Abstract :
In all countries which have to face urban traffic problems, the need of field trials for systems or strategies appears and field trials remain indispensable. The author describes the role of ZELT in answering the needs of field trials. ZELT is an urban test site which was built between 1982 and 1986 by the French Ministry of Transports with the help and cooperation of the City of Toulouse. It includes field equipment shared around 20 intersections and a central control room (PC ZELT) near the city center
