Institute of Transportation, MOTC

       Transportation signal priority system grants vehicles the right of way to pass through intersections with green signal phases upon their arrival. In public transportation, this privilege is commonly extended to buses and trams to enhance their competitiveness against regular vehicles. Additionally, emergency vehicles are currently allowed to cross intersections during red signal phases, although this practice poses a significant risk of accidents. Therefore, it is imperative for emergency vehicles to also possess signal priority rights to ensure safety and reduce travel time. The aim of this study is to propose decision logic and mathematical models to coordinate scenarios in which both emergency vehicles and trams, both equipped with signal priority, converge at intersections, determining the optimal sequence of signal phases. The study is divided into three frameworks: emergency vehicle signal priority, tram speed control, and signal coordination between emergency vehicle and tram. Mathematical model are design for tram speed control and signal coordination between emergency vehicle and tram. Gurobi is used to solve these models, and the Sumo, microscopic traffic network, with Python's Traci functions is utilized to collect simulation data and modify vehicle speeds and signal phases. The research demonstrates that implementing emergency vehicle signal priority can lead to a reduction of approximately 40% in travel time. Tram speed control method can decrease delay for regular vehicles by around 20%. Moreover, effective coordination of signal control between emergency vehicles and trams is achieved.