The words "sustainable" and "transportation" don't really fit together too well here in the U.S. For the most part, the transportation scene in America is dominated by people driving cars everywhere they go, often alone. But that's all starting to shift slightly, with more places emphasizing so-called "alternative" transportation options, like public transportation, bicycling, or simply making use of ones legs and walking. And according to a new study, the places that are making this shift most effectively are doing so because of strong top-down guidance.
Of the 225 metropolitan areas in the U.S. with populations above 100,000, those that show the most progress being made toward the widespread adoption of a multi-modal transportation diet are those located in states where comprehensive transportation planning is mandated. By looking at how transportation patterns changed between 1980 and 2008 in all these areas, Ohio State University researcher Anna McCreery found the most positive change in the places with top-down planning requirements.
McCreery measures what she calls the "transportation ecoefficiency" of each metro based on the various commuting patterns and demographic trends, such as the percentage of commuters driving to work alone, the percentage of residents taking public transit, the percentage walking or riding a bicycle to work and the population density of each area. Those with mandated planning efforts had better transportation ecoefficiencies than those that don't.
This work also found a positive correlation between improved transportation ecoefficiency and higher per-capita income. Richer places tended to have more sustainable transportation patterns.
The major caveat here is that, overall, transportation ecoefficiency is going down. It's only going down slightly less in the metros with stronger top-down planning requirements. Car-oriented land use and mobility patterns over the past few decades continue to dominate transportation in the U.S., and are increasing at a faster rate than the alternatives.
Though McCreery's work suggests that top-down planning efforts can play a big role in developing more sustainable transportation patters in urban areas, there's still a long-standing trend in the U.S. of cities and metropolitan areas being hugely dependent on the personal vehicles to keep things moving. That trend doesn't look to be changing dramatically any time soon.
Image credit: Bret Hartman / Reuters