University of California Transportation Center
A Faster Path-Based Algorithm for Traffic Assignment
- Jayakrishnan, R. ;
- Tsai, Wei T. ;
- Prashker, Joseph N. ;
- Rajadhyaksha, Subodh
This paper takes a fresh look at the arguments against path-enumeration algorithms for the traffic assignment problem and provides the results of a gradient projection method. The motivation behind the research is the orders of magnitude improvement in the availability of computer storage over the last decade. Faster assignment algorithms are necessary for real-time traffic assignment under several of the proposed Advanced Traffic Management System (ATMS) strategies, and path-based solutions are preferred. Our results show that gradient projection converges in 1/10 iterations than the conventional Frank-Wolfe algorithm. The computation time improvement is of the same order for small networks, but reduces as the network size increases. We discuss the computer implementation issues carefully, and provide schemes to achieve a 10-fold speed-up for larger networks also. We have used the algorithm for networks of up to 2000 nodes on a typical computer work station, and we discuss certain data structures to save storage and solve the assignment problem for even a 5000 node network.
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A FASTER PATH-BASED ALGORITHM FOR TRAFFIC ASSIGNMENT
This paper takes a fresh look at the arguments against path-enumeration algorithms for the traffic assignment problem and provides the results of a gradient projection method. The motivation behind the research is the orders of magnitude improvement in the availability of computer storage over the last decade. Faster assignment algorithms are necessary for real-time traffic assignment under several of the proposed Advanced Traffic Management System (ATMS) strategies, and path-based solutions are preferred. Our results show that gradient projection converges in 1/10 fewer iterations than the conventional Frank-Wolfe algorithm. The computation time improvement is of the same order for small networks, but reduces as the network size increases. We discuss the computer implementation issues carefully, and provide schemes to achieve a 10-fold speed-up for larger networks also. We have used the algorithm for networks of up to 2000 nodes on a typical computer work station, and we discuss certain data structures to save storage and solve the assignment problem for even a 5000 node network.
- http://www.uctc.net/papers/191.pdf
- Find a library where document is available. Order URL: http://worldcat.org/issn/01935860
- Paper presented at the 73rd Annual Meeting of the Transportation Research Board, Washington, D.C., January 9-13, 1994.
University of California, Irvine
- Jayakrishnan, R
- PRASHKER, J N
- Rajadhyaksha, S
- Publication Date: 1994-1
- Features: Figures; References; Tables;
- Pagination: 24 p.
- Publication of: California University, Irvine
- Publisher: University of California, Irvine
- ISSN: 0193-5860
Subject/Index Terms
- TRT Terms: Advanced traffic management systems ; Algorithms ; Implementation ; Real time control ; Real time data processing ; Strategic planning ; Traffic assignment
- Uncontrolled Terms: Computation time
- Old TRIS Terms: Network size
- Subject Areas: Highways; Planning and Forecasting; Research; I72: Traffic and Transport Planning;
Filing Info
- Accession Number: 00643536
- Record Type: Publication
- Report/Paper Numbers: UCI-ITS-WP-94-3
- Files: TRIS
- Created Date: Mar 7 1994 12:00AM