土木工程(道桥方向)专业外文翻译-路(公路)

毕业设计（论文）外文资料翻译系别： 土木系 专业： 土木工程（道桥方向） 班级： 工077 姓名： 学号： essiishvil gieerig ecaics 附 指导教师评语指导教师评语：签字： 年 月日1、 外文原文（复印件）Theroad(highway)Theroadisonekindoflinearconstructionusedfortravel.Itismadeoftheroadbed,theroadsurface,thebridge,theculvertandthetunnel.Inaddition,italsohasthecrossingoflines,theprotectiveprojectandthetrafficengineeringandtheroutefacility.Theroadbedisthebaseofroadsurface,roadshoulder,sideslope,sideditchfoundations.Itisstonematerialstructure,whichisdesignedaccordingtoroute'splaneposition.Theroadbed,asthebaseoftravel,mustguaranteethatithastheenoughintensityandthestabilitythatcanpreventthewaterandothernaturaldisasterfromcorroding.Theroadsurfaceisthesurfaceofroad.Itissingleorcomplexstructurebuiltwithmixture.Theroadsurfacerequirebeingsmooth,havingenoughintensity,goodstabilityandanti-slipperyfunction.Thequalityofroadsurfacedirectlyaffectsthesafe,comfortandthetraffic.Theroutemarkingisonekindoftrafficsafetyfacilitypaintedbyoilpaintormadebytheconcreteandtilesonhigh-level,lesshigh-typesurface.Itsfunctioniscoordinatingthesigntomaketheeffectivecontroltothetransportation,directingthevehiclesskiproadtravel,servingunimpededandthesafepurpose.Ourcountryroadroutemarkinghasthelanemedianline,thetrafficlaneboundary,thecurbline,theparkingline,theconductioncurrentbelt,thepedestriancrossingline,thefourcornerscentercircle,theparkingazimuthline.Theroutemarkinghasthecontinualsolidline,thebrokenlineandthearrowindicatoranditscolorusesthewhiteortheyellow.Thearchofbridgeisthestructurewhichstridesoverrivers,mountainvalleyandchannel.Itismadegenerallybysteelrod,concreteandstone.Thetunnelisthecavewhichconnectsbothsidesoftheroad.Thetechniqueofthisconstructionisverycomplex,thecostoftheprojectsishigherthancommonroad.However,itreducesthedrivingdistancebetweentwoplaces,enhancesthegradeofthetechnicalinbuildingtheroadandguaranteesthecarscandrivefastandsafely,thusreducesthecostoftransportation.Theprotectiveprojectistoprotectandconsolidatetheroadbedinorderthatitcanguaranteetheintensityandthestabilityoftheroad,thusmaintainstheautomobiletopassthroughsafely.Inordertoguaranteethatsafeoperationofthehighwaytransportation,besidesthehighwayengineeringandthevehiclesperformance,itmusthavesometrafficsignal,routemarking,eachkindofdirectoranddemonstratefacility.Thehighwaymarkingusescertainmarkanddrawsymbol,simplewordsandnumber,theninstallsinthesuitableplacetoindicatethefrontroad'sconditionortheaccidentconditionincludingtheinformationalsign,thewarningsignal,theprohibitorysign,theroadsignandsoon.TheroadwhichJoincity,villageandindustry,mainlyareusedfortheautomobileandhascertaintechnicalstandardandthefacilitypathcanbecalledthehighway.hehighway”inChineseisthemodernview,butitwasnotexistedinoldday.Itgetsthenamefromthemeaningofbeingusedforthepublictraffic.Wherearethehuman