The only car that will be paying attention to what your car is saying is the the nearby cop car. That’s what this is all about.
New roadways probably have subsurface conduit installed, just waiting for the hardware details to be finalized. Cars will be dumping data at every milepost marker, at least. State or Federal DOT will route police or other emergency services to your location, based on what the car "says".
Bingo! One of the things your car will be saying is “I’m going 70 in a 55 zone.” To which the Gestapo-mobile on the overpass will reply “Decelerate, move to the shoulder, and await my ticket. Or simply press 1 to plead guilty.”
My first thought as well. Would anyone like to take bets against them having the ability to 'squawk' on command, to transmit the last few hours worth of driving information in a compressed stream?
This entire concept is really, really, really bad.