Background and Purpose
Active travel has proven health benefits.  Walking and bicycling are effective ways to meet the Surgeon General’s Guidelines for physical activity with significant results for health.  In a study comparing 14 countries, all 50 US states, and 47 of the largest US cities, Pucher et al. (2010) found a strong relationship between active travel, physical activity, and self-reported obesity.  In the San Francisco Bay Area, Maizlich et al. (2013) found that increasing median daily walking and bicycling from 4 to 22 minutes reduced the burden of cardiovascular disease and diabetes by 14%.

The transportation demand management (TDM) programs and strategies used by Arlington County Commuter Services (ACCS) promote active travel through BikeArlington and the region-wide bikesharing program, Capital Bikeshare; WalkArlington which strives to get more people walking more of the time; and services to support use of public transit which is also correlated with increased active transportation (Wasfi et al., 2013; Freeland et al., 2012; Lachapelle, 2011).  However, limited tools are available to help municipalities calculate the return on their investment in TDM, including walking and bicycling programs and strategies.  Such data would be beneficial in discussions about effectively prioritizing limited funding for transportation.

Objectives
This study aimed to assess the return on investment of ACCS programs by monetizing the measurable health outcomes of increased physical activity of residents and employees of Arlington County due to these programs.  The results will support ACCS in translating the well-accepted linkages between active transportation and healthy living into data for effective program planning and policy.

Methods
Two existing tools were applied to the Arlington context to calculate the cost savings of helping 1% of the Arlington County population increase their level of physical activity from 1 minute per week to 150 minutes per week.  The World Health Organization (WHO) Health Economic Assessment Tool (HEAT) calculates the savings from reduced mortality due to increased physical activity, specifically walking and bicycling.  Changes in the amount of walking or cycling in a given population are converted to economic costs savings using mortality rates, the Value of a Statistical Life (VoSL) and the duration of time over which the benefits are realized (WHO, 2013).  The Physical Inactivity Cost Calculator developed by East Carolina University, Department of Health and Promotion (2006), calculates the external benefits of increased physical activity for a population that goes from inactive to 150 minutes a week of moderate exercise (i.e. walking or biking).  Cost savings are estimated in three categories - medical care, workers’ compensation, and lost productivity.

Results
The HEAT demonstrated that if just 1% of physically inactive Arlington adults increase their physical activity to CDC-recommended levels, it could save the country 3.17 deaths per year and result in cost savings of over $7.5 million per year for the first 5 years.  Annual benefits will be even higher for year 6 onwards, once health benefits and update of cycling/walking have reached maximum levels.  The PICC showed that if 1% of physically inactive Arlington adults increase their physical activity to CDC-recommended levels, external cost savings in terms of lost productivity, workers’ compensation and medical care would amount to $12 million per year.  When compared to the FY2013 budget for ACCS of $10.5 million, the savings provide a 200% rate of return on investment for physical activity benefits alone.

Conclusions
TDM programs influence travel behavior with implications for the health and safety of individuals and the community.  Improved public health and safety is not just a laudable community goal but have an economic value which is a great boon for constrained budgets in both transportation and health sectors.  Investments in active transportation have a calculable impact on public health.

Implications for Practice and Policy
In an effort to develop healthier communities, many municipalities are looking for ways to increase the variety of available transportation choices, particularly walking and bicycling.  Calculating the return on investment of active transportation contributes to discussions about prioritizing limited funding for transportation projects by helping identify the full cost and benefit of various modes of transportation.  Tools such as the HEAT and the PICC show how an initial investment in transportation provides significant returns in terms of public health and can help municipalities move active transportation from a novel idea to an established program.

The study also helps identify key factors that can improve the accuracy, consistency, and ease of calculating these cost savings in the future, particularly in using the HEAT and the PICC.   The Arlington County cost savings calculations were based on available data and reasonable estimates.  More accurate data would improve the accuracy of the calculations.  In particular, more accurate data is needed on the number of adults that are influenced by ACCS programs to increase their physical activity, on medical costs and insurance claims, workers compensation claims and payments, and on the mortality rate and the VoSL of Arlington County.

References

1. Pucher, J., R. Buehler, D. R. Bassett, and A. L. Dannenberg. 2010. Walking and Cycling to Health: a Comparative Analysis of City, State, and International data. American Journal of Public Health, Vol. 100, No. 10, 2010, pp. 1986-1992.
2. Maizlish N, Woodcock J, Co S, Ostro B, Fanai A, Fairley D. 2013. Health Cobenefits and Transportation-related Reductions in Greenhouse Gas Emissions in the San Francisco Bay Area. American Journal of Public Health, Vol. 103, No. 4, 2013, pp. 703-709.
3. Wasfi, R., N. A. Ross, and A. M. El-Geneidy. 2013. Achieving recommended daily physical activity through commuting by public transportation: Unpacking individual and contextual influences levels through commuting by public transportation: Unpacking individual and contextual influences. Health and Place, Vol. 23, Sep., 2013, pp. 18-25.
4. Freeland, A. L., S. N. Banerjee, A. L. Dannenberg, and A. M. Wendel. 2012. Walking Associated With Public Transit: Moving Toward Increased Physical Activity in the United States. American Journal of Public Health, Vol. 103, No. 3, 2012, pp. 536-542.
5. Lachapelle, U., B. E. Saelens, J. F. Sallis, T. L. Conway. 2011. Commuting by Public Transit and Physical Activity: Where You Live, Where You Work, and How You Get There. Journal of Physical Activity & Health, Vol. 8, supplement, January, 2011, pp. S72-S82.
6. World Health Organization. 2013. Health economic assessment tool (HEAT) for cycling and walking. www.euro.who.int/en/what-we-do/health-topics/environment-and-health/Transport-and-health/activities/promotion-of-safe-walking-and-cycling-in-urban-areas/quantifying-the-positive-health-effects-of-cycling-and-walking/health-economic-assessment-tool-heat-for-cycling-and-walking. Accessed July 23, 2013
7. East Carolina University. 2006. Quantifying the Cost of Physical Inactivity. Department of Health Education and Promotion, Greenville. www.ecu.edu/picostcalc/. Accessed July 23, 2013.

Support / Funding Source
Arlington County Commuter Services (ACCS) is the Transportation Demand Management (TDM) agency of Arlington County, Virginia. ACCS was established in 1989 in order to enhance Arlington's economic vitality.