Give it enough time and manual driving will be outlawed.
Thing is, every specific thing that computers are designed to do, they do a LOT better than human beings. Humans DO beat them at being diverse in our capabilities, but when a single thing needs to be done, like calculating the day’s interest on a few thousand interest bearing accounts, or adjusting the color and lighting in every pixel in a photograph, computers do things that would be either extremely tedious or so difficult for humans as to be rendered impossible. HDR in photo processing is a good example.
And it will spill over into autonomous cars. A road designed specifically for these vehicles would not need traffic lights. Cars would zip through intersections making constant close calls with other autonomous cars in the same way that every time you take a step the toe of your shoe barely misses the ground as you bring your leg forward.
With autonomous cars, roads could handle substantially more traffic at significantly higher speeds. However, the coordination of events would be so orchestrated as to be impossible to navigate with a manually controlled vehicle. A human being controlled car simply could not be a part of such a system.
And, of course, eventually, no roads would allow human controlled vehicles. The good news is that by the time it happens, nobody would want to. Lamenting about the disappearance of the human controlled automobile will be like lamenting over the disappearance of the horse and buggy as a primary means of transportation. I don’t lament over the latter and my grandchildren will not lament over the former.
Nothing lasts forever.