A path-based traffic assignment algorithm based on the TRANSYT traffic model

This paper presents a path-based traffic assignment formulation and its sol ution algorithm for solving an asymmetric traffic assignment problem based on the TRANSYT traffic model, a well-known procedure to determine the queue s and delays in a signal-controlled network with explicit considerations of the signal coordination effects and platoon dispersion on the streets. The solution algorithm employs a Frank-Wolfe method to identify the descent di rection at each iteration, which requires the input of the derivatives info rmation. A post-simulation sensitivity analysis is developed to estimate th e derivatives in the TRANSYT traffic model. Good agreement of results with the values determined by numerical differentiation is obtained. Using these derivatives information, the Frank-Wolfe method shows a good convergence b ehavior to the equilibrium solution. Comparison with other methods is also discussed in a numerical example to demonstrate the effectiveness of the pr oposed methodology. (C) 2001 Elsevier Science Ltd. All rights reserved.