A lane mark detection system is a driver assistance tool that automatically recognizes the lane mark painted on the road and the lane that he is travelling in. Such a system can warn the driver when has the tendency to move out from the lane, without being aware of it. This kind of system is a part of Advanced Driver Assistance Systems (ADAS), systems that has the goal to improve road safety. In this paper we propose an algorithm that automatically emphasizes the lane marks and recognizes them from digital images, by the use of Hough transform.