Autonomous vehicles, and user-driven vehicles with an emergency intervention capability, can communicate to avoid collisions using 5G/6G technology, but this level of cooperation is possible only if the threatened vehicles have already determined the relative location and wireless address of the other vehicle. Disclosed is a method for wireless vehicles in traffic to exchange distance and angular information of the other vehicles in view, from which a position map can be prepared indicating the relative locations of each participating and non-participating vehicle. In addition, the traffic map can be annotated with the wireless addresses of the participating vehicles, thereby enabling them to communicate instantly in an emergency. The traffic map may be prepared or updated by one of the vehicles in traffic, or by a roadside access point. Satellite data is not necessary for the relative localization, but may be included if available.