ASTM_E_2532-09R2017.pdf

This international standard was developed in accordance with internationallyognized principles on standardization established in the Decision on Principles for theDevelopment ofInternational Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.Designation:E2532-09(Reapproved 2017)NTERNATIONALStandard Test Methods forEvaluating Performance of Highway Traffic MonitoringDevices1This standard is issued under the fixed designation E2532;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.Scope2.Referenced Documents1.1 Purpose-The two test methods contained in this stan-2.1 ASTM Standards:3dard define acceptance tests for evaluating the performance ofE177 Practice for Use of the Terms Precision and Bias ina Traffic Monitoring Device(TMD)according to the functionsASTM Test Methodsit performs,the data it provides,the required accuracy of theE867 Terminology Relating to Vehicle-Pavement Systemsdata,and the conditions under which the device operates.E1318 Specification for Highway Weigh-In-Motion(WIM)Acceptance tests are recommended whenever a TMD isSystems with User Requirements and Test Methodspurchased,installed,or performance validation is desired.TheE2300 Specification for Highway Traffic Monitoring De-tests are performed in a field environment and result in anvicesaccept or a reject decision for the TMD under test.3.Terminology1.2 Exceptions-Exceptions and options to the test methodsmay be included in any derivative test method presented by a3.1 Definitions of terms and definitions of terms specific touser as part of the procurement process for TMDs.Sellers maythese test methods are given below.offer exceptions and options in responding to an invitation to3.2 Definitions:bid.3.2.1 accepted reference value,n-value attributed to aparticular quantity(for example,vehicle class by number of1.3 Units-The values stated in inch-pound units are to beaxles and interaxle spacings,vehicle count,lane occupancy.orregarded as standard.The values given in parentheses arevehicle speed)and agreed upon by the user and seller inmathematical conversions to SI units,2 which are provided foradvance of testing of a TMD,which has an uncertaintyinformation only and are not considered standardappropriate for the given purpose.E23001.4 The following safety procedures apply to Sections 6 and7,which describe the details of the acceptance test methods.3.2.2 accuracy,n-closeness of agreement between a valueindicated by a TMD and an accepted reference value.E2300When a test site accessible by the public(for example.a streetor highway)is used for the acceptance test of the TMD.obtain3.2.3 axle.n-axis oriented transversely to the nominalapproval from the public authority having jurisdiction over thedirection of vehicle motion,and extending the full width of thesite for the traffic control procedures to be used during the test.vehicle,about which the wheels at both ends rotate.E867.This standard does not purport to address all of the saferyE1318concerns,if any,associated with its use.It is the responsibiliry3.2.4 axle count,n-number of vehicle axles enumerated atof the user of this standard to establish appropriate safety anda point on a lane or roadway during a specified time interval.health practices and determine the applicability of regulatoryE867limitations prior to use.3.2.5 bias,n-a generic concept related to a consistent orsystematic difference between a set of test results from theprocess and an accepted reference value of the property beingThese test methods are under the jurisdiction of ASTM Committee E17 onmeasured.E177Vehicle-Pavement Systems and are the direct responsibility of Subcommittee3.2.6 correct detection,n-an indication by a TMD that aE17.52 on Traffic Monitoring.Current edition approved Jan.1,2017.Published January 2017.Originallyvehicle actually passing over the detection area of the TMD isapproved in 2006.Last previous edition approved in 2009 as E2532-09.DOI:detected by the TMD.E230010.1520/E2532-09R17.Standard Practice for Use of the Interational System of Units(SI):TheModer Metric System,IEEE/ASTM SI 10TM-2002.The Institute of Electrical andFor referenced ASTM standards,visit the ASTM website,www.astm.org.orElectronics Engineers(IEEE).Inc.3 Park Avenue,New York.NY,10016-5997.contact ASTM Customer Service at serviceastm.org.For Annual Book of A.STMUSA and American Society for Testing and Materials(ASTM).100 Barr HarborStandards volume information,refer to the standards Document Summary page onDrive,West Conshohocken,PA 19428-2959,USA,ISBN 0-7381-3317-5.the ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700.West Conshohocken,PA 19428-2959.United StatesCopyright by ASTM Intl(all rights reserved):Sat Oct 7 03:56:41 EDT 2017Downloaded/printed byUniversity of Edinburgh(University of Edinburgh)pursuant to License Agreement.No further reproductions authorizedE2532-09(2017)3.2.7 data item,n-characteristic associated with individualand other parameters typically used to portray trafficvehicles(for example,count,class,and speed)or the con-movement.E2300tinuum of vehicles at a location(for example,density,flowE23003.2.20 vehicle class by axle,n-characterization of a vehiclerate,and queue length).by its number of axles and interaxle spacings.E23003.2.8 detection area,n-road surface area above which asensor detects a vehicle or vehicle component.E23003.2.21 vehicle class by length,n-characterization of ve-hicles by their total length.E23003.2.9 electronics unit,n-device that provides power to oneor more sensors,filters and amplifies the signals produced by3.2.22 vehicle count(volume),n-total number of vehiclesthe sensors,and may perform other functions such as sensitiv-observed or predicted to pass a point on a lane or roadwayity adjustment,failure indication,and delayed actuation ofduring a specified time interval.E2300traffic control signals.E23003.2.23 vehicle,n-one or more mobile units coupled to-3.2.10 false detection,n-an indication by a TMD that agether for travel on a highway;a vehicle contains one poweredvehicle not actually passing over the detection area of the TMDunit and may include one or more non-powered full-trailer oris detected by the TMD.E2300semi-trailer units.E8673.2.11 flow rate,n-number of vehicles passing a given3.2.24 vehicle passage,n-sensor output pulse signal pro-point or section of a lane or roadway during a designated timeduced when an initial vehicle detection is made in the detectioninterval,usually 15 min,but expressed as an equivalent hourlyarea of the sensor.E2300rate in vehicles/h.E23003.2.12 lane occupancy,n-percent of selected time interval3.2.25 vehicle presence,n-sensor output signal producedthe entire time a vehicle is detected in the detection area of thethat vehicles are detected in the detection area of a sensor;thesensor.E2300time interval during which the lane occupancy is measured isusually 20 to 30 s.5E23003.3 Definitions of Terms Specific to This Standard:3.2.13 missed detection,n-an indication by a TMD that a3.3.1 aliasing,n-phenomenon that occurs when a signalvehicle actually passing over the detection area of the TMD iscontaining frequencies greater than one-half the samplingnot detected by the TMD.E2300frequency is digitized,causing those frequencies in excess of3.2.14 precision,n-a generic concept related to the close-one-half the sampling frequency to be folded back into theness of agreement between test results obtained under pre-digitized signal spectrum.scribed like conditions from the measurement process being3.3.2 straddling vehicle,n-a vehicle that has one or moreevaluated.E177tires in an adjacent lane or shoulder.3.2.15 sensor;n-device for acquiring a signal that provides3.3.3 vehicle density,n-number of vehicles occupying adata to indicate the presence or passage of a vehicle or of agiven length of a lane or roadway at a particular instant,usuallyvehicle component over the detection area with respect to timeexpressed in units of vehicles/lane-mile(lane-km).(for example,flow rate or number of axles and their spacing),or one or more distinctive features of the vehicle such as height4.Summary of Acceptance Test Methodsor mass.E23003.2.16 speed,n-rate of vehicle motion expressed as dis-4.1 Two categories of acceptance tests are described.TheE2300first,the Type-approval Test,is intended for TMDs that havetance per unit of time.never been type-approved.The second,the On-site Verification3.2.17 time stamp,n-recorded date and time at which aTest,is applicable to production versions of TMDs that havemeasurement was made;information and format may bepreviously passed a Type-approval Test,but are now beingtailored to the application,but usually consists of month,day,installed at a new location or have been repaired.Fig.lyear,hour,minute,second,and subsecond.E2300illustrates the procedure for determining which of the tests is3.2.18 tolerance,n-allowable deviation of a value indi-applicable.The rigorous Type-approval Test verifies the func-cated by the device under test or a device in service from antionality of all features of the TMD and provides informationaccepted reference value.E2300for evaluating the