Simulating Performance Impacts of Bus Lanes and Supporting Measures

This study used the TRANSYT-7F simulator to examine changes in performance measures of through buses and adjacent traffic following the introduction of reserved lanes in an urban arterial. In addition, the TRANSYT-7F simulator was used to examine the specific impacts on modal performance of two policy measures implemented in conjunction with lane introduction. The results showed that TRANSYT-7F provided relatively accurate estimates of bus delays and auto speeds. However, the study identified one area of improvement for TRANSYT-7F to model priority treatments on arterials more effectively. The simulation results showed that the performance of the average bus improved after project implementation, whereas the performance of the adjacent through traffic deteriorated. However, the deterioration exceeded the improvement. Other aggregate estimates of performance were examined and discussed. The simulations also showed that modifications to left-turn movements would have a minor impact on both bus and adjacent traffic performance, whereas the removal of taxis from the reserved lanes would cause far more performance deterioration to the adjacent traffic than the performance improvement this policy measure would bring to buses.