Trafficproblemshavebecomeoneofthemajorproblemsincities.Streetsarealwayscrowedwithvehiclesandpedestrains,especiallyinrushhours.Whatismore,trafficaccidentshavemadestreetsbecomeoneofthemostdangerousplaces.Heavytransportationpressureinlargecitiesbringmuchinconveniencetopeople¡¯slifeandexertnegativeimpactsontheenvironment.Ontheonehand,whentrafficjamhappens,shortdistanceinthepastnowseemstobecometerriblylong,anddriverscoulddonothingbuttowait.Therefore,alotofprecioustimehasbeenwastedontheroad.Forexample,peoplehavetosetoffwellinadvancetogettoworkontimeandcomebackverylatewhentheirworkisover.Ontheotherhand,exhaustedgasemittedbycarshasincreasedtheburdenofenvironmentandcausedcarbonemission,whichhasdivertedfromtheconceptoflivingalowcarbonlife.Therearemanycausesforthisproblem,butthefollowingmaybethemostimportantones.Thefirstcauseisthegreatincreaseinthenumberofprivatecars.Carstakeupmorespacebuttheycarryfewerpeople.Peopleabusetheprivatecarstotakepublictransportinstead,whichcausedmorecarsputintouse.Thesecondcauseistheslowandinefficientconstructionandimprovementoftheroadsandstreets.Therapidincreasingpopulationisagootexplanationoftheanswer.Morepeoplemeansheaviertraffic.Becausemorespacehastobeusedtomeettheneedsofthehousingproblem,itisalmostimpossibletowidenthestreets,whichmakesthesituationevenworse.Withalargepopulationandnumbersofautomobilesincreasing,someroadsstillremainunimproved,whichwillsurelyleadtoproblems.Thelastcauseistheinsufficientmanagementofthetrafficsystemandthepeople¡¯slackofawarenessoftrafficregulations.Someprivatecardrivers,ignoringtrafficregulations,driveonlyforthesakeoftheirownconvenience,blockingthewayofotherpublictransportationvehicles.Furthermore,manypedestrianscrossthestreetsevenwhenthetrafficlightsareagainstthem,whichisanobstacletotheflowoftraffic.Sometimes,peopledriveafterdrinking,whichcausesmoretrafficaccidents.Theproblemoftrafficcongestionisanurgentonebecauseitconcernsthesafetyallofus.Everycitizenshouldrealizetheseriousnessoftheproblem.Everyonecanmakeagreatcontributiontosolvethetrafficjam.