Designation:E1442–94StandardPracticeforHighway-TrafficMonitoring1ThisstandardisissuedunderthefixeddesignationE1442;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(e)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thispracticedescribeshighway-trafficmonitoring,whichistheactivityofcollecting,summarizing,andreportingtrafficvolume,vehicleclassification,andvehicleweightdata.Thispracticeisfoundationalandisnotintendedtobeall-inclusive.Usersofthispracticeareallowed,indeedencour-aged,toexceedthepractice.1.2Trafficmonitoringresultsintraffic-volume,classifica-tion,andweight-summarystatisticswhichareusedinhighwaygeometricandpavementdesign,alternativehighwayrouteselection,roadwaydemandandserviceassessment,andaccident-exposureestimation.1.3Traffic-monitoringpracticesarebasedontheprincipleoftruth-in-data.Thisprincipleinvolvesprovidingthesupple-mentaryinformationrequiredforappropriateuseoftrafficdataandsummarystatistics.1.4Tomeasuretrafficforsummary-statisticcalculation,traffic-monitoringpracticesarealsobasedontheprincipleofuneditedbase-dataintegrity.Missingorinaccurateuneditedbasedatashallnotbecompleted,filled-in,orreplacedforanytypeoftrafficmeasurement.1.5Alimitationofthispracticeistraffic-datasummariza-tion.Traffic-datasummarizationproceduresarehypotheses,particularlyintheuseofadjustmentfactors.Thesehypothesesshallbeconsistentlycalculated,butmayalsobeexpectedtobechallengedandtochangeacrosstime.Thesechangeswillbeimportantinimprovingtheprecisionoftraffic-summarystatis-tics.1.6Theinherentlimitationoftraffic-monitoringpracticeresultsinstrictadherencetotheprincipleofuneditedbase-dataretention.Onlywithadequatehistoricaluneditedbasedatacanalternativehypothesesbetested,theimpactofthealternativehypothesesassessed,andstandardpracticerefined.1.7Thevaluesstatedininch-poundunitsaretoberegardedasstandard.1.8Thefollowingsafe...
