The optimal utilisation of the available infrastructure is an efficient and feasible way to combat the notoriously increasing traffic congestion in urban highway networks. The rapid evolution of information technologies as well as methodological advances in Automatic Control and Optimisation theories provide a solid background to this end. In the past, traffic control systems within traffic networks have been developed independently for each control measure in an attempt to locally optimise traffic flow. However, because a traffic network comprises a synectic entity with regard to the operational objectives, the user needs, and the impact of the application of several control measures, the traffic problems should be confronted through integrated rather than isolated control actions. This is due to the fact that an isolated control action may have major impacts on the surrounding traffic network. Past simulation investigations of corridor networks within the European DRIVE II project EUROCOR (EUROpean urban CORridor control) showed that a significant amelioration of traffic conditions may be achieved as a result of an appropriate integration of several control measures such as ramp metering, route diversion via variable message signs, and signal control. Based on these positive initial results, the research continued within the European DRIVE III project TABASCO (Telematics Applications in BAvaria, SCotland and Others), and an integrated traffic responsive urban corridor network control strategy called IN-TUC (INtegrated - Traffic responsive Urban Control) was developed, and field-implemented.

The aim of IN-TUC strategy is to provide, at suitably defined constant control intervals, traffic-responsive settings for the various control elements included in a corridor network area. The control decisions are based on all real-time measurement data collected from detectors that are located within the controlled area. IN-TUC is built upon well-known methods of the Automatic Control and Optimisation theories. This allowed for the development of a strategy robust with respect to measurement inaccuracies so as to be able, even in cases of insufficient data, to react correctly to the current traffic conditions, and simple so as to permit the execution of all required calculations in real time. Moreover, IN-TUC has been developed in a generic way so that it may be transferred with minor modifications to networks with arbitrary topology and characteristics.

For more information on the IN-TUC strategy you may see the following:

1. Diakaki, C., M. Papageorgiou, and partners of the Transport Telematics Project TABASCO (TR1054). Urban Integrated Traffic Control Implementation Strategies. Report for Transport Telematics Office, Brussels, Belgium, September 1997.
2. Diakaki, C., and M. Papageorgiou (1998). IN-TUC: A new integrated traffic-responsive urban corridor control. INTELLIMOTION, Vol. 7, No. 1, p. 2.
3. Diakaki, C., M. Papageorgiou, and T. McLean (1998). Applying integrated corridor control in Glasgow. Proceedings of the ASCE 5^th International Conference on Applications of Advanced Technologies in Transportation Engineering, Newport Beach, California, U.S.A., 9-16.
4. Διακάκη Χ. και Μ. Παπαγεωργίου (1998). Ολοκληρωμένα συστήματα οδικού κυκλοφοριακού ελέγχου: Μια νέα προσέγγιση. Πρακτικά 12ου Εθνικού Συνεδρίου της ΕΕΕΕ, Σάμος, υπό έκδοση.
5. Diakaki, C., M. Papageorgiou, and T. McLean (1998). Integrated traffic-responsive urban control strategy IN-TUC: Application and evaluation in Glasgow. Proceedings of the DACCORD Project Control Workshop, Lancaster, U.K., to appear.
6. Diakaki, C., M. Papageorgiou, and T. McLean (1999). Application and evaluation of the integrated traffic-responsive urban corridor control strategy IN-TUC in Glasgow. Proceedings of the TRB 78^th Annual Meeting, Washington D.C., U.S.A., to appear.