Vox has a piece on the problems of the elderly who must drive up driving. As someone who's more rapidly nearing that time than I'd like, I like it all, especially as I endorsed self-driving cars (see the label) though there's more to the piece than just that.
And here's a Technology Review discussion of such cars.
There is one problem I can see with such cars. Since we know that a human is driving the other car we see on the road, we can assume the car will behave in certain ways. It's likely early on that self-driving cars won't. An example: a cardboard box falls off a truck--from the way it falls and bounces a human will assume it's empty. A self-driving car may have to assume it's full, and to be avoided, possibly by an emergency stop, which the human driving the car behind that car won't anticipate. But such problems aren't show-stoppers.