理工类---A级CellPhonesIncreaseTraffic,PedestrianFatalities【手机增加交通行人死亡】Cellphonesareadangerontheroadinmorewaysthanone.Twonewstudiesshowthattalkingonthephonewhiletraveling,whetheryou’redrivingoronfoot,isincreasingbothpedestriandeathsandthoseofdriversandpassengers,andrecommendcrackdownsoncell1usebybothpedestriansanddrivers.Thenewstudies,lead-authoredbyRutgersUniversity,Newark,EconomicsProfessorPeterD.Loeb,relatetheimpactofcellphonesonaccidentfatalitiestothenumberofcellphonesinuse,showingthatthecurrentincreaseindeathsresultingfromcellphoneusefollowsaperiodwhencellphonesactuallyhelpedtoreducepedestrianandtrafficfatalities.However,thisreductioninfatalitiesdisappearedoncethenumbersofphonesinusereacheda“criticalmass”of100million,thestudyfound.Thesestudieslookedatcellphoneuseandmotorvehicleaccidentsfrom1975through2002,andfactoredinanumberofvariables,includingvehiclespeed,alcoholconsumption,seatbeltuse,andmilesdriven.Thestudiesfoundthecellphone-fatalitycorrelationtobetrueevenwhenincludingfactorssuchasspeed,alcoholconsumption,andseatbeltuse.Loebandhisco-authordeterminedthat,atthecurrenttime,cellphoneusehasa“significantadverseeffectonpedestriansafety”andthat“cellphonesandtheirusageaboveacriticalthresholdaddstomotorvehiclefatalities.“Inthelate1980sandpartofthe1990s,beforethenumbersofphonesexploded,cellphoneuseactuallyhada“life-savingeffect”inpedestrianandtrafficaccidents,Loebnotes.“Cell-phoneusers’wereabletoquicklycallformedicalassistancewheninvolvedinanaccident.Thisquickmedicalresponseactuallyreducedthenumberoftrafficdeathsforatime,”Loebhypothesizes.However,thiswasnotthecasewhencellswerefirstusedinthemid-1980s,whentheycauseda“life-takingeffect”amongpedestrians,driversandpassengersinvehicles.Inthoseearlydays,whentherewerefewerthanamillionphones,fatalitiesincreased,saysLoeb,becausedriversandpedestriansprobablywerestilladjustingtothenoveltyofusingthem,andthereweren’tenoughcellphonesinusetomakeadifferenceinsummoninghelpfollowinganaccident,heexplains.The“life-savingeffect”occurr