Why community design is important to public health
Most people probably don't think too much about health issues when they decide on a place to live. Many assume that exercise, diet, and habits such as smoking depend more on personal initiative and less on choice of neighborhood. To a degree, they are right. If you are determined to live a healthy lifestyle, you can do it anywhere. The reverse is also true.
Yet what is true for an individual is not necessarily true for a community. Aspects of the built environment make it easier or harder to maintain health. An environment where one can more easily get around on foot or on a bicycle will help a family to be less sedentary. That daily trip, on foot, to the park, elementary school, or store may seem unimportant. Yet it may make the difference, in the long run, as to whether a family member becomes overweight, which in turn contributes to myriad health problems.
The same is true for automobile travel. Many Americans like the freedom and convenience of being able to hop in a car. If you drive safely and are lucky, car travel may never harm your health. But we drive more than any other nation — and this transportation choice is the largest cause of deaths for children and young adults and results in at least 2.3 million injuries annually. Studies have shown (here and here) that the physical design of the community has a big impact on automobile fatalities. Each death is associated with 60 or more injuries.
The effect on the community — rather than the individual — is the premise behind active living and healthy community initiatives. We spend more on health care than any other nation — $2.7 trillion a year — and yet we have among the highest obesity rates in the world, leading to many chronic diseases. If people lived in places where there is easy access, on foot, to public places where outdoor exercise is available, the reasoning is that more people will get regular exercise. These places are known as "car optional." You can drive if you want to, but you don't have to.
Health effects related to "car-optional" — and the opposite, "drive-only" — communities are hard to prove. To put it crudely: Does sprawl make some people fat, or do more fat people choose sprawl? A recent report by MIT architects, The State of Health + Urbanism, made much of the lack of causative proof. "The direct, causal relationships between aspects of the built environment and the level of physical activity of city residents have not been proven," the authors say. Correlation is not causation, but the correlation is strong and it aligns with common sense.
Below is a graph that shows walking/biking/transit rates in various countries and rates of obesity. There's no other reasonable explanation that walking and biking makes a difference (transit use is associated with walkable places). The walking/biking/transit rates are strongly correlated with built environments in these countries that promote or hinder this behavior. The US has the most sprawl, and the lowest walk/bike/transit rates. This graph does not prove anything. Yet it is persuasive.
Source: John Pucher, Rutgers
Many studies have been done within the US with similar results. For example, a six-year analysis of 100,000 Massachusetts residents found that the lowest body mass index averages were located in Boston and its inner-ring suburbs, while the highest could be found in the 'car-dependent' outer ring surrounding Interstate 495. (Jeff Speck, Walkable City).
The strongest motivators for building walkable, mixed-use communities are economic and personal. Market demand to live in cities and compact, mixed-use places is strong, and will likely remain strong for decades. The vibrant mix of cities and towns and the way they are put together — with walkable streets and human-scale public spaces — create value.
On a final note, the MIT report praises efforts in the early part of the 20th Century to build parks in cities and towns to improve health. These projects were not based on studies that proved, beyond a doubt, that parks would improve health. They were based on sound judgement, and aren't we all glad that our ancestors made these investments?
Claims related to community design and health should be modest. Yet with a health industry that consumes more than 17 percent of the US economy, even a modest improvement can make a significant impact. If active communities, which fulfill a market demand and also help make a community more appealing, can reduce health care costs and problems even a tiny bit, the effort will be worth it.
Robert Steuteville is editor of Better! Cities & Towns.
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