In a traffic emergency, an autonomous or semi-autonomous vehicle does not care about its absolute location; it only needs to know is the relative location, such as distance and bearing, of the other vehicle. Navigation satellite signals provide no help because they only relate to one receiver's absolute location. To resolve this, one of the vehicles (or a roadside access point), can precisely determine the relative locations of the two vehicles by instructing them to acquire the same satellite signals at the same time, and then differentially analyzing those signals to determine the relative locations of the vehicles relative to each other. The vehicle can then execute a maneuver, using that precision relative location information, to solve the emergency and save lives. Optionally, the differential analysis can be done by an artificial intelligence model, provided in one of the vehicles or in a roadside access point.