If we put a wire in the road or maybe rfid tags every 40 feet, we could easily have self driving cars. However that would mean that everyone would have access to it. The idea of self driving cars now is, a winner take all situation where whichever funded effort that succeeds, generates outsized profits from licensing or going public at a high valuation.
The tags, whatever form they may take, will designate the official lanes. But people in snowy climates don't drive in the official lines because they can't be seen. They drive an emergent set of paths where everyone else drives. It's often, if not most of the time, that these paths human drives take don't follow the actual road markings.