Thursday, December 12, 2013
Slate has a nice excerpt of Charles Montgomery's new book, Happy City: Transforming Our Lives Through Urban Design, which examines how insights from psychology, neuroscience, and design can help city governments can improve many quality of life measures. This part touches on the relationship between health and road design:
When designers try to maximize the number of cul-de-sacs in an area, they create a dendritic—or treelike—system of roads that feeds all their traffic into a few main branches. The system makes just about every destination farther away because it eliminates the most direct routes between them. Connectivity counts: More intersections mean more walking, and more disconnected cul-de-sacs mean more driving. People who live in neighborhoods with latticeworklike streets actually drive 26 percent fewer miles than people in the cul-de-sac forest.
The diagram below helps illustrate how a white male living in Midtown (left), near Atlanta’s downtown, is likely to weigh 10 pounds less than his identical twin living near Mableton (right), a sprawling suburb. This is partly owing to road geometry and land-use mix: a 10-minute walk from a home amid the traditional grid in Midtown will get you to grocery stores, schools, bus stops, cafés, a bank, and the glorious lawns of Piedmont Park. But the spread-out and homogeneous system of Mableton pushes destinations beyond walking range, which means residents are likely to drive whether they like driving or not. (Each bullet represents a school, church, grocery store, dry cleaner, bank, day-care center, police station, transit stop, or hospital. If restaurants, cafés, bars, and other services were included, the Mableton map would not change, but the Midtown map would be sprayed with dozens more bullets.)