I read a study about Houston recently that actually had another perspective on that. There's not "zoning" laws per se - you can build whatever you want - but there are minimum lot sizes and parking requirements that effectively limit the density of the city to the point where cost effective public transit is impossible. It's not really all that free. I think this was it. [ http://austinzoning.typepad.com/austincontrarian/files/ssrni... ]