SPECTRAL-ANALYSIS OF HIGHWAY PAVEMENT ROUGHNESS

This paper reports new findings in the spectral analysis of pavement roughness. Elevation profiles of federal and interstate highways were measured with a profilometer, and spectral analysis was used to compute power spectral densities for the longitudinal elevation of pavements. The longitudinal profiles obtained were also used to compute the International Roughness Index (IRI) using a quarter-car simulation method. An extensive review of the existing techniques for pavement spectral analysis was done from which it was found that previously developed models do not explain pavement spectral properties very well, especially for long wavelengths in the spectral decomposition. A new equation that fits the power spectral density curves for several pavement types was developed. A set of models was also developed to predict the power spectral density as a function of pavement type and age, and the IRI.