This paper presents a vision technique for platoon driving of a fleet of homogeneous electric cars. These cars, under supervision from a central computer, will form a novel public transportation system now under development in France. In the first version of the system, the public cars are driven by their users but their operation will be automated in some instances when no-one is on board. For later versions, fully automated driving (with passengers) is considered on dedicated tracks and on low-traffic road networks at slower speed. The paper will focus on the vision and control techniques now developped for the first version. We wish to be able to drive a „train” of empty public cars with only one driver (in the front car). This fonction is needed to pick up cars which have been abandonned in various locations and to redistribute them to appropriate locations. Trains can be up to six cars long and the distance between cars will vary between 0 and 5 meters depending on the speed.