The connection between transportation reform — an emphasis on land use that makes biking and walking as viable as auto travel for routine trips — and health reform is one that’s not often made, despite the best efforts of the Obama administration.
But a team of researchers led by Lawrence Frank of the University of British Columbia took a particularly novel approach to the relationship between transport and health for a study recently published in the journal Preventive Medicine. For their observations, the group eschewed Chicago, New York, Portland, or other highly walkable cities in favor of sprawl-heavy Atlanta.
Frank, Steve Winkelman of D.C.’s Center for Clean Air Policy, and
Michael Greenwald of the Seattle-based firm Urban Design 4 Health used data from Atlanta’s SMARTRAQ survey to map the amount of calories burned by various blends of walking, transit, and car use. That calorie-burning factor was dubbed the "energy index."
The "energy index" of Atlantans increased significantly as their neighborhoods grew denser, according to the study, and the number of calories they used on motorized travel shrank in denser, more walkable areas.
But interestingly enough, the study’s density factor only examined residential properties — and in neighborhoods where mixed-use development grew, bringing housing closer to commercial property, the energy used for driving and walking decreased, leaving Atlantans’ "energy index" unaffected.
"This result likely demonstrates that the energy required to travel in a very mixed land use pattern is lower for both walking and driving — with no real impact on the relationship between the two modes," the study’s authors wrote.
The authors also noted the significance of a documented link between dense residential development and public health in a city known more for its grinding traffic jams and struggling transit:
The Atlanta region is relatively skewed in terms of walkability, with a low proportion of survey participants actually walking and limited variation in urban form. While this presented some difficulty, the large sample size and oversampling of residents of walkable neighborhoods allowed for reasonable estimates of association. The fact that these results emerged in the auto-oriented Atlanta region is an indication that relationships are robust; associations are expected to be stronger in regions with higher overall variations in walkability and/or transit access.