Arterial-based control of traffic flow in urban grid networks

Urban networks are typically composed of a grid of arterial streets. Optimal control of the traffic signals in the grid system is essential for the effective operation of the network. In this paper, we present mathematical programming models for the development of optimal arterial-based progression schemes. Such schemes are widely used for traffic signal control in arterial streets. Under such a scheme, a continuous green band is provided in each direction along the artery at the desired speed of travel to facilitate the movement of through traffic along the arterial. Traditional schemes consist of uniform-width progressions. New approaches generate variable bandwidth progressions in which each directional road section is allocated an individually weighted band that can be adapted to the prevailing traffic flows on that link. Mixed-integer linear programming is used for the optimization. Simulation results indicate that this method can produce considerable gains in performance when compared with traditional progression methods. By introducing efficient computational techniques, this method also lends itself to a natural extension for incorporation in a dynamic traffic management system. (C) 2002 Elsevier Science Ltd. All rights reserved.