THE FUTURE OF TRAFFIC mAnAgEmEnT - Robert L....
Transcript of THE FUTURE OF TRAFFIC mAnAgEmEnT - Robert L....
THE FUTURE
OFTRAFFIC
mAnAgEmEnTState of the Art,
Current Trends and Perspectives for the Future
THE FUTURE
OFTRAFFIC
mAnAgEmEnTState of the Art,
Current Trends and Perspectives for the Future
Page 6
1. The Social and economic Urgency of Traffic managemenT
Page 11
2. Traffic managemenT: how doeS iT work?
Page 19
3. STaTe of The arT and cUrrenT TrendS
Page 26
4. PerSPecTiveS for The fUTUre
Page 30
5. There iS STill work To do
Page 43
6. fUTUre reSearch agenda
COnTEnTS
BACkground TRAFFIC mAnAgEmEnT In THE nETHERlAndS
Traffic management applies measures to adjust the demand and capacity of the traffic network, in time and space, to better “match” the traffic demand and supply (capacity).
Examples of traffic management measures in the Netherlands are:
• Rampmetering • Dynamicrouteinformation • Dynamiclanemanagement • Queuestorage • Nationaldatawarehouse • Incidentmanagement • Tapering • Variablespeedlimits • Peak-hourlanes(hardshoulderrunningduringpeakhours) • Pluslanes(dynamicleftlane) • Sectioncontrol(variablespeedlimitandenforcement) • Queuetailwarning
At least eight entities are used for traffic management, which deter-
mine the total traffic system, and which are constantly interacting:
• Trafficmanagementcenter/emergencymanagementcenter • Measures • Controlprinciples/scenarios • Vehicles • Road/infrastructure • Roaduser • Organization • DataandInformation • Roadinspectors • Serviceproviders/police/emergencyservices
5
1. THE SOCIAl And ECOnOmIC URgEnCy OF TRAFFIC mAnAgEmEnT
In just a few years, traffic management has been transformed from an everyday, passive task for the highway authority to an important policy instrument. This transformation is not without reason.
Traffic management has improved the safety and operations on our roadways, while it is relatively inexpensive, flexible and rapidly deployable. Transportation professionals are also convinced that
the potential of traffic management is far greater than previously imagined.
Weknowthattherearecriticalproblemsthatcallfortrafficmanagementsolutions.DespitethefactthattheNetherlandsboaststhehighestmotorwaydensityintheEuropeanUnion,westillspendabout65millionhoursperyearincongestion.Theeconomiccostofthiscongestionises-timatedatanamountbetween2.5and3.4billioneuroseachyear.
Becauseourroadnetworkalongkeyroutesisalreadyheavilyloaded,eachper-centincreaseintrafficflowcompoundstheproblem.
Promising SolutionsSolutionstoimprovemobility,accessibilityandreliabilityarethereforenecessaryandverymuchdesired.Trafficmanagementisobviouslynottheonlyapproachtowardsolvingcongestionandmobilityproblems(seealsothepage9),butitiscertainlyoneofthemostimportant,cost-effectiveandpromisingtoolsinourtoolbox.
Whatdowemeanbytrafficmanage-ment?Definitionsvaryslightly,butsimplyput,wetrytoinfluencesupplyanddemandwithtrafficmanagement,suchthatthetraf-
ficdemandandthesupply(capacity)ofthenetworkbettermatch,alongboththedi-mensionsoftimeandspace.Theproblemsthatoccurontheroadprimarilyconcernspecificbottlenecks(pointsinspace)andspecificmomentsintime(peakperiods,incidentsandspecialevents).Theaimistospreadboththetrafficdemandandthesupplyofinfrastructure(capacity)inordertoadaptdynamicallyandthusmakebetteruseoftheexistingroadnetwork.Thefieldoftrafficmanagementincludesbothtrafficcontrolandtravelerinformation.
6
Typicaltrafficmanagementmeasuresin-cluderampmetering,dynamicspeedlimits,peakhourlanes(hardshoulderrunning),andtravelerinformationdisplayedonvari-ablemessagesignsabovetheroadwayorviaotherchannels.Themeasureshavebeenprimarilyintendedtoimprovemobil-ity,accessibility,andreliability,buttheyarealsoincreasinglydeployedtoimproveroadsafety(forexample,congestionorqueuewarningsviathevariablespeedlimitsigns)ortoimprovelivability(forexamplebyspeedrestrictions).
Benefits of Traffic ManagementWearestillworkingonthequestionofexactlyhoweffectivetrafficmanagementmeasuresareinpractice,andthisisanimportantdiscussion.Weparticularlyneedtounderstandthecumulativebenefitsofthejointdeploymentofmultiplemeasures,whichisdifficulttodetermine.Butwearecertainthattrafficmanagementmeasuresleadtorealbenefitstosafety,mobilityandsustainability.Forexample,theNether-landsInstituteforTransportPolicyAnalysis(KiM)hasestimatedthatduringtheperiod
2000to2010trafficmanagementintheNetherlandssucceededinreducingdelaysby14%,withafractionofthecostoftheconstructionofnewroadways.
Itisexpectedthattrafficmanagementcanresultinaddedbenefitsbyencouragingandfacilitatingclosercooperationbetweenroad authorities, other transport entities, emergencyresponders,andtheprivatesec-tor,partlythankstotheavailabilityofnewtechnology.Giventhemobilityproblemsforbothpassengerandfreighttravelin
theNetherlands,weconsidertrafficman-agementtobesociallyrelevantandevenurgent.
Thereappeartobesufficientreasonstoconsiderthispolicyinstrumentmoredeeply.Whydoesitwork?Howisitcur-rentlydeployed?Whatkindsofneartermdeploymentsdoweenvision?Andhowcanweensurethatthepotentialbenefitsoftrafficmanagementarefullyrealized?Inthisdocumentwewilldiscusseachofthese topics.
7
SOlUTIOnS BEyOnd TRAFFIC mAnAgEmEnT
Constructing new roads, improving bot-
tlenecks or widening existing roads are obviousapproachesforsolvingmobilityproblems.Theseareusuallyeffectiveandsometimesevennecessary.However,therearedrawbacks.Sometimesaddressingonebottlenecksimplyshiftsthebottlenecktoanotherlocation.Also,constructioninahighlydevelopedenvironmentisexpen-siveandtimeconsuming,anditselfhastrafficimpacts.Givenitsspatial,socialandenvironmentalconsequencesnewcapacityshouldonlybeconsideredwithcaution.
The rational pricing of the infrastruc-
ture, such as road pricing and distance
basedcharging,isanotherpossiblesolution.Oneapproachistodevelopachargingsystemthatisconstantintimeandspace.Itisalsopossibletovarythepricingratesintimeandspacewhichwillmakepeakperiodtravelandcongestedrouteslessattractiveandtherebyreducecongestion. road pricing is seen as of-feringinterestingpossibilities,butsofarthemajorpoliticalhurdleshaveproventoodifficult.Onepossibleexplanationisthatcomplexdecision-makingmustbehandledbyonegovernment,whiletheimplementationandmanagementdependsonthepoliciesofthenextgovernmentad-
ministration.Inanycase,suchasolutionwilllikelynotbeintroducedintheNeth-erlandsintheshortterm.
Transportation demand management in-cludeseffortsbygovernmentagenciesandemployerstoreducetravelbyusingmeas-uressuchasteleworkingortelecommut-ing,measurestoshiftthetravelmodetowalking,cyclingandpublictransportation,andmeasurestoshifttraveltooff-peakperiods.Transportationdemandmanage-mentisoftenusedasameasuretosupportlarge-scaleinfrastructureconstructionormaintenanceprojects,butdoesoffermorepossibilities.
Traffic management is not the only tool for maintaining mobility, accessibility and reliability.
What other solutions are there?
9
Driverstypicallychoosetheirpreferredoroptimalroutesfromtheiroriginstotheirdestinations.Aslongastrafficislight,transportationsystemusersdonotcauseanysignificantdisruptionstooneanother.Onthemotorway,driverswillspreadthemselveseffectivelyacrossthelanes,leadingtoasynchronizedsituation.Thegreatthingisthatindividualchoicesofsystemusersalsoresultinabalancedsituationatthenetworklevel,inwhichtheavailablespaceisusedefficiently.
Butthisself-organizationhasitslimits.Astrafficbecomesheavierorthereareunforeseenincidents(suchasacrash,abreakdown,orotherrandomevents),thetrafficsystemcanbecomeunstable.Injustafewminutes,trafficconditionscantransitionfrom“runningsmoothly”to“severedelays.”
