Real-time route diversion control at congested motorway off-ramp areas - Part I: User-optimum route guidance

This paper investigates the application of real-time route diversion policies in the case where recurrent motorway traffic congestion is created due to a saturated off-ramp. In particular, the proposed route diversion policies attempt to avoid the off-ramp queue spill-over onto the motorway mainstream and the resulting motorway congestion by re-routing the motorway vehicles through nearby off-ramps towards the same destination. In particular, this paper addresses the case where real-time route guidance strategies, based on user-optimum considerations, are sufficient to resolve the spill-over and motorway congestion problem; while other cases are treated in a companion paper. The proposed route guidance concepts are tested for a hypothetical but quite typical network infrastructure and traffic scenario by use of macroscopic simulation. The obtained simulation results are compared to the case where no route guidance is applied to the network and reveal interesting features and the potential for significant improvements.