... when self-driving cars become safer than human-driven cars, the public may outlaw the latter...
This may happen incrementally...
Imagine that left 'carpool' lane of the freeway turned into a 'auto-drive' only lane. 180 speed limit. Auto-drive cars merging effortlessly into and out of the lane. People sleeping, texting, eating, watching movies as they zip by.
After a few years, only the right lane is open for 'human driven' cars. They will be stuck behind whoever the slowest driver in their lane is. Their insurance rates will be crazy high.
You won't even need to outlaw human drivers, any more than you need to outlaw people taking a horse and buggy to commute to work these days.