Estimation of Waviness of the Longitudinal Road Profile from Straightedge Measurement

Abstract

The paper presents a method for estimation of power spectral density (PSD) parameters (unevenness index and waviness) of a longitudinal road profile in the short wavelength band from data collected by straightedge (SE) measurement (distance of contact points of the lath and maximum clearance from the straightedge between the supports). This method is based on the estimation of mean values of straightedge measurement parameters established by simulated artificial profiles of different waviness levels from 1.5 to 3.5. The method was validated on a series of simulated profiles with different waviness values and on some in-service road profile records. The method provides a reliable estimate of waviness as a complement to the currently used straightedge indicators based on the mean maximum clearance under the straightedge. Thus, mutual conversion between SE- and PSD-unevenness indicators is possible.