseasilydistinguishableontheroadsinoperation16.Table7-ModeofoperationforeachAsianHighwayclass17

Class Primary ClassI ClassII ClassIII

Description Access-controlledhighways

4ormorelanes 2lanes 2lanes

Modeofoperation

Controlled-access Full No18 No18 No

At-gradeintersections Notpermitted Yes18 Yes18 Yes

Overtakingonopposinglane Notpermitted Notpermitted Yes Yes

Pedestrians Notpermitted Yes18 Yes18 Yes

Slowvehicles19 Notpermitted Yes18 Yes18 Yes(source:adaptedfromUNESCAP,2004)

16NHAclassifiestheroadsinfourmaincategories:

1. Motorways andExpressways are fouror six lanedividedhighways.Theaccessof theMotorways isfullycontrolled,whiletheaccessofExpresswaysispartiallycontrolled.

2. PrimaryRoadsarebasicallytheNationalHighwaysandProvincialRoadsontheprimaryroutes.Theyarefurthersplitintothreecategories:• PrimaryI(P-I),• PrimaryII(P-II),and• PrimaryIII(P-III),

dependingonthenumberoflanesandpavementofshoulders.3. SecondaryRoads(S-I)areProvincialRoadsthatserveasfeederroadsfortheprimaryroutes.4. TertiaryRoads(T-I)arebasicallythecollectorroadsforthesecondarynetwork.

17AsianHighwayDesignStandardsdonotapplytobuilt-upareas18Unlessspeciallydesignedforcontrolled-accessoperation19Bicycles,lowpowermotorcycles,agriculturalvehicles,mopeds,animal-drawncarts,animalherds

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3.4 Speedmanagement3.4.1 OverviewTheissueofspeediscentraltoroadsafety,anditsmanagementrequiresworkacrossseveralroadsafetysectors.Effectivespeedmanagementcomprisesaseriesofinterventionsthatcanhavegreatbenefitsforroadsafety.AccordingtotheWorldHealthOrganisation(WHO,2008),addressing speed management policies and programs plays a critical role in improving acountry’sroadsafetyrecord.Asseeninsection3.1,theroleofspeedhasbeenrecognizedasoneofthemostimportantelementsofa‘safesystem’anditsrelevancetoeachofthepillarsoftheUnitedNationsDecadeofActionforRoadSafetyhasbeennoted.

According to Organisation for Economic Co-operation and Development (OECD, 2006),tensionexistsbetweentheperceptionthatspeedisasignofimprovedefficiencyandatoolforprogress versus the negative consequences of speeding. Indeed, it is noted that individualsand the community as a whole perceive the benefits and dis-benefits of lower speedsdifferently.So,forcommunities,theoverallcostofcrashesishigh,butfortheindividualtheriskmaystillbequitelow.Arguablytheenvironmentalbenefits(e.g.airpollutionandnoise)ofreducingspeedsforindividuals(perhapswiththeexceptionofareducedfuelbill)arelessapparentthanforsocietyattheaggregatelevel.

Speedinghasbeenwidelyrecognizedtofallintooneoftwocategories:

• Excessivespeed:driversexceedingthepostedspeedlimit• Inappropriate speed: drivers choosing a speed that is not safe for the given

conditions

Both types of speeding can potentially raise the likelihood of a crash occurring throughincreasingthestoppingdistancebyincreasesto:

• Thedistance thevehicle travelsbetween the initialperceptionof anevent requiringthevehicletostopandtheactualmotoractiontakentostoporslowthevehicle.

• Thestoppingdistanceofthevehicleatagivenspeed.

Figure28illustratesthestoppingdistancerequiredatvariousspeeds.

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Figure28-Brakingdistances(sourceAustralianTransportSafetyBureau,ascitedbyWHO,2008)

Speedalsoaffects theseverityofcrashes.Higherspeedcrashesinvolvemorekineticenergy(kineticenergyisproportionaltothespeedsquared)andthemoreenergythatisdispersedinacrash,themoresevereittendstobe.Itisthescaleofthisenergyexchangethatdeterminestheseverityofinjury.The likelihoodofbeing involved inaseriousor fatalcrash increasessignificantlywithevensmallincreasesinvehiclespeedasshowninFigure29.Readingacrossthex-axis(bottom)ofthisgraph,itcanbeseenthatanincreaseinmeanspeedsof5%leadstoanincreaseininjurycrashes of 10% (black dotted line), and a 20% increase in fatal crashes (black continuousline).Similarly,ifmeanspeedsweretodecreaseby5%,thenareductioninallinjurycrashesof10%andareductioninfatalcrashesof20%shouldbeexpected.

Figure29–Changeinnumberofinjuredonchangeinmeanspeed(source:WHO,2008)

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Speeddifferential(differencesinspeedstravelledbydifferentvehicles)isalsocrucialfactorinfluencingcrashratesandoutcomes.Thisisparticularlythecaseinurbanareas;howeveritisalsoan issueonhigh-speedroads.Speeddifferential isstrongly linkedto fatalityratesonruralroadsandurbanarterials(OECD,2006).

Researchonurbanroadsindicatesthatcrashratesincreaseastheproportionofdriverswhoexceedthespeedlimitincreases.ResearchinAustralia(Kloedenetal.,ascitedinOECD,2006)showsthat fasterdrivershaveahighercrashriskasshowninFigure30(asaveragespeeddrivenbyadriverincreasesalongthex-axis,relativecrashriskincreasesparticularlystronglyforurban roads).The sameFigure indicates that slowerdriversdonothaveahigher crashrisk.

Figure30-Relativeinjuryaccidentrateonurbanroadsandruralroadsforvehiclesgoingfasterandslowerthanaverage

speed(source:Klodenetal.,ascitedinOECD,2006)

Increasingthespeedatwhichactivitiescanbeundertaken isgenerally takenasabenefit tosociety.Intransportation,speedisseenasakeyelementasitreducesjourneytimeand,asaconsequence,itcanreducebusinesscostsandallowpeopletoenjoyactivitiesbeforeorafterthe journey for longer. Smooth and quick journeys are often seen as an indication of anadvancedandefficienttransportationsystem.

However, there are also significant dis-benefits associated with speed. The severity andfrequency of crashes are closely linked to increased speed (see section 3.2.2). This isparticularlythecaseinurbanareas.

Thereareanumberoffactorsthatdriverswilltakeintoaccountwhenchoosingthespeedtotravel,asindictedinFigure31,andthepostedspeedlimitisonlyoneofthem.Inaccordancewith themulti-facetednatureof theproblem,effective treatmentof speedalsoneeds tobemulti-facetedinordertoadequatelyaddressthecomplexreasonsbehindspeeding.

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Figure31–Factorsaffectingspeedchoice(source:OxleyandCorben,ascitedinWHO,2008)

Eventhoughsomeresearchhasshownthatspeed limitshaveapositive influenceonactualspeeds, however, it should be stressed that other research has indicated that changing thespeed limit alone has little effect. In placeswhere speed limits have been changed and nootheractiontaken,thechangeinaveragespeedisonlyaboutonequarterofthechangeofthespeed limit (DETR, 2000). Any changes in speed limits should ideally be accompanied byappropriateenforcement,engineeringandeducationalmeasures. Internationalbestpracticesuggests that the best results are likely to be achievedwhen engineering, educational andenforcement interventions are implemented to compliment and reinforce speed limitadherence.In particular engineering refers to the design of the road and any physical interventionswhich have a direct impact on driver speed choice. Interventions can range from themanipulationof thegeometryof theroad(curveradius, inclineandsightdistance), to fixedinterventionssuchasroadhumps.Engineeringmeasurescanalsobeusedtopreventcrashesorreducetheseverityofcrashesthat do occur. In the previous sections has already been described as a road can be self-explaining (i.e. engineering measures can enhance the degree to which speed limits arecredibleandunderstoodbydriversandriders;seesection3.2.3)orforgiving(i.e.roadscanbedesignedsuchthatwhenacrashhappens,crashforcesareeffectivelydissipatedbetweenthevehicleandtheroad;seesection3.2.4).Roadscanbealsoself-enforcing,i.e.atparticularlocationsphysicalmeasures (e.g. speedhumpsor chicanes) canensure thatspeedsare low

Driver speed choice

Driver factors

Vehicles factors

Road factors

Traffic conditions

Crash and injury risk

Enforcement sanctions

Speed zone/limit

Education promotion

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(i.e. ‘traffic calming’ measures). These locations include areas where there is a highconcentrationofvulnerableroadusers, forexample inresidentialareasandoutsideschoolsorbusyshoppingareas.Speedmanagementisacomplexissueand,asseeninFigure31,thereisnosinglesolutiontothe problem of excessive and inappropriate speeds and a package of countermeasures isnecessary. The countermeasures should complement one another and increase the overalleffectivenessof,andcompliancewith,thespeedlimit.Aneffectivespeedmanagementpolicytargetsbothinappropriateandexcessspeedusingengineering,enforcementandeducationalmeasures to reduce speeds that will ultimately result in fewer speed-related crashes andreducedseverityofcrashesthatdooccur.

Speed management requires therefore a systematic approach incorporating all of thefollowingelements:

• Settingandsigningspeedlimits:Speedlimitsneedtobeappropriatefortheroadtowhich they apply and should reflect the road function, traffic composition, frontagedevelopmentandroaddesigncharacteristics.Thedrivershouldalwaysknowwhatthespeed limit is. The conventionalway to achieve this is to use traffic signs and roadmarkings.

• Road engineering measures: The road infrastructure can be designed such thatroadsareself-enforcing(atcertainlocationsroaddesignssuchasspeedhumpsmaybeusedtomakeitdifficultformotoriststotravelathigherspeedsthandesired)andself-explaining (roaddesignsare intuitiveandclear such that roadusersunderstand thespeedlimitandthespeedlimitiscredible).Inaddition,roadsshouldbealsoforgiving(theroadandvehicleincombinationprotecttheroaduserfromseriousorfatalinjuryatlegallypermittedspeeds),

• Education: The provision of information and education for drivers is also a veryimportant activity. If drivers understand the importance of speed limits, it is morelikelythattheywillcomplywiththem.

