We already have the DLR in London, which is basically a driverless train system. And yes I know that those are programmed to only do certain routes and they know where other trains on the lines are, but if all cars were driverless then they could all be communicating with one another to prevent accidents and there's only so many places that you can go anyway - once you get obscure, like to a specific house or a specific village, there's likely to be so few people around that's accidents are less likely anyway.