What Can Go Wrong Fortrafficmanagementmeasurestopost-pone or prevent the onset of congestion, it
isimportanttounderstandtheunderlyingprocesses.Inotherwords:whatexactlyhappenswhencongestionarises?
Onephenomenonthatarisesistheca-
pacity drop.Capacityismeasuredasthemaximumnumberofvehiclesthatcanpassagivenpointovertime(usuallyinvehiclesperhour).Whencongestionoc-curs,thecapacitytypicallydropsanaver-ageof14%,sometimesasmuchas30%.Thishappensatfixedbottlenecksbutalsofrequentlyinmovingshockwaves.Shock-
Most of the time, traffic can organize itself. But as traffic gets busier, the system is confronted with phenomena such as spillback and capacity drop. Through careful
intervention aimed at optimizing traffic flow – traffic management – we aim to prevent or at least mitigate problems.
2. TRAFFIC mAnAgEmEnT: HOw dOES IT wORk?
11
wavesoccurwhen,forexample,adriverbrakessharply,resultinginaqueueform-ingbehindwithhigherdensityandlowerspeed.Theshockwaveactslikeawaveofbrakelightsmovingagainstthedirectionthattrafficismoving,withaspeedofap-proximately18km/h.Theshockwavecansometimespersistlongerthanonehour.
Onceweobservethecapacitydrop,itistoolate–congestionhasformedanditwilltaketimetodissipate.Thechallengehereistoactuallyanticipatetheformationofcongestionandtherebypreventorpost-ponethelostcapacity.
The sub-optimal route choices of indi-vidualtravelerscanalsocauseproblemsforotherusers.Obviouslynotwhentrafficislight.Ifyouthenchoosealessoptimalroute,atmostitleadstoalongertraveltime(plusaddedfuelconsumptionandemissions)foryourself.Butiftrafficisheavy,oneperson’schoicewillimpacttheothers’–travelerBspendsmoretimeinthequeuebecausetravelerAspendsmoretimeonthenetwork.Sincemostroadusersreceivenoinformationabouttheconsequencesoftheirroutechoice,they
continuetomakeinefficientchoices.Afinalprocessthatwewanttohigh-
lightisspillback.Thisoccurswhenaqueueemanatingfromabottleneckatonelocationobstructstrafficflowatanother(upstream)location.Theabovefigureshowsanexampleofspillbackonamotorway.Thereissomuchtrafficen-teringthemotorwayatrampAthatthisleadstotheformationofaqueueonthemotorway.Thequeuegrowsandgrows,propagatingupstreamuntilexitBisblocked.TheresultisthatmotoristswhowanttouseexitB(andsohavenothingtodowithrampA),areblocked.Thisjust
causesthetrafficjamtocontinuegrowingasitspreadslikeanoilslickacrossthenetwork.Justremember:weshouldneverblockanexitwherepeopleactuallywanttoleavethesystem!
Fundamental Diagram Thephenomenadescribedabovearegoodexamplesofwhytrafficcanbecomeun-stable.Therearemoreprocessesworkingtogether,buttheendresultisalwaysthesame:ataparticularmomentthesystemwillcollapseanditwilltakehourstore-cover.
Atthenetworklevelthiscanbede-
ExitB RampA
Exampleofspillback
12
scribedbyaverysimplerelationship,knownasthefundamental diagram. This diagram,asshowninthefigureonthispage,showstherelationshipbetweenthenumberofvehiclesinthenetworkandthe“production”(thenumberofvehiclesleav-ingthenetworkperunittime).Iftrafficislight,anincreaseinthenumberofvehiclesinthenetworkleadstoaproportionalincreaseintheproduction.Butbeyondacertainpointwhentrafficbecomesheavier,productivityincreaseslessrapidlyandataspecificpointitevenstartstodecrease.Inthatregion,anincreaseinthenumberofvehiclesleadstofewervehiclesleavingthenetwork.Wecallthisstagnation!
Traffic Management SolutionsThisfundamentaldiagramisinfactabasicbuildingblockforalltrafficmanagementstrategies.Ifthenumberofvehiclesinanytrafficnetworkapproachesthecriticalpointandyoufailtointervene,theproblemsquicklybegintomultiply.
Ofcourseitisimportanttointervenecor-rectly.Thegoodnewsisthatthepreviouslydiscussedcausesandphenomenaprovide
usefulguidanceforthedevelopmentofin-telligentwaysofmanagingtrafficinanet-work.Wecanidentifyfourbasictypesofsolutionsinthefieldoftrafficmanagement:
1. Increase ThroughputOnewaytocombatcongestionistoin-creasetrafficflowatcriticallocations.Forexample,youcanadjustcapacitytemporar-ilybyusinganadditionallaneduringthepeakperiod.Combatingthecreationofshockwavesisanotherwayofincreasingtrafficflow.Congestionleadstoacapacitydrop.Ifyoueffectivelycombatshockwaves
(byslowingthetrafficthatisdrivingto-wardsashockwave)thisincreasestheca-pacityandthusthethroughput. 2. Effectively Distribute Traffic Across the NetworkThesecondkeyapproachisthebetterdis-tributionoftrafficoverthenetwork.Thisisimportantbecausethesub-optimalchoicesoftravelersleadtoanunbalancedandinef-ficientuseoftheinfrastructure.Thismeansthatoneroutemaybecomesignificantlyoverloadedwhileotherroutesremainfreelyflowing.Byprovidinghelpfulinformation
Production
Numberofvehiclesinthenetwork
Ifitbecomesbusier,thentheproductionwilldecreasemoreandmore
13
touserssothattheycanmakebetterdeci-sions,theentirenetworkismoreefficientlyutilized. 3. Regulate the Inflow of TrafficThethirdsolutioninvolvesregulatingtheinflowoftrafficsothatthenumberofroaduserstravelingintoanarearemainsbelowthecriticalnumber–belowthetippingpoint.Consideramotorwayringaroundacity–keepingtheringmovingcanbecru-cialformaintainingaccess.Onepossibilityistoregulatetheinflowontheringwithmeasuressuchasspeedlimitsonaccessroads,trafficsignals,orrampmetering(“onevehiclepergreen”)aton-ramps. 4. Prevent SpillbacksThefourthandfinalapproachispreventingspillback.Thiscanbeaccomplishedinsev-eralways.Inthesituationoutlinedonpage12youcanregulatetheinflowtothebottle-neckusingrampmetering.Thiswouldpre-ventthequeuefromformingatthatpoint
andfrompropagatingupstreamtoexitB.Weshouldbearinmindthatthismaycauseaqueuetobackupontotheunderlyingnetwork.Butthattrafficcanbetemporarilystoredinabufferareainalocationwhereaqueuewillnotdisruptlocalroadways.Traf-ficinthebuffermustwaitforashortwhile,butthesystemasawhole,andultimatelyalltravelers,arebetteroff.
Inaddition,wenotethattheabovefoursolutionsfocusonimprovingtheperfor-mance(theefficiency)ofthetrafficflow.IntheDutchframeworkofSustainableTrafficManagement(GGB),otherkeyobjectivesarerelevantsuchasimprovingroadsafetyandreducingtheemissionsandfuelcon-sumption.Torealizetheseobjectivesothersolutionsemergesuchas:•Managingorcontrollingthespeedof
traffic.•Improvingthesafetyofvehicles(such
measuresfallundertheconceptsof eSafety).
•Improvingthesafetyoftheroadwayinfra-
structure(suchashighrisksitemanage-ment).
Is More Possible?Theabovesolutionsarefairlycommoninthetransportationandtrafficengineer-ingcommunities.Mostroadauthoritiesaredevelopingtheirtrafficmanagementprogramsalongtheselines.Aswehavepointedout,thesetechniqueshavebeenrelativelysuccessful(intheNetherlandsan14%decreaseindelayhasbeenreportedduetotrafficmanagementimprovementsbetween2000and2010).Buttrafficexpertssuggestthatthereisstillmorepossiblewithtrafficmanagement,forexamplewithare-gional,coordinateddeploymentofmutuallycomplementaryandreinforcingmeasures.Animportantissueisalsothatthefieldoftrafficmanagementisconstantlychangingalongtechnologicalandsocietaldimen-sions. To ensure thattrafficmanagementiseffectiveinthefuture,itisimportanttorespondorbetteryet,anticipate.
