Planning decisions often have significant indirect effects. As planners, our challenge is to clearly describe these impacts and quantify them as much as possible so they can be incorporated into decision making. An example of this is the effect that transportation planning decisions have on human health. These impacts are significant but often overlooked or undervalued in the planning process. I have worked on several research projects that explore the nexus between transport planning decisions and public health, and are developing practical tools for incorporating them into planning. Let me share some of my current thinking about this issue.
My report, Evaluating Public Transportation Health Benefits was recently published by the American Public Transportation Association. It summarizes research indicating that people who live in areas with high quality public transit tend to have much lower traffic accident fatality rates, produce less air pollution, exercise more, and, if they don't drive, have better access to healthcare services and healthy food.
Several other recent studies give further evidence of the effects that common planning decisions can have on public health. For example, MacDonald, et al. (2010) found that construction of a light-rail system (LRT) resulted in increased physical activity (walking) and subsequent weight loss by area residents. Boarnet, Greenwald and McMillan developed a framework for valuing the health benefits of urban design improvements that increase walking activity, and concluded that simple design changes such as increased street connectivity and more compact and mixed development can provide hundreds or thousands of dollars in health beneifts per capita. de Hartog, et al (2010) show that the health benefits of cycling significantly outweigh users incremental traffic crash risks. Kahlmeier, et al. (2010) describe existing methods for evaluating the health benefits of increased walking and cycling, and recommend development of better tools for doing this.
This is good news overall because it indicates that modest changes to planning practices can provide large public health benefits, and many of these changes are justified for other reasons: they help reduce road and parking facility costs, better respond to changing consumer demands, and provide environmental benefits.
Conventional transport policy and project evaluation does consider traffic accident risks and air pollution impacts, but generally ignores physical activity impacts, which tends to exaggerate the benefits of roadway expansion, and undervalues improvements to alternative modes and smart growth land use policies.
The basic target, recommended by the U.S. Center for Disease Control and other major health organizations, is that adults should engage in at least 150 minutes a week (about 22 minutes a day) of moderate physical activity such as brisk walking or moderate-paced cycling, and children should engage in about twice this amount. Currently, about half of North Americans fail to meet these targets, which helps explain high rates of obesity and diseases such as heart attacks, strokes, diabetes and cancer.
When people hear about this issue they often assume the solution is to promote sports and gym exercise, that is, to treat physical fitness as a commodity, a special product that consumers must purchase. But that approach generally fails the people who need it most, those who are sedentary and overweight, because they often lack the money, time and motivation needed to participate. In fact, few people can maintain a rigorous exercise program over the long-run: health clubs generally sell about five memberships for each person that they can really accommodate because most people drop out after a few months.
A better approach is to integrate physical fitness into daily life by increasing the amount of walking and cycling that occurs for normal transportation and neighborhood recreation. Research indicates that people who live and work in communities designed for nonmotorized transport do walk and cycle much more than residents of automobile-dependent communities. This requires:
What does this mean for planners? It is not our role to force people to increase their walking and cycling activity for health sake. Rather, our role is to help decision-makers and the general public understand the full impacts of their decisions, including indirect impacts such as long-term public fitness and health effects. They can then make informed decisions when designing communities and transport facilities, creating transport policies, or chosing where to live.
Transportation agencies often use standard methodologies for evaluating accident reduction benefits by assigning a dollar value to reduced crash injuries and deaths. These tools can be expanded to also calculate the value to society of planning decisions that increase public fitness and health, and therefore reduce morbidity and mortality. The results turn out to be significant. For example, a New Zealand study estimates the health benefit value of an additional mile of walking at $0.48, and an additional mile of cycling at $0.19. This can justify large investments in walking and cycling facilities, and possibly other community design changes to support more walking and cycling activity. A recent study by Guo and Gandavarapu concluded that the provision of sidewalks in residential neighborhoods is justified based on health and air pollution reduction benefits. Improved walkability also tends to increase local property values, suggesting that many people recognize these benefits, an effect that will probably increase in the future as more people understand the health benefits of living in a walkable community.