accuracy of the data item outputs when3.2.19 traffic monitoring device,n-equipment that countsmonitoring vehicle flows consisting of a mix of all anticipatedand classifies vehicles and measures vehicle flow characteris-vehicle classes under a specified range of operating conditions.tics such as vehicle speed,lane occupancy,turning movements,The On-site Verification Test provides the TMD user and sellerwith a means for determining whether the production versionof a TMD installed at a particular site meets the performanceand user requirements identified in Specification E2300.BothKlein,L.A.,Gibson,D.,and Mills,M.K.,Traffic Detector Handbook:ThirdEdition,FHWA-HRT-06-108(Vol.I)and FHWA-HRT-06-139(Vol.II),U.S.categories of acceptance tests compare the outputs of the TMDDepartment of Transportation,Federal Highway Administration,Washington,DC,under test with those of equipment that produce acceptableOct.2006.Also available at:http:/www.tfhrc.gov/its/pubs/06108/and http:/reference values.If all features of the TMD function properlywww.tfhrc.gov/its/pubs/06139/.5 Different sensor models or technologies used to measure lane occupancy mayand the output data are within the agreed upon tolerances,thenhave different detection area sizes and,hence,produce different occupancy values,the TMD is reported to have passed the acceptance test.If not,although all devices are operating properly.the TMD is reported to have failed the test.Copyright by ASTM Intl(all rights reserved);Sat Oct 7 03:56:41 EDT 20172Downloaded/printed byUniversity of Edinburgh(University of Edinburgh)pursuant to License Agreement.No further reproductions authorized.4E2532-09(2017)TMD purchasespecification(E2300)Type-approvalNoTest previouslypassed?YesConduct On-site Verification TestConduct Type-approval Testusing test methods specifiedusing test methods specifiedin E 2532,paragraph 7.3in E 2532,paragraph 7.2NoNoTest passed?Reject TMDTest passed?Reject TMDYesYesAccept TMDAccept TMDFIG.1 Process for Determining Applicable TMD Acceptance Test5.Device Classificationclasses characteristic of the operating conditions in which the5.1 Type,Tolerance,and Operating Conditions-The type,device will be used.The vehicle classes shall be specified bytolerance,and operating conditions of the TMD to be testedthe user.shall be specified according to Specification E2300.6.3 Lighting-The TMD shall be tested under lighting5.2 Use of Measured Data in Support of Othercharacteristic of the operating conditions in which the deviceApplications-Additional vehicle flow parameters may bewill be used.Lighting conditions may include day,night,dawn.calculated from the recorded data.Among these parameters aredusk,and other hours where artifacts or unusual conditionsvehicle flow rate,density,headway,intersection delay,vehiclesuch as shadows and sun glint occur.The lighting conditionsgap in time or distance,queue length,and turning movements.and times of day for the test will depend on the technologyOther highway system performance measures,such as volume-used in the TMD under test.The user shall specify the specificto-capacity ratio,total vehicle hours traveled,total vehiclelighting conditions,if any,required for the tests.Table Imiles traveled,average travel speed,number and categories ofcontains lighting and environmental factors that shall beaccidents,pollutant emissions,and fuel consumption may alsoconsidered when evaluating TMDs.be calculated from data recorded by appropriate sensors.These6.4 Temperature-The user shall specify the maximum andtest methods do not address the ability of the TMD to calculateminimum ambient air temperatures in which the TMD underor provide data for these additional vehicle flow parameters orhighway system performance measures.TABLE 1 Lighting and Weather Factors That May be Included asPart of TMD Testing6.Standardization of Acceptance Test ConditionsLighting and Weather Factors6.1 Installation Requirements-It shall be the responsibility1.Dawn ambient lighting2.Dusk ambient lightingof the user to install the TMD under test in accordance with the3.Nighttime ambient lightingmanufacturers requirements.Conditions that are typically4.Sun glintspecified when installing and evaluating TMDs are described5.Rain characterized by rain rate6.Fog or dust characterized by human visual rangein 6.2 through 6.9.7.Snow characterized by snow fall rate and snow flake size6.2 Vehicle Flow Rates and Vehicle Classes-The TMDA Data gathered to verity TMD operation under these conditions may be gatheredshall be tested under flow rates that include