A procedure for real-time signal control that considers transit interference and priority

A rule-based procedure for determining real-time signal timings at a signalized intersection is described. It incorporates the effects of the traffic interference caused by on-line loading/unloading of transit vehicles at the intersection. This procedure generates a number of short-term alternative real-time phase sequences for various levels of transit priority, based on a number of decison rules. It then evaluates these signal sequences and selects the one with the least overall cost to all traffic. The procedure is illustrated in terms of a simulated application to a critical intersection in Toronto’s Queen Street corridor using real data. The preliminary simulation tests indicate the potential reduction in total delay compared to fixed-time operation, which results largely from selectively ushering transit vehicles to their loading positions at strategic times and serving cross-street traffic while the transit vehicles are loading.