A model for the dynamic system optimum traffic assignment problem

The authors describe a deterministic queueing assignment model which seeks to reduce total travel delays in a road traffic network by routeing drivers according to the total delay caused on each link (the local marginal delay). The model is approximate and is applicable to networks with many origin-destination pairs and many bottlenecks. Optimality of the solution determined by the model is discussed. It is particularly shown that, unlike in the steady state, reducing total travel times by using the local marginal delay will not generally result in an optimal solution. Results are provided for two networks.