1、Designation: E2532 09 (Reapproved 2017)Standard 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,
2、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 PurposeThe two test methods contained in this stan-dard define acceptance tests for evaluating the perform
3、ance ofa Traffic Monitoring Device (TMD) according to the functionsit performs, the data it provides, the required accuracy of thedata, and the conditions under which the device operates.Acceptance tests are recommended whenever a TMD ispurchased, installed, or performance validation is desired. The
4、tests are performed in a field environment and result in anaccept or a reject decision for the TMD under test.1.2 ExceptionsExceptions and options to the test methodsmay be included in any derivative test method presented by auser as part of the procurement process for TMDs. Sellers mayoffer excepti
5、ons and options in responding to an invitation tobid.1.3 UnitsThe values stated in inch-pound units are to beregarded as standard. The values given in parentheses aremathematical conversions to SI units,2which are provided forinformation only and are not considered standard.1.4 The following safety
6、procedures apply to Sections 6 and7, which describe the details of the acceptance test methods.When a test site accessible by the public (for example, a streetor highway) is used for the acceptance test of the TMD, obtainapproval from the public authority having jurisdiction over thesite for the tra
7、ffic control procedures to be used during the test.This standard does not purport to address all of the safetyconcerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety andhealth practices and determine the applicability of regulat
8、orylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:3E177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE867 Terminology Relating to Vehicle-Pavement SystemsE1318 Specification for Highway Weigh-In-Motion (WIM)Systems with User Requirements and Test MethodsE23
9、00 Specification for Highway Traffic Monitoring De-vices3. Terminology3.1 Definitions of terms and definitions of terms specific tothese test methods are given below.3.2 Definitions:3.2.1 accepted reference value, nvalue attributed to aparticular quantity (for example, vehicle class by number ofaxle
10、s and interaxle spacings, vehicle count, lane occupancy, orvehicle speed) and agreed upon by the user and seller inadvance of testing of a TMD, which has an uncertaintyappropriate for the given purpose. E23003.2.2 accuracy, ncloseness of agreement between a valueindicated by a TMD and an accepted re
11、ference value. E23003.2.3 axle, naxis oriented transversely to the nominaldirection of vehicle motion, and extending the full width of thevehicle, about which the wheels at both ends rotate. E867,E13183.2.4 axle count, nnumber of vehicle axles enumerated ata point on a lane or roadway during a speci
12、fied time interval.E8673.2.5 bias, na generic concept related to a consistent orsystematic difference between a set of test results from theprocess and an accepted reference value of the property beingmeasured. E1773.2.6 correct detection, nan indication by a TMD that avehicle actually passing over
13、the detection area of the TMD isdetected by the TMD. E23001These test methods are under the jurisdiction of ASTM Committee E17 onVehicle - Pavement Systems and are the direct responsibility of SubcommitteeE17.52 on Traffic Monitoring.Current edition approved Jan. 1, 2017. Published January 2017. Ori
14、ginallyapproved in 2006. Last previous edition approved in 2009 as E2532 09. DOI:10.1520/E2532-09R17.2Standard Practice for Use of the International System of Units (SI): TheModern Metric System, IEEE/ASTM SI 10TM-2002, The Institute of Electrical andElectronics Engineers (IEEE), Inc., 3 Park Avenue
15、, New York, NY, 10016-5997,USA and American Society for Testing and Materials (ASTM), 100 Barr HarborDrive, West Conshohocken, PA 19428-2959, USA, ISBN 0-7381-3317-5.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual B
16、ook of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recog
17、nized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.13.2.7 data item, ncharacteristic associated with individualvehic
18、les (for example, count, class, and speed) or the con-tinuum of vehicles at a location (for example, density, flowrate, and queue length). E23003.2.8 detection area, nroad surface area above which asensor detects a vehicle or vehicle component. E23003.2.9 electronics unit, ndevice that provides powe