• Police enforcement: Police enforcement is necessary to deter intentional speedviolations.

Thisdocumentfocusesonspeedlimitsandengineeringmeasures,abriefoverviewofwhichispresentedinthenextparagraphs.

3.4.2 SettingspeedlimitsSpeed limit settinghas traditionally reflected attempts toachieveabalancebetweensafetyandmobility.However,countriesthatrecognizetheirpoorsafetyrecordandarecommittedtoreducingroaddeathsandinjuryareshiftingthisbalanceinfavourofsafety.AccordingtotheSafeSystemapproachprinciples(seesection3.1),somecountriesarenowsettingspeedlimitswith reference to the limitsofhuman injury tolerance, that is, toa level thatwillnotusuallyresultindeathorseriousinjurytoroaduserswhencrashesoccur.GuidelinesforsettinglimitsaccordingtoSafeSystemprincipleshavebeenalreadypresentedin section 3.2.2. It is recommended to consider the ‘safe speeds’ reported in Table 3 as‘default’speedlimitsor,better,as‘nationalspeedlimitregime’.Nevertheless,theyshouldbeadaptedtolocalsituationaccordingtofactorsdescribedintheBox1.

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Box1.Factorstoconsiderwhensettingspeedlimits(source:WHO,2008)

• Trafficmixandthedifferenttypesofvulnerableroaduser.• Crashhistory,severity(injury)andcrashrate(pervehiclekilometreoftravel)wherepossible.

Roadalignment(bothverticallyandhorizontally).Crashpronestretchesofroadshouldhavelowerlimits.

• Roadshoulderwidthandpavementquality–narrowshoulderwidths(especiallythosewithpoorpavementquality)canrunanincreasedriskof‘lossofcontrol’crashes.Therefore,speedlimitsshouldbelowerfortheseconditions.

• Roaddelineation – edge and centre-linemarking, reflectors and guideposts on the edge ofshouldersandadvisoryspeedlimits.Whereroadshavepoorvisualdefinition,thespeedlimitsshouldbelowertoenabletimefordriverjudgements.

• Roadandlanewidthsshouldbeadequate(i.e.atleasttwolaneswithaminimumlanewidthof3.4metres).Narrowlanewidthsofferlittlemarginoferrorandthereforespeedlimitsmustnotexceedthatrequiredbydriverstokeepconsistentlywithinalane.

• Theintensityoflanddevelopmentabuttingacarriageway–inbuilt-upareas,thereisadualrisk of poor visibility and more varied activity of people and vehicles entering the roadenvironment,andthereforespeedlimitsshouldbelower.

• Thetypeofintersectionsandthenatureoftrafficcontrolmeasuresatintersections.Whilealltypesof intersectionpresent increasedrisk toroadusers–androadsother thanmotorwaysshouldhavelowerlimits–poorlymarkedintersectionsrequireevenlowerspeedsleadinguptothemthanother,moreclearlymarkedintersectionsorroundabouts.

• Trafficvolumeandtrafficflow–lowerspeedlimitsinareasofhightrafficvolumecanbeusedto smooth traffic flows,making for better network efficiency and environmental benefits, aswellasimprovedsafety.

• Types and standards of vehicles allowed to access – roadways that vulnerable road userssuch as cyclists areallowedtouse shouldhave lower limits than those that only allow four-wheeled(orabove)motorvehicles.

• Thefreetravelspeedoftheroad.• Theabilitytoovertakesafely(withinsightdistance)atthepostedspeed.

Oncetheappropriatespeed limithasbeendeterminedforaroadorasectionofroad,stepsmustbetakentoensuredriversadopttheappropriatespeed.

The ‘default’ speed limits, inmanycountries, arenot signposted.Nevertheless, in countrieslike Pakistan that need to tackle the problemwith determination, it is advisable that theywouldbecleartoexistingandnewdrivers(includingvisitors)enteringtheroadnetworkoraspecificroad(e.g.enteringamotorway).

Inspecificcasesalternative(todefault)speedlimitscanbeused.Theselimitsmayinclude:• linearspeedlimits(includingtransition/bufferspeedlimits)i.e.alonglengthsofroads

andstreets• area-wide residential or commercial speed limits, with signs at entry point to the

designatedarea• timebasedspeedzones:

o schoolspeedzone,usuallytwicedailytime-basedlowerlimitsforanhourorsoatschoolstartingandfinishingtimes

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o seasonalspeedzone, forexampleatholidayresorts inbusiersummermonthswhenvehicularandpedestriantrafficisgreater

• variablespeedlimits(limitsthatchangeundercertainconditionsortimesofday,e.g.inwetconditions)

• heavyvehiclespeedlimitsIt is recommended, however, not to continuously change the limit as this can lead tounexpectedandinconsistentbehaviour.Ifonaroadsectionitisnecessarytoreducethespeedinmany locations, it is advisable to adopt a lower limit than the default one on the entirestretch.

Asregardsthelowerlimitsforheavyvehicles,itisworthtoremind,thattheuseofdifferentspeedlimitsfordifferentvehiclecategoriesonasectionofroad,couldcreatetheopportunityfor substantial turbulence within traffic and may increase the frequency of overtakingmanoeuvres,which can in themselves lead to increasedcrash risk. If there is tobea lowerlimit,itissuggestedthatthisisaconsistentamountbelowgenerallimits,whetherdefaultorsigned,on all rural roads. Speeddifferential is amajor cause of crash riskonhigher speedroads(WHO,2008;seealso3.2.2).

Signs are the primary way of communicating the speed limit of a road to drivers. Carefulconsiderationneedstobegiventotheuseandplacementofsignstoensurethatalldriversonagivensectionofroadaregivenconsistent information.Therecommended intervalsareasfollows:

• urbanareas:400m• ruralareas:

o motorwaysandotherarterialroads:4/5kmo otherroads:2/3km

Inadditiontopost-mountedspeedlimitsignsnexttotheroad,markingsontheroadcanalsobeusedtoshowthecurrentspeedlimit.

Figure32–SpeedlimitsmarkedontheroadpavementinSpain

3.4.3 RoadengineeringmeasurestoreducespeedThereisalargerangeofengineeringtreatmentsthathavebeenshowntobeofvaryinguseinspeedmanagement. Thesemeasures are described in significant detail in variousmanuals;

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however,abroadoverviewofavailabletreatmentsisgivenbelow.PracticalexampleswillbealsodulydescribedinPartIIoftheseGuidelines.

Treatments include engineering or re-engineering the road to encourage lower speeds, ormaketheroadand itsenvironment ‘self-enforcing’or ‘self-explaining’.Theygenerallyrelatetoso-called‘trafficcalming’measures,whichincludearangeofphysicalfeaturesthathavebeen developed by road safety and traffic management engineers to encourage, or force,drivers to drive more slowly. Many of these treatments have the effect of making it feeluncomfortabletodriveinexcessofthelegalorrecommendedspeed.Measurescanbegroupedinthreemainmethods:

a) Narrowingb) Horizontaldeflection�c) Verticaldeflection�

Ofcourse,theycanbecombinedtoaddresscomplexsituationswheretheindividualmeasurewouldbeineffective.Atypicalexampleisthetreatmentattheentranceofsettledareaswherea‘gateway’20isgenerallyaccompaniedbyothermeasuresaimedtoalertthedriversandforcethemtoadaptthespeed.

3.4.3.1 NarrowingWiderroadsinvitedriverstoselecthighertravelspeeds.Thismaybebecausetheperceivedmarginforerrorisgreater.So,narrowerroadwidthstendtoslowtrafficspeeds.Actually,roadnarrowingcannotbeconsideredasaspeed-reducingdeviceinitself,butitcanact as a reminder or encouragement to drive slowly or calmly. It uses a psycho-perceptivesenseofenclosuretodiscouragespeeding.Where traffic capacity is not a problem, thecross section of the road should changewherethebuilt-upareabeginsandthewidthof lanes canbe reduced. Inmanycases, it ispossible to change a four-lane road into atwo-laneroadthroughthebuilt-uparea.

The new layout can be obtained adding araisedislandlocatedalongthecentrelineofaroad that narrows the travel lanes. Fittedwith a gap to allow pedestrians to walkthrough at a crosswalk, they are also veryusefulas‘pedestrianrefuges’.

Ifitisnotadvisabletoreducethecapacity,asimple ‘optical’ narrowing can be effective

20Gatewaysaredevicesusedtomarkathreshold–usuallytoavillageorhigherrisklocationontheroad–wherelowerspeedsarerequiredfromdrivers.Gatewaysrelyonhighlyvisibleverticaltreatmentstocapturedriver/riderattentionandusuallyincludesigns,pavementmarkings,speedlimits,butalsoarchitecturalandruraltreatmentssuchaspicketfencingorgates,earthmoundsandrockwalls.

Figure33–RoadnarrowinginanurbanstreetintheUSA

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too.Inthiscasethecross-sectionremainsunchanged,whereastheshoulderischanged(e.g.buildingasidewalkwithkerbstone,plantingtreesorbushes,etc.). 3.4.3.2 HorizontaldeflectionHorizontal measures use forces of lateralaccelerationtodiscouragespeeding.Generally, all horizontal shifts may beclassified as chicanes, more or lesspronounced. In caseofpresenceof a centralisland,theymainlydifferbecauseofitswidth.

A chicane consists of a displacement of theroad axiswith a significant deflectionof thetrajectory.

This is a traffic calming measure used toemphasize the transition between the ruralenvironment and the built-up area. It isgenerally located after the sign of beginningof settlement and strengthens the image oftheentranceintothesettlement.

Dependingonthesiteconfiguration,twotypesofchicanesarepossible:

• Chicanewithacentralisland:• Chicane without a central island (simple or double): suitable in case the speed is

alreadysubstantiallyloweredbeforethechicaneThe extreme case is represented by a roundabout that, of course, accomplishes alsootherfunctions. Roundabouts are effective in reducing the severity of crashes at an intersectionbecause they require traffic to deviate from a straight path and therefore slow down toundertake the manoeuvre. The reduced speeds of travel through an intersection that aroundabout can achieve, together with the non-right-angle nature of side-impact crashesbecauseofthegeometryoftheroundabout,resultinreducedcrashseverity.3.4.3.3 VerticaldeflectionMuchcanbeachievedbyroaddesignandthesimple physical countermeasures describedabove.

