Abstract
The paper shows the state of the art of the development of systems capable to reason about the traffic behaviour and evolution in similar terms to an expert traffic operator. This type of system may not be conceived to replace the human operator but to act as intelligent assistants that co-operate in the task of defining and applying traffic control decisions. Such concept of system is that of the Intelligent Traffic Management System (ITMS); a system that embodies a knowledge model of traffic behaviour at a strategic level. As this type of knowledge is built from theoretical frameworks together with common sense criteria for making reasonable assumptions, specific methods and techniques have been developed along the last twenty years.