[b]Density——[/b]thenumberofvehiclesoccupyingaroadlaneperunitlengthatagiveninstant.[b]Flow——[/b]thenumberofvehiclespassingapointperunitoftime;oftencalledvolumewhenthetimeunitisonehour.[b]Gap——[/b]thetimeintervalbetweenthepassageofconsecutivevehiclesmovinginthesamestream,measuredbetweentherearoftheleadvehicleandthefrontofthefollowingvehicle.[b]Headway——[/b]thetimeintervalbetweenpassageofconsecutivevehiclesmovinginthesamestream,measuredbetweencorrespondingpoints(e.g.frontbumper)onsuccessivevehicles.[b]InterruptedFlow——[/b]occurswhenflowisperiodicallyinterruptedbyexternalfixtures,primarilytrafficcontroldevices.[b]JamDensity——[/b]thedensitywhenspeedandflowarezero.[b]PHF(PeakHourFactor)——[/b]Thisdescribestherelationshipbetweenhourlyvolumeandthemaximumrateofflowwithinthehour:PHF=hourlyvolume/maximumrateofflow.Forthe15minuteperiods,PHF=volume/4x(maximum15minutevolumewithinthehour)[b]Shockwaves——[/b]Shockwavesoccurasaresultofdifferencesinflowanddensitywhichoccurwhenthereareconstrictionsintrafficflow.Theseconstrictionsarecalledbottlenecks.Thespeedofgrowthoftheensuingqueueistheshockwave,andisthedifferenceinflowdividedbythedifferenceindensity.[b]SpaceMeanSpeed——[/b]thearithmeticmeanofthespeedofthosevehiclesoccupyingagivenlengthofroadatagiveninstant.[b]Spacing——[/b]thedistancebetweenvehiclesmovinginthesamelane,measuredbetweencorrespondingpoints(fronttofront)ofconsecutivevehicles.[b]Speed——[/b]thetimerateofchangeofdistance.[b]TimeMeanSpeed——[/b]thearithmeticmeanofthespeedofvehiclespassingapointduringagiventimeinterval.[b]TravelTime——[/b]thetotaltimerequiredforavehicletotravelfromonepointtoanotheroveraspecifiedrouteunderprevailingconditions.[b]UninterruptedFlow——[/b]occurswhenvehiclestraversingalengthofroadwayarenotrequiredtostopbyanycauseexternaltothetrafficstream,suchastrafficcontroldevices.[b]Volume——[/b]Trafficvolumeisthemostbasicandwidelyusedparameterintrafficengineering,vehiclespermile,orvehiclesperkilometer.Bit钻头BitPerSecondbps每秒传输的位数Bitumen沥青BituminousJointFillers沥青接缝填充料BituminousMaterial沥青材料BituminousOverlay沥青封层BituminousPavementRoad沥青铺路BituminousPenetrationMacadam灌入式沥青路面BituminousPressureDistributor沥青压力散布机BituminousSandSlurry沥青沙浆BituminousSurfaceTreatment沥青表面处理BituminousWaterProofCoating沥青防水层BituminousTreatedBaseBTB沥青处理底层BituminousTreatedSandGravel沥青处理砂砾Black-HoleEffect黑洞效应BalanceCutandFill挖填之平衡Blast开炸BlastPad喷气防护坪BlastingMethod炸移法Bleeding路面冒油Blightproofcourses病虫害防治Bloodalcoholconcentration血液中酒精浓度BlownAsphalt吹制沥青Boiling砂涌BondingAgent黏着剂Bore钻凿Boredpile钻掘桩Borehole钻孔Boring钻探Boringlog钻孔柱状图Boringmachine钻机BoringRod钻杆Boring-core钻孔岩心Borrow借土；借方Borrowarea借土区BorrowPit借土坑；取土坑Bottleneckcontrol瓶颈路段（地点）管制法BottleNeckRoad瓶颈段；瓶颈路Bottleneck瓶颈BottomCourse底层BottomFlange下翼绿Boulder卵石Boxcaisson沉箱；箱式沉箱；匣式沉箱BoxCulvert箱涵；箱形涵洞BoxDrain水沟渠；匣形沟渠Boxgirder箱形梁Bracing支撑Bracket/Chassis拖架Brakefailure,Defectivebrake煞车失灵Brakelight煞车灯BrakeReactiontime煞车反应时间；制动反应时间BrakingDistance剎车视距（停车视距）Brakingsystem煞车系统BranchandBoundAlgorithm分枝界定法Breakdowns故障BreakingofEmulsion乳化沥青黏结BreakingWave碎波Breakaway脱离式接头Breathalcoholconcentration...
