You know what I look forward to? Self driving cars on icy roads.... I don't think you can program a computer for that. Especially if it's patchy ice.
Too much of the self-driving stuff relies on reacting to other vehicles around you. But at 2am on a country road, your cars computer doesn't get to see another car hit that patch of ice first. It might assume the speed limit is just fine, when reality is you should be driving a lot slower.