1.1 This guide covers a procedure for obtaining subjective numerical ride ratings for a group of representative highway pavement sections having a broad spectrum of physical characteristics.

1.2 The intent of this guide is to describe a procedure for generating a set of comparative scaled ride ratings, subjectively derived, for a subgroup of pavement sections having a ride quality distribution approximating the general population of highways of interest. This set will provide statistical estimates of the average subjective ride ratings which would be obtained for the same group of pavement sections if the entire population of users could be interrogated.

1.3 For the data to be a reasonable representation of the average ride quality judgments of the total highway pavements, certain sampling theory precepts must be observed. The size of the rating panel, the selection of its members from the user community, the method of quantifying the individual judgments as well as the selection of the sample pavement sections are all important areas to be considered.

1.4 An important use of the resulting ride quality data would be to determine the ability of various hypothesized deterministic functions of physical parameters of the pavement samples such as measured longitudinal profile, etc., to provide an estimate of subjective ride quality judgments.

1.5 This guide is based on guidelines described in Appendix F of NCHRP Report 275, and in Appendix E of NCHRP Report 308.

1.6 The values stated in both inch-pound units and SI units are to be regarded separately as the standard. The units given in parentheses are for information only.

1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.