This is already much better than average, enough that it's going to take over. No one cares about car accidents in this country enough to stop this, even if it was only slightly better than average. For proof: Tesla.

Self-driving being the dominant form of driving is now a done deal, thanks to Waymo (and probably Tesla, though that's a policy failure imo), it's just a question of how long it takes.

My money is on a decade.