There is. Mostly 460 and 900 MHz packet modems that only speak UDP. It's for telemetry data and data between trucks. As of 2000, there were working prototype

There is. Mostly 460 and 900 MHz packet modems that only speak UDP. It's for telemetry data and data between trucks. As of 2000, there were working prototypes of both an anti-collision system and fully autonomous driving / grading.