Monday, July 07, 2014

One Way of Measuring Sprawl

I'm still in Atlanta this week and I did something unusual today: got into a car and drove solo. (Living a car-free existence in New York, I feel like this is a pretty exotic experience.)

Anyway, I noticed that traffic was far worse as I got outside of Atlanta. When I reached the so-called perimeter — Interstate 285, which rings the city — more cars poured onto the freeway.

Atlanta traffic. Photo courtesy of the Atlanta Journal-Constitution.

This got me thinking: The city of Atlanta itself is a tiny part of the region. It has a population of about 444,000, which means it's smaller than Sacramento or Mesa, Ariz. That's crazy for a place with a total metro-area population of about 5.5 million.

To gauge just how unusual this is, I looked at the 20 largest metro areas in the U.S. and measured the percentage of residents living in the region's major city.
Portion of metro population in largest city:
San Diego: 42.2%
New York: 42.1%
Houston: 34.8%
Phoenix: 34.4%
Los Angeles: 30%
Chicago: 29%
Philadelphia: 26%
Baltimore: 22%
San Francisco: 18.54%
Dallas: 18.47%
Seattle: 18.1%
Detroit: 16%
Boston: 14%
Tampa: 12.3%
Minneapolis: 11.6%
St. Louis: 11.3%
Washington, D.C.: 10.9%
Atlanta: 8%
Riverside: 7.23%
Miami: 7.17%
Regions like Atlanta, Miami and Riverside/San Bernardino were below 10 percent. I feel like that means citizens don't have as much pride and money invested in the local urban area. In Atlanta, for instance, cultural institutions have moved outside city limits without much backlash.

Note, though, that this isn't a perfect system. Texas cities such as Houston have basically annexed every municipality around them, creating a situation where you have a lot of sprawl despite there being one giant metropolis at the center of it. San Diego, which ranks No. 1, is basically in that situation.

The 405 in San Diego. Photo courtesy of KCRW.

Even some fairly dense cities like Boston and D.C. score poorly, mostly due to building restrictions that make it tougher for people to live at the urban core. (But I would argue this spotlights some failures in urban planning.)

In any case, it's an interesting way of viewing our nation's urban areas. And I think most of us would agree that the best metro areas are places in which people want to live in the inner city — not ones where residents flee for the suburbs.