This sounds stupid, and also, even if it were true then this is something that gets solved the more autonomous cars you get on the road:
* You get more computer driven cars on the road, the roads will become more computer-car friendly. Think of signs or markings on the road that will tell the car where it is, or what kind of hazards are coming up via for example a QR code.
* Once you get more driver-less cars you get inter-car communication. Car up ahead does the full sensor sweeps and pass the results down the train, saving power for all the other cars.
* Once most cars are driverless, you'll get dedicated driverless car lanes which should be made easy to navigate for them
* And when human driven cars are totally extinct I expect cars to be able to navigate roads with something equal to a raspberry pi today.