交通研究trafficstudies調(diào)查

ReasonsfortrafficManagingthephysicalInvestigatingtrendsoverUnderstandingtheneedsandchoicesofthepublicandindustryCalibratingbasicrelationshipsorAccessingtheeffectivenessofAccessingpotentialEvaluatingfacilityorsystemTypesofVolumeSpeedTravel-timeDelayDensityAccidentParkingGoodsTransitPedestrianCalibration

ObservanceManualofEngineeringStudiesITEPublishingDate:VolumeVolumeThenumberofvehicle(orpersons)passingapointduringaspecifiedtimeperiod,whichisusuallyonehour,butneednotbeRateofflow（流率Therateatwhichvehicles(orpersons)passapointduringaspecifiedtimeperiodlessthanonehour.Thenumberofvehicles(orpersons)thatdesiretotravelpastapointduringaspecifiedperiodThemaximumrateatwhichvehiclescantraverseapointorshortsegmentduringaspecifiedtimeperiod TheimprovementprojectwouldhavetoaddressboththeexistingandhiddenbottleneckstoachieveasuccessfulresultThedemandresponsetoanarterialbottleneckismuchhardertodiscernCongestioninasurfacestreetnetworkseverelydistortsdemandpatterns,andobservedvolumesaremoreareflectionofcapacityconstraintsthantruedemandVolumepatternsandThepeakhourofthedaytypicallycontainsfrom10to15%ofthe24-hourDemandvariesbytimeofday,bydayoftheweek,bymonthorseasonoftheyear,andinresponsetosingulareventsHourlytrafficvariationTheabsenceofclearAMandPMpeakinmanymajorurbanareaisaspreading15minutesasstandardperiodforflowPHF

DailyvariationTypicallymonthlyvariationManualcountEstimatingcountforthewholecountingperiodAllpersonnelmustbeNostudyshouldplacesomanypersonalthatdistractdrivers’attentionAtypicalobservershouldonlycountoneheavymovementortwolightmovementsCountingtimeshouldbeSomereliefpersonnelmustbeFieldsheetLocationofcountmustbeSpecificmovements,lanes,and/orclassificationincludedonthefieldsheetmustbenotedWeather,roadwayconditions,andtrafficincidentsoraccidentsduringthecountshouldbenotedObserver’snamemustbeDateandtimeofstudyandofspecificcountsmustbeCountingperiodsmustbeidentifiedandlinkedtoclockEachsheetshouldhavepagexofy365dayMagnetic-loopdetectorsarewidelyVideoimagingprocessing

PanosG. Universityof易平老師 Autoscope4Typicalat-grade4-leg12separateCars,taxis,trucks,Aminimumnumberof4observersandonechiefisneededArrivalversusdepartureDemandlessthanVolumesarecountedastheydepartedtheDemandgreaterthanUnstablequeuebuildArrivalvolumesareLimitednetwork500streetlinksand500intersectionsstudyinManhattanAsamplingmethodologyisThebasic–Entirenetworks,oridentifiablesubportionsofnetworkshavesimilardemandpatternsTwokindsofControlcountThereshouldbeonecontrolcountlocationsforevery10to20coveragecountlocationsDifferentcontrolcountlocationsshouldbeestablishedfordifferenttypeoffacilitiesDifferentcontrolcountlocationshouldbeestablishedforportionsofthenetworkwithmarkedlydifferentland-useEstimatingvehiclemilesAtypicalnetworkflowOriginanddestinationHomebasedinterviewforplanningWeavingareaFreewayMajoractivitycenterLicense-platePostcardInterviewAcordonisanimaginaryboundaryaroundastudyareaofinterestLargeenoughtodefinethefullareaofinterest,smallenoughsothataccumulationestimateswillbeusefulforparkingandothertrafficplanningCrossallstreetsandhighwaysatmidblockNaturalorman-madebarrierscanbeusedaspartofcordonhaverelativelyuniformSpeed,traveltime,anddelayAveragetravelspeedisusedasmeasureofeffectivenessforarterialsandtwo-laneruralhighwaysControldelayforsignalizedandstopcontrolledintersectionsDensityforSpotTheaveragespeedofavehiclepassingapointonahighwaySpeeddefinitionofAverageortimemean85thpercentileUsesofspotspeedEstablishingtheeffectivenessofneworexistingspeedlimitsorenforcementpracticesDeterminingappropriatespeedlimitsforEstablishingspeedtrendatthelocal,state,andnationalleveltoassesstheeffectivenessofnationalpolicyonspeedlimitsandenforcementSpecificdesignapplicationsdeterminingappropriatesightdistances,relationshipsbetweenspeedandhighwayalignment,andspeedperformancewithrespecttosteepnessandlengthofgradeUsesofspotspeedSpecificcontrolapplicationsforthetimingof“yellow”and“allred”intervalsfortrafficsignals,properplacementofsigns,anddevelopmentofappropriatesignalInvestigationofhigh-accidentlocationsatwhichspeedissuspectedtobeacontributingcausetotheaccidentMeasurementoftraveltimesasvehiclestraverseashortmeasureddistancealongthehighwayUseofhand-heldorfixed-mountedradarRadarThemeanThemedianThemodalThestandardThe85thand15thpercentilePercentvehicleswithintheTMSTimemeanspeed(TMS)（時(shí)間平均車速）TheaveragespeedofallvehiclespassingapointonahighwayorlaneoversomespecifiedtimeperiodSpacemeanspeed(SMS)（空間平均車速）TheaveragespeedofallvehiclesoccupyingagivensectionofhighwayorlaneoversomespecifiedtimeperiodTraveltimeToidentifyproblemlocationsonfacilitiesbyvirtueofhightraveltimesand/ordelayTomeasurearteriallevelofservice,basedonaveragetravelspeedsandtraveltimesToprovidenecessaryinputtotrafficassignmentmodels,whichfocusonlinktraveltimeasakeydeterminantofrouteselectionToprovidetravel-timedataforeconomicevaluationoftransportationimprove