vehicle-to-vehiclesimultaneously with data used to verify operation at the vehicle flow rates and mixof vehicle classes specified in 6.2.gaps both less than and greater than I s and a mix of vehicleCopyright by ASTM Intl(all rights reserved):Sat Oct 7 03:56:41 EDT 20173Downloaded/printed byUniversity of Edinburgh(University of Edinburgh)pursuant to License Agreement.No further reproductions authorized.E2532-09(2017)test(including sensor components installed on,under,or aboveand model of TMD offered has previously passed a type-the roadway and components installed in roadside cabinets)isapproval test,the user will not be assured of the capability ofexpected to operate properly and under which it will be tested.the TMD and shall either(1)require a Type-approval Test be6.5 Other Environmental Conditions-The user shallperformed at a site conforming to the conditions defined in 6.1specify other environmental conditions under which the TMDthrough 6.9(the test site may be one supplied by the user or ashall be tested.These include rain and rain rates,fog andthird party),or(2)reach an agreement with the seller before thevisibility range,snow and snowfall rate,wind-borne dust,acceptance test begins as to the tolerance values that will bemovement caused by wind and vibration,and any otheracceptable if the test site conditions provided by the user do notconditions that are perceived by the user to affect the perfor-incorporate those specified in 6.1 through 6.9.In the latter case.mance of the TMDthe responsibility for inadequate TMD performance can liewith the seller.the user,or both.6.6 Evidence that TMD Can Operate Under Specified En-6.10.2 On-site Verification Test Requirement-The On-sitevironmental Conditions-If applicable,the seller shall supplyVerification Test described in 7.3 may be used after theevidence that the device offered has been tested and foundspecified brand and model of TMD has passed a suitablecapable of operating under the specified environmental condi-Type-approval Test and the production version of such a TMDtions.is offered by the seller.If the seller provides satisfactory6.7 Power-The user shall provide and maintain electricalevidence that such a TMD has already passed the applicablepower at each test site or specify an optional power source thatType-approval Test and the user provides site conditions thatcan supply the power required by the TMD and the dataincorporate those given in 6.1 through 6.9,the TMD will berecording equipment.expected to perform at the site within the tolerances specifiedfor the TMD output data.If the TMD fails to perform within6.8 Data and Video Communication-If specified,the userthese tolerances in such an On-site Verification Test,theshall provide and maintain an adequate data and video com-installed TMD will be declared faulty and the seller shall bemunication link between the test site and the data recordingresponsible for corrective action.equipment.This link may also transmit information to monitorthe performance of the TMD under test and adjust its settings,7.Procedureif applicable.Such a communications link may be wireless.TMD output data and video shall be recorded in a synchronized7.1 Scope-The procedures for conducting a Type-approvalmanner as specified by the user to support TMD evaluation.Test and an On-site Verification Test for each type of TMDspecified according to Specification E2300 are described in this6.9 Options,Exceptions,and Added Features-Any desiredsection.options,exceptions,or added data display or data recording7.1.1 Accuracy Required of Accepted Reference Value Mea-features needed to evaluate the performance requirements ofsuring Equipment-The data-measuring accuracy requirementsthe TMD shall be specified by the user.If applicable,the userfor all equipment used to obtain accepted reference value data.shall also specify the data items to be included in the display,that is,the data with which the performance of the TMD underthe number of vehicle records to be displayed simultaneously.test are compared,shall be agreed upon before testing beginsand whether the display of selected records must occur withoutby the user and the seller,or their designated representatives.interference with the continuous acquisition of data.Where possible,it is recommended that the equipment used to6.10 Acceptance Test Requirement-The user shall specifyobtain reference value data have an accuracy at least an orderthe acceptance test category,Type-approval or On-site Verifi-of magnitude greater than the accuracy specified for the TMDcation using the process