Shortest paths in traffic-light networks

• Published in: Transportation research. Part B: methodological Vol. 34; no. 4; pp. 241 - 253
• Main Authors: Chen, Yen-Liang, Yang, Hsu-Hao
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.05.2000; Elsevier
• Series: Transportation Research Part B: Methodological
• Subjects: Applied sciences; Buildings. Public works; Exact sciences and technology; Ground, air and sea transportation, marine construction; Road network; Road operations (signalization, lighting, safety and accessories, snow clearance, acoustical panel, etc.); Road transportation and traffic; Shortest path; Time window; Traffic light; Transportation infrastructure; Shortest path; Traffic light; Road network; Time window; Intersection; Traffic lights; Example; Traffic control; Minimization; Numerical simulation; Road traffic; Algorithm; Time analysis; Constrained optimization
• ISSN: 0191-2615; 1879-2367
• DOI: 10.1016/S0191-2615(99)00023-5

The time-constrained shortest path problem (TCSPP) is an important generalization of the shortest path problem (SPP) and has attracted widespread research interest in recent years. This paper presents a novel time constraint, called traffic-light constraint, to simulate the operations of traffic-light control encountered in intersections of roads. Basically, the constraint consists of a repeated sequence of time windows. In each window, only the cars in specified routes are allowed to pass through the intersection. In a practical sense, this means that a car needs to wait if the light for its direction is red and can go if it is green. For this kind of network, a shortest path algorithm of time complexity O( r × n 3) is developed, where n denotes the number of nodes in the network and r the number of different windows in a node. In addition, we also prove that the time complexity of this algorithm is optimal.