EXPERT SYSTEMS FOR TRAFFIC SIGNAL CONTROL.

The level of service achieved by a pretimed signal timing control strategy implemented at an isolated intersection incurring saturated and over-saturated demand varies with actual traffic flows. The volatility of traffic flows often renders pretimed signal control suboptimal when such volatility cannot be predicted by the traffic engineer who designed the control strategy. Even when volatility is somewhat predictable, timing strategies must be made to best accomodate peak flow characteristics, thereby rendering these strategies accepting of a suboptimal situation when near-peak or below-peak demand is encountered. This paper introduces a new computer-based approach for managing signal control at isolated intersections to address these issues. The approach prescribes the application of realtime knowledge based expert system technology.