Signal Control for Oversaturated Intersections Using Fuzzy Logic

The fuzzy logic controller (FLC) presented in this paper simulates the control logic of experienced human traffic controllers such as police officers who supersede signal controls at over-saturated intersections during special events. Given real-time traffic information, the FLC controller decides on whether to extend or terminate the current green phase based on a set of fuzzy rules. A microscopic simulator, the Intersection Control Simulator (ICS), was developed to facilitate the evaluation of the proposed FLC strategy. The FLC strategy was compared with pretimed and actuated control strategies using a typical intersection with varying traffic volume levels. Based on delay, speed, % stops, time in queue and throughput-to-demand ratio statistics, the FLC strategy produced significant improvements over pretimed and actuated control strategies under heavy traffic volumes. This indicates that FLC has the potential to improve operations at over-saturated intersections.