A great deal of effort and attention has gone into a mobile data technology that you may not be aware of. This is "Vehicle to Vehicle" (V2V) communication designed so that cars can send data to other cars. There is special spectrum allocated at 5.9ghz, and a protocol named DSRC, derived from wifi, exists for communications from car-to-car and also between cars and roadside transmitters in the infrastructure, known as V2I.

This effort has been going on for some time, but those involved have had trouble finding a compelling application which users would pay for. Unable to find one, advocates hope that various national governments will mandate V2V radios in cars in the coming years for safety reasons. In December 2016, the U.S. Dept. of Transportation proposed just such a mandate. [....] "Connected Autonomous Vehicles -- Pick 2."