Impact of design elements on the capacity and speed of Bus Rapid Transit (BRT): the case of a single lane per direction

Despite its booming growth, the BRT industry is still far from reaching maturity. As trial-and-error and empiric techniques were largely used as insights for innovations in design, some BRT systems achieved great successes in terms of performance and became world-class flagships whereas others would be most properly classified as busway systems requiring major improvements. In this paper we explore the performance of a single lane per direction no-overtaking BRT corridor, in terms of capacity and operating speed, by conducting a design of experiments that comprised the simulation of 324 alternative scenarios. In the simulation runs we varied demand levels, boarding and alighting rates, spacing of stations, vehicle loadings, quantity of berths per station, and traffic signal positioning in relation to stations. The qualitative analysis reveals that such a BRT system can achieve a capacity around 15,000 pass/h/dir along its critical section with an operating speed of 20 km/h. Preliminary statistical analysis enabled the estimation of a regression model representing the impact of BRT design elements on the operating speed. Our findings provide useful insights for designers of high-performance BRT corridors.