Recently drove in Scotland where built up areas generally have 20mph speed limits. I found It made little difference in overall journey time Felt safer, stopping distance much reduced Easier to join the traffic Similar speed as cyclists Felt safer and more relaxed as a pedestrian, easier to cross the road
Won’t need so many nurseries or schools either. Actually, if you can’t stop, how are you going to refuel? Maybe we won’t need gas stations either.
Trash heaps are going to get big though.