However, some drivers will still drive veryfast despite the signs. The hazards thesedrivers create can only be tackled by strongphysicalmeasuressuchas:

• speedhumps• speedtables• rumblestrips

Theseverticalmeasuresuseforcesofvertical

Figure34–ChicanewithacentralislandinFrance

Figure35–SpeedhumpinFrance

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accelerationtodiscouragespeeding.In general, thesemeasures, except for rumble strips, aim to reduce the speed to 30 km/h.Therefore, for safety reasons, CERTU (CERTU, 1994) recommends implementing thesemeasuresonlyiftheapproachingspeedofthe85thpercentileofusersislessthan60km/h.Ifthis value is exceeded, other preliminary measures (i.e. narrowing, horizontal deflection)mustbeimplementedinthepreviousroadsection.Thesemeasuresshouldnotbestand-alone,buttheyshouldbeimplementedinseries.

3.4.4 SeparationofvulnerableroadusersSpeed should be limited to ensure that vulnerable road users are not exposed to risk ofserious injury. If this is not possible, separating the vulnerable road users frommotorizedtrafficisanalternative.

Pedestrianfencingisusefulforimprovingthesafetyofpedestriansbydirectinglargerflowsofpedestriansawayfromrandomcrossinglocations(particularlyinbusypedestriancrossinglocations) to safer crossing points, whichmay be equippedwith treatments such as speedhumpsorraisedplatformsintheroadway,orasetoftrafficsignals.Refugeislandsandmedianscanassistpedestriansincrossingtheroadbyallowingastagedcrossingandsimplifyingdecision-making.Kerbextensionscanalsoimprovepedestriansafetyby reducing the crossingdistance, and theareaand time inwhich thepedestrian is at risk.Thisisparticularlyhelpfulforolderordisabledpedestrianswhomayhavedifficultychoosingasafegapintrafficataconventionalcrossingpoint.Inmanysituationsinrural(andurban)areastherewillnotbeanyfootpathprovisionforthelargenumbersofpedestrianswalkingfrompointtopoint.Theywilloftenbeforcedtowalkonthe carriageway. Provision of a walking path is a highly effective means of removing thepedestriansfromamediumtohigh-speedcarriageway.Bicyclesshouldbeseparatedfrommotorizedtrafficaswell,ifatallpossible.

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4 RoadinfrastructuresafetymanagementSafer roads are the Pillar 2 of the UN Decade of Action for Road Safety 2011-2020 (WHO,2010)andareoneoftheaspectoftheSafeSystemapproachasdiscussedinsection3.1.

Asseenat length inChapter3,saferoadsareroadsthatareself-explainingandforgivingofmistakestoreducetheriskofacrashoccurringandtoprotectroadusersfromfatalorseriousinjury should a crash occur. This requires roads and roadsides to be designed, built, andmaintainedtoreducetheriskandseverityofcrashes.

To achieve this objective, a comprehensive strategy for road infrastructure safetymanagementneedstobeputinplace.Withoutit,infact,thereisarealriskofimplementingdisconnectedinterventionsinaframeworkofhighinefficiencyandconsequentpossiblewasteofresources.Thestrategy,whichisbasedontheSafeSystemprinciples,isoutlinedintheFigure36andisdescribedindetailinthefollowingparagraphs.

AverygoodbenchmarkinthisfieldistheEuropeanDirective2008/96/ECoftheEuropeanParliament and of the Council of 19 November 2008 on road infrastructure safetymanagement. This Directivemandates all EUmember States to establish and implement awell-defined set of procedures relating to abovementioned strategy. This Directive will bereferredtoseveraltimesinthefollowingparagraphs.

Figure36-Roadsafetymanagementapproachesthroughouttheprojectlife-cycle(adaptedfromAfDB,2014)

• RSIA at feasibility stage• RSA at preliminary and

detailed design stages

Design

• Pre-opening RSA

Construction• Post-opening RSA• RSI (proactive)• Data analysis and

treatement of crash locations (reactive)

Operation

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4.1 RoadsafetystrategiesThe treatment of crash locations and correcting safety problems across the road networkwhichmay result in road traumabyundertakingRoadSafetyAudits (RSA)and Inspections(RSI)formanintegralpartofaSafeSystem.

Thesemethodsbelongtotwomainroadsafetystrategies:

• Proactiveapproach,assessingadesignorconceptbeforeitisbuilt(andthusbeforecrasheshappen),orthesafetyofanexistingroadoncebuiltbasedonsafety featurespresenttoidentifyanytreatmenttoreducethelikelihoodorseverityofacrash.

• Reactiveapproach,respondingtoanexistingcrashproblem.

Effective road safety management programs should exercise an optimal balance betweenreactiveandproactivestrategies.

4.1.1 ProactiveapproachAproactiveapproachfocusesontheevolving‘scienceofsafety’,thatis,whatisknownaboutthe evolving specific safety implications of road design and operations decisions. Theproactive approach applies this knowledge to the roadway design process or to theimplementationofimprovementplansonexistingroadstodiminishthepotentialofcrashesoccurringpriortotheroadbeingbuiltorreconstructed.Conducting RSAs is an example of a proactive road safety strategy, but also RSIs canconductedfollowingthisapproach.

Theadvantagesofaproactiveapproachinclude:

• Crash prevention: it is not necessary for crashes to occur before crash preventionmeasuresaretaken(‘preventingisbetterthancuring’).

• Lower costs: changing plans is easier and less costly than to implement animprovementplanonaroadopentothepublic.

4.1.2 ReactiveapproachAreactiveapproachtoroadsafetyisbasedontheanalysisofexistingcrashdata.Roadsafetyimprovementsproposedareconsidered inreactionto identifiedsafetyproblemsbrought tolightbycrashesthathaveoccurredaftertheroadhasbeendesigned,built,andopenedtothetravelingpublic.

Traditionalreactiveroadsafetyengineeringprocessesincludesuchactivitiesasinformationcollectionandmanagement(crash informationsystems), identificationofproblemlocationsontheroadnetwork,analysis,developmentandimplementationofcountermeasures.

A ‘blackspot programme’ is an example of reactive approach to crash frequency and/orseverityreduction.

Limitationsofthereactiveapproachareasfollows:

• Itrequirestheidentificationofhighcrashlocationsbeforeimprovementplansmaybedevelopedandimplemented.

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• The supporting crash data is often dated, incomplete and/or insufficient to supportaccuratediagnosisandintervention.

• It may also be costlier, since improvement plans are necessarily implemented on aroadalreadybuiltandopentopublic.

Despite these limitations, no road safety management system can be considered completewithoutareactivecomponentasitisapowerfultoolforaddressingexistingsafetyproblems.

4.2 RoadsafetyimpactassessmentAccording to the European Directive 2008/96/EC ‘road safety impact assessment’ (RSIA)means a ‘strategic comparative analysis of the impact of a new road or a substantialmodificationtotheexistingnetworkonthesafetyperformanceoftheroadnetwork’.TheRSIAshouldbecarriedoutattheinitialplanningstagebeforetheinfrastructureprojectisapproved.Itshouldindicatetheroadsafetyconsiderationswhichcontributetothechoiceoftheproposedsolution.Itshouldfurtherprovideallrelevantinformationnecessaryforacost-benefitanalysisofthedifferentoptionsassessed.Any new infrastructure project realignment or change to existing infrastructure thatsubstantiallyaffectstheperformanceofthenationalroadnetworkshouldbeassessed.RSIAisrequired onlywhere the anticipated effect on themain road network is substantial. Smallprojectsgenerallydonotrequireassessment.

RSIAshouldbecarriedoutattheinitialplanningstagesofaprojectandshouldbeusedasoneof thetools forprojectselection.Thisassessmentshouldconsiderthesafety implicationsofthedifferentalternativesaswellastheoptiontonotproceedwiththeproject.

As the project design progresses theRSIA should be regularly reviewed to ensure that theroadsafetyimplicationsofalldesignrevisionsareconsidered.RSIAisanintegralpartofthedesignprocessandcanbecarriedoutwithinthedesignteam.Theassessment team,generally comprisingat least two individuals, should includeat leastone experienced road design engineer and at least one experienced road safetyengineer/auditor. In the absence of competence in RSIA within the design team, anassessmentteamshouldbesourcedfromelsewhereandshouldjointhedesignteamforthisspecifictask.

It is important to note that a RSIA is not a separate audit of the project carried out by anindependentteam.Itisanon-goingtaskwithinthedesignprocessandgenerallycarriedoutwithinthedesignteam. If anexternalassessmentteamisbrought in toprovideroadsafetyexpertise,thenthatteamshallbeviewedastemporarilypartofthedesignteam.In this view RSIA does not replace or preclude RSA, which is carried out by a teamindependentofthedesignprocess.RSAisdescribedinthefollowingparagraph.TheRSIA should be carried outwhile the project is still at concept stage. At this stage theassessmentexplorestheroadsafety implicationsofeachoptionbeingconsidered, includingthe Do-Nothing and Do-Minimum options. The assessment should provide all relevantinformationnecessaryforcomparisonoftheoptionsandselectionofthesolution,includinga

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comparative analysis of the road safety implications of each alternative considered and anevaluationoftheroadsafetybenefitsanddis-benefitsarisingfromeachalternative.

TheobjectiveofRSIAistoconsidertheproposedprojectfromaroadsafetypointofview,tocompare the impactonroad safetyof eachproposedoptionand todeterminewhichwouldgivethebestroadsafetyoutcome.Witheveryprojectthereisthepossibilitythattheexistingsituationwouldbepreferabletoanyoftheoptionsconsidered,andsoitisessentialthatthisalternativeisalsoconsideredintheassessment.

Roadsafetyimpactisonlyoneoftheaspectsconsideredbyadesignteamwhenselectingthepreferred option. It is important that the reasoning behind the conclusions of the impactassessmentismadeclear,sothatitisgivendueweightintheselectionprocess.Thisshouldminimisetheriskofcollisionsoccurringinthefutureeitherasaresultofplanningdecisionsorasaresultofunintendedeffectsofthedesignofroadschemes.

