They already are. You have cars that will brake themselves, keep themselves in the lane, even adaptively match speed of the car in front. Everything is there for self driving except one thing, real computer readable markers in the roadways. Until we force all states at gunpoint to embed in the pavement what is needed we will be stuck with trying to make human markings readable by a computer, and then force all car makers, again at gunpoint, to all use a common standard. Yes this does work and you benefit from it. ODB-II was a forced requirement on all car makers, and it improved things for everyone by forcing car makers to stop being assholes.
Embedding magnetics in the roadway is cheap and easy. road side transponders delivering data is cheap and easy. Problem is as a society it is not important, Killing other people in other countries is far more important. until the united states stops being a war mongering country led by war hungry leaders we will have very slow progress.