# ASTM E867-06 (Reapproved 2012)

Designation: E867 − 06 (Reapproved 2012)Standard Terminology Relating toVehicle-Pavement Systems1This standard is issued under the fixed designation E867; 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 terminology covers definitions for approved stan-dards under the jurisdiction of ASTM Committee E17 onVehicle-Pavement Systems. Definitions of terms specific to anindividual standard are listed in the appendix. For additionalinformation, see Terminology D8, Terminology F538, SpecialReport 113Special Report 113,Standard Nomenclature andDefinitions for Pavement Components and Deficiencies3, andSAE J 2047, or contact ISO, PIARC, or CEN.1.2 Other publications may reference this terminology forterms used therein.1.3 The standard containing the term and the responsiblesubcommittee of Committee E17 is listed at the end of eachdefinition. Revision of the listed standard by that subcommitteewill include review of the definition and approved changes oradditions will be incorporated herein.1.4 The terms in this terminology standard are listed incategories of the five groups of Committee E17. These aredefinitions that are in multiple standards in various subcom-mittees in Groups II to V. The structure of E17 is as follows:Group II on Skid Resistance, E17.21, E17.22, E17.23, E17.24,Group III Roughness E17.31,E17.32, Group IV PavementManagement E17.41, and Group V Intelligent TransportationSystems E17.51, E17.52, E17.54.1.5 This terminology lists the definition as presented in theapproved standards. Variation of any term is also listed andreferenced to the defined term (for example the termhydroplaning, viscous is also listed and referenced to thedefined viscous hydroplaning).1.6 The term and its elements should appear in the follow-ing order; term; abbreviation; symbol; dimensions ofquantities, measurement units; part of a speech; delimitingphrase; statement of meaning, including specifications limitswhere applicable; cross references to synonyms or relatedterms; attribution.2. Referenced Documents2.1 ASTM Standards:2D8 Terminology Relating to Materials for Roads and Pave-mentsE274 Test Method for Skid Resistance of Paved SurfacesUsing a Full-Scale TireE556 Test Method for Calibrating a Wheel Force or TorqueTransducer Using a Calibration Platform (User Level)E950 Test Method for Measuring the Longitudinal Profile ofTraveled Surfaces with an Accelerometer EstablishedInertial Profiling ReferenceE965 Test Method for Measuring Pavement MacrotextureDepth Using a Volumetric TechniqueE1166 Guide for Network Level Pavement ManagementE1170 Practices for Simulating Vehicular Response to Lon-gitudinal Profiles of Traveled SurfacesE1215 Specification for Trailers Used for Measuring Vehicu-lar Response to Road RoughnessE1274 Test Method for Measuring Pavement RoughnessUsing a ProfilographE1318 Specification for Highway Weigh-In-Motion (WIM)Systems with User Requirements and Test MethodsE1337 Test Method for Determining Longitudinal PeakBraking Coefficient of Paved Surfaces Using StandardReference Test TireE1448 Practice for Calibration of Systems Used for Measur-ing Vehicular Response to Pavement RoughnessE1489 Practice for Computing Ride Number of Roads fromLongitudinal Profile Measurements Made by an InertialProfile Measuring DeviceE1656 Guide for Classification of Automated PavementCondition Survey EquipmentE1703/E1703M Test Method for Measuring Rut-Depth ofPavement Surfaces Using a StraightedgeE1778 Terminology Relating to Pavement DistressE1845 Practice for Calculating Pavement MacrotextureMean Profile Depth1This terminology is under the jurisdiction ofASTM Committee E17 on Vehicle- Pavement Systems and is the direct responsibility of Subcommittee E17.14 onTerminology.Current edition approved Dec. 1, 2012. Published December 2012. Originallyapproved in 1982. Last previous edition approved in 2006 as E867 – 06. DOI:10.1520/E0867-06R12.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at service@astm.org. For Annual Book of ASTMStandards volume information, refer to the standard’s Document Summary page onthe ASTM website.Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1E1859 Test Method for Friction Coefficient MeasurementsBetween Tire and Pavement Using a Variable Slip Tech-niqueE1889 Guide for Pavement Management ImplementationE1926 Practice for Computing International Roughness In-dex of Roads from Longitudinal Profile MeasurementsE1927 Guide for Conducting Subjective Pavement RideQuality RatingsF538 Terminology Relating to the Characteristics and Per-formance of Tires2.2 Transportation Research Board Standard:Special Report 113, Standard Nomenclature and Definitionsfor Pavement Components and Deficiencies32.3 SAE Standard:SAE J2047 Tire Performance Terminology42.4 NIST Handbook:National Institute of Standards and Technology (NIST)Handbook 4453. Definitions that are in Multiple Standardsindex, n—(synonymous with “number in Committee E17usage, for example; PSI, RN), a number or formula express-ing some property, form, ratio, etc. of the relation orproportion of one amount or dimension to another.