,therearetheroad.Itisatruth.However,theroadisnotthehighway.Ifwetalkthehistoryabouttheroad,theearliesthighwayisthatbuiltbytheoldEgyptiansformakingthepyramid.NextisthestreetwhichbuiltbytheBabylonpeopleabout4000yearsago.Allthesearemuchearlierthanourcountry.About500B.C.,thePersianEmpireroadhaslinkedupEastandWest,andconnectedtheroadtoChina.ItistheearliestandlongestSilkRoad.2500yearsago,itmightbethegreatestroad.TheancientRomeEmpireroadwasoncecelebrated;ittookRomeasthecenter,allaroundbuilt29roads.Thereforeitcameoutonecommonsaying:everyroadleadstoRome.Theroad'sconstructionistheprocesstoenhancetechniqueandrenewthebuildingmaterials.Theearliestistheoldroad,itiseasytobuildbutitisalsotodestroy.Ifthereistoomuchwaterorcars,itwillbeunevenandevenbedestroyed.ThemacadamroadappearedintheEuropewhichoutbalancedtheearliestmudroad.ThenthebrickroadappearedwhichwasearlierthanChina.Itwasonegreatbreachthatwemoldedbitumenonthemacadamroad.Fromancienttimestothepresent,Chinahascourierstationandcourierroad,whilethefirstmoreadvanceroadwastheonethatfromLongZhouinGangXitoZhenNanGuanin1906.ThedifferencebetweenRoadandpathThepathistheprojectforeachkindofvehiclesandpeopletopassthrough.Accordingtoitsfunction,wecandivideitintotheurbanroad,theroad,thefactoriesandminespath,theforestroadandcountyroad.TheclassificationofroadFirst,accordingtoadministrativerank,itincludesnationalhighway,provinceroad,countyroadandthespecialroad.Generallythenationalhighwayandprovinceroadarenamedmainline;thecountyroadisnamedbranchline.Thenationalroadisthemainlineandhaspoliticalandeconomysignificance,includingtheimportantnationaldefenseroadandtheroadcollectingourcapitalwithotherprovinces,autonomousregionsandmunicipalities.Itisalsotheroadlinkstheeconomycenter,seaporthinge,factoryandimportantstrategicplace.Thehighwaystridingoverdifferentprovincesarebuilt,protectedandmanagedbythespecialorganizationswhichareapprovedbytheministryofcommunications.Theprovincialroadisthemainlinebuilt,protected,managedbytheroadmanagedepartment.Itisfullofpoliticalandeconomicsensetothewholeprovince.Thesinglewayfourlevelsofroadscanadaptbeloweachdayandnightmedium-dutytruckvolumeoftraffic200.Thecountyrouteisreferstohascounty-wide(county-levelcity)politics,theeconom-icsignificance,connectsinthecountyandthecountythemaintownship(town),theprin-cipalcommoditiesproductionandthecollectionanddistributioncenterroad,aswellasdoesnotbelongtothefederalhighway,provincialroad'scountybordertheroad.Thecoun-tyroutebythecounty,thecityroadDepartmentresponsiblefortheworkisresponsibletoconstruct,themaintenanceandthemanagement.Thetownshiproadreferstomainlytheroadwhichforthetownship(town)thevilla-geeconomy,theculture,theadministrationserves,aswellasdoesnotbelongtoabovet-hecountyroutebetweenroad'stownshipandthetownshipandthetownshipandtheexte-riorcontactroad.Townshipisresponsiblebythepeople'sgovernmenttoconstruct,them-aintenanceandthemanagement.Thespecial-purposeroadisreferstofeedsspeciallyormainlysuppliesthefactoriesandmines,theforestregion,thefarm,theoilfield,thetouristarea,themilitaryimportantplaceandsoonandtheexternalrelationsroad.Thespecial-purposeroadisresponsiblebythespecial-purposeunittoconstruct,themaintenanceandthemanagement.Mayalsoentrustthelocalroaddepartmenttoconstruct,themaintenanceandthemanagement.Second,accordingtotheuseduty,thefunctionandadaptsthevolumeoftrafficdivision.Accordingtoourcountrypresent"HighwayengineeringTechnicalstandard"theroadaccordingtotheuseduty,thefunctionandtheadaptationvolumeoftra-fficdividesintohighway,arterialroad,second-classroad,tertiaryhighway,fourlevelofroadfiveranks:1st,thehighwaytofeedspeciallytheautomobileandshouldcontrolthedifferencec-ompletelyrespectivelytowardthedividingstriponroadstravelthemultiplehighway.Thefourtrafficlanehighwaysoughttobeabletoadapteachkindofautomobilereducepassengervehicle'syearmeandiurnalvolumeoftraffic25000~55000.Thesixtrafficlanehighwaysoughttobeabletoadapteachkindofautomobilereducepassengervehicle'syearmeandiurnalvolumeoftraffic45000~80000.Theeighttrafficlanehighwaysoughttobeabletoadapteachkindofautomobiler-educepassengervehicle'syearmeandiurnalvolumeoftraffic60000~100000.2nd,thearterialroadtosupplytheautomobileandmayaccordingtoneedtocontrolthedifferencerespectivelytowardthedividingstriponroadstravelthemultiplehighway.Thefourtrafficlanearterialroadsoughttobeabletoadapteachkindofautomobilreducepassengervehicle'syearmeandiurnalvolumeoftraffic15000~30000.Thesixtrafficlanearterialroadsoughttobeabletoadapteachkindofautomobilereducepassengervehicle'syearmeandiurnalvolumeoftraffic25000~55000.3rd,thesecond-classroadtosupplytheautomobiletravelthetwo-lanehighway.Canadapteachdayandnights3000~7500medium-dutytruckvolumeoftrafficgenerally.4rd,tertiaryhighwaystomainlysupplytheautomobiletravelthetwo-lanehighway.Canadapteachdayandnights1000~4000medium-dutytruckvolumeoftrafficgenerally.The5,fourlevelsofroadstomainlysupplytheautomobiletravelthetwo-laneorthesingle-lanehighway.Thetwo-lanefourlevelsofroadscanadaptbeloweachdayandnightmedium-dutytruckvolumeoftraffic1500.HighwayengineeringincludesHighwayplanninglocationdesignandmaintenance.BeforethedesignandconstructionofanewhighwayorhighwayimprovementcanbeundertakentheremintbegeneralplaningandconsiderationoffinancingAspartofgeneralplanningitisdecidedwhatthetrafficneedofthereawillbeforaconsiderableperiod,generally20years,andwhatconstructionwillmeetthoseneeds.Toassesstrafficneedsthehighwayengineercollectsandanalyzesinformationaboutthephysicalfeaturesofexistingfacilities,thevolume,distribution,andcharacterofpresenttraffic,andthechangestobeexpectedinthesefactor.Thehighwayengineermustdeterminethemostsuitablelocationlayout,andcapacityofthenewrouteandstructures.Frequently,apreliminarylineorlocationandseveralalternateroutesarestudied.Thedetaileddesignisnormallybegunonlywhenthepreferredlocationhasbeenchosen.Inselectingthebestroute,carefulconsiderationisgiventothetrafficrequirementsterraintobetraversedvalueoflandneededfortheright-of-way.andestimatedcostofconstructionforthevariousplans.Thephotogrammetricmethod,whichmakesuseofaerialphotographsisusedextensivelytoindicatethecharacteroftheterrainonlargeprojectswhereitismosteconomical.Onsmallproject,Financingconsiderationsdeterminewhethertheprojectcanbecarriedoutonetimeorwhetherconstructionmustbeinstageswitheachstageinitiatedasfundsbecomeavailable.Indecidingthebestmethodoffinancingthework,theengineermakesananalysisofwhomitwillbenefit.Importanthighwaysandstreetsbenefit*invaryingdegrees,threegroups*usersownersofadjacentpropertyandthegeneralpublic.Usersofimprovedhighwaysbenefitfromdecreasedcostoftransportation,greatertravelcomfort,increasedsafetyandsavingoftime.Theyalsoobtainrecreationalandeducationalbenefits.Ownersofabuttingoradjacentpropertymaybenefitfrombetteraccess,increasedpropertyvalue,moreeffectivepoliceandfireprotection,improvedstreetparkinggreaterpedestriantrafficsafety,andtheuseofthestreetright-of-wayforthelocationofpublicutilitiessuchaswaterlinesandsewers.Evaluationofvariousbenefitsfromhighwayconstructionisoftendifficultbutisamostimportantphaseofhighwayengineering.Somebenefitscanbemeasuredwithaccuracy,buttheevaluationofothersismorespeculative.Asaresultnumerousmethodsarcusedtofinanceconstruction,andmuchengineeringworkmayheinvolvedinselectingthebestprocedure.Environmentalevaluation.Theenvironmentalimpactofconstructinghighwayshasreceivedincreasedattentionandimportance.Manyprojectshavebeendelayedandnumerousotherscanceledbecauseotenvironmentalproblems.Theenvironmentalstudyorreportcoversmanyfactors,includingnoisegeneration,airpollutiondisturbanceofareastraverseddestructionofexistinghousingandpossiblealternateroutes.Highwayengineersmustalsoassistintheacquisitionofright-of-wayneededfornewhighwayfacilitiesAcquisitionofthelandrequiredforconstructionofexpresswaylendingintothecentralbusinessareasofcitieshasprovedextremelydifficultithepublicisdemandingthattrafficengineersworkcloselywithcityplanners,architects,sociologistsandallgroupsinterestedinbeautificationandimprovementofcitiestoassurethatexpresswaysextendinxthroughmetropolitanareasbebuiltonlyaftercoordinatedevaluationofallmajorquestions,includingthefollowing;(1)Issufficientattentionbeingpaid-tobeautificationoftheexpresswayitself?(2)Wouldachangeinlocationpreservemajornaturalbeautiesofthecity?(3)Couldadepresseddesignhelogicallysubstitutedforthosesectionswhereanelevatedexpresswayisproposed?(4)Canthegeneraldesignheimprovedtoreducethenoisecreatedbylargevolumesoftraffic?