2. TRAFFIC mAnAgEmEnT: HOw dOES IT wORk?
14
mEASURES In RElATIOn TO THE mAIn SOlUTIOnS
ThetrafficmanagementmeasuresthatwearefamiliarwithandapplyintheNetherlandscanbelinkedtothefourtypesofmainsolutionsdescribedabove.Inthetableonthispageweillustratethisforarangeofspecifictrafficmanage-mentapplications.Notethatthemeasuresshowncangenerallybeusedtoaddressmorethanoneproblemandsointhatrespectaremultifunctionalandcomplemen-tary.
mAIn SOlUTIOnS RAmp mETER TRAvElER InFORmATIOn
pEAk HOUR SHOUldER lAnES
dynAmIC SEpARATIOn OF THROUgH And lOCAl TRAFFIC
InCREASE THROUgHpUT
Effective capa-cityincreasebypostponingqueueformation
- Increasecapacitybyopeninganextralaneduringpeakperiods(shoulderand/orre-striping)
Increaseinca-pacitybydecre-asingweavingmovements
EFFECTIvEly dISTRIBUTE TRAFFIC
Reducecut-throughtraffic(ratrunning)
Informdriversaboutrouteswithresidualcapacity
- -
REgUlATE InFlOw Regulateente-ringtraffictomainroadway
Informdriverswhichon-rampto use if options areavailable
- -
pREvEnT SpIllBACkS
Prevent queue spillbackonthemainroadwaytoanupstreamexit
Informdriverstochooseexitifoptions are avai-lable
Preventspillbackbybufferingtraffic
Preventspillbackbychannelingexitingtraffictodedicatedlanes
Relationship between traffic management measures and primary solutions
15
3. STATE OF THE ART And CURREnT TREndS
STATE OF THE ARTWehaveappliedtrafficmanagementintheNetherlandsforseveraldecades.Whatbeganinthe1980sasasingleinitiativeofRijkswaterstaat(executiveagencyoftheMinistryofInfrastructureandtheEnviron-ment)hasnowbecomeabroadfieldwithmultipledifferentplayersandawiderangeofsolutions,measuresandtechnologies.
MeasuresForcontrollingandmanagingtrafficflows,road authorities have a range of instru-ments:rampmetering,adaptivetrafficsig-nalcontrolsystems,greenwaves,roadsidepanelsfordynamicrouteinformation,and
dynamicdedicatedlanes.Mostofthesesystemsareprimarilyfocusedonimprovingtrafficflow,butsomehavebeendevelopedwiththebenefitsofimprovingsafety,liv-abilityandsustainability(includingreduc-ingfuelconsumptionandemissions).Ex-amplesofthisincludethemotorwaytrafficmanagementsystem,andthequeuetailwarningsystemandvariablespeedlimits(toimproveairquality)whicharepartofthat.
Travelerandtrafficinformationisavail-ableviaradio,television,computer,smart-phoneandin-vehiclenavigationsystem.Theinformationitselfischangingfrompre-tripexpectationstoreal-timepre-tripand
en-routeinformation(insomecasesevenmultimodal).Wenowareaimingtowardmeetinguserexpectationsbyprovidinginformationthataccuratelydescribesthecurrentandfuturetrafficconditions,andisaccessiblesafely,anytime,andanywhere.Thistransitionisnotyetcomplete–inparticularweneedtoimprovetheaccuracyandpersonalizationoftravelerinformation.
Collecting Traffic DataCurrentlyitisprimarilytheroadauthoritiesthatcollecttrafficdata,typicallythroughinfrastructure-basedsensorsofdifferentkinds,includinginductiveloops,radar,videoandBluetooth.IntheNetherlands,
It is clear that traffic management works and will continue to be effective in the future. But what does that future look like? To provide such a vision, it is important to describe the current state of the art first. In other words, where do we stand with traffic management?
A look at the trends will then provide insights into the direction we’re heading.
19
thedataarearchivedintheNationalDataWarehouseforroaddata(NDW)andmadeavailableforafeetoserviceproviders.
However,moreandmoretheprivatesectorisactivelycollectingadditionaldatafrommultiplesourcesincludingvehiclesandsmartphones.Thesedatamostoftenincludeposition,speedandtraveltime.Thechallengeishowtobringthesecom-plementarydatasourcestogether.
PlayersGovernmentagencies–intheNetherlandsincludingRijkswaterstaat,theprovinces,andmunicipalities–havetheresponsibilityforcontrollingandmanagingtraffic.Thisisdonefromthedifferenttrafficmanagementcenters.Theprivatesectorplaysaleadingroleininformingroadusers.Thatsubdivi-sionofresponsibilitiesisnotentirelyacci-dental.Bycontrollingandmanagingtraffic,governmentagenciesareinvolvedinpri-marily“communityinterests”suchasac-cessibility,qualityoftheenvironmentandsafety,andthoseinterestsaretraditionally
providedbythegovernment.Theprivatesectorisdrivenbytheprofitmotiveandthereforefocusesmoreontheindividualinterestsofroadusers:trafficinformationservicestohelpcustomersavoidtrafficjams,providingalternateroutesandrealtimeinformation.
CooperationThecooperationandcollaborationbetweengovernmentagenciesforcontrollingandmanagingtrafficisreasonabletogood.Thetrafficmanagementapproachwasuntilre-cently“locationbased,”wherethevariousroadauthoritiesfocusedmainlyonisolatedbottlenecksandontheroadswithintheirparticularjurisdictions.Withtheincreaseinthenumberandcomplexityofmobilityproblems,ithasbecomeclearthatamoreregionalapproachisrequired,includinginthetrafficmanagementcenters.ThankstomethodologiessuchasSustainableTrafficManagement(GGB),thefocushasshiftedtoamorenetwork-orientedapproach.Trueoperationaltrafficmanagementatthere-
gionallevelisstillrare,butinmanyregionsthere is good cooperation on the strategic andtacticallevels.Alsoduringmajorroadconstruction,cooperationisfine(e.g.,co-ordinatingworkanddetoursondifferentjurisdictions’roads).
However,whenwelookatthecoopera-tionbetweengovernmentagenciesandtheprivatesector,inotherwordsbetweencon-trollingandmanagingononehand,andinformingontheother,thepictureislessclear.Thedomainsdonotalwaysreinforceoneanother–andsometimestheyevenworkagainsteachother.Takeforexam-ple,thegrowinggroupofroaduserswho,thankstothetrafficinformationontheirin-vehiclenavigationsystems,avoidsprob-lemsonthemainnetworkbychoosinganalternativeroutevialocalroads,sometimesthroughvillagecenters.Inthatcasethereisaconflictbetweentheindividualinter-estofroadusersandthecollectivepublicinterest(qualifyoflifeandsafety)wheregovernmentagenciesandroadauthoritiesareresponsible.
3. STATE OF THE ART And CURREnT TREndS
20
CURREnT TREndSIncomingyearswewillseemanychang-esinthefieldoftrafficandtransporta-tion.Societalanddemographictrends,technologicalandeconomicdevelopments–theywillall,toacertainextent,impactthedevelopmentandapplicationoftrafficmanagementsolutions.Inthefollowingwewillhighlightthemostrelevantinflu-encingfactorsforthenext10to25years.
Societal TrendsSocietywillfurtherpersonalize,within-creasingemphasisonindividualcitizensandtheirfreedomofchoice.Atthesametime,however,citizenswillexpectgovern-mentagenciestopursuethesocialgoalsofsafety,accessibility,livability,andsus-tainability.
road users have access to accurate andintelligenttrafficinformation,andwillthereforebeabletomanagetheirindividualobjectives(includingcomfortandoptimaltraveltime).Futuretrippur-posesandtravelpatternswillcontinuetochange,partlyasaresultofdemographicshifts,theagingpopulationandsocialme-
dia(“GenerationY”).Thesechangesmayleadtolesstraditionalcommuting,buttomoreleisureandrecreationaltrafficandmorepublictransportuse.Theinterestforflexibleworkenvironments(teleworking,teleconferencingandhoteling)willgrowaccordingly.Thishasimplicationsforresidentiallocations,departuretimes,andcommutingdistances.Astrafficvolumescontinuetoincrease,discussionsabout
roadpricing(payingfortheuseofinfra-structure)willlikelyreturn.
Organizational TrendsFromthetrafficengineeringandadmin-istrativeperspectiveweseeanincreasingintegrationofmajorroads,provincialroadsandurbannetworks.Thisincludesdatacollection,trafficmanagementplan-ningactivitiesandimplementation.
