TRANSIMS: Applications and Development Workshop
April 8–9, 2010
Dynamic Origin-Destination Matrix Estimation in TRANSIMS Using Direction-Guided Parallel Heuristic Search Algorithms
Adel W. Sadek, Ph.D.
Associate Professor
University at Buffalo, The State University of New York
233 Ketter Hall
Buffalo, NY 14260
Phone: (716) 645-4367
FAX: (716) 645-3733
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List of Authors
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Adel W. Sadek, Ph.D.
Shan Huang
Liya Guo
University at Buffalo, The State University of New York
Abstract
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To better address emerging transportation issues, there has recently been an increased interest in the development and application of large-scale micro-simulation models, such as TRANSIMS, for areas that traditionally had been modeled using a four-step model. In this presentation, we provide a comprehensive evaluation of the ability of heuristic search algorithms to estimate dynamic travel demand in large-scale micro-simulation models, utilizing both a priori known Origin-Destination (OD) matrices and field traffic counts. We select Genetic Algorithms (GA) as an example of a heuristic search algorithm that has often been used for transportation model calibration, and completely custom-develop it for tackling the OD estimation problem. Specifically, the GA is equipped with special operators and mechanisms to aid OD estimation, including a mutation operator which is direction guided by means of analyzing simulation output files. We also propose several ideas in order to reduce the GA runtime and optimize memory usage. Two test networks are utilized: (1) a synthetic network, which is used first to gain insight into the characteristics of the problem; and (2) a realistic network of Chittenden County in northwestern Vermont. The results indicate that GAs appear to have a significant impact on improving the quality of the solutions.
Biography
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Dr. Sadek is an Associate Professor in the Department of Civil, Structural and Environmental Engineering at the University at Buffalo - The State University of New York, and has more than 18 years experience in transportation systems engineering. He is the recipient of the 1998 Milton Pikarsky Award for the best dissertation in the field of Transportation Science and Technology awarded by the Council of University Transportation Centers, and of the National Science Foundation (NSF) CAREER award. His research interests span a wide range of topics including transportation modeling and simulation, intelligent transportation systems, artificial intelligence applications in transportation, traffic engineering, transportation planning, and infrastructure management. Dr. Sadek is co-author of two Transportation textbooks, Fundamentals of Intelligent Transportation Systems Planning published by Artech House, and Transportation Infrastructure Engineering - A Multimodal Integration published by Cengage Learning. He is a member of the TRB committee on Artificial Intelligence and Advanced Computing Applications (ABJ70), and the committee on Surface Transportation Weather. He is also a member of the Advanced Technologies committee of the Transportation and Development Institute (T&DI) of the American Society of Civil Engineers (ASCE).