(E867, E 17.14)DISCUSSION—“Numeric” and “metric” also have meanings which aresynonymous with index. However, either number or index is thepreferred term for use in Committee E17 standards.pavement characteristic, n—a physical feature or property ofa pavement surface such as type, roughness, texture, andskid resistance. (E867, E 17.14)present serviceability, n—the current condition of a pavement(traveled surface) as perceived by the traveling public.(E867, E 17.14)present serviceability rating (PSR), n—a mean rating of theserviceability of a pavement (traveled surface) establishedby a rating panel under controlled conditions. The acceptedscale for highways is 0 to 5, with 5 being excellent. (E867,E 17.14)traveled surface, n—any man-made, solid surface for vehicu-lar travel, for example, highways, runways, rails, guideways.(E867, E 17.14)weigh-in-motion, n—the process of estimating a movingvehicle’s gross weight and the portion of that weight that iscarried by each wheel, axle, and axle group, or a combina-tion thereof, by measurement and analysis of dynamicvehicle tire forces. (E1318, E 17.52)4. Definitions of Technical Group on Skid Resistancebaselength, n—the length of a segment of a pavement macro-texture profile being analyzed required to be 100 mm.(E1845, E 17.23)calibration platform—on a moving platform for applying aforce in the contact plane of a tire, and associated means formeasuring the applied force. The calibration platform con-sists of a rigid plate with a high friction surface, in contactwith the tire footprint, supported on a frictionless, preferablyair, bearing. It may also be instrumented to measure verticalforces (loads). (E556, E 17.21)calibration reference signals—repeatable signals in the rangeof expected wheel-force transducer system loading. Thesesignals could either be constant voltages or preferablyproduced by a strain-gage calibration shunt resistor. (E556,E 17.21)chirp test, n—the progressive application of brake torquerequired to produce the maximum value of longitudinalbraking force that will occur prior to wheel lockup, withsubsequent brake release to prevent any wheel lockup (tireslide). (E1337, E 17.21)crosstalk, n—the undesired effect of force readings appearingon an unloaded axis of a transducer while applying force toanother. (E556, E 17.21)dynamic hydroplaning, n—hydroplaning of pneumatic tireswith separation caused by a thick fluid film due principallyto the generation of fluid inertial forces. (E867, E 17.14)estimated texture depth, (ETD), n—the estimate of meantexture depth (MTD), by means of a linear transformation ofmean profile depth (MPD). (E1845, E 17.23)horizontal traction (traction)—a force acting in a horizontalaxis through the wheel transducer; that is, locked wheel dragforce. (E556, E 17.21)hydroplaning (aquaplaning) of pneumatic tires, n—a phe-nomenon that occurs when the load-bearing surface of apneumatic tire is separated from a solid surface by asubstance (usually a fluid and usually water).(E867, E 17.14)hydroplaning, dynamic—see dynamic hydroplaning.hydroplaning, rubber reversion—see rubber reversion hy-droplaning.hydroplaning, viscous—see viscous hydroplaning.hydroplaning speed, n—the initial speed at which a pneumatictire begins to full dynamic hydroplaning under a given set ofconditions. (E867, E 17.14)hysteresis—the maximum difference between correspondingtransducer outputs (of the wheel force transducer system) atincreasing and decreasing applied calibration force, ex-pressed as a percentage of full load output. Proven outliersare excluded. (E556, E 17.21)3Available from Transportation Research Board, 500 Fifth Street, NW,Washington, DC, 20001.4Available from Society for Automotive Engineers, 400 Commonwealth Drive,Warrendale, PA 15096-0001.5Available from National Institute of Standards and Technology, 100 BureauDrive, Stop 3460, Gaithersburg, MD 20899-3460.E867 − 06 (2012)2mean profile depth (MPD), n—the average of all of the meansegment depths of all segments of the profile.(E1845, E 17.23)mean segment depth, n—the average value of the profiledepth of the two halves of a segment having a givenbaselength. (E1845, E 17.23)mean texture depth (MTD), n—the mean depth of thepavement surface macrotexture determined by the volumet-ric technique of Test Method E965. (E1845, E 17.23)nonlinearity—the maximum deviation of the transducer out-put(s) (of the wheel force transducer system) from thebest-fit linear relation to the applied calibration force,expressed as a percentage of full scale. Proven outliers areexcluded. (E556, E 17.21)pavement macrotexture, n—the deviations of a pavementsurface from a true planar surface with the characteristicdimensions of wavelength and amplitude from 0.5 mm (0.2in.) up to those that no longer affect tire-pavementinteraction. (E965, E 17.23)pavement-micro texture (micro-rugosity) , n—the deviationsof a pavement surface from a true planar surface withcharacteristic dimensions of wavelength and amplitude lessthan 0.5 mm (0.2 in.). (E867, E 17.14)profile depth, n—the difference between the amplitude mea-surements pavement macrotexture profile and a horizontalline through the top of the highest peak within a givenbaselength. (E1845, E 17.23)rubber reversion hydroplaning, n—hydroplaning of pneu-matic tires with separation caused by devulcanized rubber.(E867, E 17.14)skid number (friction number), n—the number that is used toreport the results of a pavement skid test conducted inaccordance with Test Method E274. (E867, E 17.14)skid number-percent normalized gradient, n—the speedgradient divided by the skid number, both at the same speedand multiplied by 100. The percent normalized gradient isusually designated by the symbol PNGvwhere v is the speedat which the percent normalized gradient is determined.(E867, E 17.14)PNGv5 100~G/SN!v(1)skid number-speed gradient, n—the slope of skid numberversus speed multiplied by −1. The gradient is normallydesignated by the symbol Gv, where v is the speed at whichthe slope is determined, SN is the skid number, and V is thespeed:Gv52~dSN/dV!, that may be approximated by: (2)2~SN12 SN2!/~V12 V2!(E867, E 17.14)skid resistance (friction number), n—the ability of thetraveled surface to prevent the loss of tire traction. (E867,E 17.14)test wheel—a wheel and test tire assembly mounted to a testvehicle by means of a force or torque transducer. (E556,E 17.21)texture shape factor, n—average of weighted sum of the ratiosof amplitude to wavelength, as determined from an ampli-tude versus wavenumber (reciprocal of wavelength)spectrum. (E867, E 17.14)tire-wet pavement interaction, zone concept, n—a divisionof the load-bearing surface of a moving pneumatic tire intothree basic zones; noncontact, partial contact, and contact.(E867, E 17.14)vertical load (load)—force acting in a vertical axis through thewheel transducer; that is, weight. (E556, E 17.21)viscous hydroplaning, n—hydroplaning of pneumatic tireswith separation caused by a thin fluid film due principally tothe generation of fluid viscous forces. (E867, E 17.14)water depth-nominal, n—the nominal thickness of the waterlayer, that is, the volume of water divided by the area of thewetted pavement surface. (E867, E 17.14)water depth-positive, n—the distance from the water surfaceto the reference plane which is the top of the pavementasperities. (E867, E 17.14)wheel force transducer system—a force-to-electrical signalconverter system including transducer(s), associated signalcondition, zeroing, amplifying, recording, and monitoringinstrumentation. (E556, E 17.21)5. Definitions of Technical Group on Roughnessaliasing, n—the spectrum of a digitized data record exists overthe range of frequencies from zero to one half the samplingfrequency. If the spectrum of the original signal extendsbeyond one half the sampling frequency, then those compo-nents of the signal at frequencies higher than one half thesampling frequency will, when digitized, be folded back intothe spectrum of the digitized signal. The excessive highfrequency components will thus be “aliased” into lowfrequency components. (E950, E 17.33)anti-aliasing filter, n—a low-pass analog filter applied to theoriginal analog profile signal to suppress those componentsof the signal at frequencies higher than one half the intendeddigital sampling frequency. (E950, E 17.33)frequency domain filtering, n—a filtering operation per-formed by first calculating the spectrum of the profile recordand then multiplying the spectral components by the fre-quency response transfer function of the filter.(E950, E 17.33)half-car roughness index (HRI), n—an index resulting from amathematical simulation of vehicular response to the longi-tudinal profile of a pavement using the half-car simulationmodel described in Practice E1170 and a travelling speed of50 mph (80 km/h). (E1448, E 17.31)DISCUSSION—Units are in inches per mile or metres per kilometre.E867 − 06 (2012)3international roughness index (IRI), n—an index computedfrom a longitudinal profile measurement using a quarter-carsimulation at a simulation speed of 50 mph (80 km/h).(E1926, E 17.33)DISCUSSION—IRI is reported in either inches per mile (in./mile) ormetres per kilometre (m/km). (Note—1 m/km = 63.36 inches/mile).international roughness index, true—see true internationalroughness index.longitudinal profile, n—the perpendicular deviations of thepavement surface from an established reference parallel tothe lane direction, usually measured in the wheel tracks.(E867, E 17.14) (E1656, E 17.41)longitudinal profile measuremen