Sensors in autonomous vehicles have to be extremely reliable, since in the future motorists will no longer constantly monitor traffic while underway. In the past these sensors were subjected to arduous road tests. The new ATRIUM testing device from Fraunhofer Institute for High Frequency Physics and Radar Techniques FHR now makes it possible to move a large portion of these road tests to the laboratory. ATRIUM puts on a show for the vehicle’s radar sensor, generating artificial scenery that comes very close to the actual conditions encountered in street traffic.