Intelligent transportation systems (ITS) use novel technology relying on computer vision to provide traffic parameters such as average speed in the road, lane changes, vehicles’ accelerations/decelerations, vehicles classification, etc. In this paper a mixture algorithm is proposed for velocity detection. The algorithm is based on object tracking, and relies on a perspective transformation. A novel heuristic is proposed to detect cars and trace them. The algorithm is fast enough to run real-time on a normal laptop which makes it efficient in practice (e.g. to be used by police force). There are still some open issues such as shadow detection and cancellation, and occlusion handling that will be considered in future works