Assessment of Pavement Damage from Bus Rapid Transit: Case Study for Nevada

This study presents the determination of rutting and fatigue-based load equivalency factors (LEFs) for the bus rapid transit (BRT) buses operating in northern and southern Nevada. The methodology presented in this study was based on performance models calibrated to local material, traffic, and environmental conditions. The objectives of this study were accomplished by obtaining pavement responses corresponding to all cases of bus loading and climatic conditions by using the three-dimensional Move software, Version 2.1. The critical pavement responses were then used to estimate the LEFs for the various BRT vehicles. In the assessment of pavement damage, simplified and extended methodologies were developed. The interaction between pavement temperature and axle loading for both northern and southern Nevada BRT buses was considered in the extended method, which considered seasonal distributions of pavement temperature and bus passenger ridership to determine LEFs. In the simplified method, pavement responses from a single combination of the analysis temperature with either the average ridership loading or gross axle weight rating were considered. Results showed that pavement damage from BRT buses in Nevada was significantly influenced by variability in climatic conditions and passenger ridership. Of the two distress types evaluated in this case study, fatigue-based LEFs occurred at a significantly higher rate than rutting-based LEFs. Thus, for a given pavement structure, more fatigue damage is anticipated under the passage of a BRT bus.