21
Public-privaterelationshipswillalsochangeinthecomingyears.WithDesign,Build,Finance,MaintainandOperate(DBFMO)contracts,forexample,newgovernmentandprivatesectorroleswillemerge.Theresponsibilityformainte-nance,administrationandmanagement
willfallincreasinglyontheprivatesector.Alsowiththegrowthintheuseofin-vehicletechnologies(suchasnavigationsystemsandmoreadvancedcooperativesystems)theprivatesectorcouldultimate-lytakeonmoretrafficmanagementtasksthanjustprovidinginformation.
Finally,fortheNetherlandsthereisthefurtherinternationalizationoftranspor-tationpolicies.Europe’stransportationpoliciesaredeveloping,andthisalsohasimplicationsfortrafficmanagement.TheNetherlandswillhavetotakeintoaccounttheEuropeanCommission’sActionPlanfortheIntroductionofIntelligentTrans-portSystemsinEurope(ITSActionPlan,2008)andtheITSDirective(2010).Forexample,withthisDirectivetheECmayissuebindingspecificationsforintelligenttransportationsystemsinthefuture.
Technological DevelopmentsTechnologicalinnovationsinthefieldoftrafficinformation,driverassistancesystemsandinterventioninhazardoussituationswillmakeitpossibletodevelopfurthertrafficmanagementinnovations.Forexample,imaginetheenormousop-portunitiesofferedbythecommunicationbetweenin-vehicleandroadsidesystems.Newcooperativesystemswillbeplatformsforservicesbeyondtravelerinformation
3. STATE OF THE ART And CURREnT TREndS
22
alone–suchasindividualguidance,rout-ing,hazardwarningsandcrashavoidance.Givensufficientpenetrationintothevehiclefleet,newtrafficmanagementsystemswillbepossibleduetothepresenceofincreas-ingproportionsofprobevehicleswithmoreaccuratepositioningdataleadingtopreventative intervention. Secure and con-venientfinancialtransactionswillalsobepossiblethroughsuchaplatform,usefulforanykindofpricingmechanismdesiredinthe future.
Forintelligenttransportationsystems(ITS)tobeeffectivelyusedasatrafficman-agementmeasure,asufficientlyhighpen-etrationrateof30to70%isnecessary.Theautoindustryassumesthatin-vehiclesys-temswillbestandardforallnewvehicles.Governmentagenciescanactivelysupportthisdevelopment.Standardizationisarequirement–thiswillfacilitatethedevel-opmentofnewfunctionalitiesandservicesandthusacceleratetheimplementation,reduceunitcostsandincreaseconfidenceininvestments.StandardizationcanbeorganizedfromtheEU,butalsofromthe
automotiveandsupplierindustries.Thede-velopmentsinothermajormarkets(Japan,U.S.)willcertainlyplayarole.
Itisnotyetcleartowhatextentin-vehiclesystemscomplimentarytoroadsidesystemscanandwillbeusedforregulationandenforcement.
Economic TrendsThereisastrongrelationshipbetween
trafficdemandandeconomicdevelop-ment.Economicfluctuationscanthereforeleadtosubstantialchangesinthedeploy-mentoftrafficmanagementstrategies.Particularlyinagrowingeconomyitwillbenecessarytousetheexistingcapacityoftheroadnetworkaseffectivelyaspos-sible.Theeconomicsituationalsoaffectstheinvestmentclimateandbusinessop-portunitiesformobilityservices.
23
TREnd AnAlySIS COnClUSIOnS
Relationships between trends and developments, supply and demand, goals and traffic management.
The above discussion provides a glimpse
into the current and foreseeable
problems around traffic and mobility, along with various trends and possible
future developments. The adjacent figure
outlines these developments and shows the
relationships between the trends, goals,
demand, supply and traffic management.
Technological developments
Economictrends
Trafficmanagement
(incl. instruments)
Supply
Goals
Demand
Aging population, “Generation Y”Teleworking and teleshopping
Acceptance of road pricing
Cooperative systems Development of traffic management instruments
Stronger role of the marketRegional approach
In-car technology
Economic development
Focus on economicallyimportant zones
Energy guaranteeEconomic development
IndividualizationImportance sustainabilityPerspective mobility
Societaltrends
Organizational trends
24
Itisclearthatweexpectsignificantshiftsintrafficdemandasaresultofsocialandeconomictrends,butalsointhemobilityobjectives.Forexample,weforeseemorefocusonsustainability.Atthesametime,wehavesubstantialopportunitiesforincreasingtheeffectivenessoftrafficmanagement.Cooperativesystems,furtherdevelopmentofthetoolsfordynamictrafficmanagement,andnewperformancemeasuresandmethodsareallpossible.Alsoattheorganiza-tionallevel,wewillbeabletogainbenefitsfrombet-terregionalcooperation,furtherdevelopmentsintheprivatesectorandfuturepublic-privatepartnerships.
Asideeffectofpersonaltrafficinformationandtherolethattheprivatesectorplays,isthatroadus-ersarebecominglesseasytoinfluence,forexample,withqualityoflife,livability,orsafetyasobjectives.Thismeansthatinthefutureitisevenmoreimpor-tantthatthegovernmentandtheprivatesectorwork
togetherininforming,managingandcontrollingtraf-ficstreams.Individualinterestsrepresentedbytheprivatesectorandsocialinterests(government)mustbereconciled.Ifnot,thegovernmentwillneedtobe-comemorestrictinpreventingunwantedbehaviorofknowledgeableusers–forexample:travelthroughatowncenterbecauseitisjustalittlefaster.
Finally,inthefuturechangesinmobilityobjec-tivesmayberequiredinordertoallowamoreflex-ibledeploymentoftheinfrastructureandaproactiveinfluenceonthetrafficdemand.Thisleadsalmostautomaticallytoanextensionoftheroleoftrafficmanagement.Ifweaddtheeconomicdevelopmentandsocialrestraintsontheconstructionofnewinfra-structure,thenitbecomesclearthattheopportunitiesandpossibilitiesfortheeffectivedeploymentoftrafficmanagementwillonlyincreaseinthecomingyears.
3. STATE OF THE ART And CURREnT TREndS
25
4. pERSpECTIvES FOR THE FUTURE
Theprimarytaskoftrafficmanagementistheappropriateoptimizationandmatch-ingoftrafficsupplyanddemandaccord-ing to infrastructure constraints. Even nowthisistheprimarytask,buttheim-portanceofthesupply/demandalignmentwillonlygrowinthecomingyears.
Thefirstlevelofoptimizingormatch-ingtransportationsupplyanddemandoccursatthenetworkplanninglevel.Theregularpatternofdemand,insofarasitexists,willestablisha“baseload”forthenetwork,definingthequantityoftraffic
thatneedstobeaccommodated.Acertaindegreeofcongestionisallowedduetothepeakingphenomenon.Whatexactlyisal-lowed,determinesthenecessityofroadcapacity.
Oncethenetworkcapacityhasbeenes-tablished,thenthebalancebetweensup-plyanddemandisanoperationalissue,withtrafficmanagementasanimportantinitialinstrument.Trafficmanagementmakesitpossibletodynamicallyrespondtotheever-changingtrafficsupplyanddemand.Trafficmanagementisalso
particularlycriticalduringnonrecurrentandunexpectedsituations,suchasroadconstruction,specialeventsorincidents.Thiswillleadtoabetterbalancebetweenindividualinterestsandtheinterestsoftheroadauthorityandsociety.Individualchoicesmustbeadjustedsothattheen-tirenetworkwillbenefit.
High DemandsIfwewanttrafficmanagementinhighdemandsituationstobesufficientlyeffec-tive,themeasuresmustbepowerfuland
Traffic management of the future needs to be especially flexible, cooperative and proactive. We should be able to quickly respond to changes
in supply and demand, to deploy coordinated measures and manage the different networks as a whole. What is required? One requirement is that road authorities, private sector partners and research/education institutes
should work together and cooperate more closely.
26
impactful.Withmoreflexiblemanage-mentofsupplyanddemand,therewillbegreateropportunitiesforcoordinationandthusforcombatingcongestion.Thisrequiresahighdegreeofinstrumentationonrouteswheretrafficcanbeguidedanddirected(includingmotorways,arterialsandlocalroads).Wemustalsoconsiderwhattypesofmeasuresarerequired:themechanismsforinforming,controlling,andmanagingaswellasthepenaltiesandrewardsthatareavailable.Themeasuresshouldbewellcoordinatedandshouldberapidlydeployable.Inaddition,atransi-tionfromreactivetrafficmanagementtoproactivetrafficmanagementisnecessary.Thisrequiresagreaterroleforrouteguid-anceandtrafficcontrolundernormalandincident-relatedconditions.Predictionisanimportantcomponentofthisvision.