AmethodologyforRSIAissetoutintheIrishguidelines(NRA,2016)andisreportedinBox2.

Box2.RSIAmethodology(adaptedfromNRA,2016)

i. Definetheprojectanditsobjectives:

• Clarifytheobjectivesoftheproject(e.g.toincreasecapacity,toremovetrafficfromavillage,toeliminatepooralignment,toprovideanamenity,etc.).

• Clarifywhetherthemajorobjectiveoftheschemeistoaddressroadsafetyissues.

ii. Definethestudyareaandtheareaofinfluenceoftheproject:• Clarifytheextentsofthesurroundingroadnetworkwhereanyoftheproposedoptionswould

affect the operation of the network. Check the likely changes to drivers’ route choice andchoiceoftravelmodeortime,andthusthelikelyeffectsontrafficpatterns.

• Theentirestudyareashallbeexaminedwhenassessingeachproposedoption,sothatlikecanbecomparedwithlike.

iii. Establishtheexistingroadsafetyproblems:• Examineexistingcollisionstatisticsandcarryoutananalysis.• Establish any patterns in the collisions and any high collision locations, either stretches of

roadorsinglesitesatjunctionsorotherconflictpoints.• Establish any patterns over time of day or year, or any patterns involving road user type.

Examineanyroadsafetyreviewsthatmayhavebeencarriedoutpreviouslyonallorpartofthearea.

• CollisionstatisticsfornationalroadsareavailablefromNH&MP.Forprovincialprojects,itisrecommended to contact the local authorities (e.g. Police, Communication & WorksDepartments,etc.)whomighthaveinformationoncrashesthattheyhaveattended.

iv. Roadsafetyobjectives:• Definetheroadsafetyobjectivesofthescheme.• This will usually include addressing the existing road safety problems, but there may be

further objectives, such as improving pedestrian access to an amenity or improving publictransportaccess.

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v. Theoptions,includingDo-NothingandDo-Minimum:• Examinethedrawingsofeachproposedoptionfortheproject.• Include theexistingDo-Nothingsituationwhichwouldprevail ifnoworksatallwere tobe

implemented.• IncludetheDo-Minimumsituation,wheretheveryminimumpossibleistobeimplemented,

suchasprovisionofsigns,surfaceoverlayandanycommittedschemes.• Visitthesitetovisuallyestablishthealignmentofeachproposedoptionandthesurrounding

topography.Asitevisit is importantas itmay identifyexistingarrangementsorpatternsofusethatmaynotbeevidentinthedrawingsandotherinformationexamined.

• Examinebothexistingandproposedtrafficflows.Itmaybenecessarytoestablishpeaktimesofuseforcertainpartsofthenetwork,suchasaccesstoschoolsorsportsgroundsorweeklymarkets,sothattheappropriateflowscanbeexamined.

• Patterns of use of all road users must be considered. In general pedestrians and othervulnerable road users are affectedmore acutely than other road traffic by both changes inroadalignmentandchangestoavailableroutesoftravel.

vi. Analysisofimpactsonroadsafetyoftheproposedalternatives:• The main element of the assessment is the comparison of the road safety effects of each

alternativeproposal.ThismustincludeDo-NothingandDo-Minimumoptions.• The effects on the entire study area must be examined for each proposed option. Where

proposed alternatives differ in scale and cover differing lengths or areas of the existingnetwork,theremainderoftheroadnetworkoutsidetheproposedworksmustbeincludedintheanalysis.Theassessmentareamustbethesameforalloptionsbeingcompared.

• An assessment of the effects of each alternativemust be carried out in terms of predictedcollisions. Quantitative indicators can be used such as collision rates and collisions perjunctiontype.

• Toassess the likelycollisionoccurrence in theproposedoptions, it is recommendedtouseestablishedlocalcollisionratesinthesurroundingareaforequivalentroadtypes.Iftheseareunavailable,thenthecollisionratesforroadtypesatnationallevelshouldbeused.

• Toestablishtheeconomiccollisioncostofeachoption,inabsenceofaPakistaniassessment,itissuggestedtorefertoaveragevaluesbasedonlocalGDP21.

• All effects on traffic flowand traffic patternsmust be considered. Any projected change inmodalsplitasaconsequenceoftheproposalsisimportantasthismaynotonlyaffectthemixofvehiclecategorywithinthetrafficflow,butmayalsoimpactonpatternsofpedestrianandcycletravelandlocationswhereconflictswithothervehiclesoccur.

• Seasonal and climatic conditions such as the likelihood of flooding and foggy conditionsshouldbeconsidered,asthismightdifferbetweenoptions.

• Thepossibilityofseismicactivityshouldalsobeconsidered.

vii. Comparisonandranking:• Comparison of the alternatives should not only give a qualitative list of benefits and dis-

benefits,butshouldalsoincludeacostbenefitanalysisoftheroadsafetyaspects.• Theoptions,includingtheDo-NothingandDo-Minimumoption,shouldberankedintermsof

roadsafetyconsiderations,givinganorderofpreferenceandanindicationofthemagnitudeofdifferencebetweenoptions.Ifoneoption,oragroupofoptions,showsconsiderablymore

21AccordingtoiRAPthevalueofafatalityisabout70*GDP/Capita,whereasthevalueofaseriousinjuryis17*GDP/Capita(McMahon&Dahdah,2008)

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or less benefit than the others then this should be highlighted. Conversely, if there is littledifference inroadsafetytermsbetweentwoormoreof theproposalsthen theseshouldbegiventhesameranking.

4.3 RoadsafetyauditsTheRSAprocesswas initiatedwhen road safetyengineers realised that theywere carryingoutcollisionremedialschemesonrelativelynewroads.Adoptingtheprincipleof‘preventingisbetterthancuring’,theydecidedtousesomeofthesafetyexperiencethattheyhadgainedfromtheremedialworktodesignsafetyintonewroadschemes.Sincethentheconceptgrewover theyears froman informal checkofnewschemes to the current systemofRSAasanessentialintegralpartofdesignandconstructionprocedures.AccordingtotheEuropeanDirective2008/96/EC‘roadsafetyaudit’meansan‘independentdetailedsystematicandtechnicalsafetycheckrelatingtothedesigncharacteristicsofaroadinfrastructureprojectandcoveringallstagesfromplanningtoearlyoperation’.

Accordingly,RSAshouldbecarriedoutforallroadinfrastructureprojectsandshouldformanintegralpartoftheirdesignprocessatleastatfollowingstages:

• Preliminarydesign• Detaileddesign• Pre-opening• Earlyoperation

PracticalinstructionsonhowtocarryoutandmanageanRSAcanbefoundontheCARECRSAmanual(ADB,2018a).

ItishereimportanttohighlightthatanRSAshouldbecarriedoutbyanauditorappointedinaccordancewiththefollowingprovisions:

• She/heshouldhaveundergoneaninitialtrainingresultingintheawardofacertificateofcompetence

• She/he should have relevant experience or training in road design, road safetyengineeringandcrashanalysis

• She/heshouldnotatthetimeoftheauditbeinvolvedintheconceptionoroperationoftherelevantinfrastructureproject

Itisthereforequiteobviousthatauditorapprovalisacrucialtaskforanyroadauthority.Asstated in theCARECmanual, it issuggested that every countryestablishes itsownnationalregister of auditors. In Pakistan, besides a national register, which ideally should beadministeredbyNHA,differentregisterscanbeestablishedineachprovinceorterritory.In any case it is of paramount importance to establish clear requirements to approveapplicants.Firstly,itisstronglyrecommendedthatapplicationwouldbelimitedonlytocivilengineers(orequivalent)thathaveatleastexperienceinroaddesignand/ortrafficplanning.Inaddition,asrecommendedbytheCARECRSAmanual,itisrecommendedthatanapplicant,inordertoberegisteredasanRSAteamleader(i.e.seniorauditor),should:

• havecompletedanapprovedroadsafetyaudittrainingcourse,

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• haveaminimumof3years’practicalexperienceinaroadorroadsafety-relatedfield,and

• have completed at least five road safety audits under the guidance of a senior roadsafetyauditor,ofwhichatleastthreeofthefiveauditsmustbeatadesignstage.

Finally,toberegisteredasateammember,anapplicantshould:

• havecompletedanapprovedroadsafetyaudittrainingcourse,and• haveaminimumof2years’practicalexperienceinaroad-orroadsafety-relatedfield

Accordingtothisschemeisveryimportanttopromotetheinvolvementoflocalengineersinauditing.Inthefirstperiod(2/3years)theauditswillbenecessarilyleadedbyinternationalauditors, but only following this approach the local practitioners can gain sufficientexperiencetoleadanauditinthefuture.The RSA training courses should be officially recognised by national authorities (e.g. NHA,MoC, etc.), should be at least of 5 days’ duration, presented by an experienced road safetyauditor,andshouldincludeafinalexam.Onlyapplicantspassingsuccessfullytheexamshouldbeallowedtoberegistered.Thecourseshouldcontainaprogramofpresentationsthatshouldbenotlimitedtotheauditprocess but should describe in detail thewhole road safety engineering process. Technicaltopicsmayincludesafetyingeometricdesign,vulnerableroadusers,signs,delineation,safetyatroadworks,androadsidehazardmanagement.

Box3.Casestudy:RSA&ItrainingcourseatNUSTUniversity

A7-dayRoadSafetyAuditing&InspectiontrainingcoursewasheldintheNUSTUniversity(Islamabad)in February 2018. The course was approved and funded by the ADB in order to support theGovernmentofPakistanto:

• buildcapacitytoidentify,treatandeliminatehighcrashandhazardouslocationsasidentifiedintheNationalHighwayAuthorityRoadSafetyActionPlan2018-2020,and

• establishateamofinformedandskilledfocalpersonstocoordinatedisseminationandpilotingroadsafetyengineeringbestpractices.

