Abstract
This paper presents the approach taken in project CAPITALS/MADRID for the design, implementation and demonstration of a wide area traffic control system in which the controlled area is divided into several zones, each one controlled by its own traffic control system. The paper describes the functional architecture of a Supervisor system which achieves the co-ordination between the local control systems through an information interchange, some predictive capabilities and the resort to a detailed microscopic simulation to estimate the short term evolution of the traffic conditions on the controlled area.