A macroscopic model for integrating bus signal priority with vehicle rescheduling

When a bus breaks down on a scheduled trip, one or more vehicles need to be rescheduled to serve that trip and other scheduled trips. A bus breakdown certainly delays the trip being served by the disabled bus and possibly delays or cancels other trips. The vehicle rescheduling problem (VRSP) is to reassign and reschedule the bus fleet to minimize the sum of operating costs, delay costs, schedule disruption costs, and trip cancellation costs. Bus operations may also be improved by bus signal priority (BSP), which can reduce bus delays at signalized intersections. If BSP is provided to the backup bus that travels to service the disabled bus' passengers, it may reach the breakdown point more quickly. However, other buses that also pass through the corresponding intersections may be affected by signal priority. Therefore, a tradeoff must be made so that the backup bus can travel faster while other buses are not significantly delayed. A macroscopic model that integrates bus signal priority with bus rescheduling is proposed in this paper. Computational results show that the combination of BSP and VRSP effectively reduces the delay of the backup bus and decreases the delay costs.