The course was designed to provide road engineers with a theoretical and practical knowledge ofmain road safety engineering tools and specifically to build the knowledge and skills required toconductroadsafetyauditsandinspections.Itreferencedthestrategiccontextforsaferoadswithinthedraft National Road Safety Strategy 2018-2030, with particular reference to Pillar 2 – Safe Roads.Specificobjectiveswereasfollows:

• Totrainandqualifyafirstkernelofroadsafetyauditors• To train roadauthorities officials on road safety engineering practices to identify and treat

highcrashclusterlocations• Totrainroadauthoritiesofficialsonpreventiveroadsafetyinspections• Toshareinternationalbestpracticesinsaferoaddesign• Todiscussmainissuesconcerningroaddesignstandardsandtheircurrentimplementationin

Pakistan

The course included theory sessions, best practices and case studies taking into account the local

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practice, small group sessions, participant workshops, site visits, submission of a Road SafetyInspectionReportandafinalexamination.

The training team – contracted by theDanish firmNTU - included both international and nationalexperts, covering various aspects of road safety (engineering, road crash investigation, crash dataanalysis,institutionalaspects).

Thecoursewasarticulatedover:

• 9days(includingaweekend)• 10modules(boththeoreticalandpractical)• workshops• homework• finalexamination

TheTrainingCourseprogramwasasfollows:

• Day1:o Module1:Roadsafetynationalandinternationalframeworko Module2:Crashinvestigation

• Day2:o Module3:Roadsafetyengineeringprocess

• Day3:o Module4:Conflictstudieso Module5:Themanagementsystemofcrashdata

• Day4:o Module6:Roadsafetyauditsandinspections

• Day5:o Module7:Sitevisit

• Days6/7:o Self-directed preparation of the Road Safety Inspection Report for examination

assessmentandpreparationforthecourseexamination• Day8:

o Module9:Thesaferoaddesign• Day9:

o Module10:Principlesoftrafficengineeringo Finalexamination

A total of 26 participants completed the course, including representatives from National HighwayAuthority (NHA), Capital DevelopmentAuthority (CDA), PakhtunkhwaHighways Authority (PKHA),Communication and Works Departments of Governments of KP and Balochistan, EngineeringConsultancyServicesPunjab(ECSP),NUST,UniversityofKarachi.Only4participantsdidnotpassthefinalexam.

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Groupphoto

Workshopsonsite(left)andintheclassroom(right)

4.4 RoadsafetyinspectionsRSI shouldbeundertaken in respectof the roads inoperation inorder to identify the roadsafetyrelatedfeaturesandpreventcrashes.AccordingtotheEuropeanDirective2008/96/EC‘roadsafetyinspection’meansan‘ordinaryperiodical verification of the characteristics and defects that require maintenanceworkforreasonsofsafety’.

TheterminologyofthisdefinitiongivesanindicationofthescopeoftheRSIasfollows:

• Thetermordinaryindicatesthatanin-depth,forensicinvestigationisnotexpected.• The measures to be carried out in response to the inspection are described as

maintenancework;thissuggeststhatmajorchangestothelayoutoftheroad,entailinghigh cost, are not envisaged as counter-measures; however, engineering works areoftenrequiredtoremediatetheissues.

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• The term periodical indicates the need for inspections to be repeated at intervals,ratherthanbeingaonce-offevent.Their frequencyshouldbesufficiently frequent tosafeguardadequatesafetylevelsfortheroadinfrastructureinquestion22.

RSIisanon-goingprocess,withroadsbeingsubjecttore-inspectionatregularintervals.The iRAPprogramme can be considered as an evolution of theRSI as described here. Thismethodologyturnstheroadfeaturesdetectedduringtheinspectioninquantitativeattributesthatthen,usingaquitecomplexalgorithm,provideasyntheticjudgmentaboutroadsafety.Inthiscase,theinspectionisthereforenotlimitedtotheidentificationofroadsafetyissues,butit is aimed to identify all road characteristics that, to a different extent, influence thelikelihoodofacrashanditsseverity.MoredetailsaboutiRAPandthetechniquesdevelopedunderthisprogrammearereportedintheBox4.

RSIrespondstothesafetyimplicationsofchangingconditionsontheroadnetwork.Theroadenvironment isdynamic; it is not fixedover its design life. Roadside features are added orremoved, materials forming the road deteriorate and are replaced, new developments arebuiltontheroadfrontagealteringaccessconditionsandchangingtrafficflows.Changes alsooccur to ourunderstanding of road safety and road design standards; certainengineeringdesigns thatwouldhavebeenconsideredsafe in thepast are today consideredunacceptable.Inrespectofthetiming,theinspectionshouldbecarriedout:

• By day, in both directions. An inspection by night is advisable if collision recordsshowanunexpectedshareofcrashesduringthenight.

• At timesof normaloperationof the road.Unlessotherwise required, avoid timeswhentheroadenvironmentconditionsareabnormal,suchaswhenspecialeventsareoccurring. However, if events are frequent (occurring at least weekly), and if theconditions during those events are considered to affect road safety, then the routeshouldalsobedrivenunderthoseconditions.School-timesandcommutercongestionareexamplesof factorswhichmayneedconsideration if theyapplyto therouteandare significant in safety terms. Off-peak conditions should however always beconsidered.

TheRSIshouldbeconductedbyateamofatleasttwoexperiencedpractitioners.Thebenefitsofateamapproacharethatreportsarelikelymorebalanced,andthelikelihoodtomisssomeissuesareislower.AnadditionalconsiderationisthatitisoftennotpracticaltocarryoutanRSIalone.

Itisrecommendedthatatleastoneteammember(tobeappointedasTeamLeader)wouldbean approved road safety auditor according to the scheme described in the previousparagraph. In addition, it is strongly recommended that all team members would beindependentofthemaintenanceandoperationoftheroad.Theinspectionisintendedtobeafresh, independent lookat the roadandtherefore it isnot recommended that the inspector

22Irishguidelines(NRA,2014)suggestthefollowingmaximumperiodsbetweeninspections:

• 5yearsformotorwaysandotherdual-carriagewayarterialroads• 3yearsforotherroads

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havehadaroleinthedesignormaintenanceoftheroute,withinthethree-yearperiodpriorto the inspection. It does not mean that the inspector cannot be an employee of the roadauthorityorroadoperator.Theinspectioniscarriedoutwithavehicleand,givenits‘ordinary’nature,itisnotneededtostopforin-depthinvestigations.It is strongly recommended to equip the vehicle with a high-resolution video-cameraprovidedwithaGPSdevice.Itallowsinfactaneasypositioningoftheidentifiedissuesonamap(seeFigure37).Thecameramustbetightinstalledonthewindscreenthroughasuctioncuporsimilar(thecameracannotbehandled).

Figure37–ScreenshotofasoftwaretomanagevideosfromacameraprovidedwithGPS(onthetoprightitisvisiblethe

trackingofthetravelledroute)

Box4.iRAPmethodology

AboutiRAP iRAPwasformedinEnglandin2006andwasgrantedcharitystatusin2011. It isanumbrellaorganization forroadassessmentprogrammesworldwide(e.g.EuroRAPinEurope,AusRAPinAustralia,usRAPintheUS,ChinaRAPinChina,PakRAP–soon–inPakistan)andfacilitatesthedevelopment of road assessment work in low- and middle-incomecountries.

iRAPassumedthatreliablecrashdatawouldnotbeavailableinthesecountriesanddevelopednew‘proactive’techniquestoovercometheseshortcomings.

TodayiRAPworksinpartnershipwithgovernmentandnon-governmentorganisationto(i)inspecthigh-riskroadsanddeveloptargetedroadsafetyplans,(ii)buildlocalcapabilityprovidingtraining,

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technologyandsupport,and(iii)trackroadsafetyperformancesothatfundingagenciescanassessthebenefitsoftheirinvestments.

Roadinspection

Using vehicles equippedwith one or more cameras, inspections focus on more than 50 differentattributesthatareknowntoinfluencethelikelihoodofacrashanditsseverity.

These attributes include intersectiondesign, the number of lanes andmarkings, roadside hazards,footpathsandbicyclefacilities.

Exampleofroadattributes

StarRatings

StarRatings arebasedon road inspectiondataandprovide a simple andobjectivemeasureof thelevel of safety which is ‘built-in’ to the road for vehicle occupants, motorcyclists, bicyclists andpedestrians.

Five-starroadsarethesafestwhileone-starroadsaretheleastsafe.AccordingtoiRAP,everyextrastar rating results inahalvingof crash cost on termsof thenumberof peoplewhoarekilled andseriouslyinjured.

StarRatingscanbecompletedwithoutreferencetodetailedcrashdata(proactiveapproach).

Theprocessoffersanopportunityforroadownerstosetaperformance-basedstarratingtargetforallroadusers23.

23On21November2017WHOMemberStatesagreed12roadsafetyperformancetargets.Amongthem,Target3states:‘By2030,allnewroadsachievetechnicalstandardsforallroadusersthattakeintoaccountroadsafety,ormeetathreestarratingorbetter’

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StarratingresultsinIceland

PakRAP

InPakistanADBisassistingNHAtoassesstheroadsafetyconditionfortheentirenationalhighwaynetworkanddevelopaniRAPprogrammethatistailoredtothePakistanicondition(i.e.PakRAP).

Theprojectobjectivesareasfollows:

• Stimulatelarge-scaleroadassessments• Leverageinvestmentsfortheimplementationoflife-savingcountermeasures• Putriskassessmentatthehearthofstrategicdecisionmaking• Developingalocalteamthatiscapableofundertakingroadassessmentsonanongoingbasis

ApilotprojectcoveringtheassessmentoftheN-5highwayhasbeencompletedattheendof2017.In2018–2019 it is expected that theprogrammewill cover the remainderof thenational highways(approximately5,500km).

4.5 TreatmentofcrashlocationsThe treatment of crash locations involves a step-by-step process starting with theidentificationandrankingofsectionsofthenetworkinoperationwhichhaveahighcollisionconcentration.

Thisanalysisisthereforebasedoncrashdata(i.e.reactiveapproach).Inotherwords,itmeanstoanalyseandranksectionsoftheroadnetworkwhichhavebeeninoperation for more than three years24 - and upon which a large number of crashes haveoccurred - in order to recognise the causes, select possible countermeasures and identifythosehavingapotentialforimprovement.