ConclusionInsummarywecansaythatthetrendsanddevelopmentsdescribedhereofferexcellentopportunitiesfortrafficmanage-ment.Buttrafficmanagementmustmeetanumberofimportantrequirements:
•Trafficmanagementofthefuturemustbemoreflexibleinhandlingchangesinsupplyanddemand.
•Measuresmustbecoordinatedandusedacrossthenetwork.
•Trafficmanagementmustbeproactiveandcanbeusedtoachievearangeofpolicyobjectives.
•Roadauthorities,privatesectorparties
andresearch/educationinstitutionswillneedtostrengthencollaborations.
Onlythencanwecontinuetodelivertraf-ficmanagementasaconstructivecontri-butiontothequalityofthetransportationsystem.
27
5. THERE IS STIll wORk TO dO!
Flexibility in Supply and DemandFortrafficmanagementtobereallyeffec-tive,itisnecessarytoinfluenceboththedemandandsupply.Atpresent,allroadauthoritieshaveavarietyofmeasurestoaccomplishthis.Buttotakeasignificantstepforward,thescopeofthesemeasuresshouldbeincreased.
Influencingtravel demandischalleng-ing.Dynamicroadpricingisapotentiallyeffectiveinstrument,butintheNeth-erlandsdeploymentislimitedtostatic
tollingandcurrentlyitisnotdeployedfortrafficmanagementpurposes.Therearealsoinitiativesthatrewardroadusersfortravelingoutsideofthepeakperiods.Thisformofpricinghasbeentestedex-perimentally.Itmaybesuitablefortem-porarysituations,suchaslarge-scaleroadconstructionwithcapacityimpacts.Amuchbroaderdeployablesolutionsuchasanoverallkilometercharge,hasthusfarbeenprovenpoliticallyinfeasible.There-fore,intheshorttermitisappropriatetoexplorewhetheralimitedpricingmeasure
suchashighoccupancytoll(HOT)lanes(wheresingleoccupantvehiclescanpaytoenteracarpoollane,withstaticordy-namicprices)ashavesuccessfullybeenimplementedintheU.S.,canbeeffectiveintheNetherlands.
Anotherwaytoinfluencedemandisbyprovidingtrafficinformation.Thiswayyoucanencouragetravelerstoreconsidertheirmobilitybehavior.Theinformationmustbeofhighqualityandtailoredtotheindividual.Thenitmaybepossibletoen-courageuserstotravelatadifferenttime,
We now understand the promise of proactive traffic management in the Netherlands. But we have also established that there will be significantly more required of traffic management in the future. How can we elevate the field of traffic management to the
next level in the coming years? What steps are needed?
30
change their route, choose a different des-tinationoradifferentmode,orworkandshopfromhome.
on the supply sidethereismuchthatcanbedonetoincreaseflexibility.Therehasbeeneffectiveuseofpeakandpluslanesaswellasrampmeteringinstal-lations,butthesecanbedeployedevenmoreintelligently.Thesesystemscanbeimplementedinatrulydynamicwaysothatactualconditionsaremeasuredinordertodeterminewhentheyshouldandshouldnotbeactivated.Inadditionthedifferentinstallationscanbecoordinatedmorefully.Anotherpossibilityistoex-pandthenumberofreversiblelanesandbufferlanes.Othercountries,suchastheU.S.,applythesemeasuresmorebroadlythantheNetherlands.
When designing the infrastructure it isimportanttotakeintoaccounttheap-plicationofthefullrangeoftrafficman-agementmeasurestobeapplied.Theroadnetworkshouldberobustenoughtodealwithrecurrentconditions.Inaddi-tion,preciselybecausethenetworkinthe
Netherlandsisoverloadedandsovulnera-ble,itisimportantfortrafficmanagementmeasurestodealwithnonrecurrentandunexpectedsituations–incidents,events,constructionandotherunusualcircum-stances.Currentlywedeploytrafficman-agementmeasuresatroadconstructionsites,butitneedstobemorecomprehen-siveandmoreeffective.Theabilitytoab-
sorbfluctuationsindemandisenhancedbybuildinginflexibilityandredundancyintothenetwork.Therefore,whenextracapacityisneeded,thereisanopportunitytoaccommodatethedemand.
More CooperationWithaviewtoeffectiveness,itisimpor-tantfortrafficmanagementtobecoordi-
31
5. THERE IS STIll wORk TO dO!
natedanddeployednetwork-wide.Onlythencanwereallysolveproblemsinsteadofshiftingbottlenecksandproblemstodifferentlocations.Suchanetwork-wideapproachrequirescooperationamongroadauthoritiesandbetweenroadau-
thoritiesandserviceproviders(theprivatesectorpartiesthatprovidetrafficinforma-tion).Giventhelargenumberofstake-holders,thisisnotasimpleprocess.
Fortunately,thepartiesconcernedintheNetherlandsarealreadyorganizedin
variousways.Thereisaplatformwheregovernmentagenciesandprivatesec-torpartiesconsiderthepossibilitiesandapplicationsoftrafficmanagement,andthereareregionalcollaborationsthattargetregionaltrafficproblems.Inordertoconsiderfuturestrengthenedcollabora-tion,itmaybeusefultolookatincidentmanagement:thecooperationiseffective,thereareclearagreementsinplace,lead-ingtoabetter“product.”
Itisalsousefultolookinternation-ally.Forexample,intheU.S.,therearemanycollaborativepartnershipsbasedonMemorandaofUnderstandingandtrustineachother’sgoodintentions.Thereisquiteoftenacommongoal,whichmakesiteasiertosharefunding(pooledfunding)forajointprojectorresearch.IntheU.S.,thefocusismainlyoncorridors,butthemethodcanequallywellbeappliedtore-gionalnetworks.
Apositivedevelopmentisthatthereis increasing coordination and coopera-
32
tionbetweenthevariousroadnetworks(motorways,provincialroads,andurbanroads).However,thetrafficengineeringaspect of this deserves further investiga-tion:howcantrafficmanagementmeas-uresbefullycoordinatedanddeployed?Therehavebeensomeinstancesofco-ordinationofmeasuresonarouteorinaportionofanetwork,buttherearenotmanycontrolconceptsavailablethatcanhandlethis.Therefore,theseconceptsmustbedevelopedandextensivelytested,bothinsimulationsandinfieldtrials.
Anotherissueisthebalanceamongmodesoftransportation(road,rail,publictransport,cycling,pedestriansandwater)andbetweenpassengerandfreighttrans-portation.Onthatleveltherehasbeenlit-tleprogress:thefocusisstilltoomuchonthebetterusewithinasinglemode. Cooperative SystemsWiththeadventofcooperativesystems–whereinfrastructureandvehiclesys-temscommunicatecloselyasonesystem–therewillbemoreopportunitiesforcoordinationinthenearfuture.In-vehicle
systemsalreadyplayasmallroleintraf-ficmanagement.Navigationsystemsandqueuemessagesontheradiocaninflu-encetheroutechoiceofaroaduser.Ifve-hicle-infrastructurecommunicationisadd-ed,thesemeasureswillbecomemoresig-nificantastoolsforinformationandcon-trol.Thisisexpectedduetotheincreasedvehicle-vehicleandvehicle-infrastructure
communicationsinthefuture.Thefactthatthevariouscomponentsofthetraf-ficsystemcancommunicatemeansthatthesystems(comparedwithstand-alonesystemsinvehiclesandinfrastructuresys-tems)aremoreintelligentandbasedonmorethanjustcurrentinformation.Thereisinasensecooperation–ormaybeitisbettertotalkofnegotiation–amongve-
33
hiclesandtheinfrastructure(oracentraltrafficcenterorbackoffice).Thus,newandmoreefficient,predictivemeasureswillbepossible.Examplesarecoopera-tiveadaptivecruisecontrolandintelligentnavigationsystemsthatprovideadvicere-
gardingthecurrent(andpredicted)trafficandparkingsituations,possiblyincludingmultimodaltravelinformation.Alltrafficmanagementstakeholders(governmentagencyandprivatesector)seeopportuni-tieswithcooperativesystems.Itisimpor-
tanttoconsiderhowcooperativesystemsshouldbedesigned:whatsystems,howtotestthem,andhowtoorganizethedevel-opment,deploymentandmaintenance.
