这些标志以道路规则的形式受法律制约-e-Business

Unit3StandardPoliceWeaponsCriminalInvestigationUnit3AmericanRoadTrafficControlSystemThecommutetimefortheaveragecommuterintheUnitedStatesin2000was26minutes,upfrom22minutesin1990.Inlargercities,thesituationismuchworseand,insomecities,theaveragecanbeashighas39minutes.Itisnotunheardofforapersontocommuteaslongas2.5hourseachway,eachday.ItisestimatedthattrafficjamsarecostingAmericans$68Billionayearinlosttimeandproductivity.Inastudyof75majorcities,rushhourislastinganaverageof7hourseachday,upfrom4.5in1982.CriminalInvestigationUnit3Butwhatcanbedonetoremedythisescalatingsituation?Therearecountlesscausesofdelaysandaccidentsthatcouldbedoneawaywithbyremovingthehumanfactor.Considertailgating,recklessdriving,unsafespeeding,unsafelanechanges,rubber-neckingdelays,driverstalkingoncellphones,eating,oradjustingthestereo,andthecountlessotherbaddecisionsmadebydriversontheroadeveryday.Thesedelaysandhazardsareallresultsofhumanoperators,ratherthantheinfrastructurewithinwhichtheyoperate.Thepurposeofthissystemistoremovethehumanelementinroadtraffic,andthusoptimizetrafficflow,reducetrafficviolationsCriminalInvestigationUnit3andaccidentstonearzero,andimprovefuelefficiencybycentrallycontrollingthemovementandroutingofallthecarsinthemetropolitanarea.Thesystemconsistsofthreemajordivisions:acontrolcenter,“smart”vehiclesandanetwork.Itbehavesinthefollowinggeneralmanner.Thecentralcontrolcenterisresponsibleforroutingvehicles,determiningvelocitiesandcorrectingfordeviationsfromdesignatedroutes.Thevehicleisresponsibleforfollowingtheroutingandvelocitycommandsissuedbythecontrolcenter,aswellasupdatingthecontrolcenterastoitspositionandvelocity.Inaddition,thevehicleperformsself-diagnosisandalertsthecontrolCriminalInvestigationUnit3centerofrelevantinformationconcerningfuelandoillevels,tirepressure,enginetemperature,personalstops,obstaclesintheroad,etc.Thecentralcontrollerusesthisinformationforactivere-routing.Eachvehiclecommunicateswithitsneighborstoensureproperfollowingdistanceandtoalerteachotherofemergencystops.Italsoreceiveslocationinformationfromactivemile-markersontheroad,whichitthenprovidestothecontrolcenter.Allofthismustbedonewithincertaindesignconstraintstobeprovided.Thegoalisanaffordable,incident-freetrafficnetworkthatoperatesatalltimeswithoptimalfuelandtimeefficiency.Unit3Roadtrafficcontrolatitsmostelementallevelisachievedthroughtheuseofasystemofsigns,signals,andmarkings,andtheyaresubjecttolegalcontrolviatherulesoftheroad.TrafficControlandSafetyUnit3Themarkingofroadwaysurfaceswithpaintedlinesandraisedpermanentmarkersiscommonandeffective.Asolidlineisawarningorinstructionnottocross,andabrokenlineisforguidance.Thus,solidlinesindicatedangerousconditions(suchasrestrictedsightdistancewhereovertakingwouldbedangerous),pavementedges,stoplines,andturninglanesatintersections;brokenlinesindicateinteriorlanelinesandcentrelinesontwo-wayroads,wherethesightdistanceisgood.Linesareusuallywhite,butyellowisusedforcentrelinesinNorthAmerica.Unit3Signsadvisethedriverofspecialregulationsandprovideinformationaboutdangersandnavigation.Theyareclassifiedasregulatorysigns,whichprovidenoticeoftrafficlawsandregulations(e.g.,signsforspeedlimitsandforstop,yieldorgive-way,andnoentry);warningsigns,whichcallattentiontodangerousconditions(e.g.,sharpcurves,steepgrades,lowverticalclearances,andslipperysurfaces);andguidesigns,whichgiverouteinformation(e.g.,numbersordesignations,distances,directions,andpointsofinterest).Unit3Legalrulesgoverningthemovementoftrafficmaybedividedintothreecategories.Firstarethoseapplyingtothevehicleandthedriver,suchasvehicleanddriverregistration,vehiclesafetyequipment,accidentreporting,financialliability,andtruckweightsandloads(toprotectpavementsandbridgesfromdamage).Secondarethemovementrulesfordriversandpedestrians,knownastherulesoftheroad;thesedictatewhichsideoftheroadtouse,maximumspeeds,right-of-way,andturningrequirements.Thirdarethoseregulationsthatapplytolimitedroadsections,indicatingspeedlimits,one-wayoperations,andturningcontrols.Unit3Rapidandcontinuousadvancesincommunicationsandcomputertechnologyarebringingahostofnewconceptsinroadtrafficcontrol.Automobilesequippedwithon-boardcomputersandcommunicationsdeviceswillreceiveinstructionsabouttheoptimalpathtoadestinationfromatrafficcontrolcentre.Spacesatellite,computersandsensorswithinthevehiclewillmonitortheoperationofcriticalsafetysystems(e.g.,brakes,steeringwheel),warningthedriverwhenconditionsexceednominalvalues.Unit3Communicationsandcomputersalsowillaidthemovementoftrucksandothercommercialvehiclesinurbanareas.Driversonlong-distanceinter-citytripscanbewarnedofcomingbadweather.Theyalsocanreceivewarningsiftheyareenteringacurvetooquicklyoranintersectiontoofast.Roadsafetyshouldbegreatlyenhancedbysuchsystems.Maximumflowsareexpectedtoincreasefrom2,000vehiclesperhourperlanetoasmanyas10,000to20,000.Theincreasedflowswillmeansubstantialreductionsincongestionand,becausevehiclesareautomaticallycontrolled,roadsafetywillimproveenormouslythroughtheeliminationofaccidentsduetodrivererror.Unit3More…这些标志以道路规则的形式受法律制约。…the