Transition Options Delays Software for Efficiency Estimation of Transition Options

At coordinated signals, a signal may go to transition due to oversized pedestrian timing, transit signal priority (TSP), or emergency vehicles. In these situations, a signal tries to bring back disrupted coordination to its original plan by a transition option. There are several options for transitions, including Dwell, Max Dwell, Add, Subtract, and Short way. To have a quantitative tool to analyze different transition options, mathematical models of transition methods were developed. Then the mathematical models of transition options were implemented into software called TOD (Transition Options’ Delays), which is an open-source program available for anyone who is interested in using it. With this software, practitioners simply input the common timing parameters such as cycle length, vehicle and pedestrian volume, and required pedestrian timing. The software will then give a recommendation based on the overall delay. The mathematical models and the related TOD software are expected to provide improved recommendations when dealing with pedestrian crossings at coordinated signal systems.