That urban design improves the quality of people’s lives is an old idea. A new study, Measuring Sprawl 2014 , now finds that people who live in densely populated regions benefit in many ways. In brief, they have greater economic mobility, they’re healthier, and they live longer.

University of Utah city planning professor Reid Ewing and graduate research assistant Shima Hamidi helmed the study, which was commissioned by advocacy organization Smart Growth America. The study scored sprawl in 221 metropolitan areas (200,000 people or more) and in 994 counties, using measures such as development density, the mix of land use, the proximity of people and businesses, and the size of street networks.

Ewing then compared those scores to various measures of quality of life, including rates of obesity, chronic disease, safety, and the cost of living.





The results were startling. Poverty, the report suggests, is far from intractable. Living in a densely populated city appears to help people achieve success. For example, For every 10% leap toward density in the sprawl score, there was a 4.1% increase in the chance that a child born in the bottom 20% of the national income distribution would graduate to the top 20% by age 30.

It’s also cheaper to live in dense cities. In those areas, people spend slightly less of their income on the combined cost of housing and transportation. (They have more low-cost transportation options, including walking, which of course is free.) Also useful, in the report, are a run-down of specific investments that some cities have made to improve quality of life. Madison, Wisconsin, instituted programs that help people buy homes, and Los Angeles is adding light rail.

In the U.S., Ewing tracked fewer fatal car crashes in counties with less sprawl. More densely populated counties actually had more car crashes (more traffic), but fatalities were lower. So a person living in Walker County, Georgia, is three times as likely to be killed in a car crash than a person living in Denver County, Colorado.

People who live in compact cities also tend to live about three years longer than people who live in less compact cities. The gap is probably thanks to more driving (which means more fatal crashes), a higher Body Mass Index, higher blood pressure, and more diabetes in less-compact cities. A useful way to look at it is the scale: A 5′ 10″ man in Arlington County, Virginia, typically weighs four pounds less than a peer in Charles County, Maryland. Obesity, as we know, has many health implications.