Active Transit Signal Priority for Streetcars

Although streetcar systems benefit from a strong identity, they face considerable challenges as a result of mixed traffic operations. These problems have been compounded by growing urban auto traffic, which has increased competition for limited road space and time. Active traffic signal priority (TSP) has been identified as a cost-effective way to improve the management of manage traffic systems to make on-street public transport more reliable, faster, and more cost-effective. Although the implementation of TSP is growing throughout the world, relatively few studies have examined its application to streetcar-based systems. This paper reviews the experience with TSP in Melbourne, Australia, and Toronto, Canada. These cities run some of the world's oldest and largest streetcar-based TSP systems. This paper describes the TSP systems adopted in the two cities, including key experiences. TSP performance is reviewed, and identified problems and issues are assessed. The review established that the TSP systems in the two cities have many similarities including the configuration of approach and request loop and stop line and cancel loop detection, the degree of priority provided, and the targeting of clearance phases for turning traffic at intersections. There are some slight differences in the handling of bunching trams and opposing tram movements, which are better handled in the Toronto case. The two systems see rather different futures for TSP development. Toronto is focused on full systemwide TSP implementation and advancement of TSP algorithms, whereas Melbourne aims to make priority more conditional on the degree of lateness of trams and on the degree of traffic congestion experienced.