The treatment of crash locations is therefore a multi-stage process that follows the stepslistedbelow:

24Threeyearsistheminimumperiodtoassurestatisticalreliability

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a) Initialdesktopstudyb) Detaileddesktopstudyc) Sitevisitd) Diagnosingthecrashprobleme) Treatingthecrashproblemsf) Prioritisingtheschemesonthenetworkg) Monitoringandevaluation

4.5.1 InitialdesktopstudyTheinitialdesktopstudyisbasedonthecrashanalysis.The availability of comprehensive and accurate data about crashes is therefore crucial,becausethewholeprocessofinvestigating,analysingandeffectivelytreatingcrashlocationsrelies on them. Data about road and traffic characteristics of the crash locations are alsoimportant.Gooddatapermits,amongstotherthings(Austroads,2009):

• crashlocationstobeaccuratelypinpointed• thesequenceofeventsinacrashtobeappreciated• the contributing factors in a crash or a group of crashes to be identified, so that

treatmentcanbedirectedatthosefactors• commonfactorsacrossanumberofcrashestobeidentified• thecostconsequencesofasinglecrash,allcrashesatonelocationorseveralcrashes

withcommonfactorstobeidentified• severalcrashsitestoberanked,sothattreatmentcanbeappliedtotheworthiestsites

firstUnfortunately, thedatasetcurrentlyavailable inPakistandoesnotallowmostof theaboveanalysis,butitissufficienttoimplementthebasicsofthisstrategy.

The desktop analysis should be carried out taking into account only collisions resulting inpersonalinjurybecausethereportinglevelofmaterialdamagecollisionsisvariableandtheinformationrecorded–ifany–isminimal.Itisrecommendedthatthenumberofcollisionsbetakenintoaccountasamethod,whichmeansthatthenumberoffatalitiesandinjuriesshouldbeignored25.Thisapproachisbasedonthefollowingassumptions:

• The use of the number of casualties as a criterionmay distort the network ranking,potentiallymakingcriticalroadsectionswith fewcrashesbutmanyfatalitiesand/orinjuries26.

• The target of this methodology is the infrastructure. The road does not have anyinfluence in certain variables determining the number of casualties (i.e. number of

25Theexceptiontothis‘rule’wouldbeasitewithamuchhigherthanexpectedproportionoffatalandseriouscrashes.Forexample,onahigh-speedroadwithonefatalandthreeseriousinjurycrashesbutnominorinjurycrashes.26Asanexample,on11thNovember2014,alongtheTherrybypass(Khairpur,Sindh),apassengerbuscollidedatruck.Injustonecrash59casualtiesoccurred.Canasinglecrashdefineasiteashazardous?

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vehicle occupants) or the severity of the crash (i.e. seat belt/helmetwearing, age ofoccupants,presenceofairbagsand/orothervehiclesafetydevices,etc.).

Inordertoclassifytheroadnetwork,thefollowingindexescanbeused:• Collisionrate(pervolumeoftraffic)27• Frequencyofcollisions(orcollisionsperkmofroad)

Thedifferencebetweenthetwoaboveindexesisthatthesecondtakesnoaccountofexposure(i.e.traffic).Ofcourse,theaccuracyofthecollisionrateisdependentontheaccuracyoftrafficvolumeinformation.Inafirstphase,wheretheoverallobjectiveistoreducecrashnumbers,the frequency is a valid index and its use is recommended in case the traffic data are notreliableand/orarenotavailableforthewholenetworktobeanalysed.

Theaboveindexesmustbereferredtohomogeneousroadsections,thatis:• Layoutandtrafficflowmustnotchangesignificantlyinanysingleroute(e.g.sections

cancontaineithermotorwaylinksornon-motorwaylinks,butnotboth).• Thewholesectionmustfallalongthesamenumberedroadtoensurethatcrashdata

canberetrievedusingonlyroadnumberandchainage.• Thedesignandoperationmustbeasuniformaspossible,sothattheconditionsalong

theroutearesimilarandthecrashindexreflectsareasonableaverageoverallpartsofthesection.

• Sectionsshouldstartandendatrelevantjunctions.Besidestheabovecriteria,itisessentialtoassesslengthsthatminimisetheimpactofyear-on-year variability in crash numbers and present a stable longer-term estimate of crash risk.Research conductedby theTransportResearchLaboratory (TRL) show that thenumberofcrashesonbusynetworksoverathree-yeardataperiodforsectionsofatleast5kmprovideareasonablyrobustestimateofrisk.Sectionslessthan5kmtendtoshowgreateryear-on-yearvariability incrashnumbers inadditiontobeingmore likely tochangeriskrating fromoneperiodtoanotherandwerethereforelessreliablewhencomparedovertime.Formotorwaysanddualandsinglecarriagewaysthesedifferencesweresignificantuptosectionlengthsof10km(EuroRAP,2018).

Minimum thresholds of 10 km formotorways and dual carriageways and 5 km for singlecarriagewaysarethereforerecommended.

Followingthismethod,thisinitialstudyresultsinariskmappingthatidentifieshighcollisionsectionswhicharethensubjecttoadetaileddesktopstudy.

27!"##$%$"&()*+,+(10/0+ℎ. 34 = 67.8799:;:7<;/>?@A×CDE

FGH.IHJ@>;×KKLM×A7NO?9?<POQ(ST)

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Figure38–RiskmapofmotorwayandnationalroadnetworkofFrance

4.5.2 DetaileddesktopstudyPereachhighcollisionsection,adetailedreviewofthecollisiondatashouldbeundertakentoidentify:

• Clustersofcrashes(i.e.blackspots)• Factorswhichcanexplainhowthevariousroadusersfailedtocopeimmediatelyprior

tothecollisions

Unfortunately, the second analysis requires information that in Pakistan is not yet fullyavailable. The desktop analysis must be therefore necessarily supplemented by a siteinspectioncarriedoutfollowingaproactiveapproach(seefollowingparagraph).

Ifdataallowthiskindofanalysis, theyshould furtherlyclusteredbycommoncrash-typeorfactorslikecommonweatherordaylight,commonspeedrange,etc.28Thisanalysisshouldaimtohighlightfactorscommontoanumberofthecollisionsatthesiteintheviewthattheprevalenceofcrashesatonlysomelocations,andtheclusteringofcrash-typesatasinglelocationusuallyindicatesthattherearecommoncausesforthecrashes.Theaim of this analysis is therefore to identify sites which have ‘treatable’ collision problems

28Forthiskindofanalysis,itwouldbeveryusefultoexaminetheindividualpolicecrashreportforms.Unfortunately-inPakistanlikeinmanyothercountries-theserecordsarenotmadeeasilyavailabletopractitioners.

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amenabletoroadengineeringtreatments.Figure39showsasitewithadominantrightturnaccidentproblem,alongwithothermoreindividualaccidenttypes.

Figure39–Sitewithapredominantright-turncollisionproblem(source:DoE,1996)

If there is not a dominant crash-type, development of a remedial treatment can be verydifficult.Indeed,itmaybethatnoengineeringmeasureisapplicabletotheproblemsatthatsite.Alternatively, theremaybetwoormoremajorcrash-types,withtwoormoredifferentremedialengineeringtreatmentscalledfor.

4.5.3 SitevisitOncethecollisiondataandotherrelevantdataforaparticularlocationhavebeenstudied,itisnecessarytocarryoutasitevisit.Thesitevisitshouldonlytakeplaceaftertheinitialcollisionstudyhasbeencompleted.Thisshouldavoidthepre-judgementofcollisionproblemsthatcanhappenifthesiteisvisitedpriortothecollisiondatabeenexamined.

Theprimarypurposeof thesitevisit is to identifyanyenvironmentand trafficdeficiencieswhichmayhavecontributedtotherecordedcrashhistory.

Toensurethatroaddeficienciesareidentifieditisessentialthatsiteinspectionsarecarriedoutinanextremelysystematicandpurposefulmanner.If the crash data show a cluster of a particular crash-type, this means several people aremisreadingthesituationas theyapproach,drivethrough, turnat,walkacross,orotherwisenegotiatethelocation.Thequestionsthatalwaysshouldbedonearetherefore:

• Whatiscausingthemtodothis?• Whatismisleadingordifficulttodealwith?

Theseissuescannotbeidentifiedonlyfromcrashdata,crashreportformsorphotographs.Itisessential tocarryoutasitevisitalwaystaking intoaccountthepointofviewofdifferentroadusers(‘roleplay’).Basicprinciplesofthesitevisitareasfollows:

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• Lookatthesiteatinrelationoftheresultsofdataanalysis• Carryout thevisit inconditionssimilarof thosewhencrashesoccur(e.g.sametime,

peak/off-peak,light/dark,wet/dry,etc.)• Viewthelocationastheroadusersinacrashmayhaveseenit• Drivethroughthelocationrepeatingthemanoeuvresfeaturedinthecrashdata• Observe‘dangerousmovements’• Takenotes,photosandvideos

4.5.4 DiagnosingthecrashproblemsThe objective of this activity is - basing on crash analysis and site visit - to identify thesecommon causes and to counter them by applying appropriate remedial engineeringtreatments.It isnotpossible todefine specific rules to identify the causes.One typeof crashmayhavedifferentcausesatdifferentlocations.AlistofpossiblecontributingfactorsfordifferenttypesofcrashesisprovidedinTable8.Table8-Somepossiblecontributingfactorsfordifferenttypeofcrashes

Crashtype Possiblecontributingfactors

Rightanglecollisions

- Restrictedsightdistance.- Highapproachspeeds.- ‘Seethrough’effectonaminorapproach.- Obscuredcontrolsign,controllinesorsignallanterns.- Thepresenceoftheintersectionisnototherwiseevident(attimeofday).- TrafficvolumestoohighforGiveWayorStopcontrols(inadequategaps).

Rightturncollisionswithoncomingtraffic

- Restrictedvisibility.- Queuedoncomingrightturnersblockvisibility.- Insufficientnumberofgapsinoncomingtraffic.- Toomanylanesofoncomingtraffictofilteracross.- Complexintersectionlayout.

