Intelligent vehicles – both automated and autonomous – have gained more and more importance due to the opportunity they offer to reduce congestion and particularly increase safety. As an example, accidents may occur when vehicle trajectories change and potentially cross, like in the case of overtaking manoeuvres. In this paper, the use of GPS and GIS methods are proposed to study and analyze vehicle trajectories. The aim is to retrace vehicle trajectories that can be useful to implement on-board devices guaranteeing both automatic driving and/or driving assistance. Some tests have been realized by using floating cars and the results are very promising.