Bus Ride Index – a refined approach to evaluating road surface irregularities

The road surface quality can be assessed with ride comfort indices because of their strong correlation. Many studies on ride comfort have focused on cars and trucks, but their results are not applicable to buses, which are characterised by inherently different vehicle dynamics. In this study, a quarter-vehicle simulation concept was used to develop a Bus Ride Index (BRI) for evaluating the effect of road irregularities on bus ride comfort. A BRI model was developed to optimise ride comfort depending on seat configuration and air suspension and validated according to technical data. The results show a good regression relationship between BRI and the International Roughness Index (IRI). New IRI thresholds with regard to ride comfort and bus operating speeds were established to serve as a benchmark to develop better pavement maintenance strategies for bus lanes and to estimate road quality based on acceleration data.National Research Foundation (NRF)Accepted versionThis work is a part of PhD study of the first author and financially supported by the National Research Foundation Singapore under its Campus for Research Excellence And Technological Enterprise (CREATE) programme