5IATSSReSeARchVol.32No.2,2008trAnsportAtionidentiFicationoFFactorsinroadaccidentsthroughin-depthaccidentanaLysisMouyidBINISLAMResearchAssociate,ThailandAccidentResearchcenterAsianInstituteofTechnologyPathumthani,ThailandKunnaweeKANITPONGAssistantProfessor,TransportationengineeringProgramManager,ThailandAccidentResearchcenterAsianInstituteofTechnologyPathumthani,Thailand(ReceivedFebruary4,2008)therisingtrendofmotorizationandimprovingsocio-economicstatusofthaipeopledirectlyinfluencestheaggravatingroadsafetysituationwithfatalitiesandpermanentlydisabledinjuriesofabout130,000and500,000respectivelyoverthepastdecades.Anestimatedannualcostfromroadcrashesamountstoaboutus$2,500million,3.4percentofgrossnationalproduct(gnp),undoubt-edlyinflictsthailandwithaburningpublichealthconcerninthesoutheastAsianregion.thispaperaddressesanin-depthstudythroughcrashinvestigationandreconstructionwhichhasnotyetbeenpractisedinthailandtoidentifythecontributoryfactorsinroadcrashesbytheconcernedauthorities.thisresearchattemptstoestablishthelinkagebetweenthecausesandconsequenceswitheventclassificationofaninvestigatedcasebyhighlightingthedynamicdrivingsituationwithinitialtravelingspeed,pre-impactandpost-impactspeedoftheinvolvedvehiclestodescribethecrashscenario.moreover,inaccurateriskassessmentandlateevasiveaction,absenceofstreet-lightfacilities,inadequatelanemarkingandvisibilitywerealsooutlinedasmajorriskfactorsincreasingtheseverityofcrashandinjuryinthisinvestigatedcase.KeyWords:investigation,reconstruction,in-depthanalysis,eventtree,Factors1.introductionRoadsafetybecomesamajorpublichealthconcernwhenthestatisticsshowthatmorethan3,000peoplearoundtheworldsuccumbtodeathdailyduetoroadtraf-ficinjury1.Inaddition,roadcrashesleadtotheglobaleconomiclossesasestimatedinroadtrafficinjurycostsofUS$518billionperyear2.Thehugeeconomiclossesareaneconomicburdenfordevelopingcountries.Itisre-flectedthattheroadcrashcostsareestimatedtobeUS$100billionindevelopingcountrieswhichistwicetheannualamountofdevelopmentaidtosuchcountries2.Consider-ingwithinSouthEastAsiancountries,theeconomicgrowthrateofThailandcontinuestomoveupwardwithanaggravatingroadtrafficsituationduetotheheavyneg-ativeimpactofahigherlevelofmotorization.Over130,000fatalitiesandnearly500,000peoplewereper-manentlydisabledduetoroadcrashesoverpastdecades3.Theeconomiclossesduetotheroadcrashesare;there-fore,considerablyhigh,costingapproximatelyUS$2,500millionperyear(aboutUS$0.3millionperhour),or3.4percentoftheGrossNationalProduct(GNP).AnAsianDevelopmentBankcountryreport3fo-cusedontheseriousnessoftheroadaccidentproblemwhichisshowninFigure1withanupwardtrendofinju-riesperaccidentwhereasfatalitiesperaccidentremainedconstantwithsmallfluctuationsfrom1993-2002.How-ever,thefatalityindexdeclinedto16percentin2002from27percentin1993overthisperiodoftime.Thecollectionanduseofaccurateandcomprehen-sivedatarelatedtoroadaccidentsisveryimportanttoroadsafetymanagement4.Theroadaccidentdataarenecessarynotonlyforstatisticalanalysisinsettingprior-itytargetsbutalsoforin-depthstudyinidentifyingthecontributoryfactorstohaveabetterunderstandingofthechain-of-events.Havingtheinconsistenciesintheaimsofthepoliceandtheroadsafetyengineers,thedataanal-Fig.1Trendsincasualtiesperaccidentandfatalityindex(Tanaboriboon2004)19931.000.900.800.700.600.500.400.300.200.100.0050%45%40%35%30%25%20%15%10%5%0%19941996...