Vehicle-to-vehicle(V2V)applicationsinvolvingdedicatedshortrangecommu-nication(DSRC)areexpectedtobedevel-opedmainlybytheprivatesector,whilegovernmentagenciesaretypicallymoreinterestedinvehicle-to-infrastructure(V2I)applications.Forbothpartiesques-tionsremain:whopaysandwhobenefits?Forgovernmentagenciestherearefurtherquestionssuchas:inwhichequipmentdoweneedtoinvest,whatexistingequip-mentmustbereplaced,andifsowithwhat?Therearestillbottlenecksonthetechnicallevel(forexample,standardiza-tionandsecurity),organizationallevel(forexample,privacy),therelationshipwithroadusers(forexample,useraccept-ance)andscaleability(suchascomplexityandmanageability).
5. THERE IS STIll wORk TO dO!
34
Proactive Traffic Management“Preventionisbetterthancure,”sotrafficmanagementshouldpreferablybeproac-tive.Asafirststep,itisnecessaryforthe“traditional”reactivetrafficmanagementmeasurestobeinplace.Withtheadventofmoredata,betterforecastingmodelsandsmarterconceptsfornetwork-widemanagement,progresscanbemadeto-wardproactivetrafficmanagement.Inpracticethiswillmeanthatwepreventspillback,distributetheflowbetteracrossthenetwork,regulatetheinflowoncer-tainvulnerablepartsofthenetwork–allbeforetheproblemsreallystart.
Tomovetrafficmanagementintherightdirection,inthefutureastrongerprogramofcontrolandrouteguidancewillbeneededthanisnowthecase.Currentlythemajorityoftheeffortsareaimedatprovidingtrafficinformationandadvice,andifanactionisneededitisprimarilylefttotheroaduser(ahighdegreeofself-organization).Butaswehaveseen,self-organizationonlyworksuptoacertainpoint.Duringpeakperiods,withhightraf-ficdemand,andduringnonrecurrentcir-
cumstances,itwouldbemoreefficientforacentraltrafficauthoritytomanagetraf-fic,forexample,providingdynamicrout-inginformationtoroadusers.Thiskindofsystemmusttakeintoaccountwhattheroaduserwillfinddesirable,comfort-ableandacceptable.Thisrequiresdeepinsight into the preferences of users and a carefuldesignoftheuserinterface(inthe
vehicleandalongtheroadside).Afterall,ifroadusersdonotseetheusefulnessofthemeasureitselforseedisadvantages,theywillnotfollowtheguidance.Knowl-edgeofhumanfactorsplaysanimportantrole.Aninformation-ergonomicapproachshouldbefollowedtodevelopsafeanduserfriendlysystems.
35
Optimize for Multiple Policy GoalsTheincreasinginterestin–orrathercon-cernabout–thesocietaleffectsoftrafficmeansthattrafficmanagementmusttakeintoaccountmorediversegoalsthanbe-fore.Itisnolongersufficienttooptimizesolelyontotalflowortraveltime,butitisalsonecessarytoconsiderimprovementsinsafetyandqualityoflife(includingairquality,noise,andenergyconsumption).Inotherwords,amulti-objectiveoptimi-zationapproachisnowrequired.
Tomanagetrafficaccordingtomultipleobjectives,datacoveringthetrafficflow(speeds,traveltimes,vehicledelayhoursandreliabilityoftraveltime)arerequired,butwealsoneeddataonroadsafetyandqualityoflife/livability.Theobjectivesmustbequantified,andweneedmeth-odologiesthatmakeitpossibletounder-standandcommunicatethetrade-offs.
Integrated ApproachTrafficmanagementmustbepartofanintegratedapproach,inwhichtrafficman-agementtakesitsplacenexttomobilitymanagement,infrastructureplanningandspatialplanning.Forexample,ifitisnec-essarytoinfluencethetrafficdemandtoenableeffectivetrafficmanagement,thismustbealignedwithmobilitymanage-mentmeasuresthataimtoinfluencethenumberoftripsinanareaoronaparticu-larroute.Ashifttoothermodescanalsohelp.
Linkingtrafficmanagementtospatialplanningisimportantandcanhavemoreofaninfluenceonthestrategiclevel.Aspreviouslynoted,awell-designednetworkisthebasisforeffectivetrafficmanage-ment.Forexample,takingintoaccountthetrafficvolumesacrossthenetworkcanhelptoformanunderstandingofwhereflexibleinfrastructurefeaturessuchaspeak,plus,HOV,HOTorreversiblelanesare needed.
OrganizationRegardingtheorganizationoftrafficmanagement,therearealreadymanycomponentsinplaceintheNetherlands.Regionalcooperationcanneverthelessbestrengthenedfurther,whichisimpor-tantforthedeploymentofcoordinatednetwork-widetrafficmanagement.
Anotherissueisthewayinwhichgovernmentagenciesandtheprivatesec-torworktogether.Thisinvolvesmakinggood,clearagreements:whoisresponsi-bleforwhatandunderwhatconditions?Forsuchaclosecooperationtherearesomeinspiringexamples.Forexemple,governmentagenciesandprivatesectorhavegoodworkingarrangementsinthefieldofincidentmanagement.WecanlookabroadtoconsiderhownationalITSorganizations(withpublicandpri-vatemembers)havebeenestablishedandwhattheprosandconsoftheseap-proaches are.
Intermsoforganization,anumberof
5. THERE IS STIll wORk TO dO!
36
behavioralaspectsandhumanfactorsplayimportantroles.Cooperationbetweenvariousorganizationsandbetweendiffer-entteamsrequiresnewwaysoforganiz-ing.Cooperationinthefieldofoperationaltrafficmanagementmust,forexample,beinitiatedatthetrafficmanagementcenter.Buthowdoyoustart?Fullintegrationoftrafficmanagementtasksondifferentlev-elsoftheroadnetworkhierarchymaybedifficult.
Anotheraspectrelatedtoorganizationconcernsinnovation.Incurrentpractice,afteralongdevelopmentalprocess,in-cludingsuccessfulfieldtrials,itisstillrarethatameasureisimplementedonalargescale.Theimplementationpathforinnovationscanbebetterorganized,andagainthereneedstobeclosecoopera-tionbetweenpublicandprivateparties.Moreover,trafficmanagementmeasuresthathavethepotentialtogeneraterev-enuehavenotreceivedmuchattention.Whilethetrafficsituationisconstantlychanging,littleeffortisexpendedinthefunctionalmaintenanceoftrafficmanage-mentmeasures.
Finally,thereisanimportantroleforresearch and education institutions. Both publicandprivatepartiescouldtakebet-teradvantageoftheknowledgedevelop-mentthattakesplaceintheNetherlands.InthefieldofITS,forexample,resultsfrommanyEuropeanresearchprojectscouldbetranslatedtotheDutchsituation,whichcancreateinterestingnewmeas-
uresandsystems.Theresearchatuni-versitiesintheNetherlandsatthispointisamongthebestintheworld.Itwouldbemutuallybeneficialforallpartiestostrengthenexistingpartnershipsandex-aminenewjointventures.
Training and EducationNomatterhowwellthetrafficmanage-
37
mentsystemisorganized,theworkisultimatelycarriedoutbyindividualem-ployees.Trainingandeducationforthesestaffmembersalsodeserveattention.Thisrelatesnotonlytoresearchers,engineersandplanners,butalsotothefieldperson-nel,suchasroadinspectors,maintenanceemployeesandoperators,trafficengineersandtrafficcoordinatorsintrafficmanage-mentcenters.Ifweindeedwishfortrafficmanagementtobemoreproactive,broad-erandbettercoordinated,thisrequiresnewcompetenciesandskillsfortheseemployees,obtainedthroughcontinuingeducation and training.
Basic FacilitiesArchitectureAbasicprovisionforthehighqualityand(wherenecessary)uniformapplica-tionoftrafficmanagementisthetraffic management architecture. This consists ofadescriptionofallstepsneededtoachieveeffectiveregionaltrafficmanage-
ment:appliedtechnology,organization,funding,interoperability,legalaspects,etc.Whensuchaframeworkisinplace,aclearoverview,structureandaparticu-larstandardization(everyoneusesthesamedefinitions)emerge.Anarchitecturealsoprovidesinsightintherelationshipsbetweendevelopmentsintrafficmanage-mentinthemediumandlongterm.
Clearly,simplyhavinganarchitectureisnotenough–italsoneedstobeused.Itisespeciallyimportantthattrafficengineer-ingfunctionalitiesandrequirementsarelinkedtotechnicaldevelopments,sothatdevelopmentsbettermatch.Thatlinkisalreadypartlyimplementedintheexistingtrafficmanagementarchitecture.However,therearestillassumptions,forexamplewithregardtolife-cyclepenetrationandeffectiveness,whichshouldbefurtherclarified.
