Abstract
The most important parameter in transport planning and analysis is the distance. In order to get a better description of the reality it is often measured as time or cost. However there are many other factors which are relevant in the user's decision process, especially in metropolitan areas. The car driver selects his "optimum way" taking into account other variables: traffic flow, traffic congestion, road surface conditions, etc. In this paper a new distance is proposed - the user's operational distance - which tries to describe the user's decision process more accurately. This method has been verified by selecting the optimum way in trips through the Metropolitan Area of Madrid. (A)