ASTM_E_1957_-_04_2010.pdf

Designation:E195704(Reapproved 2010)Standard Practice forInstalling and Using Pneumatic Tubes with Roadway TrafficCounters and Classifiers1This standard is issued under the fixed designation E1957;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()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This practice covers the use of pneumatic road tubes todetect the passing of load-bearing vehicle axles as part ofroadway traffic monitoring.1.2 The practice applies only to pneumatic road tubes usedfor the detection of load-bearing vehicle axles on a roadway.1.3 The values stated in SI units are to be regarded as thestandard.The inch-pound units given in parentheses are forinformation only.1.4 This standard does not purport to address all of thesafety concerns,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.Terminology2.1 Definitions of Terms Specific to This Standard:2.1.1 axlethe axis oriented transversely to the nominaldirection of vehicle motion,and extending the full width of thevehicle,about which the wheels at both ends rotate.2.1.2 axle countera device that receives signals from anaxle sensor and indicates the cumulative number of axles thatwere detected by the sensor during a specified time interval.2.1.3 axle sensora device that generates a signal indicat-ing the passing of a load-bearing vehicle axle.2.1.4 machine countthe cumulative number of axles,vehicles,or vehicles within specified classes,or all of these,indicated or recorded by a traffic recording device for aspecified time interval.2.1.5 manual countrecorded vehicle counts or vehicleclassification counts,or both,based upon human observation.2.1.6 pneumatic road tubean elastic tube that is stretchedacross a roadway for the purpose of detecting the passage of aload-bearing vehicle axle.2.1.7 traffc countera device that indicates,and usuallyrecords,the number of vehicles or vehicle axles,or both,thatpass over a point on a lane or roadway during a specified timeinterval.2.1.8 traffc recording devicean instrument that receivessignals from a sensor(s)and registers axle count,vehicle count,vehicle classification count,speed,gap,or headway(any or allof these)for defined time intervals.2.1.9 validation countan independent count made to es-tablish an accepted reference value against which a recordedcount will be compared to determine its accuracy and reliabil-ity.2.1.10 vehicleone,or multiple,mobile unit(s)designed totravel upon a roadway;a vehicle comprises one powered unitand may include one or more non-powered trailer or semi-trailer unit(s).2.1.11 vehicle classifiera device that senses and recordsthe number of vehicles of defined types(classes)that pass apoint on a lane or roadway during a specified time interval.2.1.12 vehicle classification countthe cumulative numberof vehicles of each defined type(class)recorded for a specifiedtime interval.2.1.13 verification counta count made on the same seg-ment of roadway concurrently with a validation count to testthe performance of a traffic counter or vehicle classifier.3.Significance and Use3.1 This practice addresses the recording of trafficcharacteristics,using pneumatic tubing with recording devices.This practice provides information for use with professionaljudgment by governmental agencies and private firms in themanagement of roads and roadway traffic.3.2 Traffic monitoring is important to the safe and efficientmovement of people and goods.The purpose of this practice isto ensure that traffic monitoring procedures produce traffic dataand summary statistics that are adequate to satisfy diverse andcritical traffic information needs.4.Procedure4.1 Installation Procedures and Techniques:1This practice is under the jurisdiction of ASTM Committee E17 on Vehicle-Pavement Systems and is the direct responsibility of Subcommittee E17.52 onTraffic Monitoring.Current edition approved April 1,2010.Published April 2010.Originallyapproved in 1998.Last previous edition approved in 2004 as E1957 04.DOI:10.1520/E1957-04R10.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 4.1.1 Select a relatively straight and smooth section ofroadway with free flowing traffic throughout the duration of thedata-collection session.For example,in selecting the roadwaysection,attention should be given to avoiding proximity todriveways and intersections.The availability of a place toanchor the traffic recording device is also important.4.1.1.1 In those areas that have designated parking spaces,where a parking vehicle might impinge upon the road tube,covering the affected part of the tube with a segment of angleiron with