Service level-oriented route guidance in road traffic networks

Traffic management on a network level is not only theoretically a complex problem, but it also involves the realization of the road authorities´ traffic management policy. In the Netherlands, this policy harmonizes the interests of involved stakeholders by means of a common vision upon the network functioning expressed in road priorities and corresponding desired service levels. This paper presents a route guidance control methodology that is able to take the formulated policy into account. This is achieved by degrading and restoring service levels of routes according to their difference in importance with respect to network performance. The proposed method is the first dynamic routing approach that is able to operationalize the Dutch traffic management policy in line with how it is formulated. The proposed methodology consists of a finite-state machine that determines the desired service levels based on predicted traffic conditions. These service levels are used in a feedback controller as setpoints for the desired travel times, resulting in the corresponding output signal of Variable Message Signs. By means of a test case, the performance of the method is compared with a controller that realizes a user equilibrium and an uncontrolled scenario. The evaluation identifies the potential of route control based on service levels when dealing with differently prioritized routes.