Automatic Guidance of vehicles on a lane and automatic headway control would greatly relieve the driver from his strains. The topic of this paper is the first problem only. In order to keep a vehicle on the lane there has to exist a system on the road, which is taken as a means of orientation. As a low-coast means for this purpose a row of permanent magnetic steel nails is suggested to be fixed on the centre line of the lane, the magnetic field of which is perceived by two sensors. One sensor should be positioned at the right and one at the left of the vehicle bottom, so the relation of the fields metered by both sensors is a measure of the deviation from the central line, as long as the row of nails is located between the two sensors.