In that case it would also need to tell the difference between a cop and someone impersonating a cop, or it's going to be really easy to mess with self-driving cars.
That is literally the sales pitch. They're supposed to be better at driving than humans. And that actually means all of it, not just lane-keeping on well marked brightly lit highways.
Why? Couldn't it be "better at driving than humans" by reducing the most common errors (lapses in attention), while performing about the same as humans in less common situations (cop impersonators)?
The whole "sales pitch" is that it doesn't take any human effort to do.
They're supposed to be cheaper. Being as good is the limiting factor. Being cheaper is the pitch.
Whether we want it to be or not, vision AI at the moment is somewhat an idiot-savant when it comes to interacting with the real world.
A RFID tag would do. If you prefer going dystopia, a chip implant.
And I mean given RFID is only detectable from inches to feet range, what's the point? And isn't under skin chip just RFID under the skin?
Transportation is literally the 2nd greatest household expense [1], and the cost is dominated by labor. I'm not sure how you could conclude that the potential for massive savings is a "toy".