Health cobenefits and transportation-related reductions in greenhouse gas emissions in the San Francisco Bay area

Am J Public Health. 2013 Apr;103(4):703-9. doi: 10.2105/AJPH.2012.300939. Epub 2013 Feb 14.


Objectives: We quantified health benefits of transportation strategies to reduce greenhouse gas emissions (GHGE).

Methods: Statistics on travel patterns and injuries, physical activity, fine particulate matter, and GHGE in the San Francisco Bay Area, California, were input to a model that calculated the health impacts of walking and bicycling short distances usually traveled by car or driving low-emission automobiles. We measured the change in disease burden in disability-adjusted life years (DALYs) based on dose-response relationships and the distributions of physical activity, particulate matter, and traffic injuries.

Results: Increasing median daily walking and bicycling from 4 to 22 minutes reduced the burden of cardiovascular disease and diabetes by 14% (32,466 DALYs), increased the traffic injury burden by 39% (5907 DALYS), and decreased GHGE by 14%. Low-carbon driving reduced GHGE by 33.5% and cardiorespiratory disease burden by less than 1%.

Conclusions: Increased physical activity associated with active transport could generate a large net improvement in population health. Measures would be needed to minimize pedestrian and bicyclist injuries. Together, active transport and low-carbon driving could achieve GHGE reductions sufficient for California to meet legislative mandates.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Accidents, Traffic / statistics & numerical data
  • Air Pollutants / analysis
  • Automobiles
  • Bicycling
  • Cardiovascular Diseases / epidemiology
  • Diabetes Mellitus / epidemiology
  • Female
  • Gases / analysis*
  • Greenhouse Effect*
  • Health Behavior*
  • Humans
  • Male
  • Models, Statistical
  • San Francisco
  • Time Factors
  • Transportation*
  • Walking


  • Air Pollutants
  • Gases