Really it doesn't matter who owns the roads, it's about obstacles and unpredictable situations. While cities may have many oddities with situations that don't quite fit design standards, the paths between Universal properties are pretty straight forward and can be programed into the algorithms. In the time it would take to design, approve, and build an additional network of private roads with overpasses driver-less vehicles will become much more mainstream. And that stays closer to the price and limitations of other tracked options anyway. We have driver-less vehicles on the road today, they've just been scaled back to be extra timid and cautious in situations where the risks are not quite understood yet. That is the big jump from driver-assisted to full-auto, now it's just collecting data and fine tuning.