Urban density, public transport and the environment
Posted Nov 23 2009 10:00pm
Some sane words from Paul Mees; a senior lecturer in transport planning at RMIT. His book Transport for Suburbia: Beyond the Automobile Age will be released in December.
So it is possible to compare population densities and use of ‘’sustainable” transport (public transport, walking and cycling) across the three countries’ urban areas. Nobody has done this before, because the data did not become fully available until last year, but it can now be assembled. I have done this, using the most recent census (2006 for us and Canada; 2000 for the US).
The results are not what might have been expected. Far from being the paradigm of sprawl, Los Angeles is actually the most densely populated urban area of all. High-rise centres are not much of a guide to overall urban densities. The 8 million residents of New York City live at high densities, but the 13 million residents of the surrounding suburbs live in more spacious surroundings than their counterparts in Los Angeles, producing a lower overall figure.
The real reason Los Angeles is such an environmental disaster is not low density, but high density – combined with a huge population that depends on cars. This concentrates traffic and pollution, maximising the environmental impacts.
Melbourne, with nearly 16 people per hectare (not five), is a medium-density city, closer to the top of the table than the bottom. We are denser than Chicago, Boston and Portland, the American poster-city for ‘’smart growth”.
But relatively high densities have little to do with the use of sustainable transport. The best performer is the Canadian capital, Ottawa, which is much less dense than Los Angeles and about the same as Melbourne. Brisbane has barely half Melbourne’s density and a third that of Los Angeles, but use of sustainable transport is similar to Melbourne and more than twice the level in LA.
Sustainable transport use 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.