We absolutely do redesign roads when the existing design becomes suboptimal as indicated by an increased number of accidents or driver complaints. And we do som

We absolutely do redesign roads when the existing design becomes suboptimal as indicated by an increased number of accidents or driver complaints. And we do sometimes have lanes specifically for buses / taxis, too. We already do this stuff, and we won't need to rebuild 99% of roads. It's the "less than 1%" that are already tricky for normal humans that might need a rework. Or self-driving cars will just take suboptimal routes, if those roads / intersections aren't the only ways to important destinations.