(5)Aresomesectionsofthecitybeingisolatedbytheproposedlocation?Detaileddesign.Detaileddesignofahighwayprojectincludespreparationofdrawingsorblueprintstobeusedforconstruction.Theseplansshow,forexample,thelocation,thedimensionsofsuchelementsasroudwaywidth*thefinajprofilefor(heroad,thelocationandtypeofdrainagefacilities,andthequantitiesofworkinvolved,includingearthworkandsurfacing.Inplanningthegradingoperationsthedesignengineerconsidersthetypeofmaterialtobeencounteredinexcavatingorincuttingawaythehighpointsalongtheprojectandhowthernaterialremovedcanbestbeutilisedforfillorforconstructingembankmentsacrosslowareaselsewhereontheproject.Forthistheengineermustanalyzethegradationandphysicalpropertiesofthesoil,determinehowtheembankmentscanbestbecompacted,andcalculatethevolumeofearthworktobedone.Electroniccalculatingproceduresarenowsometimesusedforthelaststep.Electronicequipmenthasalsospeededupmanyotherhighwayengineeringcalculations.PowerfulandhighlymobileearthmovingmachineshavebeendevelopedTOpermitrapidandeconomicaloperations.,Selectionofthetypeandthicknessofroudwaysurfacingtobeconstructedisanimportantpartofdesign.Thetypechosendependsuponthemaximumloadstobeaccommodated,thefrequencyoftheseloadsandotherfactors.Forsomemures,trafficvolumemaybesolowthatnosurfacingiseconomicallyjustifiedandnaturalsoilservesastheroadway.Astrafficincreases,asurfacingofsandycluy,crushedslag,crushedstonecalichecrushedoystershells,oracombinationofthesemaybeapplied.Ifgravelisused,itusuallycontainssufficientclayandfinematerialtohelpstabilizethesurfacing.Gravelsurfacesmaybefurtherstubilizedbyapplicationofcalciumchloride,whichalsoaidsincontrollingdust.AnothersurfacingiscomposedofPortlandcementandwatermixediutotheupperfewinchesofthesuhgradeandcompactedwithrollers.ThisprocedureformsAsoil-cementbasethatcanbesurfacedwithbituminousmaterials.Roadwaysrocarrylargevolumesofheavyvehiclesmustbecarefullydesignedandmadeofconsiderablethickness.Muchofhighwayengineeringisdevotedtotheplaningandconstructionoffacilitiestodrainthehighwayorstreetandlocarrystreamsacrossthehighwayright-of-way.Removalofsurfacewaterfromtheroadorstreetisknownasurfacedruiuage.Itisaccomplishedbyconstructingtheroadsothatithasacrownandbyslopingtheshouldersandadjacentareassoastocontroltheflowofwatereithertowardexistingnaturaldrainage,suchasopenditches,orintoastormdrainagesystemofcalehbasinsandundergroundpipes.Ifastormdrainagesystemisused,asitwouldbewithcitystreets,thedesignengineermustgiveconsiderationtotherntalareadrainingontothestreet,themaximumrateofrunoffexpected,thedurationofthedesignstorm,theamountofpondingallowableateachcarchbasin,andtheproposedspacingofthecatchbasinsalongthestreet.Fromthisinformationthedesiredcapacityoftheindividualeatehbaxinandthesizeoftheundergroundpipingnetworkurccalculated.Indesigningfacilitiestocarrystreamsunderthehighwaytheengineermustdeterminetheareatobedrainedthemaximumprobableprecipitationoverthedrainagebasin,thehighestexpectedrunoffrare.andthen,using(hitinformation,mustcalculatetherequiredcapacityofllit:drainagestructure.Generallydesignsaremadeadequatetoaccommodatenotonlythelargestfloweverrecordedforthatlocationbutthegreatestdischargethatmightbeexpectedunderthemostadverseconditionsforagivennumberofyears.Factorconsideredincalculatingtheexpectedflowthroughaculvertopeningincludesize,length,andshapeoftheopening,roughnessofthewalls,shapeoftheentranceanddownstreamendoftheconduit,maximumallowableheightofwaterattheentrance,andwaterlevelattheoutletMuchengineeringundconstructionworkhasbeendonetoprovidereststopsalongmajorexpresswayroutestespeciallythenationalsystemofinterstatehighways.Thesefacilitiesmustbecarefullylocatedtopermiteasyandsafeexitandreturnaccesstothehighway.Manyunitshavebeenbuilt^sceniclocationsinforestedareastopermitpicnicgroundsandwalkwaysthroughtheforest.Theserestareasareespeciallybeneficialtotho«edriverstravelinglongdistanceswithfewstops..Thecontrolandreductionofnoisealongbusyroutes,especiallyexpressways,hasbecomeanimportantpartofhighwayengineering.Inmanycommunitieshighwallshavebeenhuiltalongeithersideoftheexpressway.Suchwallscanhecostlytoconstruct,hutcanproveverybeneficial,barrierscanreduceoverallnoiselevelsbyover50%.Constructionoperations.Althoughmuchengineeringandplaningmustbedonepreliminarytoit,theactualconstructionisnormallythecostliestpartofmakinghighwayuudstreetimprovements.Willitheawardofaconstructioncontractfollowingthepreparationofthedetailedplansandspecificationstengineersgoontotheftiteandlayouttheproject.Aspartofthisstakingout.limitsofearthworkareshown,locationofdrainagestructuresindicated,andprofilesestablished.Heavyrollersareusedtocompactthesoilorsubgradebelowtheroadwayinordertoeliminatelatersettlement.Pneumatictiredrollersandsheepsfootrollers(steelcylindersequippedwithnumerousshortsteelteethorfeetJareoftenemployedforthisoperation.Vibratoryrollershavebeendevelopedandusedonsomeprojectsinrecentyears.Onetypevibratesupto3400times/min,compactingtheunderlyingmaterialtoanappreciabledepth.Maintenanceandoperation.Highwaymaintenanceconsistsoftherepairandupkeepofsurfacingandshoulders,bridgesanddrainagefacilities?signs,trafficcontroldevices,guardrails,trafficstripingonthepavement,retainingwalls,andsideslopes.Additionaloperationsincludeicecontrolundsnowremoval,becauseitisvaluabletoknowwhysomehighwaydesignsgivebetterperformanceandprovelesscostlytomaintainthanothers,engineerssupervisingmaintenancecanoffervaluableguidancetodesignengineers.Consequently,maintenanceandoperationarcimportantpartsofhighwayengineering.2、外文资料翻译译文路（公路）公路是供汽车或其他车辆行驶的一种线形带状结构体。它是由路基、路面、桥梁、涵洞和隧道等基本部分组成。此外，还有路线交叉、防护工程和交通工程及沿线设施等。路基是路面、路肩、边坡、边沟等部分的基础，如下图所示。