Assessment of streetcar transit priority options using microsimulation modelling

The thrust of a recently published transportation vision for Toronto is focused largely on reducing automobile dependence via a number of interacting strategies, including the wide application of transit priority policies to improve transit competitiveness. This paper reports on quantifying the impacts of several transit priority schemes, with the streetcar operation along King Street in the heart of Toronto as a case study. Four scenarios were modelled in a micro simulation framework. They include the status quo (involving unconditional transit signal priority, already in operation), turning off existing transit signal priority, prohibiting all left turns, and finally prohibiting traffic from King Street. To quantify the impacts of any of the above scenarios, a set of common measures of effectiveness was used, including transit travel time and speed, effective headway, service frequency and person throughput, bunching, fleet size implications, and overall traffic and transit average speeds. The results show the relative merits of the four scenarios and two strategies for improving streetcar service along the King route are recommended. The first is to prohibit all left turns along the route, while the second, admittedly more aggressive, is to potentially transform the arterial into a transit mall accessible only to streetcars.Key words: transit signal priority, transit priority, signal control, microsimulation, streetcars.