DESIGNING TIME-OF-DAY SIGNAL PLANS WHICH REDUCE URBAN TRAFFIC CONGESTION

Congestion in towns causes pollution and inconvenience, and is also an instrumental element of the vicious circle relating the decline of public transportation and the growth in car travel. This paper is aimed at the specification and initial evaluation of a new method of achieving an immediate reduction in congestion, perhaps allowing the possibility of reversing the vicious circle. The new method involves using a traffic assignment model in which the traffic signals respond to the traffic flows. The method is as follows: within the traffic assignment-control model, traffic is assigned so as to reduce congestion, allowing the signal settings to deform according to the responsive control policy; then the signal settings which arise from the 'good' distribution of traffic and green-time are implemented on the real road network as a non-responsive time-of-day signal plan. The method is currently implemented in our version of CONTRAM.