A reverse causal-effect modeling approach for signal control of an oversaturated intersection

• Published in: Transportation research. Part C, Emerging technologies Vol. 16; no. 6; pp. 742 - 754
• Main Authors: Liu, Hongchao, Balke, Kevin N., Lin, Wei-Hua
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier India Pvt Ltd 2008; Elsevier
• Subjects: Applied sciences; Buildings. Public works; Exact sciences and technology; Ground, air and sea transportation, marine construction; Optimization models; Road operations (signalization, lighting, safety and accessories, snow clearance, acoustical panel, etc.); Road transportation and traffic; Traffic signals; Transportation infrastructure; Optimization models; Traffic signals; Intersection; Traffic lights; Traffic control; Linear programming; Road traffic; Dynamic programming; Modeling; Optimization
• ISSN: 0968-090X; 1879-2359
• DOI: 10.1016/j.trc.2008.03.003

A novel approach is presented in which signalized intersections are treated as normal highway bottlenecks for improved computational efficiency. It is unique in two ways. First, it treats the signalized intersections as common freeway bottlenecks by a reversed cause and effect modeling approach. Both traffic arrivals and departures are modeled by smooth continuous functions of time as if there were no interruptions to traffic flows from signals. The use of smooth continuous functions for departure curves instead of commonly used step functions makes it easy to apply differential calculus in optimization and future extension to a system of intersections. Second, a dynamic linear programming (LP) model is then developed to maximize the total vehicular output from the intersection during the entire period of congestion subject to prevailing capacity and other operational constraints. The continuous optimal departure flow rate (the effect) is then converted to signal timing parameters (the cause) that can be readily implemented. Two numerical examples are presented to demonstrate the properties of the proposed algorithm and examine its performance.