A Real-Time Transit Signal Priority Control Model Considering Stochastic Bus Arrival Time

摘要

Transit signal priority (TSP) strategy gives transit vehicles preferential treatments to move through an intersectionwith minimum delay. To produce a good TSP timing, advance planning with enough look-ahead time is the key. This,however, means added uncertainty about bus arrival time at stop bar. In this paper, we proposed a stochasticmixed-integer nonlinear program (SMINP) model as the core component of a real-time TSP control system. The model adoptsa novel approach to capture the impacts of the priority operation to other traffic by using the deviations of the phasesplit times from the optimal background split times. In addition, the model explicitly accounts for the randomness ofthe bus' arrival time by considering the bus stop dwell time and the delay caused by standing vehicle queues. The SMINPis implemented in a simulation evaluation platform developed using a combination of a microscopic traffic simulator anda commercial optimization solver. Comparison analyses were performed to compare the proposed control model with thestate-of-the-practice TSP system [i.e., ring-barrier controller (RBC)-TSP]. The results showed the SMINP has yielded asmuch as 30% improvement of bus delay compared with RBC-TSP in a single-bus case. In a multiple-bus case, SMINP handlesthe bus priority request much more effectively under congested traffic conditions.