illustrated in Fig.1,and the testingunder test.schedule that will be utilized prior to final acceptance by the7.2 Type-approval Test for Traffic Monitoring Devices:user and final payment to the seller before the beginning of the7.2.1 Scope of Type-approval Test-The Type-approval Testtest.The acceptance test procedure may require the user toprovides information to evaluate the performance of a brandprovide traffic control as part of TMD installation.The user orand model of TMD under a variety of field site conditions thatthe users authorized representative,in cooperation with theinclude traffic volume and vehicle classes representative ofseller,shall conduct the required acceptance test on site afteroperating environments in which the device is expected tothe TMD has been installed and calibrated.A written reportoperate.Performance requirements for each type of TMD shallcontaining the test result shall be prepared by the user or theirbe identified according to Specification E2300 and any supple-representative when testing has been completed,and a copy ofmental test requirements as defined in Section 6 of this testthe report shall be furnished to both the user and the seller.method.6.10.1 Type-approval Test Requirement-The TMD specifi-7.2.2 Significance and Use-The Type-approval Test allowscation developed in accordance with Specification E2300the user to determine whether the previously untested brandrequires that the TMD pass a rigorous Type-approval Test if itand model of TMD meets the data measuring requirementshas not previously passed such a test.The Type-approval Test,listed in the TMD specification.described in 7.2,provides information for verifying the accu-7.2.3 Approval of Site and Test Conditions-Both the userracy and functionality of all features of the TMD while itand the seller or their appointed representatives shall approvemonitors a flow consisting of a mix of anticipated vehiclethe type-approval test site and the TMD installation prior toclasses.If the seller does not provide evidence that the brandconducting the Type-approval Test.The TMD settings andCopyright by ASTM Intl(all rights reserved):Sat Oct 7 03:56:41 EDT 2017Downloaded/printed byUniversity of Edinburgh(University of Edinburgh)pursuant to License Agreement.No further reproductions authorizedE2532-09(2017)other test conditions shall be documented to verify complianceconditions in accordance with the requirements of 6.3 throughwith the test conditions described in Section 6.If traffic control6.5 when the performance of the TMD is deemed by the useris required for TMD installation and setup,the traffic controlto possibly vary under these conditions.Table 1 lists environ-procedures shall be in accordance with those of the publicmental factors that should be considered when evaluatingauthority having jurisdiction over the test site.TMDs.Not all TMD technologies will be affected by these7.2.4 Duration of Type-approval Test-The Type-approvalfactors,and some,if not all of the factors,may be eliminatedTest shall be conducted until the required data are recorded forfrom the test procedure as mutually agreed upon by the usera minimum of three hours.Additional time and tests may beand seller or their designated representatives.The test datarequired to verify proper operation of the TMD under all of therequired by the conditions specified in Table 1 may be obtainedenvironmental and other operating conditions specified by thesimultaneously with data used to verify TMD operation at theuser.vehicle flow rates and mix of vehicle classes described in 6.2.7.2.5 Calibration-The TMD under test shall be calibrated7.2.6.7 For the purposes of verifying TMD performance,by the seller and approved by the user.The calibrationstraddling vehicles are to be eliminated from consideration byprocedures shall be documented and made available for inspec-identifying them from the video recordings made in conjunc-tion by the user.tion with obtaining accepted reference value data.7.2.6 Type-Approval Test Method-The following steps7.2.7 Methods for Obtaining Accepted Reference Valueshall be performed when conducting a Type-approval Test.Data-The seller shall have primary responsibility for supply-7.2.6.1 Install the TMD according to the sellers instructionsing the equipment and personnel for obtaining the acceptedor according to another procedure mutually agreed upon by thereference value data needed for interpreting the results of theuser and seller or their designated representatives.The userType-approval Test.The user or a third party(such as a