The purpose of the traffic assignment problem is to obtain a traffic flow pattern given a set of origin-destination travel demands and flow dependent link performance functions of a road network. In the general case, the traffic assignment problem can be formulated as a variational inequality, and several algorithms have been devised for its efficient solution. In this work we propose a new approach that combines two existing procedures: the master problem of a simplicial decomposition framework is solved through the analytic center cutting plane method. Three variants are considered for solving the master problem. The third one, which heuristically computes an appropriate initial point, has shown to outperform alternative solution methods. Some computational experience is reported in the solution of real large-scale problems, including a subset of the transportation networks of Madrid and Barcelona.
Report DR2002-04 Statistics and Operations Research Dpt. Universitat Politecnica de Catalunya April 2002