>>1488740Nathan Lewis has a post on exactly this problem, if you can tolerate his idiosyncratic terminology:
https://newworldeconomics.com/arterial-hacks/Basically on a wide urban street that isn't crucial to traffic, you build in the middle of it and leave two shared-space streets on the sides, transforming the street from a massive suburban arterial to a cozy dense Japanese-style side neighborhood.
Americans would never allow it, but it's fun to think about.
