ASTM_E_1926_-_08_2015.pdf

Designation:E192608(Reapproved 2015)Standard Practice forComputing International Roughness Index of Roads fromLongitudinal Profile Measurements1This standard is issued under the fixed designation E1926;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 mathematical processing oflongitudinal profile measurements to produce a road roughnessstatistic called the International Roughness Index(IRI).1.2 The intent is to provide a standard practice for comput-ing and reporting an estimate of road roughness for highwaypavements.1.3 This practice is based on an algorithm developed in TheInternational Road Roughness Experiment sponsored by anumber of institutions including the World Bank and reportedin two World Bank Technical Papers(1,2).2Additionaltechnical information is provided in two Transportation Re-search Board(TRB)papers(3,4).1.4 The values stated in SI units are to be regarded as thestandard.The inch-pound units given in parentheses are forinformation only.1.5 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.Referenced Documents2.1 ASTM Standards:3E177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE867 Terminology Relating to Vehicle-Pavement SystemsE950 Test Method for Measuring the Longitudinal Profile ofTraveled Surfaces with an Accelerometer EstablishedInertial Profiling ReferenceE1082 Test Method for Measurement of Vehicular Responseto Traveled Surface RoughnessE1170 Practices for Simulating Vehicular Response to Lon-gitudinal Profiles of Traveled SurfacesE1215 Specification for Trailers Used for Measuring Vehicu-lar Response to Road RoughnessE1364 Test Method for Measuring Road Roughness byStatic Level MethodE1656 Guide for Classification of Automated PavementCondition Survey EquipmentE2133 Test Method for Using a Rolling Inclinometer toMeasure Longitudinal and Transverse Profiles of a Trav-eled Surface3.Terminology3.1 Definitions:3.1.1 Terminology used in this practice conforms to thedefinitions included in Terminology E867.3.2 Definitions of Terms Specific to This Standard:3.2.1 International Roughness Index(IRI),nan indexcomputed from a longitudinal profile measurement using aquarter-car simulation(see Practice E1170)at a simulationspeed of 80 km/h(50 mph).3.2.1.1 DiscussionIRI is reported in either metres perkilometre(m/km)or inches per mile(in./mile).(Note1 m/km=63.36 in./mile.)3.2.2 longitudinal profile measurement,n a series ofelevation values taken at a constant interval along a wheeltrack.3.2.2.1 DiscussionElevation measurements may be takenstatically,as with rod and level(see Test Method E1364)orinclinometer(see Test Method E2133),or dynamically,as withan inertial profiler(see Test Method E950).3.2.3 Mean Roughness Index(MRI),nthe average of theIRI values for the right and left wheel tracks.3.2.3.1 DiscussionUnits are in metres per kilometre orinches per mile.3.2.4 traveled surface roughnessthe deviations of a sur-face from a true planar surface with characteristics dimensionsthat affect vehicle dynamics,ride quality,dynamic loads,anddrainage,for example,longitudinal profile,transverse profile,and cross slope.1This practice is under the jurisdiction of ASTM Committee E17 on Vehicle-Pavement Systems and is the direct responsibility of Subcommittee E17.33 onMethodology for Analyzing Pavement Roughness.Current edition approved May 1,2015.Published July 2015.Originally approvedin 1998.Last previous edition approved in 2008 as E1926 08.DOI:10.1520/E1926-08R15.2The boldface numbers given in parentheses refer to a list of references at theend of the text.3For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book 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 States1 3.2.5 true International Roughness Index,n the value ofIRI that would be computed for a longitudinal profile measure-ment with the constant interval approaching zero.3.2.6 wave number,nthe inverse of wavelength.3.2.6.1 DiscussionWave number,sometimes called spatialfrequency,typically has units of cycle/m or cycle/ft.3.2.7 wheel track,na line or path followed by the tire ofa road vehicle on a traveled surface.4.Summary of Practice4.1 The practice presented here was developed specificallyfor estimating road roughness from longitudinal profile mea-surements.4.2 Longitudinal profile measurement