Phase I: The role of the vehicle is more important today than ever before in history, and this importance has led to congestion in metropolitan areas. This congestion, in some cases, can be so severe that there is gridlock in the center of the business district and the flow of traffic and goods is completely stopped. There are several methods to reduce the delay and keep traffic flowing in the city center, but most of these methods are very expensive and in some instances not feasible. The goal of this research is to generate some strategies to alleviate this congestion at signalized intersections through signal timing parameters. These strategies will be applicable to any oversaturated system. In order to generate these strategies, data will be collected from oversaturated intersections throughout the state of Idaho. These data will then be analyzed and used to show the effects of the strategies that are developed. Once these strategies are applied the expected results should show a decrease in oversaturation at intersections, and therefore a decrease in the delay per vehicle.
Phase II: Traffic control at signalized intersections is essential for moving vehicles through the intersection in a safe manner. The increasing number of traffic signals and traffic signal systems in urban areas influences the traffic flow pattern. Currently, fixed-time control strategies for traffic signal systems are analyzed in the signal-timing design based on the Highway Capacity Manual procedure. These methods do not provide procedures for analyzing the signal systems on a cycle-by-cycle basis. The arrival rate at an intersection varies from cycle to cycle. The cycle-by-cycle-based approach allows engineers to estimate the queue and delay at the end of each cycle. The objective of this study is to develop a methodology that selects a particular signal-timing pattern based on the fluctuations in the arrival rate for each cycle at one intersection and maintaining coordination with the adjacent intersections.