Diversion Control of Freeway Traffic

Abstract This paper discusses the application of threshold control policies to the traffic management of multi-roadway freeway systems. Specifically, this class of control policies has been used to optimally allocate traffic flows over a roadway system during those periods when the traffic demands exceed some roadway capacities. The roadway dynamics have been examined from two points of view. The first describes highway congestion in terms of controllable queues. The second utilizes a freeway simulation based on a hydrodynamic traffic flow model. The two methods yield consistent control policies which have been incorporated into a practical realtime alternate-routing system, under Contract No. DOT-FH-11-8119, to the U. S. Department of Transportation, Federal Highway Administration.