Development of a Transit Signal Priority Algorithm for Urban Corridors

Abstract

This research developed actuated signal plans for bus priority using green split optimization and the boundary conditions for cycle lengths done through Synchro® signal optimization tool. A case study was applied on a corridor’s segment that consists of four consecutive intersections on El Nahas Corridor at Nasr City, Cairo. This corridor besides being one of the most congested corridors in Cairo, has also one of the deployments of the exclusive bus lanes in an urban corridor in Cairo, Egypt. Pre-timed signal optimization was carried out using Synchro®. 8.0 for two different corridor geometric configurations: first configuration including exclusive bus lanes in the middle, and the other configuration removing the bus lanes and increasing the capacity by adding one lane in each direction (mixed traffic lanes). The optimization was carried out for split signal phasing plans, and protected signal phasing plans for peak and off-peak periods. This optimization resulted in optimized cycle lengths for each intersection in each time period as well as the optimized signal plans for the two optimized scenarios based upon protected and split phasing plans.

PTV Vissim 7.0 traffic micro-simulation tool was used in order to simulate the optimized signal plans for different exclusive bus lanes configurations for split signal phasing, protected signal phasing, and transit signal priority (TSP) scenarios. The simulation was also conducted for mixed traffic lanes configurations for split signal phasing, protected signal phasing, TSP, intermediate U-turns and left turn movements prohibited at intersections, and TSP with intermediate U-turns and left turn movements prohibited at intersections scenarios. The simulations results were used to compare the effectiveness of TSP and