10 Sprawliest Cities in the United States

The big decline in Detroit's population in the past decade has been due to people moving to the suburbs -- which means lots more commuters. Tom Carter/Photolibrary/Getty Images

Perhaps no major American city was harder hit during the recent recession than Detroit, the country's automotive capital, which has crumbled in the wake of disappearing factory jobs and a glut of home foreclosures. The city's population fell by 25 percent in a decade to just over 713,000 in 2011, the fewest residents Detroit has seen since 1910 [source: Linebaugh].

That's not a lot of people for a city that spans about 140 square miles (363 square kilometers), more space than Manhattan, Boston and San Francisco combined. It might seem like everyone is fleeing Detroit, but the truth is that most are simply moving to the suburbs [sources: Maynard, Linebaugh].

Which, of course, means more traffic. Not only are commuters coming into the city from farther out, but the population drain over the past 10 years has decimated tax revenues, some of which would have gone to infrastructure and public transportation. Forbes ranked Detroit as the second worst commuting city in 2010, noting that a mere 12 percent of commuters walk, bike, carpool or use public transportation to get to work [source: Levy].