Simultaneous Optimization of Signal Timings, Departure Time and Dynamic Speed for Bus Priority Operations

摘要

Most previous works of transit signal priority merely focus on optimization of signal timings.Bus speed and dwell time at bus stop are used as exogenous inputs. This paper presents a novelapproach for integrated optimization of bus holding time at bus stop, signal timings, and busspeed to provide priority to buses at isolated intersections. The objective of the proposed modelis to minimize the total intersection cost that includes bus delay and the impact on the overalltraffic near the intersection in the meantime, to the maximum extent possible, ensure bus clearingthe intersection without stop by the red light. A set of formulations are developed to captureexplicitly the interaction between bus speed, bus holding time and transit priority signal timings.Experimental analyses have shown that the proposed integrated operational model outperformsthe no priority, signal priority only, and signal priority with holding control strategies (no busspeed adjustment) in terms of reducing average bus delays and stops, and only causes littleacceptable negative impacts on general traffic. The sensitivity analysis has further demonstratedthe potential of the proposed approach to be applied in real-time bus priority control systemunder different levels of traffic demand.