Density, Sustainability, and Urban Transport

Continuing on the theme of yesterday's post about Melbourne/Australia's growth debate:

Paul Mees, of RMIT has an interesting column in today's paper, in which he calls into question some common assumptions about the relationship between density and public transport, and its implications for sustainability. Mees has applied a more informative density calculation to compare cities, taking into account only "urbanized" land, rather than total land. The result is that a city like Los Angeles turns out to have much higher density than many believe, while New York, which includes the normally forgotten outer Boroughs, has a much lower density than expected. Melbourne comes out somewhere near the middle.

I like Mees' conclusions, which point out that these discussions should maintain a clear focus on what we can actually do to change things in a metropolitan area:

Sustainable transport usage has more to do with transport policy than density, which is excellent news for anyone concerned about the environment. It would take many decades and vast expense to substantially change the density of a city of 4 million people, and we don't have that much time. Climate change and insecure oil supplies are urgent problems, and we need solutions now. Fortunately, transport policies can be changed more quickly and with less disruption than urban form, so we might be able to keep our leafy suburbs and still save the planet.

This echoes what I mentioned yesterday: we cannot necessarily control growth directly. What we can control (and thus, what we should be focusing on in discussions of growth) is the policy context in which growth occurs.