19、r to oneor more sensors, filters and amplifies the signals produced bythe sensors, and may perform other functions such as sensitiv-ity adjustment, failure indication, and delayed actuation oftraffic control signals.4E23003.2.10 false detection, nan indication by a TMD that avehicle not actually pas
20、sing over the detection area of the TMDis detected by the TMD. E23003.2.11 flow rate, nnumber of vehicles passing a givenpoint or section of a lane or roadway during a designated timeinterval, usually 15 min, but expressed as an equivalent hourlyrate in vehicles/h. E23003.2.12 lane occupancy, nperce
21、nt of selected time intervalthat vehicles are detected in the detection area of a sensor; thetime interval during which the lane occupancy is measured isusually 20 to 30 s.5E23003.2.13 missed detection, nan indication by a TMD that avehicle actually passing over the detection area of the TMD isnot d
22、etected by the TMD. E23003.2.14 precision, na generic concept related to the close-ness of agreement between test results obtained under pre-scribed like conditions from the measurement process beingevaluated. E1773.2.15 sensor, ndevice for acquiring a signal that providesdata to indicate the presen
23、ce or passage of a vehicle or of avehicle component over the detection area with respect to time(for example, flow rate or number of axles and their spacing),or one or more distinctive features of the vehicle such as heightor mass. E23003.2.16 speed, nrate of vehicle motion expressed as dis-tance pe
24、r unit of time. E23003.2.17 time stamp, nrecorded date and time at which ameasurement was made; information and format may betailored to the application, but usually consists of month, day,year, hour, minute, second, and subsecond. E23003.2.18 tolerance, nallowable deviation of a value indi-cated by
25、 the device under test or a device in service from anaccepted reference value. E23003.2.19 traffc monitoring device, nequipment that countsand classifies vehicles and measures vehicle flow characteris-tics such as vehicle speed, lane occupancy, turning movements,and other parameters typically used t
26、o portray trafficmovement. E23003.2.20 vehicle class by axle, ncharacterization of a vehicleby its number of axles and interaxle spacings. E23003.2.21 vehicle class by length, ncharacterization of ve-hicles by their total length. E23003.2.22 vehicle count (volume), ntotal number of vehiclesobserved
27、or predicted to pass a point on a lane or roadwayduring a specified time interval. E23003.2.23 vehicle, none or more mobile units coupled to-gether for travel on a highway; a vehicle contains one poweredunit and may include one or more non-powered full-trailer orsemi-trailer units. E8673.2.24 vehicl
28、e passage, nsensor output pulse signal pro-duced when an initial vehicle detection is made in the detectionarea of the sensor. E23003.2.25 vehicle presence, nsensor output signal producedthe entire time a vehicle is detected in the detection area of thesensor. E23003.3 Definitions of Terms Specific
29、to This Standard:3.3.1 aliasing, nphenomenon that occurs when a signalcontaining frequencies greater than one-half the samplingfrequency is digitized, causing those frequencies in excess ofone-half the sampling frequency to be folded back into thedigitized signal spectrum.3.3.2 straddling vehicle, n
30、a vehicle that has one or moretires in an adjacent lane or shoulder.3.3.3 vehicle density, nnumber of vehicles occupying agiven length of a lane or roadway at a particular instant, usuallyexpressed in units of vehicles/lane-mile (lane-km).4. Summary of Acceptance Test Methods4.1 Two categories of ac
31、ceptance tests are described. Thefirst, the Type-approval Test, is intended for TMDs that havenever been type-approved. The second, the On-site VerificationTest, is applicable to production versions of TMDs that havepreviously passed a Type-approval Test, but are now beinginstalled at a new location
32、 or have been repaired. Fig. 1illustrates the procedure for determining which of the tests isapplicable. The rigorous Type-approval Test verifies the func-tionality of all features of the TMD and provides informationfor evaluating the accuracy of the data item outputs whenmonitoring vehicle flows co
33、nsisting of a mix of all anticipatedvehicle classes under a specified range of operating conditions.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 requireme
34、nts identified in Specification E2300. Bothcategories of acceptance tests compare the outputs of the TMDunder test with those of equipment that produce acceptablereference values. If all features of the TMD function properlyand the output data are within the agreed upon tolerances, thenthe TMD is re
