[skybrian]

> Get rid of the unused on-street parking spaces and you immediately increase a suburb's density by something like 5%-10%.

As you say, only for new construction. The lack of new construction is itself the problem.

[kettlecorn]

A problem is that most municipalities require excessively wide streets with on street parking for any new developments.

Japan-width streets, despite their increased safety & land-use efficiency, are prohibited most places.