Using Microsimulation to Estimate Effects of Boarding Conditions on Bus Dwell Time and Schedule Adherence for Passengers with Mobility Limitations

Both bus dwell time and bus headway adherence are critical to the serviceability of the bus transit system. It is acknowledged that passengers with physical disabilities may greatly impact bus dwell time and bus headway adherence due to the increased time needed to safely board the bus. However, the mitigating effects of securement systems and ramp features on bus dwell time and bus schedule adherence have not yet been examined in the literature. This study investigates the impacts of the combination of bus boarding conditions and passengers who used wheeled mobility devices on bus dwell time and headway adherence. The results indicate that bus dwell time drops by 30% for the most supportive boarding conditions. Results also demonstrated that the deviations of bus headways from the scheduled headways regarding the most favorable conditions were much smaller than the traditional design of the buses under the light traffic condition. There is a 47% reduction in headway adherence coefficient under the light traffic condition with favorable ramp slopes, interior bus configuration, and securement conditions.