The challenge for planners it to clearly communicate these impacts. For example, we can point out that expanding an arban arterial from four to six lanes may improve motor vehicle traffic conditions, but will degrade walking and cycling conditions which has negative health consequences, providing additional support for alternative congestion reduction strategies. We can quantify the health benefits that result from improving walking and cycling conditions, traffic speed control programs, transportation demand management strategies, and smart growth land use policies. Similarly, we can point out that among the many benefits of improving public transit service is that, by stimulating more walking and cycling activity, this helps improve public fitness and health. We can work with public health officials so they understand the many ways that transport and land use policy and planning reforms can help achieve their goals.
For More Information
J. Ball, M. Ward, L. Thornley and R. Quigley (2009), Applying Health Impact Assessment To Land Transport Planning, Research Report 375, New Zealand Transport Agency (www.ltsa.govt.nz); at www.ltsa.govt.nz/research/reports/375.pdf.
Judith Bell and Larry Cohen (2009), The Transportation Prescription: Bold New Ideas for Healthy, Equitable Transportation Reform in America, PolicyLink and the Prevention Institute Convergence Partnership (www.convergencepartnership.org/transportationhealthandequity).
Marlon G. Boarnet, Michael Greenwald and Tracy E. McMillan (2008), "Walking, Urban Design, and Health: Toward a Cost-Benefit Analysis Framework," Journal of Planning Education and Research, Vol. 27, No. 3, pp. 341-358; at http://jpe.sagepub.com/cgi/content/abstract/27/3/341.
CDC (2010), CDC Transportation Recommendations, Center for Disease Control and Prevention (www.cdc.gov/transportation/default.htm).
Jeroen Johan de Hartog, Hanna Boogaard, Hans Nijland and Gerard Hoek (2010), "Do The Health Benefits Of Cycling Outweigh The Risks?" Environmental Health Perspectives, doi:10.1289/ehp.0901747, (http://ehp03.niehs.nih.gov/article/info%3Adoi%2F10.1289%2Fehp.0901747).
Jessica Y. Guo and Sasanka Gandavarapu (2010), "An Economic Evaluation Of Health-Promotive Built Environment Changes," Preventive Medicine, Vol. 50, Supplement 1, January 2010, pp. S44-S49; at www.activelivingresearch.org/resourcesearch/journalspecialissues.
Sonja Kahlmeier, Francesca Racioppi, Nick Cavill, Harry Rutter, and Pekka Oja (2010), "‘Health in All Policies' in Practice: Guidance and Tools to Quantifying the Health Effects of Cycling and Walking," Journal of Physical Activity and Health, Vol. 7, Supplement 1, pp. S120-S125; at www.euro.who.int/document/E93592.pdf.
Lawrence D. Frank, et al. (2010), "Carbonless Footprints: Promoting Health and Climate Stabilization Through Active Transportation," Preventive Medicine, Vol. 50, Supplement 1, pp. S99-S105; at www.activelivingresearch.org/resourcesearch/journalspecialissues.
Todd Litman (2010), Evaluating Public Transportation Health Benefits, American Public Transportation Association (www.apta.com); at www.apta.com/mediacenter/pressreleases/2010/Pages/100811_Public%20Health%20Benefits.aspx.
John M. MacDonald, Robert J. Stokes, Deborah A. Cohen, Aaron Kofner and Greg K. Ridgeway (2010), "The Effect of Light Rail Transit on Body Mass Index and Physical Activity," American Journal of Preventive Medicine, Vol. 39, No. 2, pp. 105-112; at www.ajpm-online.net/article/S0749-3797(10)00297-7/abstract.
NYC (2010), Active Design Guidelines: Promoting Physical Activity and Health Through Design, New York City Department of Design + Construction (http://ddcftp.nyc.gov); at http://ddcftp.nyc.gov/adg/downloads/adguidelines.pdf.
James Woodcock, Oscar H Franco, Nicola Orsini and Ian Roberts (2010), "Non-Vigorous Physical Activity And All-Cause Mortality: Systematic Review And Meta-Analysis Of Cohort Studies," International Journal of Epidemiology, doi:10.1093/ije/dyq104 (http://ije.oxfordjournals.org/cgi/content/abstract/dyq104).