[1337p337]

I've wondered about this while tossing around the idea with an old boss. LA is notorious for being a difficult place to build or expand a freeway, and the congestion problems are getting worse.

It seems you have to get them pretty high before you can travel very efficiently, so they don't work for going across cities. That's not even worrying about the local airports' airspace and the numerous tiny municipal airports. I don't know that these are intractable problems, though.