Portland Metro refers to the phrase “active transportation” as sustainable, multimodal transportation solutions that connect people to where they need to go (ODOT). At a local level, infrastructure is incorporated in city design in order to allow people to access what they need easily. Pedestrian focused design encourages people to get out of their cars and be active by walking, biking, and taking public transportation. It increases physical activity, decreases air pollution and gets people moving in and around their communities.
An increase of evidence documents the adverse health impacts of common land use patterns in the U.S., many zoning and subdivision regulations are not doing a very good job of protecting public health, safety, and welfare (Frank et al., 2006). Many cities separate residential areas from other land uses like transit services and retail stores. Putting all of these types of land use together in one area will eliminate the disconnectedness. People that travel in vehicles rather than by walking can produce adverse health effects through a variety of mechanisms. A survey of 10,898 people in Atlanta, Georgia showed that each additional hour spent in a car per day was associated with a 6% increase in the odds of being obese, while each additional kilometer walked per day was associated with a 4.8% decrease in the odds of being obese (Frank et al., 2006). Mixing land use types encourages people to drive less and walk more resulting in healthier communities, less traffic, and a decrease in noise and air pollution. Land use patterns affect travel behavior by altering each mode’s relative costs and convenience levels (Frank et al., 2006).
Nitrogen oxides (NOx) and volatile organic compounds (VOC) are released into the atmosphere from vehicle emissions. These pollutants react with sunlight forming harmful ozone at ground level and trigger a variety of health problems. Ozone reduces lung function causing issues such as chest pain, coughing, throat irritation, and congestion can occur, but ozone will also worsen bronchitis, emphysema, and asthma (EPA 2012). Sensitive vegetation and ecosystems are also impacted by ground level ozone. Certain species are more susceptible to ozone damage than others, many cities and neighborhoods are lined with only a few types of tree species. If there isn’t a variety of vegetation species mixed within a neighborhood, ozone could kill them all at the same time decreasing air quality even more. Mixed land uses, higher density, and greater street connectivity are coupled with significantly lower per capita emissions of NOx and VOC when calculating for income, age, vehicle ownership, and household size (Frank et al., 2006).
The quality of life in areas where there are multiple modes of transportation, mixed land uses, and a pedestrian centered layout is higher than areas that are less walkable (Frank et al., 2006). Cities and towns developed around connectivity house more active people and encourage residents to walk, bike, and to use public transportation to get to where they need to be. If more neighborhoods incorporated mixed land use there would be less necessity to drive, thus reducing environmental damage and public health issues.
Active transportation section. (2013). Retrieved from http://www.oregon.gov/ODOT/TD/AT/Pages/index.aspx
Frank, L. D., Sallis, J. F., Conway, T. L., Chapman, J. E., Saelens, B. E., & Bachman, W. (2006). Many pathways from land use to health: Associations between neighborhood walkability and active transportation, body mass index, and air quality. Journal of the American Planning Association, 72(1), 75-87. Retrieved from http://your.kingcounty.gov/healthscape/meetings/JAPAFrank06-pubversion.pdf
Ground level ozone. (2012, November 01). Retrieved from http://www.epa.gov/glo/