Unit4Publictransport【美文阅读】Whoinventedthetrafficsignal
1868年12月10日,由英国机械师德·哈特设计的一盏红、绿两色的煤气交通信号灯是城市街道的第一盏信号灯
它的出现使城市交通大为改善,也为后来交通信号灯的完善奠定了基础
Trafficlightshadbeeninuseevenbeforecarswereinvented
Inthosedays,peopleusedhorses,wagons(四轮马车)andothermeansoftransport
Butthetrafficwasstillhorrible
Soin1868inLondon,England,trafficpolicemencameupwithabasicdevice:Alanternwithtwolights-redandgreen
Greenstoodfor“caution”andredfor“stop”.Apolicemanwouldturnthelightsregularlywithalever(控制杆)
Unfortunatelythisearlytrafficlightprovedunsafe
Onemodelexplodedayearlaterandhurttheoperator
Thingsmadeaturnfortheworsewhencarswereinvented
Somepeoplewereusingnewcars,andotherswerestillridinghorses,wagonsorbicycles
Theyallsharedthesameroadsandstreetswithpedestrians(行人)
Alotofaccidentstookplaceasaresult
Atrafficpoliceofficer