Testing a traffic signal optimisation algorithm

This paper presents numerical experimental results for testing a simulation-based combined dynamic traffic assignment and signal optimisation algorithm under incident conditions. The algorithm utilises a path-based signal optimisation procedure, which uses vehicle paths information from a dynamic traffic system optimal assignment model to optimise the signals. The use of vehicle path in the signal optimisation procedure makes it much easier to interact with the path-based dynamic traffic assignment models. The algorithm is implemented and tested under normal and incident conditions. The experiments consist of implementations of the solution algorithm under different congestion levels for the test networks. Some experiments, under incident conditions for the test network, were used to examine the robustness of the solution algorithm. The algorithm is shown to reach convergence in all experiments, and to result in significant improvements over the system optimal assignment solution under different congestion levels.