An Intelligent Traffic Signal Control System Based on Fuzzy Theory

Probabilistic fuzzy logic control is developed for the signalized control of a diamond interchange, where the signal phasing and green time extension are decided in response to real-time traffic conditions, aimed at improving traffic flows on surface streets and highways. The probabilistic fuzzy logic for the diamond interchange (PFLDI) comprises two modules: probabilistic fuzzy phase timing (PFPT) that controls the green time extension process of the current running phase, and phase selection (PSL) which decides the next phase based on the pre-setup phase logic by the local transport authority. We used advanced interactive microscopic simulator for urban and non-urban network (AIMSUN) software for modeling various performances of the PFLDI algorithm. Simulation results show that the PFLDI surpasses the traffic actuated and conventional fuzzy models with lower system total travel time, average delay, and improvements in downstream average speed and downstream average delay.