The interesting part is that most of the parking lots are owned by groups of moderately wealthy folks (doctors, mid-level corporate execs) who had bought super cheap in the 70's. The income they are able to make risk-free is a huge obstacle to redevelopment.

As an example, there's lot next to my old office that gets about 250 cars into a half-block lot. At six dollars/car/weekday plus extra money on weekends that's about $400k/year before taxes split among a dozen investors. (An incredible yearly return when you consider they probably paid less than $250k to buy a run-down building and level it back in the 70's.)

If somebody wants to buy that lot to build apartments, they're going to have two hurdles.

First, all of these guys are probably retired, so they're looking for risk-free income rather than capital. With interest rates below 3%, they're going to ask for $12 - 15 million so they can invest it in bonds and still get the same income. That's a ton of money just to buy land.

Second, most of these partnership agreements are drafted such that every partner has to agree to sell rather than a majority. If one guy holds out for $20 million, it could scuttle the deal.

Slowly but surely the parking lots are being replaced, but it's happening much more slowly than it should.