Metropolitan Toronto is one of a handful of large urban centres in North America which operate trams or streetcars in mixed traffic. They constitute a critical element in the transportation system for downtown Toronto, carrying over 300,000 passengers on an average weekday. However, greater congestion has increased streetcar travel times, resulting in greater operating costs and rider dissatisfaction. This paper describes a demonstration of traffic signal pre-emption for streetcars using state-of-the-art technology. A priority request loop is situated between 80 and 100 metres upstream of the signalized intersection, while a priority cancel loop is placed just beyond the stop bar. The pre-emption algorithm must incorporate the effects of nearside transit stops and queued vehicles on the streetcar tracks. Six adjacent signalized intersections along an east-west arterial in Toronto were equipped with selective detectors and supporting hardware. A detailed before/ after study of this transit priority technique was conducted, including its impact on cross- street transit service and other road users. Because of the high variability of streetcar travel time in mixed traffic, the study design incorporated measures to ensure that changes in travel time could be attributed to traffic signal pre-emption. For example, the effect of changes in traffic patterns was minimized by performing before/ after studies on the same day. The applicability of this technique for other road sections in Metropolitan Toronto is discussed.
Samenvatting