ON CONTROL STRATEGIES FOR URBAN TRAFFIC CORRIDORS

Abstract High capacity expressways in urban areas are important facilities to handle high demand of traffic flow and transportation. However, in critical, overloaded situations and cases of incidents the surrounding network of surface streets can provide efficient supplementary alternative routes if used in a proper way. This requires a careful and traffic responsive coordination of the set of controls which act on traffic flow on the expressway and in the surrounding street network. In this paper the results of investigations to find optimal control strategies for this problem are reported. For this two dynamic models are formulated for the expressway and for the surface street network, respectively, which together form a large scale system. The determination of optimal control sequences for a given traffic situation turns out to be a complex problem of high order for which specific procedures are developed. The benefit of coordinated, traffic responsive control strategies finally is underlined by some optimization results.