<div class="htmlview paragraph">We believe today that collision avoidance systems can appreciably reduce the number and seriousness of rear-end collisions.</div> <div class="htmlview paragraph">The mode of operation of a non - cooperative collision avoidance system is shown. Demands on the radar distance measurement system are described, e. g. questions of radar pulse mode, antenna diagram and choice of frequency.</div> <div class="htmlview paragraph">The decisive problem as regards evaluation of the radar echo is the reliable separation of desired and undesired signals. The presented technique uses a time magnification process followed by discrimination according to amplitude, pattern and echo jumps. In addition, there is a radar range limitation which is dependent on speed and steering angle. With experimental vehicles - equipped with the collision avoidance system - over 100 000 km have been covered. The results were very encouraging.</div>