[Obviously, I heard a lot of interesting ideas at TRB, so I’ll try to let them speak for themselves with some brief paper excerpts.]

What would happen if the suburbs walked & biked as much as the cities did? How much healthier would retrofitting suburbia make suburbanites?

For the scenario with the highest levels of physical activity (ATC), I-THIM predicted a 15% reduction in disease burden due to cardiovascular diseases and diabetes and approximately 5% reductions each for breast cancer, colon cancer, dementia, and depression. Risk reduction of this magnitude would rank among the most notable public health achievements in the modern era, and reduce the estimated $34 billion in California annual costs from cardiovascular disease and other chronic conditions such as obesity.

In the most ambitious active transport scenario, this potential harm [from road traffic injuries] is approximately 14% of the benefit from physical activity. [i.e., benefits outweigh harm by 7X]

The other principal finding is that wide scale adoption of active transport could have as large an impact on carbon reduction as strategies based on… reengineering automobiles and fuels.

From the California Department of Public Health, “Health Co-Benefits and Transportation-Related Reductions in Greenhouse Gas Emissions in the Bay Area” by Neil Maizlish with James Woodcock, Sean Co, Bart Ostro, Amir Fanai, and David Fairley.