DYNAMIC TRAFFIC ASSIGNMENT FOR URBAN ROAD NETWORKS
This paper describes a dynamic traffic assignment (DTA) algorithm for urban road networks. The DTA algorithm is intended for application to large transportation planning networks with flow dependent travel costs and multiple origin and destination zones. The static user-equilibrium assignment problem (SUE) is a nonlinear programming problem with linear constraints that is typically solved by methods of linear combinations. The dynamic user-equilibrium assignment problem with multiple origins and destinations (DUE) is a nonlinear programming problem with nonlinear constraints that cannot be solved by these methods. Moreover, the constraints needed to ensure temporal flow continuity at the nodes cannot be properly specified with DUE. DTA is not a solution algorithm for DUE, but was designed instead to produce assignments that approximate the optimality conditions of DUE. Alternative approaches to dynamic assignment are discussed, including those that have been formulated as optimization problems and others that have been developed to simulate or approximate observed traffic conditions. Test results presented in this paper show that DTA generates both static and dynamic assignments that approximately satisfy the user-equilibrium of those problems.
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Oak Ridge National LaboratoryP. O. Box 2008
Oak Ridge, TN United States 37831
- Janson, B N
- Publication Date: 1989-7
- Features: Figures; References; Tables;
- Pagination: 27 p.
- TRT Terms: Algorithms; Dynamic tests; Equilibrium (Mechanics); Equilibrium methods (Structural analysis); Networks; Optimization; Origin and destination; Roads; Solutions (Chemistry); Statics; Traffic flow; Traffic simulation; Travel budgets; Travel costs; Trip length; Urban highways; Urban transportation
- Uncontrolled Terms: Dynamic analysis; Road networks
- Old TRIS Terms: Equilibrium methods, structural; Solutions; Static conditions
- Subject Areas: Highways; Operations and Traffic Management; I71: Traffic Theory;
- Accession Number: 00494850
- Record Type: Publication
- Source Agency: National Technical Information Service
- Report/Paper Numbers: CONF-900121-2
- Files: TRIS
- Created Date: Jun 30 1990 12:00AM