它是按照路线的平面位置和设计高程在地面上开挖和填筑成一定断面形式的线形人工土石料构造物。路基作为行车部分的基础，必须保证有足够的强度和稳定性，能防止水及其他自然灾害的侵蚀。路面是公路表面部分。它是用一定级配的混合料铺筑于路基之上的单层或多层结构物。路面要求平整，具有足够的强度，良好的稳定性和抗滑性能。路面质量的好环，直接影响到行车的安全性、舒适性和车辆的通行能力。路面标线是在高级、次高级路面上用漆类物质喷刷或用混凝土预制块、瓷瓦等作的一种交通安全设施。它的作用是配合标志牌对交通运输作有效的管制，指引车辆分道行驶，达到畅通和安全的目的。我国公路路面标线有行车道中线、车道分界线、路缘线、停车线、禁止超车线、导流带、人行横道线、交叉路口中心圈、停车方位线、导向箭头等。路面标线有连续实线、间断线和箭头指示线等三种形式，其颜色采用白色或黄色。桥涵是公路跨越河流、山谷、通道等障碍物而架设的结构物。一般用钢筋混凝土、块石等材料建造而成。隧道是连接山岭两侧公路的一条山洞。隧道修筑施工技术复杂，工程造价比一般路面高，但它缩短了两地间行车距离，提高了公路的技术等级，保证了行车快速安全，从而降低运输成本。公路防护工程是对路基进行防护和加固，以保证路基的强度和稳定性，从而维持正常的汽车通行和行车安全。交通标志为了保证公路运输的安全运行，除公路工程和车辆性能所要求的设备和条件外，还必须有交通标志、路面标线等各种指挥、显示设施。公路标志，是用一定的标记，绘以符号、图案、简单文字、号码等，装设在适当的地点，预示前方公路的状况或事故发生的状态。包括指示标志、警告标志、禁令标志、指路标志等。联接城市、乡村和工矿基地之间，主要供汽车行驶并具备一定技术标准和设施共交通之路得名；外国人叫它highway，看来是它建设地基较高，利于行车而来。有人必有路，走的人多势必成路，这是真理。不过，这路并非公路。若说公路的历史，公元前三千年，古埃及人为修建金字塔而建设的路，应是世界上最早的公路。次之是大约公元前二千年古巴比伦人的街道，比我们中国公路要早很多。公元前五百年左右，波斯帝国大道贯通了东西方，并连接起通往中国的大道，形成了世界上最早、最长的丝绸之路，这可算是二千五百年前最伟大的公路了。古罗马帝国的公路曾经显赫一时，它以罗马为中心，向四外呈放射形修建了二十九条公路，号称世界无双。所以产生了至今人们还常用的外国俗语，“条条道路通罗马”。公路的修建也有个不断提高技术和更新建筑材料过程。最早当然是土路，它易建但是也易坏，雨水多些，车马多此，便凹凸不平甚至毁坏了。欧洲较早出现了碎石路，这比土进了一大进。再后出现了砖块路，也比中国早很多。在碎石上铺浇沥青是公路史上一大突破，这是近代的事了。中国自古有驿站驿路，但是真正第一条较先进的公路，是1906年铺设的广西龙州至镇南关的公路。公路和道路的区别道路是供各种车辆（无轨）和行人通行的工程设施。按其使用特点分为城市道路、公路、厂矿道路、林区道路及乡村道路等。公路的分类一、按行政等级划分公路按行政等级可分为：国家公路、省公路、县公路和乡公路（简称为国、省、乡道）以及专用公路五个等级。一般把国道和省道称为干线，县道和乡道称为支线。国道是指具有全国性政治、经济意义的主要干线公路，包括重要的国际公路，国防公路、连接首都与各省、自治区、直辖市首府的公路，连接各大经济中心、港站枢纽、商品生产基地和战略要地的公路。国道中跨省的高速公路由交通部批准的专门机构负责修建、养护和管理。省道是指具有全省（自治区、直辖市）政治、经济意义，并由省（自治区、直辖市）公路主管部门负责修建、养护和管理的的公路干线。县道是指具有全县（县级市）政治、经济意义，连接县城和县内主要乡（镇）、主要商品生产和集散地的公路，以及不属于国道、省道的县际间公路。县道由县、市公路主管部门负责修建、养护和管理。乡道是指主要为乡（镇）村经济、文化、行政服务的公路，以及不属于县道以上公路的乡与乡之间及乡与外部联络的公路。乡道由人民政府负责修建、养护和管理。专用公路是指专供或主要供厂矿、林区、农场、油田、旅游区、军事要地等与外部联系的公路。专用公路由专用单位负责修建、养护和管理。也可委托当地公路部门修建、养护和管理。二、按使用任务、功能和适应的交通量划分根据我国现行的《公路工程技术标准》（JTJ001-1997），公路按使用任务、功能和适应的交通量分为高速公路、一级公路、二级公路、三级公路、四级公路五个等级：1、高速公路为专供汽车分向分车道行驶并应全部控制出入的多车道公路。四车道高速公路应能适应将各种汽车折合成小客车的年平均日交通量25000～55000辆。六车道高速公路应能适应将各种汽车折合成小客车的年平均日交通量45000～80000辆。八车道高速公路应能适应将各种汽车折合成小客车的年平均日交通量60000～100000辆。2、一级公路为供汽车分向分车道行驶并可根据需要控制出入的多车道公路。四车道一级公路应能适应将各种汽车折合成小客车的年平均日交通量15000～30000辆。六车道一级公路应能适应将各种汽车折合成小客车的年平均日交通量25000～55000辆。3、二级公路为供汽车行驶的双车道公路。一般能适应每昼夜3000～7500辆中型载重汽车交通量。4、三级公路为主要供汽车行驶的双车道公路。一般能适应每昼夜1000～4000辆中型载重汽车交通量。5、四级公路为主要供汽车行驶的双车道或单车道公路。双车道四级公路能适应每昼夜中型载重汽车交通量1500辆以下。单车道四级公路能适应每昼夜中型载重汽车交通量200辆以下。高速公路工程包括高速公路计划.选址.设计和高速公路保养。当一项高速公路工程设计建设或是改造之前，必须大致地计划考虑一下费用问题。作为概要计划的一部分，该地区在可预见的时段内（如20年）的交通流量，以及何种建设才能满足这种需求将是决定因素。为了评估交通需求量，高速公路工程师通过采集分析现有设备提供的物理数据信息——包括车流量，分布，现有交通工具的特征以及蕴涵在这些因素中的可以预知的变化。高速公路工程师必须决定新路线建筑最适合的位置.布局以及容量。通常情况下，一条初步的线路或选址和若干备选路线都会被拿来研究。细节方面设计通常在一个更佳的选址确定下来之后才开始。为了选择最佳路线，需要仔细考虑的问题包括：交通需求，（路线）横贯的地带，可通行道路的土地价值以及各种方案的结构开销的预算。在一些大型项目中，利用了航拍技术的摄影测量法被广泛用于显示该地带的特征，这也是一种最经济的方法。在那些小型工程中，地面绘图法已经很完美了。资金方面的考虑决定了一项工程是一次性实施还是是否必须分阶段建设，每阶段建设等资金到位后才开始。在决定最经济的实施方案时，工程师通过