Dynamic Equilibrium for Combined Signal Settings and Dynamic Traffic Assignment

Abstract

Intelligent Transportation Systems (ITS) focus on increasing the efficiency of existing surface transportation systems through the use of advanced computers, electronics, and communication technologies. The interaction between signal setting and traffic assignment is an important issue in designing efficient ATMS. This research focuses on finding dynamic user equilibrium between signal setting and route assignment. The problem is solved through a bi-level framework. The upper level solves for signal setting parameters, including cycle length, green splits, and offsets. The lower level solves for user equilibrium Dynamic Traffic Assignment (UEDTA) flows in a traffic network. The signal setting is adjusted through two methods: the Webster formula and Adaptive Signal Control. UEDTA flow patterns are solved through a simulation-based DTA model, DynaTAIWAN. This bi-level framework can be applied in cities with signalized networks. Numerical experiments are conducted based on a sub-network of Kaohsiung City to illustrate the proposed framework.