I think one lane such as a metro lane will be the answer for self driven cars, they can drive fast and wont be able to change lanes but theyll be aware of whats in frt of them and behind them as a system allowance , certain stops or lane openings will be part of that lane structured grid.I really believe its an viable tech of the future with one big problem, these car designers are leaving out one big problem and solution, infrastructure. Their wont be a SDC with out smart lanes to interact with them ,tax payers will be seeing the bigger expense for the future of the techie vehicles to hit the road.I see an inflatable rear bumper being the next techie idea coming from these brainey cars .