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

This paper presents a path-based traffic assignment formulation and its solution algorithm for solving an asymmetric traffic assignment problem based on the TRANSYT traffic model, a well-known procedure to determine the queues and delays in a signal-controlled network with explicit considerations of the signal co-ordination effects and platoon dispersion on the streets. The solution algorithm employs a Frank-Wolfe method to identify the descent direction at each iteration, which requires the input of the derivatives information. A post-simulation sensitivity analysis is developed to estimate the 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 behavior to the equilibrium solution. Comparison with other methods is also discussed in a numerical example to demonstrate the effectiveness of the proposed methodology.