Citation

Sayers M, Gillespie TD. Transp. Res. Rec. 1981; 836: 35-41.

Copyright

(Copyright © 1981, Transportation Research Board, National Research Council, National Academy of Sciences USA, Publisher SAGE Publishing)

DOI

unavailable

PMID

unavailable

Abstract

Recent research on methods for calibrating road roughness measuring systems has shed new light on improving the use of the currently popular Mays and Portland Cement Association (PCA) roadmeters. The measurement provided by these meters (accrued displacement between the rear axle and vehicle body) is discussed and shown to relate best to pavement serviceability when normalized by the time duration of the test, thus yielding a simple statistic called the average rectified velocity (ARV) of the axle-body motion. Unlike the inches per mile statistic that is commonly calculated, the ARV is shown to be valid for comparing pavements that are measured (and used) at different speeds. At the same time, the ARV concept provides a logical basis on which to establish calibration for roadmeter systems. In the absence of a universal calibration, the measurements obtained from different systems cannot be compared except in the special case where empirical correlations have been established. Accordingly, an absolute roughness scale is specified based on a reference ARV (RARV) statistic determined from a quarter-car simulation. RARV constitutes an absolute roughness statistic, rigorously defined at a given test speed, whose validity as a calibration reference has been established from field-test experience with in-use roadmeter systems. An appreciation for the ARV is important to highway engineers because the concept provides the link in understanding between current roughness measurement practice and serviceability of roads as seen by the public at normal traffic speeds.