Improvements to traffic control systems and policies by means of interactive route guidance data. Part b: an integrated observer for the intersection: use of dynamic route guidance data for improving the real time estimation.

Any real time intersection control scheme aims at improving the traffic performance by optimising delays, travel times, number of stops and any other traffic index taking into account any safety constraint; to obtain this effect an accurate knowledge of the state of the intersection is needed. The state of an Intelligent Intersection is not directly measured by the normal traffic measurements but is usually derived by estimation and prediction processes. Traffic control engineers have been engaged for a long time in the improvement of these estimation methods. It is intuitively understandable that cars, capable of transmitting traffic related messages about their trips, offer new and extraordinary possibilities for the improvement of traffic state estimation both at the junction and at the area level. Further the integration of these with conventional measurements can be expected in a further improvement. In this paper, a possible scheme for the integrated use of data at the junction level will be presented; besides, the results coming out from the proposed Integrated Intersection Observer will be presented and the validation experiments carried out in Turin in June 1989 in the framework of the CAR-GOES project.