Chart of the Day: Necessary Road Space per Traffic Mode for Houston Metro Evacuation

Traffic during the evacuation of Hurricane Rita in 2005.

Right now, even in Minnesota, all eyes are on the flooding and storm impact in Houston, Texas. Earlier today I read an article about why the Mayor of Houston did not put out a call for an evacuation of the city ahead of the landfall of Hurricane Harvey. It turns out the answer was that a premature evacuation, and the resulting congestion on Houston area freeways, was also something of a disaster.

Here’s the key point from the NPR article:

In 2005, just a few weeks after Hurricane Katrina devastated New Orleans, Hurricane Rita made its way toward Houston. Rita was even stronger than Katrina — and Houstonians had just witnessed what happened to New Orleans residents who decided to wait out the storm. Nobody wanted to repeat that mistake.

The result: The largest evacuation in U.S. history, according to PBS. Texas legislators estimated that 3.7 million people left the Houston region in the evacuation effort.

The evacuation was a disaster in itself. NPR’s John McChesney reported from the scene in 2005:

“In searing 100-degree heat, cars crept up north I-45, windows down, air conditioning off to save precious gasoline. The traffic jam stretched for over 100 miles and has been going on for over a day and a half. … Gasoline was not to be found along the interstate and cars that ran dry made the gridlock even worse. Abandoned vehicles littered the shoulder lanes.”

Dozens of people died on the road — in a horrific bus fire, in traffic accidents, of heat stroke.

The line that caught my eye was this one, a quote from Houston Mayor Sylvester Turner:

“You literally cannot put 6.5 million people on the road.”

Especially given Houston’s famously mammoth highways, that’s quite the statement!

Anyway, here’s your chart. Via Twitter user Alan Kessler, it’s actually a pair of charts. The first shows the amount of space taken up by a car, on average:

The second illustrates how much land that might be in the Houston area:

On Twitter, Kessler writes that “If you had the buses, you could fit them in about 49M sq.ft. (~18 sq. mi) Here’s 11M sq. ft. for scale.” I guess the lesson here is that if you’re going to evacuate a city, use buses.

Meanwhile, keep the people of Houston in your thoughts.

Bill Lindeke

About Bill Lindeke

Pronouns: he/him

Bill Lindeke has writing blogging about sidewalks and cities since 2005, ever since he read Jane Jacobs. He is a lecturer in Urban Studies at the University of Minnesota Geography Department, the Cityscape columnist at Minnpost, and has written multiple books on local urban history. He was born in Minneapolis, but has spent most of his time in St Paul. Check out Twitter @BillLindeke or on Facebook.