The effects of dynamic route guidance in London

Advances in technology have enabled dynamic route guidance systems to reach the stage of implementation on the road network. Dynamic route guidance measures vehicle journey times and flows through a road network and calculates and conveys to individual drivers information on the best route to a destination. A small scale trial of route guidance systems has been demonstrated and shown to work satisfactorily in Great Britain (Catling, 1991) and Germany (Sparmann, 1989). This report summarises two studies that estimate the impact of introducing dynamic route guidance to the London area bounded by the M25-orbital motorway. The studies used a large scale traffic assignment computer model (DTp, 1987), and comprised a number of tests with varying proportions of guided traffic. The tests included: estimates of the benefits for guided and unguided traffic in the peak period and the inter-peak period, the effect of increased traffic demand on the network, the restriction of guided traffic to strategic sub-networks, and potential accident cost savings. (A)