Straightaheadrearendcollisions

- Queuedrightturnvehiclesfurtherahead.- Trafficsignalsaroundcurveorovercrest.- Otherunexpectedcauseofdelayfurtherahead.- Inadequateskidresistanceorpavementdrainage.- Wrongoffsettimingoflinkedsignals.- ‘Seethrough’effectofconsecutivetrafficsignals.- Inadequateinter-greenphaseonsignals.- Presenceofparkedcars.- Unstableflowonhighspeedroad.

Rightorleftturnrearendcollisions

- Turningvehicleswheretheyarenotexpected(e.g.justbeforeorjustaftersignals).

- Aleftturnsliplanepermittinghighspeedturns.

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Crashtype Possiblecontributingfactors

Hitfixedobjectcrashes

- Islandsnotvisible.- Complexlayout.- ReasonsasforRun-off-roadcrashes

Crashesinvolvingaparkedvehicle

- Unexpectedparkedvehicleintrafficlane.- Edgelinenotvisible.- Lanestoonarrow.

Side-swipecollisions

- Lanestoonarrow(fortrafficcomposition,speed,curvatureofroad,angleoflanes).

- Lanelines,edgelinesnotvisible.- Presenceofparkedcarsorotherobstruction.- Unexpectedlanedropormergearea.- Inadequatedirectioninformation.

Head-oncollisions

- Lanestoonarrow(fortrafficcomposition,speedorcurvatureofroad).- Centrelinenotvisible.- Severityofcurvecannotbejudged.- Ahiddendiporcrest.- Insufficientovertakingopportunities.- Roadsurfacedeficiencies.

Run-off-roadtypecrashes

- Narrowlanesornarrowseal.- Severityofcurvecannotbejudged.- Edgeoftheroadisnotevident.- Gravelshouldersdonotallowrecoveryofcontrol.- Alignmentofroadisdeceptive.- Inadequateskidresistanceorpavementdrainage.

Pedestriancrashes

- Toomuchtrafficforadequategaps.- Highspeed,multi-laneandtwo-waytraffic.- Complexorunexpectedtrafficmovements.- Traffichiddenbyparkedcars,otherobjectsorexcessivelandscaping.- Amarkedcrossingwhichisnotevidenttodrivers.- Longsignalcycleswhichencouragepedestrianstodisobeysignals.- Inappropriatedeviceorlackofdevicesformixofpedestrians(e.g.disabled).- Inadequatelighting.

Railwaylevelcrossingcrashes

- Locationofcrossingisnotevident.- Impendingpresenceoftrainisnotevident.- Formofcontrolisnotaccuratelyidentified(orisinconsistent).- Driver’sattentiondistractedbyintersectionorotherfeature.- Obscuredcontroldevices.

(source:Austroads,2009)

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4.5.5 Treatingthecrashproblems4.5.5.1 ApproachestocrashreductionOnce the crash patterns and causes are identified, the issues can be approached usingdifferentstrategies.Ingeneral,thefollowingfourapproachescanbereferredto:

i. Single site: Crashes occurring at an individual site are examined in detail, commoncrashtypesareidentifiedandmeasuresintroducedtotreattheproblemsidentified.Anexamplecouldbethe introductionofachevronsignonabendwitha lossofcontrolaccidentproblem.

ii. Routeaction:Sectionsofroadareidentifiedandtreatedtogether.Anexampleofthiscouldbetheintroductionofedgelinemarkingsalongaroutewitharecordofvehiclesleavingtheroad,ortheintroductionoftrafficcalmingandgatewaysthroughavillageonanationalroute.

iii. Mass action: Groups of sites are identifiedwith common crash causes and a singlemeasureintroducedatallthesites.Anexampleofthisapproachcouldbetoidentifyaseriesofsiteswithwetskidaccidentsandapplyanti-skidsurfacingtothosesites.Themass action approach is particularly useful in rural areas on local roadswith smallcrashnumbers.

iv. Area-wideaction:Partsofanurbanareaareidentifiedwherecrashesofaparticulartypecanbeidentified,butarenotconfinedtosinglesitesorroutes.Anexampleofthiscouldbetheintroductionoftrafficcalmingtoreducepedestrianaccidentsinanurbanarea.

Theseapproachesillustratethevariouswaysinwhichanauthoritycantackleitsroadsafetyproblems.Eachapproachhasadifferentemphasisandislikelytoproduceavariationinthetypeofcrashlikelytobetreated.

Figure40–Possibleapproachestocrashreduction(source:DoE,1996)

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4.5.5.2 SelectingthecountermeasuresHavingidentifiedtheelementsoftheroadandtrafficenvironmentwhichcontributedtothecrashes, the next step involves consideration of countermeasures. For a solution to beeffective,itmustbeappliedtoaparticularproblemwhichitisknowntoaffect.Itmustbeaneffectivecountermeasure.

Theaimofcountermeasuredevelopmentisto:

• selectcountermeasureswhich,onthebasisofprofessionaljudgementandexperience,canbeexpectedtoreducethenumberorseverityofcrashesofthetype(s)dominantatthelocation

• checkthatadoptedcountermeasuresdonothaveundesirableconsequences,eitherinsafetyterms(e.g.leadtoanincreaseinthenumberorseverityofanothercrash-type)orintrafficefficiencyorenvironmentalterms

• be cost-effective, i.e.maximise the benefits from thewhole program of expenditureoveranumberofsites

• beefficient,i.e.producebenefitswhichoutweighthecosts.

There are several criteria for countermeasure selection, including (Ogded, as cited inAustroads,2009):

• technical feasibility: can the countermeasure provide an answer to the safetyproblemswhichhavebeendiagnosedanddoesithaveatechnicalbasisforsuccess?

• economic efficiency: is the countermeasure likely to be cost-effective and will itproducebenefitstoexceeditscosts?

• affordability:canitbeaccommodatedwithintheprogrambudget;ifnot,shoulditbedeferred,orshouldacheaper,perhapsinterimsolutionbeadopted?

• acceptability:doesthecountermeasureclearlytargettheidentifiedproblemandwillitbereadilyunderstandablebythecommunity?

• practicability: istherelikelytobeaproblemofnon-compliance,orcanthemeasureworkwithoutunreasonableenforcementeffort?

• political and institutional acceptability: is the countermeasure likely to attractpolitical support and will it be supported by the organisation responsible for itsinstallationandongoingmanagement?

• legalconformity: isthecountermeasurealegaldevice,orwillusersbebreakinganylawbyusingitinthewayintended?

• compatibility:isthecountermeasurecompatibleandconsistentwithotherstrategies,eitherinthesamelocalityorwhichhavebeenappliedinsimilarsituationselsewhere?

Thekey to the selectionof countermeasures is to concentrateon theparticular crash-typeswhichhavebeenidentifiedinthediagnosisphaseandwhichareamenabletotreatmentwithroad or traffic engineering measures. If this relationship between detected issues andcountermeasuresfails,theinvestmentisdestinedtobenotcost-effective.Often there will be a number of alternative remedial treatments which could be applied,either individually or in combination. The final choice about which countermeasure(s) toselect requires road safety engineering experience and judgement about the factorswhich

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have led to the crashes. A catalogue of possible countermeasures to be implemented inPakistanisreportedinthePartIIoftheseGuidelines.

4.5.5.3 AssessingthecrashreductionOncethecountermeasureisselecteditseffectincrashreductionmustbedeterminedaswellasitsimplementationcost(evenifapproximated).Several studieshavebeenperformed toestimate the safety impactof various typesof roadinfrastructure improvements.ManyexistingCrashModificationFactors(CMF)29arederivedfrom these evaluation studies, like before-and-after analysis of actual countermeasuresimplementation(see,forinstance,Elviketal.,2009)30.

An alternative method, more pragmatic, guesstimates collisions savings comparing thecurrent crash patterns with a situation where the measure is already implemented. Inpractice,itisassumedthatunlesssomethingisdoneatthesitetheexistingpatternofcrasheswill be repeated over time. The collision record is therefore re-examined, and each crashassessed todeterminewhether that particular crashwould have happened if the proposedmeasurehadbeenimplemented.

AnapplicationispresentedinBox5.

Box5.Assessmentofcollisionsavings(example)

Thereisanurbanpriorityjunctionwithahistoryof10injurycollisionsin3years,distributedasfollows:

- 4overshootsfromsideroad- 3rightturnsfrommainroad- 3pedestrianscrossingmainroad

Itisproposedtoinstalltrafficsignals.

29ACMFisamultiplicativefactorusedtocomputetheexpectednumberofcrashesaftermodifyingtheroadcharacteristicsataspecificsite(e.g.byimplementingagivencountermeasure).ACMFhigherthan1isassumedtoincreasethelikelihoodorseverityofatargetcrashtype,whileiflowerthan1decreasescrashlikelihood/severity.30AusefulreferenceisSafetyCube,aresearchprojectfundedbytheEuropeanCommissionundertheprogrammeHorizons2020(www.safetycube-project.eu).UnderthisprojectaninnovativeroadsafetyDecisionSupportSystem(DSS)providingdetailedinteractiveinformationonalargelistofroadcrashriskfactorsandrelatedroadsafetycountermeasureshasbeendeveloped(www.roadsafety-dss.eu).

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Howcanthereductionofcrashesbeestimated?

Thefollowingtablecanbeusedasareferenceguide.

Typeofmeasure Collisionreduction

Measuretotallyeliminatingtheriskfactor(e.g.segregationofdifferenttrafficstreams)

-75/100%

Measurepartiallyeliminatingtheriskfactor(e.g.newtrafficsignal)

-35/75%

Measurenoteliminatingtheriskfactor,butmakingusersawareofitspresence(e.g.newmarkings)

-25/35%

Withreferencetotheaboveranges,thefollowingreductionscanbeassumed:

Manoeuvre Potential%collisionreduction

Potentialcollisionsaving

Crossover 75%x4 3.0

Rightturn 50%x3 1.5

Pedestrian 33%x3 1.0

Total 5.5

Itmaybeneededtoaddcollisionsgeneratedbythescheme(e.g.shuntsattrafficsignals).