Onewell-knownexampleofa(sub)architectureistheSustainableTrafficManagement(GGB)approach,whichde-
scribesindetailthestepstowardajoint,broad-basednetworkvisionandanarea-wideregionaltrafficmanagementstruc-ture.GGBhasalreadyprovenitsvalueinpracticeinmanyregionsintheNether-lands,butsomegapsinthearchitecturehaveemerged.Therefore,nowGGBPlus hasbeendevelopedwithamajornewcomponentconsistingofthefunctionalclassificationoftheroadnetwork.InGGBPlustheroadsareclassifiedaccordingtotheirfunctioninthenetwork,suchas“mainhighway”or“urbanroad.”Thisoffersopportunitiestoemphasizeaspectssuchassafetyandlivability. MonitoringHighquality,timelyandcompletetraf-ficdataareessentialfortheprovisionoftimelyandcorrecttrafficinformationtoroadusersandforthedeploymentoftraf-ficmanagementmeasures.IntheNether-landsweobtainthevastmajorityofdatafrominductiveloopdetectorsintheroad.
5. THERE IS STIll wORk TO dO!
38
Thereareminorquantitiesofotherdetec-tionsystemsdeployedandalsovehiclesplaytheroleofsensor,butthatisstillnotadominantfeaturefordatacollection.Therefore,datafusion,whichincludesmethodstocombinedatafromdifferentsources,isofinterest.Thiscallsformoreintelligenceingatheringandprocessingthedata.Thedatamustbecollectedattherightplaces,measuredwiththecor-recttechniquesandthedatacollectedmustbewellcombined.Definingthedataqualityrequirementsdependsonwhatisdonewiththeinformation.Datafortraf-ficmanagementforexamplehasdifferentrequirementsthandataforpolicydevelop-ment.Itiscertainlynotnecessaryforalldatatobecollectedwiththesamequalityrequirements.Itisimportanttoviewthesensing,aggregating,qualityassessment,archivinganddistributionofsensordataholistically;atpresentthesecomponentsarehandledinafragmentedmanner.
Anotherissueistrafficinformationaround nonrecurrent events and incidents. Informationisnowavailable(trafficde-mandatevents,durationofincidents,
andalternativeroutes),butisagaintoofragmented.Atthistime,moreintegrationisneededamongtheserviceprovidersforprovidingtheinformation,inordertoim-proveresponsetimesandtheabilitytore-spondquicklytochangingcircumstances.Forthistooccuritisbetterthattheroadauthoritiesacceptgreaterresponsibil-ity.Thisisparticularlytrueinsituations
wheretrafficinformationcanbecrucial,suchasdisasters,majorincidents,events,andsevereweatherconditions.Anaddi-tionaladvantageisthattheroadauthorityismorevisibletotheroaduser. Models and PredictionWithtrafficmodelsitispossibletopro-vide quantitative insight into the effects
39
oftrafficmanagementmeasureson,forexample,safety,mobilityandtheenviron-ment.However,itisimportanttousethecorrecttypeofmodelforeachsituation.Forexample:fortheassessmentofpolicyleveloptions,staticmodelsareoftenused,evenifthepolicyoptionistrafficmanagement.Butstaticmodelsarenotsuitabletodeterminetheeffectsoftrafficmanagement.Dynamicmodelsneedtobedeployedforthispurpose.
Inthefuturemodeldeveloperswillneedtotakeactiontoimprovethissitua-tion.Theremustbeabetterlinkbetweenstaticanddynamicmodels.Thefunc-tionalityofdynamicmodelsshouldbeextended,sothatitispossibletoassesscertainpolicyoptions.Itisalsoimportantformodelresultstobepresentedwellandclearlyexplained.Onlyinthiswaywillpolicymakersandadministratorstakemodelresultsseriouslyintoconsiderationwhenmakingdecisions.
Alsothereal-timeapplicationoftraffic
modelsisofinterest.Wehavepreviouslyconcludedthatinordertoallowproactivetrafficmanagement,weshouldbeabletopredictthetrafficflow.Trafficmodelsareessentialforthispurpose,buttheyneedtobeimproved.
Finallywesuggestthatbehavioralmod-els–behavioralsimulationsofeconomic,psychologicalandsocialdecision-makingprocesses–requireextraattention.Thesefeaturesshouldbecomemoreprominentingenerictrafficmodels.Examplesofap-plicationsincludedeterminingtheeffectsofhabitualbehavior,thepotentialforpriceincentivestochangebehaviorandtheimpactofpersonalizedinformation.Further understanding is needed regarding the interdependence of these processes. Forexample,howcanweencouragemod-ificationofhabitualbehaviorusingintelli-gentandpersonalizedinformation?Afur-therunderstandingofthiswouldneedtobebasedonthelatestinsightsonhumanfactors.Thatinfluenceisnotlimitedtoa
specificbehaviorallevel(strategic,tacti-cal,operational).Sothechallengeistoex-ploittheinteractionsbetweentheselevels:e.g.departuretime,speed,routechoiceandmodechoice.Theseinteractionsalsorequireconnectionsbetweenthemacro-,meso-andmicroscopicmodels. Traffic Management Centers
Thefieldoftrafficmanagementhasdevel-opedinitiallyfromtheneedsandrequire-mentsofroadauthorities.Butsincethenalothaschanged:theprivatesectorisplayinganincreasinglylargerrole,therearein-vehiclesystemstobetakenintoac-countandthepossibilitiesofmobilecom-municationareincreasingexponentially.Thesechangeshaveledtoarangeofnewtoolsandopportunitiesfortrafficinforma-tionandtrafficmanagement.Theroleandnecessityoffacilitiesalongandabovetheroad,intermsofeffects,time,costsanddepreciation,havebecomepointsofdiscus-sion.Fortrafficmanagementcentersthis
5. THERE IS STIll wORk TO dO!
40
hasanumberofimportantconsequences:
•Trafficmanagementcenterswillbedeployedinthenearfuturefornet-workwidetrafficmanagementofallroadauthoritiestogether.Theywillthereforebeattheserviceofregionalcooperation–andnotattheserviceofonlyoneroadauthority.
•Trafficmanagementcenterswillincreasinglyfocusontheinterplaybetweeninforming,controllingandmanagingtrafficflows.
•Trafficmanagementcentersinthefuturewillbeinextricablylinkedwithcooperativesystems,includingvehicle-to-vehicleandvehicle-to-infrastructuresystems,withroadsidedevicesandin-vehiclesystems.
•Trafficmanagementcenterswillinthefuturebetheplatformfromwhichbothroadauthoritiesandservicepro-vidersoperate.Bothpartiesshouldworkfromacommonplatform.
Thetrafficmanagementcenterofto-morrowwillalsoplayasignificantrolefortheapplicationofpredictionmodelsanddecisionsupportsystems.Thesetoolssupportthetrafficmanager,forexample,inthepreparationoftrafficmanagementscenarios.Inthisnewcontext,theques-tionsofeducation,traininglevelandtheworkloadofthetrafficmanagerwillrequire further attention. We need to con-sidertheoptimalwaysfortheworktobeaccomplishedandforthetrainingtobeprovided,sothatthetrafficmanagerscandotheirworkaseffectivelyaspossible.
Further InnovationIntheprecedingsectionsmanytopicswerediscussed,butitisimportanttocontinuetolookforfurtherinnovationsoutsidethetrafficworldthatmaybeofinterestfortrafficmanagement.Forexam-ple,wetrytomakefulluseofnewinfor-mationandcommunicationstechnology(ICT)developments.Sofartherehasbeen
littlerigorousfocusontheinfluenceofsocialmediaontheuseoftrafficinforma-tion.
Inaddition,itisprudenttokeepaneyeopenfordevelopmentsinothersectors.Astudyofanalogiescandeterminewhetherdevelopmentsandinnovationselsewheremayalsobeusefulforapplicationintraf-ficmanagement.
5. THERE IS STIll wORk TO dO!
41
6. FUTURE RESEARCH AgEndA
Inthischapterweidentifythevariousresearchthemesresultingfromthediscussionabove.Wehavegroupedtheresearchthemesunderseveralcategories.Theboldthemesarethemosturgent.Toindicatewherethegreatestinterestmaylieinaparticularresearchquestion–andwhichkindoforganizationwouldmostlikelyleadtheresearcheffort–wehaveassignedeachresearchtopictofourcategories:
Strategic/Policy These are themes that are par-
ticularly important for policy.
