ASTM_E_1442_-_94.pdf

Designation:E 1442 94Standard Practice forHighway-Traffic Monitoring1This standard is issued under the fixed designation E 1442;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon(e)indicates an editorial change since the last revision or reapproval.1.Scope1.1 This practice describes highway-traffic monitoring,which is the activity of collecting,summarizing,and reportingtraffic volume,vehicle classification,and vehicle weight data.This practice is foundational and is not intended to beall-inclusive.Users of this practice are allowed,indeed encour-aged,to exceed the practice.1.2 Traffic monitoring results in traffic-volume,classifica-tion,and weight-summary statistics which are used in highwaygeometric and pavement design,alternative highway routeselection,roadway demand and service assessment,andaccident-exposure estimation.1.3 Traffic-monitoring practices are based on the principleof truth-in-data.This principle involves providing the supple-mentary information required for appropriate use of traffic dataand summary statistics.1.4 To measure traffic for summary-statistic calculation,traffic-monitoring practices are also based on the principle ofunedited base-data integrity.Missing or inaccurate uneditedbase data shall not be completed,filled-in,or replaced for anytype of traffic measurement.1.5 A limitation of this practice is traffic-data summariza-tion.Traffic-data summarization procedures are hypotheses,particularly in the use of adjustment factors.These hypothesesshall be consistently calculated,but may also be expected to bechallenged and to change across time.These changes will beimportant in improving the precision of traffic-summary statis-tics.1.6 The inherent limitation of traffic-monitoring practiceresults in strict adherence to the principle of unedited base-dataretention.Only with adequate historical unedited base data canalternative hypotheses be tested,the impact of the alternativehypotheses assessed,and standard practice refined.1.7 The values stated in inch-pound units are to be regardedas standard.1.8 The following safety hazards caveat applies only to thetraffic data collection portion,Section 6,of this practice.Thisstandard does not purport to address all of the safety concerns,if any,associated with its use.It is the responsibility of the userof this standard to establish appropriate safety and healthpractices and determine the applicability of regulatory limita-tions prior to use.2.Referenced Documents2.1 ASTM Standards:E 1318 Specification for Highway Weigh-in-Motion(WIM)Systems with User Requirements and Test Method23.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 adjustment factors,ntraffic summary statistic cor-rections for multiple-axle vehicles,weekday-traffic variation,seasonal-traffic variation,and regional-traffic characteristics;and,the estimate of annual growth or decline for traffic-summary statistics on road segments not recounted during ayear.3.1.2 annual average daily traffc(AADT),nthe estimateof typical traffic on a road segment for all days of the week,Sunday through Saturday,over the period of one year andcalculated from permanent-counter data as the sum of MonthlyAverage Daily Traffic(MADTs)divided by the number ofMADTs,and for short-term counts by using adjustment factors.3.1.3 annual average days of the week,(AADW),natraffic volume mean statistic for each day of the week,over theperiod of one year,and calculated from included permanent-counter data as the sum of Monthly Average Days of the Week(MADWs)for a year divided by the number of MADWs.3.1.4 annual average weekday traffc,(AAWDT),ntheestimate of typical traffic over the period of one year,for thedays Monday through Thursday,calculated from permanentcounter data as the sum of Monthly Average Weekday Traffic(MAWDTs)divided by the number of MAWDTs.3.1.4.1 DiscussionFriday traffic may be included inAAWDT calculation at a permanent-counter site or for sum-mary statistics from permanent counters by functional andoperational classification if the inclusion of these data does notincrease the AAWDT coefficient of variation.3.1.5 annual average weekend traffc,(AAWET),ntheestimate of typical traffic over the period of one year,for thedays Saturday through Sunday,calculated from includedpermanent-counter data as the sum of Monthly Average Week-end Traffic(MAWETs)divided by the number of MAWETs.3.1.5.1 DiscussionFriday traffic may be included in1This practice is under the jurisdiction of ASTM Committee E-17 on VehiclePavement Systems and is the direct responsibility of Subcommittee E17.52 onTraffic Monitoring Device Interconnect.Current edition approved April 15,1994.Published June 1994.Originallypublished as E 1442 91.Last previous edition E 1442 92a.2Annual Book of ASTM Standards,Vol 04.03.1AMERICAN SOCIETY FOR TESTING AND MATERIA