Correlation among Road Unevenness Indicators and Vehicle Vibration Response

Abstract

This paper estimates the correlations among nine vertical vibration responses on two vehicle planar models (passenger car and heavy truck) and 27 different road unevenness indicators (RUI) of longitudinal road profile. The correlation between approximation model (linear or power function) and calculated data was analyzed to indicate the ability of different RUIs for the robust reflection of the vehicle vibration response. The correlation was analyzed as a function of vehicle velocity, category of response (ride comfort and ride safety), and type of surface (asphalt concrete versus cement concrete). The aim was to compare RUIs based on the vibration response statistic (so-called response-type indexes) and RUIs based on the direct statistics of road elevation. In total, 6,984 road profile records from the Long Term Pavement Performance (LTPP) Program were processed. The results were dependent on velocity and category of vibration response and indicate high correlation not only for the response-type RUIs (International Roughness Index and Ride Number) but also for the road indexes based on the direct statistic of road profile elevation as parameters of a road spectrum (unevenness index) as well as road elevation root-mean square (RMS) values in the medium-wave or shortwave bands or straightedge indexes. About 25% of analyzed road indexes showed a correlation