Operations Research Journal

Operations Research Journal

Journal of the Eastern Asia Society for Transportation Studies, Vol. 6, pp. 1426 - 1438, 2005

A SHORTEST PATH ALGORITHM FOR REAL ROAD NETWORK BASED ON PATH OVERLAP Yongtaek LIM Assistant Professor Division of Transportation and Logistics System Engineering Yosu National University San 96-1, Dundeok-dong, Yosu city Chunnam, 550-749, KOREA Fax:+82-061-659-3340 E-mail:limyt@yosu.ac.kr Hyunmyung KIM PhD Student Department of Civil Engineering Institute of Transportation Studies University of California, Irvine USA Fax: (949) 824-8385 E-mail: hyunmyuk@uci.edu

Abstract : Existing k-shortest path algorithms has some weaknesses such as path similarity among determined paths and network expansion for describing turn prohibitions. Path similarity represents that many of the alternative paths derived from the k-shortest path algorithm are likely to share a lots of links, so they could not represent heterogeneity. The turning restrictions popularly adopted in real road may violate Bellman’s principle of optimality in searching shortest path, so network expansion technique is widely used to avoid such difficulty. But, this method needs additional works to expand the network. This paper proposes a link-based shortest path algorithm to generate dissimilar paths for the travel information in real road network where exists turn prohibitions. The main merit of proposed model is to provide efficient alternative paths under consideration of overlaps among paths to alleviate the path similarity. Another merit is that it does not require extra nodes and links for expanding the network. Thus it is possible to save the time of network modification and of computer running. The algorithm is tested with some example networks and then will be expanded to a dynamic case. Key Words : dissimilar path, path overlap, turn prohibition, link-based algorithm, k-shortest path

1. INTRODUCTION A shortest path problem is for finding a path with minimum travel cost from one or more origins to one...

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