Abstract
The authors present a measurement tool consisting of a video camera, a video interface and a minicomputer. Using this system pictures of traffic flows are converted into traffic behaviour parameters like car speed and following time. The interface is used to separate cars and road surface and is also capable of determining the car's position in the video frame. The car's position on the road is then calculated by the computer knowing the position in the video frame. A series of successive car positions yield the car's speed. Some results, gathered with this system, are added.