Road Roughness Limit Values Based on Measured Vehicle Vibration

Abstract

This study identified longitudinal road roughness limit values based on measured vibration induced in a road-vehicle-driver interaction system. The relations between measured vehicle vibration response and the international roughness index (IRI) were summarized. Frequency-weighted acceleration on the seat and dynamic load coefficient (DLC) were used to quantify ride comfort, ride safety, and the dynamic load of the vehicle and road. Linear relationship coefficients were identified or taken from references. The expected large range of vibration response root mean square (RMS) values was observed for the same level of IRI. IRI limit values were derived for chosen threshold values of vehicle vibration response as a function of vehicle velocity. Velocity-related IRI limit curves were proposed based on the fitting of IRI limit values lower envelope. IRI limit curves were compared with threshold proposals of other authors and width thresholds used in road maintenance. Some of the estimated IRI limit curves for DLC response were below thresholds used for road maintenance.