ASTM_E_1489_-_08_2013.pdf

Designation:E148908(Reapproved 2013)Standard Practice forComputing Ride Number of Roads from Longitudinal ProfileMeasurements Made by an Inertial Profile MeasuringDevice1This standard is issued under the fixed designation E1489;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 an estimate ofsubjective ride quality,termed Ride Number(RN).1.2 The intent of this practice is to provide the highwaycommunity a standard practice for the computing and reportingof an estimate of subjective ride quality for highway pave-ments.1.3 This practice is based on an algorithm developed inNational Cooperative Highway Research Project(NCHRP)123(1 and 2),2two Ohio Department of Transportation ridequality research projects(3 and 4),and work presented in Refs(5 and 6).1.4 The computed estimate of subjective ride quality pro-duced by this practice was named Ride Number(RN)inNCHRPResearch Project 123(1 and 2)to differentiate it fromother measures of ride quality computed from longitudinalprofile.Eq 1 of Section 8.2 represents the mathematicaldefinition of Ride Number.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 ReferenceE1170 Practices for Simulating Vehicular Response to Lon-gitudinal Profiles of Traveled SurfacesE1364 Test Method for Measuring Road Roughness byStatic Level MethodE1500 Practice for Computing Mean Square Numerics fromRoad Surface Elevation Profile Records(Withdrawn1998)4E1656 Guide for Classification of Automated PavementCondition Survey EquipmentE1927 Guide for Conducting Subjective Pavement RideQuality Ratings3.Terminology3.1 Terminology used in this standard conforms to thedefinitions included in Terminology E867.3.2 Definitions:3.2.1 Rideability Index(RI)an index derived from con-trolled measurements of longitudinal profile in the wheel tracksand correlated with panel ratings of rideability.3.2.2 Ride Number(RN)rideability index of a pavementusing a scale of 0 to 5,with 5 being perfect and 0 beingimpassable.4.Summary of Practice4.1 The practice presented here was developed specificallyfor estimating subjective ride quality from longitudinal profilemeasurements.4.2 This practice uses longitudinal profile measurements fortwo wheel tracks as an input to a mathematical computation ofestimated subjective ride quality(RN).The profile must berepresented as a series of elevation values taken at constantintervals along the wheel tracks.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 Dec.1,2013.Published February 2014.Originallyapproved in 1996.Last previous edition approved in 2008 as E1489 08.DOI:10.1520/E1489-08R13.2The boldface numbers in parentheses refer to the list of references at the end ofthis standard.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.4The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 4.3 The range of the computed subjective ride qualityestimate is 0 to 5.0 Ride Number(RN)units where an RN of5.0 is considered to be a perfect ride quality road.The 0 to 5.0Ride Number scale is defined in Refs(1,2,3,4,and 5).4.3.1 In the 0 to 5.0 Ride Number rating scale,the endpoints and some of the intermediate points have the followingdescriptions:Ride Number Rating ScaleDescriptionRide NumberPerfect5.0Very good4.54.0Good3.53.0Fair2.52.0Poor1.51.0Very poor0.5Impassable0.04.3.2 The end points are further defined by the followingdescriptions(1):Perfect:A road which is so smooth that at the speed you aretraveling you would hardly know the road was there.Youdoubt that if someone made the surface smoother that theride would be noticeably nicer.Impassable:A road which is so bad that you doubt that you or the carwill make it to the end at the speed you are traveli