city,shall satisfy any site-specific installation requirements,such ascounty,or state agency or a university facility)may conduct thelightning protection.The installation procedures shall be re-test or provide other assistance.corded and made part of the report specified in 7.2.9.7.2.7.1 The detection area of the TMD under test shall be7.2.6.2 Adjust variable TMD operating parameters to valuesmarked with tape,paint,or other means so that it is visible inagreed upon by the user and seller or their designated repre-the recorded imagery,and yet appear as inconspicuous assentatives and enter these values in the report specified in 7.2.9.feasible to drivers.If it is not possible or safe to physicallyEnsure that the TMD under test is calibrated.mark the detection area of the TMD as described above,thedetection area may be distinguished by a digital overlay on the7.2.6.3 Record all data output by the TMD under test usingdigitized video.The effective detection area boundaries of thea device capable of time stamping the data.Similarly recordTMD under test shall be established by driving one or morethe output from the equipment used to gather accepted refer-vehicles,representative of those in the vehicle classes to beence value data.Each vehicle detection event shall be outputdetected,over the detection area of the TMD.The effectiveby the TMD in a format that can be directly correlated with thedetection area of the TMD under test is found by noting thevideo.Acceptable data formats are roadway-based events andvehicle location with respect to the TMDs marked detectionvehicle-based events.Roadway-based events consist of:(1)sensor ID corresponding to a specific detection area in aarea when the TMD indicates an output signal and when theoutput signal is dropped.particular lane,(2)start time of the detection event(synchro-7.2.7.2 Axle count reference values shall be determined bynized with the time recorded on the video),(3)at least one ofanalysis of imagery recorded by a video camera installed in athe following items-(3a)duration of the detection event ormanner that gives it an unimpeded view of the vehicle axles as(3b)end time of the detection event,and(4)contact closuressynchronized with the start and end of the detection event whenthey pass over the effective detection area of the TMD undertest.Time shall be indicated on the video recording to the samethose contact closures refer to a specific detection area in aparticular lane.Vehicle-based detection events consist of:(1)precision as the TMD time stamp data.The video recordingtime stamp shall be synchronized with the TMD time stamp.Itlane number,(2)start time of the detection event,and(3)atis recommended that the other data items output by the TMDleast two of the following three items-(3a)detection eventunder test also be indicated on the video recording.If the videoduration,(3b)vehicle speed,and(3c)vehicle length.Allis digitized,a time reference shall be provided and synchro-detection events must have a time resolution equal to or greaternized with the TMD data.Two or more human observers shallthan one video frame resolution,which is equal to so s foreach record the number of axles and the corresponding time ofNational Television System Committee(NTSC)video.Theeach detection event by viewing the video imagery.Thesedigitizing of data from the TMD and the reference valueobservations may be recorded as manual entries in a dataequipment shall occur at a sampling frequency sufficient tonotebook or manually entered into a separate computer dataprevent compromising of data quality by aliasing.screen that is synchronized with the TMD data and video.Each7.2.6.4 Document the test and test conditions with the timeobserver shall view the imagery for no longer than a 15-minof day,TMD identifier,vehicle class,ambient lighting,interval before taking a rest of at least 5 min to help assureweather,and other items specified in Section 6.accurate determination of the reference value for the number of7.2.6.5 TMD performance shall be evaluated for the vehicleflow rates and mix of vehicle classes described in 6.2.7.2.6.6 TMD testing shall also be conducted under various Suggested items to be included in a specification for a video camera utilized tolighting,temperature,weather,and other local environmentalgather accepted reference value data are listed in Appendix X1.Copyright by ASTM Intl(all rights reserved);Sat Oct 7 03:56:41 EDT 20175Downloaded/printed byUniversity of Edinburgh(University of Edinburgh)pursuant to License Agreement.No further reproductions authorized.