4.5.6 Prioritisingtheschemesonthenetwork31Havingdecidedupontreatments forhighcollisionsites, theroadauthorityshouldprioritiseallpotentialschemeswithintheirnetwork32.Thisshouldbedoneusinganeconomicappraisalthatessentiallyconcernswiththeeconomicefficiency of alternative proposals. With this appraisal economic costs of a proposal arecomparedwiththeeconomicbenefits.Theoutcomeisnotonlyanassessmentofthequalityofan individual project (i.e. there is a net economic benefit, such that the community iseconomically better off by implementing the project than by not doing so), but also - andaboveall-anindicationofwhichproject(orsetofprojects)isthebest.

While the assessment of costs is rather simple and does not require any additionalinformation,theassessmentofbenefitsismorecomplex.Benefitsareassessedbyassigningamonetaryvaluetothecrashessaved.

There is in fact a cost incurred to the communitywhen a road crash takes place. Collisioncostscanbeclassifiedinto:

• lostoutputduetodeathorinjury

31Thismethodologymainlyreferstoa‘singlesite’approach32Thedescribedmethodologycanbeappliedalsotoasinglesiteincaseitisnecessarytochoosebetweenalternativeoptions

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• humancostsofpain,griefandsuffering• resourcecostintermsof:

o hospitalo emergencyserviceo damagetopropertyo insurancecosts

At this stage,no studiesareavailable toestimate this social cost forPakistan.For the timebeing,therefore,wecanonlyrelyonproxyanalyses.

iRAPprovidesastatisticalevaluationoflifethatcanbeappliedworldwide,alongwithtypicalfataltoseriousinjuryratios(McMahon&Dahdah,2008).Therecommendedvaluesformiddleandhigh-incomecountriesareasfollows:

• Valueoffatality=70xGDPpercapita• Valueofseriousinjury=25%oftheValueoffatality

It should be borne inmind that these figures should in any case be related to the ‘averagecrash’inPakistan.Inpractice,thetotalcostofthecrasheshastobecalculatedusingtheabovemethodandthendividedbythenumberofinjurycrashes.

Once costs and benefits are estimated, it is possible to compare them and decide the bestschemestobeimplemented.

ThemostefficientmeansofprioritisingistousetheFirstYearRateofReturn(FYRR)thatisa simple way of calculating whether a scheme can be justified in economic terms33. Themethodcanbeusedtorankproposalsatdifferentsites,butalsotorankdifferentoptionsatasite.TheFYRRiscalculatedusingtheformula:

VWXX =Y&&Z)#["##$%$"&%)0$&\%

][ℎ+4+["%*

TheoptionwiththehighestFYRRisthenchosenforimplementation.However, there should be a note of caution here in that high FYRR values are generallyachievedwithschemescostinglittlemoneybutsavingfewercrashes(thetemptationtosolveeveryproblembyputtingupasignshouldbeavoided!).Thenumberofcrashessavedwithineachoptionshouldthereforebetakenintoaccount.Itissuggestedthataminimumpredictedaccidentreductionof25-30%shouldbeachievableforeachsite.

33ItshouldbenotedthatthereisamorerigorousmethodofeconomicassessmentofproposalsknownastheNetPresentValue(NPV).TheNPVmethodtakesalonger-termviewthanFYRRandcalculatesbenefitsovera10or15-yearschemelife,usingdiscountfactorstoassesscostsandbenefitsatyear1prices.ItmaybemoreappropriatetousetheNPVmethodforhighercostschemes.

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4.5.7 MonitoringandevaluationMonitoring is the systematic collection of data about the performance of road safetytreatmentsaftertheirimplementation.

Evaluation is thestatisticalanalysisof thatdatatoassess theextent towhichthetreatment(orawidertreatmentprogram)hasmetcrashreductionobjectives.Post-implementationmonitoringisessentialtoascertainthepositiveandnegativeeffectsofatreatment and thus improve the accuracy and confidence of predictions of that treatment’seffectiveness in subsequentapplications.There is aduty toensure that thepublicdoesnotexperienceadditionalhazardsasaresultoftreatmentsandthisdutycarrieswithitanimpliedneedtomonitorwhathappenswhenaschemeisintroduced.Thepurposesofmonitoringatreatmentareto(IHT,ascitedinAustroads,2009):

• assesswhatchangeshaveoccurredincrashoccurrenceandwhethersafetyobjectiveshavebeenmet

• assess the treatment’s impact on the distribution of traffic and the speeds ofmotorvehicles

• callattentiontoanyunintendedeffectsontrafficmovementsorcrashoccurrence• assesstheeffectsofthetreatmentonthelocalenvironment• learn of the public’s response to the treatment: its acceptability in general and any

concernsaboutsafetyinparticular.

Therearethreeelementstomonitoringandevaluation(CountySurveyors’Society,ascitedinAustroads,2009):

• Pay careful attention to a site immediately after treatment in case things go badlywrong.

• Assesstheeffectsoveralongertimeperiod,saythreeyears,toattempttodeterminethe influence of the treatment on crashes or other performance measures. Thisrequirescarefulstatisticalanalysis,correctingforexternalfactorsandbearinginmindthatcrashfrequenciesmaybesolowthatanyobservedchangesincrashesmaynotbestatisticallysignificant.

• Focus, over this longer time period, upon the crash-types which the treatment wasintendedtocorrectandassesswhetherthesehavedeclined.

Thefirstparametertobemonitoredis,ofcourse,thefrequencyofcrashes.Themainproblemisthattohavereliablebefore-aftercomparisonsathree-yearperiodofanalysisisneeded.

Anearlyindicationofsafetybenefitscanbeobtainedfromotherobservationslike:

• trafficandspeedsurveys• conflictstudies34

34A‘conflictstudy’isatechniquethatinvolvesobservationoftheconflicts,or‘nearcrashes’,experiencedbyroadusers.Conflictscanbedefinedas‘situationsinvolvingoneormoreroaduserswhoapproacheachothersuchthatthereisariskofcollisioniftheirmovementsremainunchanged’.Inaconflictstudythenumbersofconflictsarerecordedandgradedaccordingtothescaleofseverityrangingfromcontrolledevasivemanoeuvrestoextremeemergencyaction.

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REFERENCES

AASHTO(2011)–APolicyonGeometricDesignofHighwaysandStreets–Washington,USA

ADB(2018a)–CARECRoadSafetyEngineeringManual1/RoadSafetyAudit

ADB(2018b)–CARECRoadSafetyEngineeringManual2/SaferRoadWorksADB(2018c)–CARECRoadSafetyEngineeringManual3/RoadsideHazardManagement

AfDB(2014a)–RoadSafetyManualsforAfrica–ExistingRoads:ProactiveApproaches

AfDB(2014b)–RoadSafetyManualsforAfrica–ExistingRoads:ReactiveApproaches

AfDB(2014c)–RoadSafetyManualsforAfrica–NewRoadsandSchemes:RoadSafetyAuditAustroads(2009)–GuidetoRoadSafetyPart8:TreatmentofCrashLocations–Sydney,AustraliaBuchanan,C.(1963)-Trafficintowns;Astudyofthelongtermproblemsoftrafficinurbanareas-London,UK

CERTU(1994)-Lesralentisseursdetypedosd’âneettrapézoïdal[Speedhumpsandspeedtables](Lyon,France)

DepartmentofEnvironment(1996)-AGuidetoRoadSafetyEngineeringinIreland–Dublin,Ireland

DETR(2000)–Newdirectionsinspeedmanagement:areviewofpolicy–London,UK

DHV(2005)–Sustainablesaferoaddesign–Apracticalmanual–TheWorldBank,Washington,USA

Elvik,R,HoyeA,Vaa,T,Sorensen,M.(2009)-TheHandbookofRoadSafetyMeasures.SecondEdition-EmeraldGroupPublishingLimited,Bingley,UK

EuroRAP(2018)–RAPRoadRiskMappingManual:TechnicalSpecifications–Basingstoke,UK

McMahon,K.&Dahdah,S.(2008)–Thetruecostofroadcrashes.Valuinglifeandcostofaseriousinjury–iRAP,Basingstoke,UKNRA(2014)–RoadSafetyInspectionGuidelines-Volume5Section2,Part2,NRAHA17/14-Dublin,IrelandNRA(2016)–RoadSafetyImpactAssessmentGuidelines–Volume5Section2,Part2,NRAHA18/16-Dublin,Ireland

OECD(2006)–Speedmanagement–Paris,FranceOECD(2008)–TowardsZero:AmbitiousRoadSafetyTargetsandtheSafeSystemApproach–Paris,France

PIARC(2015)–RoadSafetyManual–AmanualforpractitionersanddecisionsmakersonimplementingSafeSysteminfrastructure!–Paris,France

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UNESCAP(2004)–IntergovernmentalagreementontheAsianHighwayNetwork–Shanghai,China

UNESCAP(2017a)-DevelopmentofroadinfrastructuresafetyfacilitystandardsfortheAsianHighwayNetwork(draftversion)–Bangkok,Thailand

UNESCAP(2017b)-RecommendedDetailDesignGuidelinesonRoadInfrastructureSafetyFacilitiesfortheAsianHighwayNetwork(draftversion)–Bangkok,ThailandVanSchagen,I.N.L.G.,Dijkstra,A.,Claessens,F.M.M.&Janssen,W.H.(1999)-Recognitionofsustainablysaferoadtypes-SWOVInstituteforRoadSafetyResearch,Leidschendam,TheNetherlands

Wegman,F.&Aarts,L.(2006)-AdvancingSustainableSafety:NationalRoadSafetyOutlookfor2005-2020-SWOVInstituteforRoadSafetyResearch,Leidschendam,TheNetherlandsWHO(2008)-Speedmanagement:aroadsafetymanualfordecision-makersandpractitioners–Geneva,SwitzerlandWHO(2010)–GlobalPlanfortheDecadeofActionforRoadSafety2011–2020-Geneva,Switzerland

WHO(2015)–Globalstatusreportonroadsafety2015–Geneva,Switzerland

Road Safety Guidelines Part-I...PIARC World Road Association RSA Road Safety Audit 7 ADB Project...

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