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UW-Madison Trainee Shows That Biking Represents a Four Way Environmental Win


Three years ago, trainees Maggie Grabow, Melissa Whited, and Micah Hahn produced a research report on the economic impact of bicycling in Wisconsin. Our IGERT training program has been institutionalized in a graduate Certificate on Humans and the Global Environment (CHANGE), and the capstone course in CHANGE requires students to work together in interdisciplinary teams on real-world environmental problems. Their report was a capstone project produced at the request of a Wisconsin state legislator. The report the Trainees produced was unique because it did not just look at the direct economic impacts of bicycling, but also analyzed potential health benefits, avoided pollution (from reduced car trips), and other issues to present a much more complete analytical picture of bicycling. Ms. Grabow had participated in this project because of her growing research interest in understanding how bicycling was potentially linked to issues of environment and health.

For five years, Ms. Grabow collaborated with an interdisciplinary team (including IGERT PI Jonathan Patz and co-PI Tracey Holloway) to conduct a more comprehensive research project on the potential impacts of increased bicycling. Trainee Grabow was the lead author on a paper (published in 2012) in Environmental Health Perspectives that quantified the environmental, health, and economic benefit of bicycling short trips in the 11 largest cities in the Upper Midwest during the warmest 6 months of the year. The cities were chosen because they represent densely populated areas where biking is a reasonable transportation choice during warmer times of the year. The paper united state-of-the-science approaches to modeling transportation, emissions, air pollution in the form of fine particulates (PM2.5) and ozone (O3), and the health effects of air pollution and active transport. Using a “what-if” scenario approach, the authors calculated that if all car trips less than 5 miles during these months were replaced by bike trips, the net health benefit from improved air quality alone would be $4.94 billion per year, saving 608 lives. Bicycling half of these short car trips would save $3.8 billion annually from increased physical activity (due to avoided mortality and reduced health care costs). For air quality, the models showed a reduction in annual average urban fine particulate air pollution (PM2.5) by 0.1 µg/m3. This is a small change in tiny particles, but the health and economic benefit is great because it occurs right where people are living. The authors found slight increase in summer average ozone (O3) (a major component of smog) in cities with a decrease in ozone regionally. Total combined benefit from both improved air quality and increased physical activity in the region is estimated at about $8.7 billion with mortality declining by 1,295 deaths per year.

As a result of this study, Ms. Grabow was asked to speak at conferences of urban planners, cycling advocates, and public health officials. As she noted in the paper and in various talks on the subject, the paper is not trying to promote a huge paradigm shift. The study does not suggest people get rid of their cars, instead it suggests that significant environmental, economic, and health benefits can come from relatively minor changes in transportation behavior. The paper shows this would represent a four-way win – swapping bikes for cars, we gain in fitness, local air quality, a reduction in greenhouse gases that affect global climate, and the personal economic and quality of life benefits of biking when it’s easier and faster than driving. Thus, bicycling can be promoted as a cost-effective investment with tremendous, multiple returns.

The research was presented to many different audiences – the public health community, the environmental science community, the bicycle advocacy community, and more. It was picked up by national media, advocacy groups, and even foreign press (the links below are representative, NOT comprehensive). It was well received as a “common sense” solution to societal problems of obesity, poor air quality, weakening economy, and increasing carbon emissions.

The research has already had an impact on national transportation and environmental discussions. It was presented to hundreds of people who attended the National Bike Summit in Washington DC, and attendees used it as evidence that bicycling has multiple benefits and deserves legislative support. Attendees went on to lobby with their federal legislators, supporting funding for bicycle and pedestrian infrastructure. While the research was designed to answer technical questions about the potential impacts of replacing some car trips with bicycling in a particular region, its implications have resonated with a diverse public. This is exactly what one would hope for from interdisciplinary, public scholarship.

Original Paper: Grabow ML, Spak SN, Holloway T, Stone B, Mednick AC, Patz JA. Air quality and exercise-related health benefits from reduced car travel in the midwestern United States. Environ Health Perspect. 2012 Jan;120(1): 68-76

Representative articles/news about the paper:

Address Goals

This activity meets the “Discovery” strategic goal by expanding the frontiers of knowledge in an area that has the potential to directly affect public health and welfare. The Trainee’s research is among the first to quantify the potential environmental, health, and economic benefits of bicycling behavior changes across a broad region of the US using state-of-the-science modeling. The use of linked models to examine the effects of bicycling transportation choices is unique.

This activity meets the “Learning” strategic goal because Ms. Grabow and the authors publicized the research broadly, which gave citizens, advocates, public officials, and other researchers important new analytical tools with which to understand the effects of bicycling.