JOURNALOFTRANSPORTATIONENGINEERINGEVALUATIONOFVEHICLE-SPECIFICINFORMATIONINTRAFFICCONTROLSYSTEMSByAlirezaKamyab,T.H.Maze,andReginaldR.Souleyrette（ReviewedbytheUrbanTransportationDivision）Abstract:Thispaperassumesthatinanintelligenttransportationsystem(ITS)trafficcontrolenvironment,trafficcontrolsystemswillbeabletotrackvehiclesindividuallyinatrafficstreamthroughautomaticvehicle-specificidentification(AVSI).AsavehiclepassesanAVSIroadsidereadersite,itisassumedthatthereaderrecordsthearrivaltimeandtypeofdetectedvehicle.Thereadersendstheinformationreceivedtoalocalmicroprocessor-basedtrafficsignalcontroller.Thecontroller'sbuilt-insignalcontrollogicthenusestheinformationtoadjusttrafficsignaltimingtoreflectthepresenttrafficstream'scharacteristics.Giventhisassumedcapability,asimulationmodelisdevelopedtoevaluatethebenefitsoftheuseofAVSI.TomakeuseofAVSI,anewvehicle-specificadaptive(VSA)trafficcontrollogicisbuiltintoasimulationofanisolatedintersection.Throughthesimulation,identifiable,measurable,andsignificantbenefitarefoundfromtheuseofAVSIinadaptivetrafficsignalcontrollogicwhentheincorporatedVSAcontrolstrategyistestedagainstthepretimedcontrolsystem.IntroductionOneoftheobjectivesofintelligenttransportationsystems(ITS)istoallowvehicles,highways,andpassengerstointeractasasystemratherthanasindependentelements.Thispaperreportsonanevaluationwhichassumescloserintegrationofvehiclesandsignalizedtrafficcontrol.Thefundamentalissueexplorediswhethertherearebenefitstoautomaticallyprovidingsignalcontrollerswithvehicle-specificinformationandhowthisinformationmightchangetheassignmentofgreentimetoimprovethetrafficflowperformanceofanintersection[1].Currentstate-of-the-practicevehicledetectortechnologyislimitedtodetectingthepresenceandpassageofvehicles.Whencoupledwithatrafficsignalcontroller,detectorsareusedtoderivetrafficvolume,vehiclespeed,laneoccupancy,andqueuelength[2].Theyare,however,unabletodeterminethetypeandperformancecharacteristicsofthedetectedvehicles.Automaticvehicle-sp