The results presented in this chapter have been developed within the PROMETHEUS project, a research activity in the frame of the EUREKA initiative. The main goals of PROMETHEUS (PROgraM for a European Traffic with Highest Efficiency and Unprecedented Safety) are the use of the state-of-the-art information and telecommunication technologies to support vehicle drivers, to optimize the effectiveness of the guidance devices and to link road traffic with other transport systems for the benefit of everybody. Among the techniques that can be exploited to reach the project goals, Computer Vision had a wide attention during the project...