风险认知概述,英文版课件.ppt

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1、IntroductionThereexistedriskincrossingaroad.Riskwasthusdefinedrelativelytotheindividual,notinanabsolutesense.Thesubjectswereunawarethattheywereunderobservation.Thepresenceofriskwasmeasuredintermsoftheproportionofindividualsuccesses.Thebehaviorstudiedwasthatofpeoplecrossingaro

2、adfromacentreislandtothepavement,orvice-versa,againstonestreamoftraffic.Itwouldnotbefar-fetchedtoassumethateachpedestrianintendedtocrosstheroadsafelywithoutbeinginjuredbyavehicle.Aperson'stacitbeliefsaboutthechancesofsafelycrossingaroad,whichwasregardedashissubjectiveprobabili

3、tyofsafety(orinjury),maybeassumedtoberelatedtothespeedanddistanceofapproachingvehicles.MethodofObservationAcrossingsuitableforthepresentstudywaschosenonamainroadinabusypart.Therewasnozebracrossing,trafficlightsorpolicecontrol.Trafficdensitywasmoderatelyheavy.Thestudyextendedov

4、eraperiodofonemonthand1,189observationsweremadeon491persons.MethodofObservationFourkindsofobservationwererecordedforeachmemberofthesample:(i)age,(ii)sex,(iii)speedanddistanceofvehicle,(iv)crossingornotcrossing.Ageandsexwerebothestimatedfromthepedestrian'sappearanceandattire.Am

5、easureofthespeedanddistanceoftheapproachingvehiclewasobtainedbyrecordingthetimefromthemomentthepersonsteppedtotheedgeoftheroadandlookedattheoncomingtraffictothemomentwhenthefirstvehiclereachedthecrossing.Measurementsweretakentothenearestsecond.Preliminaryobservationshadindicat

6、edthatwhenvehiclesweremorethan10secondsawaypedestrianswithoutexceptionwouldcrosstheroad.Ouranalysiswasthereforelimitedtovehicleswithinthatdistance.Thusobservationsofwhetherpersonsdidordidnotcrossweremadeinrelationtothespeedanddistanceofvehiclesasmeasuredbythetimetakenbythemtor

7、eachthesiteofthecrossing.Pedestrianscrossingingroupswereignored.Thenumberofbicyclesontheroadwasverysmallascomparedwithmotorvehiclesandthereforetheobservationsmadeofpedestrianbehaviorinrelationtocyclistswerenotusedinthepresentstudy.Results1Frequencyofroad-crossingagainstapproac

8、hingtraffic.ASSUM1:Aperson'ssubjectiveprobabilityofsafety,tha