Modeling and evaluation of conditional transit signal priority on large scale networks

A framework for modeling and testing Conditional Transit Signal Priority CTSP strategies has been presented. A Hybrid simulation tool has been used to evaluate the regional impacts of Transit Signal Priority (TSP) and various CTSP strategies. A large scale model of the Chicago area has been used to capture the impacts of TSP and CTSP implementation on intersecting and parallel corridors.; The primary objective of the study is to quantify the impacts of implementing TSP and CTSP at a network level, corridor level, and individual vehicle and traveler level. Unconditional signal priorities with green phase extension and red phase truncation are the two TSP treatments that have been formerly implemented and tested as Strategy 1 and Strategy 2. Using these two strategies as bases, Strategies 3 and 4, giving priority only to buses running behind schedule, also have been formerly modeled and tested. Further, the following CTSP strategies were modeled and tested: Strategies 5 and 6 give priority only to buses with occupancies surpassing a predetermined minimum occupancy; Strategies 7 and 8 give priority to a bus only if the time since the last priority has exceeded a prespecified minimum; and Strategies 9 and 10 give priority to a bus only if the queue length on the cross-street does not exceed a prespecified maximum acceptable length.; The Chicago area network model was adopted from the "Regional Traffic Simulation/Assignment Model for Evaluation of Transit Signal Priority" study. Information available through this study includes network, transit, signal and automobile demand data. The ten TSP and CTSP strategies described above were tested. The simulation period covered the two morning peak hours. Each of the ten strategies was tested and evaluated for four different scenarios. The first scenario implemented the various TSP and CTSP strategies on one corridor; the second scenario implemented the strategies on two parallel corridors; the third scenario implemented the strategies on three parallel corridors; and the fourth scenario implemented the strategies on eight corridors. Results at a network, corridor, and individual vehicle level have been summarized. Conclusions and recommendations for implementing TSP and CTSP are given in chapter 7.