Ins and Outs of Emergency Evacuation

Officials in Texas and elsewhere blamed the clogged highways on several factors: the size, strength and uncertain landfall of Hurricane Rita at the time the evacuation orders were issued; and fresh images of the devastation along the Gulf Coast from Hurricane Katrina, which may have prompted many more people in Texas to leave their homes and get in their cars.

Others said the size and speed of the exodus simply overwhelmed the highway system. "In Texas, you've got 2.7 million people who evacuated," said Robert B. Stephan, assistant secretary for infrastructure protection at the Department of Homeland Security. "That just taxes every transportation asset. I don't care if you're the most brilliant leader in the world, there's no way to anticipate all the branches and sequels to that."

When the evacuation order was given, the storm's projected path showed Rita landing between Galveston and Corpus Christi along the south Texas coast. Later, the path shifted north and east, with the projected landfall closer to the Beaumont-Port Arthur area nearer the Louisiana border. That meant residents in a huge area were scrambling to safety, with many funneling through the Houston area.

Because the Houston region has had previous experience with storms and flooding, officials also believed it was essential to move early, even as those tracking the storm were trying to estimate its severity and location. Seeking to avoid a repeat of what happened in New Orleans, officials gave a high priority to evacuating hospitals as well as residents who could not get out themselves.

Almost by definition, even a successful evacuation while underway will produce images of transit routes at the limits of their capacity, emergency managers said. Only when travel has ceased can a fair measure of the evacuation be done.

The Rita evacuation occurred with unusual advance warning. Texas authorities had at least up to four days' notice of Rita's approach, issued voluntary evacuation orders about 72 hours ahead of time and mandatory orders for the most vulnerable areas beginning about 60 hours before expected landfall, perhaps motivated by Katrina's example to make the hard decision early.

"A traffic jam doesn't mean a failure of your evacuation," said Virginia homeland security adviser George W. Foresman, whose state evacuated parts of populous Hampton Roads for Hurricane Isabel in September 2003. "There has been sufficient time, based on all the study data, to know that the decisions were made in the right time frame."

To an extent, emergency managers said, the public, not the government, created Thursday's crisis. Evacuation studies are premised on three factors -- traffic volume estimates, flood models and polling-based behavioral studies that project what people in particular neighborhoods will do when told to leave.

In the face of a high-category hurricane, perhaps 70 to 90 percent of people in evacuation areas are expected to follow mandatory orders. But Katrina and Rita may have changed the standard for public behavior, requiring changes in hurricane plans.

Staff writers Blaine Harden in Houston and Steve Hendrix in Austin, and researcher Meg Smith in Washington contributed to this report.