Method and device for determining map data

A vehicle (1) is provided with two video cameras (6) which record the distances (S1,S2) from the road verges (4). These also record other road characteristics e.g. lane bends, roadway characteristics and signs at road verges. The position of the vehicle is determined based on a satellite GPS and this is fed to a map data determining device. The data is then combined with that recorded by the cameras and stored in a local store.