The Walkability Challenge: Measuring the Impact of Health and Environment
Do people who live in more densely populated areas get more physical activity than those who live in sprawling neighborhoods? Is walkability a solution to a number of health problems, both physical and mental? How do you measure the benefits? These relationships are extremely complex, said Dr. Ann Forsyth, professor of urban planning and director of the Masters in Urban Planning program at Harvard University. She shared findings from her extensive research on making large scale communities more sustainable and healthy at a recent Straight from the Source event at Volpe, The National Transportation Systems Center.
"Walkability, even though everybody knows it when they see it…is a very murky concept," said Forsyth. It has many meanings relating to economics, cultural values, and physical capacities. Forsyth's research is focused on behavior and environment. "There has been tremendous hopefulness that walkability is going to be a solution to a number of health problems—obesity, physical activity, mental health, and so on,'" she said. She also cautioned that walking was just one component of overall health.
Forsyth said it's important to decide on what is being measured—the behavior of walking or overall physical activity, walkable environments, or perceptions and preferences. She added that rarely are direct health-related outcomes, such as obesity, measured.
Forsyth gave examples of "how complex the relations are between environment and health."
- In one 2003 U.S. study measuring health effects of sprawl in different counties, researchers found obesity levels were higher in lower density or "sprawling" areas even though exercise levels were the same.
- In contrast, a 2010 study found obesity levels were higher for youths in higher density areas of China.
- Forsyth's 2004 Twin City study showed how results can also vary between leisure walking and travel walking for low and high density areas. Low density areas had a higher rate of leisure walking and a lower rate of travel walking, whereas high density areas had just the opposite—a lower rate of leisure walking and a higher rate of travel walking.
"The very local environment matters a lot when measuring active transportation," said Forsyth, based on her recent 2009 study in Colorado. There are many national data collection efforts, but only a few have useful local level data. These include Walk Score and Google bike/walk maps. "The easiest-to-measure items may have the fewest health links so we have a dilemma in trying to measure health and environment," said Forsyth.
To learn more, view the video highlights from Ann Forsyth's talk.