In cities you'd have instead of roads for cars, to cover each individual need, rolling sidewalks, going all different directions. Which means a lot of interconnected stuff to cover everything. If I want to go to my friend who is 3 blocks to the right and then a U turn and 5 more blocks to the left currently I take a car and I am there in 5 minutes. But if this society where individual cars don't exists but something else covers that highly customized needs for each individual - how you'd envision said technology? I would envision sidewalks on different levels, interconnected with elevators, and all of them on winches and trolleys and whatnot. Hence a lot more expensive technology to deploy/maintain. Or are we talking Sci-Fi and some alien technology became available to us?