ASTM_E_1572_-_93.pdf

Designation:E 1572 93Standard Practice forClassifying Highway Vehicles from Known Axle Count andSpacing1This standard is issued under the fixed designation E 1572;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 covers the classification of highway ve-hicles into categories relating to axle or unit configuration.1.2 Traditionally,observers have classified vehicles visu-ally.Because of cost,safety considerations,and the need fornighttime classifications,visual classification has become im-practical.This practice classifies vehicles by methods otherthan visual observation,on the basis of axle count and spacing.1.3 This practice defines a method that,when applied to avehicles known axle count and spacings,generates an axleconfiguration code and a modifier code.The axle configurationcode describes the arrangement of axles,axle groups,and bodyunits on the vehicle.The modifier code defines the vehiclesapproximate load-carrying capacity.1.4 This practice also defines procedures for optionallycomputing two-and six-digit codes that the Federal HighwayAdministration(FHWA)and states have used to classifyvehicles from the axle configuration code and modifier code.1.5 This practice does not address specific methods formeasuring axle count and spacing,but rather the interpretationof such measurements obtained by unspecified automatedequipment.1.6 The degree of agreement between vehicle classificationsdetermined by this practice and visual classifications dependson the accuracy of measured axle count and spacings and oninteractions between selected classification parameters and thevehicle mix to which the classification is applied.These effectsare complex and have not yet been quantified.1.7 This practice applies only to vehicles that travel publichighways.1.8 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.The values stated in each system are not exact equiva-lents;therefore,each system must be used independently of theother.Combining values from the two systems may result innonconformance with this practice.1.9 This standard does not purport to address all of thesafety problems,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1Miscellaneous Documents:Traffc Monitoring Guide,October 1992,FHWA-PL92-0172A Vehicle Data Acquisition System,1988,Idaho Transporta-tion Department3Vehicle Identification Algorithm,1990,Idaho TransportationDepartment33.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 axle configuration code,nalphanumeric code,up tonine characters long,defining the number and type of units ina vehicle,number of axle groups in each unit,and number ofaxles in each axle group.3.1.2 axle count,nthe total number of a vehicles axles incontact with the pavement.3.1.3 axle group,none or more adjacent axles,usuallysharing a common connection to the body of a vehicle,whichjointly support a portion of the vehicles weight.3.1.4 axle spacing,nfor each axle,the horizontal distancebetween the center of that axle and that of the preceding axle;the axle spacing for the vehicles front axle is assumed to bezero.3.1.5 classification,nsee vehicle classification.3.1.6 commercial vehicle,na vehicle with heavy-dutychassis and suspension designed for commercial freight haul-age.3.1.7 dolly,nan assembly equipped with a hitch and oneor more axles,typically used to support the forward end of asemitrailer.3.1.8 full trailer,na freight trailer supported at both endsby attached axles.3.1.9 group delta,nthe maximum allowable differencebetween axle spacings within an axle group and the averageaxle spacing within the group.3.1.10 group limit,nthe maximum axle spacing permittedfor axles within an axle group.1This practice is under the jurisdiction of ASTM Committee E-17 on Vehicle-Pavement Systems and is the direct responsibility of Subcommittee E17.52 onTraffic Monitoring Device Interconnect.Current edition approved Sept.15,1993.Published January 1994.2Available from U.S.Department of Transportation,Federal Highway Admin-istration,Office of Highway Information Management,Washington,DC 20590.3Available from Idaho Transportation Department,3311 W.State St.,P.O.Box7129,Boise,ID 83707.1AMERICAN SOCIETY FOR TESTING AND MATERIALS100 Barr Harbor Dr.,West Conshohocken,PA 19428Reprinted from the Annual Book of ASTM Standards.Copyright ASTM3.1.11 group spacing,nfor each axle group,the horizontaldistance between the midpoint of that axle group and thepreceding axle group;the group spacing of the vehicles frontaxle group is a