35、ported to have passed the acceptance test. If not,the TMD is reported to have failed the test.4Klein, L. A., Gibson, D., and Mills, M. K., Traffc Detector Handbook: ThirdEdition, FHWA-HRT-06-108 (Vol. I) and FHWA-HRT-06-139 (Vol. II), U.S.Department of Transportation, Federal Highway Administration,
36、 Washington, DC,Oct. 2006. Also available at: http:/www.tfhrc.gov/its/pubs/06108/ and http:/www.tfhrc.gov/its/pubs/06139/.5Different sensor models or technologies used to measure lane occupancy mayhave different detection area sizes and, hence, produce different occupancy values,although all devices
37、 are operating properly.E2532 09 (2017)25. Device Classification5.1 Type, Tolerance, and Operating ConditionsThe type,tolerance, and operating conditions of the TMD to be testedshall be specified according to Specification E2300.5.2 Use of Measured Data in Support of OtherApplicationsAdditional vehi
38、cle flow parameters may becalculated from the recorded data.Among these parameters arevehicle flow rate, density, headway, intersection delay, vehiclegap in time or distance, queue length, and turning movements.Other highway system performance measures, such as volume-to-capacity ratio, total vehicl
39、e hours traveled, total vehiclemiles traveled, average travel speed, number and categories ofaccidents, pollutant emissions, and fuel consumption may alsobe calculated from data recorded by appropriate sensors. Thesetest methods do not address the ability of the TMD to calculateor provide data for t
40、hese additional vehicle flow parameters orhighway system performance measures.6. Standardization of Acceptance Test Conditions6.1 Installation RequirementsIt shall be the responsibilityof the user to install the TMD under test in accordance with themanufacturers requirements. Conditions that are typ
41、icallyspecified when installing and evaluating TMDs are describedin 6.2 through 6.9.6.2 Vehicle Flow Rates and Vehicle ClassesThe TMDshall be tested under flow rates that include vehicle-to-vehiclegaps both less than and greater than 1 s and a mix of vehicleclasses characteristic of the operating co
42、nditions in which thedevice will be used. The vehicle classes shall be specified bythe user.6.3 LightingThe TMD shall be tested under lightingcharacteristic of the operating conditions in which the devicewill be used. Lighting conditions may include day, night, dawn,dusk, and other hours where artif
43、acts or unusual conditionssuch as shadows and sun glint occur. The lighting conditionsand times of day for the test will depend on the technologyused in the TMD under test. The user shall specify the specificlighting conditions, if any, required for the tests. Table 1contains lighting and environmen
44、tal factors that shall beconsidered when evaluating TMDs.6.4 TemperatureThe user shall specify the maximum andminimum ambient air temperatures in which the TMD underFIG. 1 Process for Determining Applicable TMD Acceptance TestTABLE 1 Lighting and Weather Factors That May be Included asPart of TMD Te
45、stingLighting and Weather FactorsA1. Dawn ambient lighting2. Dusk ambient lighting3. Nighttime ambient lighting4. Sun glint5. Rain characterized by rain rate6. Fog or dust characterized by human visual range7. Snow characterized by snow fall rate and snow flake sizeAData gathered to verify TMD opera
46、tion under these conditions may be gatheredsimultaneously with data used to verify operation at the vehicle flow rates and mixof vehicle classes specified in 6.2.E2532 09 (2017)3test (including sensor components installed on, under, or abovethe roadway and components installed in roadside cabinets)
47、isexpected to operate properly and under which it will be tested.6.5 Other Environmental ConditionsThe user shallspecify other environmental conditions under which the TMDshall be tested. These include rain and rain rates, fog andvisibility range, snow and snowfall rate, wind-borne dust,movement cau
48、sed by wind and vibration, and any otherconditions that are perceived by the user to affect the perfor-mance of the TMD.6.6 Evidence that TMD Can Operate Under Specified En-vironmental ConditionsIf applicable, the seller shall supplyevidence that the device offered has been tested and foundcapable o
49、f operating under the specified environmental condi-tions.6.7 PowerThe user shall provide and maintain electricalpower at each test site or specify an optional power source thatcan supply the power required by the TMD and the datarecording equipment.6.8 Data and Video CommunicationIf specified, the usershall provide and maintain an adequate data and video com-munication link between the test site and the data recordingequipment. This link may also transmit information to monitorthe performance of the TMD under test and adjust its setti
