Houston, sprawl, and densityAs a followup to my earlier post on sprawl, I came across this interesting report that shows Houston had one of the highest density increases among cities in the 1990s (chart p.3) - the highest among what they called "unconstrained" cities - meaning we had no natural geographic or regulatory constraints to sprawl. Our density actually increased at the same rate as Portland or San Francisco: 8% (to 3,856 people/sq.mile in our case). Much more density increase than my earlier example city, DC (2%), which did not build many roads and invested heavily in transit. And if you're thinking it's all about immigration: San Antonio proportionally gets as much or more immigration as Houston, yet actually lost density.
Again, I would argue that because we invested heavily in freeways, jobs stayed in the core, which made the core more attractive and led to more dense development. If you look at the bottom of their list, a lot of those cities have lost most of their jobs to their surburban and exurban periphery, so there's no incentive for development in the core, leading to density loses in those cities - even big transit-investing cities like Boston, Chicago, and Philly.