Operational/ Road Authorities
Themes that are important
for the road authority.
Knowledge ApplicationThemes that are important
both for policy and road au-
thorities and for which the
knowledge is present to apply
them.
Knowledge Development
Research topics for which it is
difficult to find a direct client
and so could be advanced by
universities or research or-
ganizations.
If we want to fulfill the true future potential for traffic management we must take the necessary steps forward. This is not a simple matter. Most of the first steps require further investigation. That is why we close this brochure about the future of traffic management
with a recommended research agenda.
43
Flexibility in Supply and Demand
Flexible infrastructure (more flexible deployment of the available capacity) is an effective way to temporarily address capacity shortages or spikes in traffic demand. But where and when exactly is it useful to deploy flexible infra-structure?
Dynamic road pricing is potentially a powerful tool to influence demand, but it is also politically sensitive. It is therefore necessary to explore what other less far-reaching possibilities there are to apply pricing. Perhaps a high occu-pancy toll (HOT) lane is an option.
Mobilitymanagementisusedsuccessfullyatroadcon-structionsites.Mobilitymanagementforrecurrentconditionsand/ornonrecurrent/incidentconditionsshouldbeexamined,suchthatbettertuningispossiblebetweentrafficmanagementandmobilitymanagement.
More Cooperation
Much is expected from coordinated network-wide traffic management. There are already actions in place aimed at im-plementing this, but further examination and development
is needed. Network-wide traffic management also has con-sequences for the design and organization of traffic manage-ment centers.
Inthenearfutureweexpectagreatdealfromcooperativesystems.Buthowwillthesesystemsactuallycontributetoabet-tertransportationsystem?Whichspecificapplicationsareonthehorizonandwhenwilltheybeintroduced?Whoisresponsibleandwhatistherelationshipbetweenroadsidedevicesandin-vehiclesystems?
IntheU.S.thereisawell-establishedsystemforpoolingresearchfunds(seewww.pooledfund.org).Regionalpartiesto-gethercreateafundtotackleaspecificproblemortoconductresearch.ThequestionnowishowthisfinancingmechanismcanbeadoptedintheDutchsituation.
Morecoordinationisneededbetweenthevariousroadnetworks(motorways,provincialroads,urbanroads)andmodesoftransport(car,publictransport,bicycle).Itisnecessarytoexaminehowtheinterfacesbetweentheroadnetworksandthenetworksoftheothermodescanbebetterplanned,designed,managedandoperated.
44
Proactive Traffic Management
To achieve the desired coordinated network-wide traffic management we need prediction. Further research is needed to determine which concepts can be used and what further development is needed for forecasting models.
Thequalityofthetrafficinformationcanbeimproved.Weshouldexamineunderwhatcircumstanceswhichparticularinformationisnecessaryanduseful,andwhichtrafficdatamustthereforebeobtained.
Operationaltrafficmanagementisextremelyimportantinnonrecurrentsituationsandincidents.Inthatrespect,thequal-ityofdecisionsupporttoolsintrafficmanagementcentersmustbeenhanced.Thisincludesaneedtobetterassessandpredictthetrafficsituation.Theeffectsofmeasureswouldneedtobeincluded.
Optimize for Multiple Policy Goals
Multi-objective traffic management would consider
more than just mobility but also accessibility, safety and quality
of life. What methods are available for such an integrated assess-
ment, and what optimization techniques are suitable?
Integrated Approach
More research into the role of human factors is impor-tant to ensure that road users understand and comply with the traffic management measures that are applied. Human factors knowledge should therefore be included in traffic management by default. Research is needed in this area, for example in the development of systems, the implementation of operational measures and the application of traffic manage-ment.
Therobustnessofthenetworkhastodowiththecoordi-nationbetweentheplanningoftheinfrastructure(thestructureoftheroadnetwork)andtheoperationalapplicationoftrafficmanagement.Itisnecessarytoexaminehowcoordinationcanbeimproved,forexamplebyexploringwhereintheDutchnet-workredundancyisneeded.
6. FUTURE RESEARCH AgEndA
Strategic/Policy
Operational/Road Authorities
Knowledge Application
Knowledge Development
45
Thereisagapbetweenthedesiredtrafficengineeringfunctionalitiesandtechnicaldevelopments.Itisnecessarytoexaminehowabettermatchbetweenthesetwodo-mainscanbeachieved.Ononehand,itinvolvesabetteruseofavailabletechnologies,andontheotherhand,toletthedesiredfunctionalitydrivethetechnologicaldevelopments.
Itisalwaysusefultoexaminedevelopmentsinotherfieldsandseeifthereareanyanalogieswithtrafficmanagement,inparticularaboutthewayinwhichtransport(particlesandinfor-mation)isregulatedandmanaged.
Thefunctionalmaintenanceoftrafficmanagementcompo-nentsisanimportantissue.Butwhataretheoptimalinvestmentlevelsinfunctionalmaintenance?
Organization
In the Netherlands the effectiveness of traffic management is sometimes doubted. In the U.S. it appears that this is less of a problem. In some states and metropolitan regions “branding” for traffic management is a normal course of action. The question is how important the application of traffic management in Netherlands is and how we can shape a branding initiative in the Netherlands.
There is currently discussion about the roles of road authorities and the private sector on the distribution of traffic information. An important research question is under what circumstances it is useful and desirable for a road authority to provide information. What would be the quality requirements of that information and what is the most appropriate division of responsibilities between government agencies and the pri-vate sector? What business models are needed?
Notonlyinprovidingtrafficinformation,butalsoinap-plyingtrafficmanagementinitiativestheprivatesectorwillplayalargerrole.Itisnecessarytoexaminehowtherolesandresponsibilitiesbetweengovernmentagenciesandtheprivatesectorcanbedividedandharmonized.Towhatextentcaninter-nationalITSorganizationsserveasexamples?
46
Basic Services and Other
Traffic management uses all kinds of data and data sources. It is important to examine how the data can be gath-ered, analyzed and combined more intelligently, taking into account the differences in quality. Improvement is needed quickly given current inefficiencies in the system that relies on fixed sensors (for example, during conditions of low flow, incidents or poorly tuned sensor controllers).
Thereisinsufficientinsightintothevalidityofmodelsandtherefore,thereisalotofdebateabouttheresultsofmodel-basedstudies.Researchintotheaccuracyofdriverbehav-iormodelsisneeded.Thisincludesmultiplelevels(forexample,lanechangingandroutechoicebehavior)andtheinteractionsbetweenthem.
Inmodelingthereissometimesagapbetweenpolicyandpolicy-supportingmodels.Ononehand,fromthepolicysidebettermodelsshouldbedeveloped,whileontheotherhand,theresultsofmodel-basedstudiescanbebetterpresented.Thequestionishowthatcouldbedone.
Socialmediaarestronglyontherise.Wehavetothinkabouttheroletheycouldplayinprovidingtrafficinformationsafelyandeffectively,bothoutsideandinthevehicle.
6. FUTURE RESEARCH AgEndA
Strategic/Policy
Operational/Road Authorities
Knowledge Application
Knowledge Development
47
Publication Information
Text:
prof.dr.ir.SergeHoogendoorndr.ir.HenkTaaleir.IsabelWilminkprof.dr.RobertL.Bertinidr.ir.RonaldvanKatwijkprof.ir.BenImmersir.HenkSchuurman
Illustrations:
EwoudLuppens
Editing and design::
EssenciaCommunicatie,TheHague
© 2012 TrafficQuest
Nopartofthispublicationmayberepro-
ducedinanywaywhatsoeverwithoutthe
priorwrittenpermissionofthepublisher.
Thegreatestpossiblecarehasbeentakenin
compilingthedatainthispublication.The
publishercannotacceptliabilityforanyerrors
oromissions.
48
About TrafficQuest
TrafficQuest, the Center of Expertise in
traffic management, is a collaboration
between Rijkswaterstaat, TNO and TU
Delft.
In the world of traffic management a lot is happening and developmentsmove quickly. Traffic Quest helps to keep track of these developments by systematically collecting, developing and transferring knowledge. The part-ners in TrafficQuest together cover the entire spectrum including the funda-mental, theoretical knowledge about traffic management, and the opera-tional expertise about the application of traffic management in practice. The activities of TrafficQuest consist of an-swering specific questions, giving ad-vice on projects, conducting research on specific topics and to establish and disseminate knowledge.
www.traffic-quest.nl