Effective Coordinated Optimization Model for Transit Priority Control Under Arterial Progression

With the goal of providing effective priority control for transit while minimizing adverse impacts on general traffic movements along the arterial, this paper presents a coordinated transit priority control optimization model with the following features: (a) the control unit is defined as the coordinated intersection group between two successive bus stops; (b) buses are detected after leaving the upstream stop before their arrival at the first intersection of a control unit; (c) the dynamic interactions of priority strategies between adjacent intersections within a control unit are modeled by using a bus delay model and an ineffective priority time model; and (d) a linear program model is developed to generate the optimal priority strategies to reduce bus travel time when priority is necessary and to ensure that every priority treatment implemented at each intersection is effective. Extensive experimental analyses, including time-space diagram-based deterministic analysis and simulation-based analysis, were performed, and results were compared with conventional transit signal priority strategy and no-priority scenarios. The proposed model presents promising outcomes in the design of transit priority signal control in terms of decreasing bus delay, improving bus schedule adherence, and minimizing the negative impacts on general traffic under different traffic demand patterns.