Evacuation: What We Can - and Cannot - Learn from Hurricanes

Somewhere downtown, people are falling to the ground. Within minutes, the first patrol car pulls up. It's obvious there's been some kind of release, but it will take time to identify the agent.

Meanwhile thousands of people in their homes and cars have already heard the news. They're listening to the panicked voices of people calling into local radio stations. One caller erupts into coughing and the line falls silent.

Ten minutes have passed. The authorities have not yet identified the chemical agent, but thousands of people are making their own decisions about the danger. Some are jumping into their cars and fleeing from downtown. Others are driving straight into the affected area to find loved ones.

As the packed roads slow to a crawl, local authorities go on the air. They warn anyone near the release zone to shelter in an interior room and block the vents. They ask people outside the downtown area to evacuate. Meanwhile, a light breeze begins to disperse the chemical agent over hundreds of cars stalled in downtown traffic.

This is the type of worst-case evacuation scenario that keeps emergency planners and responders up at night. Traffic. Panic. Media frenzy. Lack of preparation. Uncertainty.

Yet this scenario's most chilling aspect is that so many of its elements are well known to experts who have managed large-scale hurricane evacuations in Louisiana, Florida and North Carolina. What they have learned in dealing with mass evacuations provides many useful guidelines for planning a response to weapons of mass destruction (WMD) as well as hazardous material releases.

The Same and Different
Certainly, WMD emergencies are very different from hurricane evacuations. "People often draw analogies that if you can evacuate for hurricanes then you can evacuate for WMD," says Craig Fugate, director of Florida's Division of Emergency Management. "But if a hurricane is coming at you, it's a well-defined threat and you have time to prepare. You can go on TV, explain the risk, show maps, and tell people what they have to do.

"With WMD, everything happens much faster. You may not even know what's going on at first. If there's a large release, some areas will be enveloped so quickly all you can do is tell people to shelter in place and evacuate the surrounding areas," Fugate explains. As he and others acknowledge, instructing some people to take shelter while asking others to evacuate has not always worked.

Yet much can be learned from the type of work done to prepare for hurricane evacuations, says Eric Tolbert, director of the Federal Emergency Management Agency (FEMA) Response Division in the Department of Homeland Security (DHS). Tolbert knows because he was involved in much of that planning himself and was at the helm of North Carolina's Division of Emergency Management when Hurricane Floyd struck the state in 1999.

He points to a 20-year history of hurricane evacuation studies by FEMA, the U.S. Army Corp of Engineers, and the Department of Transportation. "Those studies lay out the mechanical pieces of an evacuation, such as highway capacity, the ability to reverse lane [to redirect traffic], and where people can shelter along the evacuation corridor," he explains.

"They tell you the number of police officers needed at each intersection, and provide definitive standards for new and temporary signage. They show how many people can be evacuated per hour. These studies are of extreme value to decision makers in the management of the evacuation process," he says.

Granted, most communities do not have such meticulous studies of potential evacuation routes. But all towns within 10 miles of a nuclear power plant are required to have detailed evacuation plans. And many communities near chemical manufacturing and transportation facilities have also pondered how to move people away from a leak, spill or fire.

Lessons Learned
When planning for mass evacuations, experienced emergency managers make several recommendations:

Know your infrastructure...and reengineer it. Bob Darcey was part of the team that helped evacuate 450,000 people from New Orleans and surrounding Jefferson Parish when Hurricane Georges struck in 1998. As Jefferson's hazmat and WMD coordinator, he has been looking for ways to relieve the traffic bottlenecks that developed as residents waited until the last few hours to leave.

"There are only a few major highways out of the area, and most of them go from four lanes to two lanes once they leave the city," he explains. To break the bottleneck, he plans reverse laning. This involves stopping inbound traffic and using all available lanes to move cars away from the emergency.

This is not as easy as it sounds. First, all the surrounding communities need to coordinate to block any inbound traffic from entering the road. They also must fund asphalt crossover lanes with removable sand barriers that enables traffic to cross from one side of the road to the other. They have already purchased the first electronic signage to tell drivers where and when to cross over. They have also agreed to station wreckers along the route to remove breakdowns fast.

John Sorensen, a national evacuations expert at the Department of Energy's Oak Ridge National Laboratory Emergency Management Center, seconds most of Darcey's plans but warns that reverse laning is still untested. "We've modeled certain scenarios for hazardous material emergencies and reverse laning should reduce evacuation time," he says. "For it to work, communities must preplan and mobilize resources quickly enough to implement it."

Know where you're going...and how to get there. Almost everyone in the suburbs can drive away from an emergency. A key to rapidly moving people out of an area is to know how far they need to go, speed them to the safety perimeter, and provide shelters once they get there.

Life is different in major urban areas. Darcey estimates that 25 percent of the people in New Orleans — almost 100,000 people — have no transportation. Hauling them to safety even when given a 3-day hurricane warning is a chore. Doing it in the face of a WMD incident is far more difficult. "We're looking at mass transportation, school buses, trains, anything to move people," says Darcey, who notes glumly "planning for that is still going on."

In addition, he and others say, responders must also evacuate special needs cases, such as hospital patients and people who require respirators, oxygen, dialysis or other medical equipment to survive. "We've seen estimates that up to 10 percent of the population is special needs, but it's hard to get a solid number. Some people don't want to give out that information. Other times, people say they qualify when they don't, or family members try to pass on their responsibilities to emergency personnel."

Establishing special needs shelters is also a juggling act. New Orleans tried using the Superdome as a last-resort shelter during Hurricane Georges, but people showed up who were not special needs. When the threat subsided, they broke into concessions and carried off furniture. Planners have since identified future special needs shelters, but they do not plan to announce them to the general public.

Expect chaos. "People don't listen, point blank they don't listen," says Mike Deroche, director of the Office of Homeland Security and Emergency Preparedness in Louisiana's largely rural Terrebonne Parish. He and every other emergency manager is constantly frustrated when people know a dangerous storm is coming but wait until the last possible second to evacuate.

They may discount the danger because they've survived other storms. But WMD evacuations may prompt the opposite response. "The public is very rational," says Fugate. "If you have something toxic in your living room, would you stay there? Once it gets on the media, people are going to leave no matter what you tell them."

"I've seen a lot of plans that are very complex," adds Fugate. "They require a lot of things to behave seamlessly and for the public to react predictably. But if I'm supposed to evacuate in one direction and my kid's in day care on the other side of town, which way do you think I'm going to drive? Any plan that doesn't take these types of actions into account isn't going to work."

Sorensen goes even further: "People tend to evacuate whenever another group is told to evacuate. If officials ordering a protective action cannot explain really well why some people might need to evacuate while others shelter in place, it is an invitation to leave. We know from research that people won't listen to something that they don't perceive will improve their safety."

In the past, says Sorensen, telling some people to shelter while asking others to leave has not worked well. This suggests that even a WMD emergency that affects only a small part of town could spark widespread panic that jams roads and increases exposure risk for everyone.

Go with the flow. "Any plan has to be based on where the roads go, rather than trying to force people to take different routes," says Fugate. "Once they start moving, we're not going to be able to stop them, so we had better facilitate that movement. That means we have to figure out how to communicate with them and find a point where we can begin moving them off the road and start thinking about decontamination."

Ensure clear communications. In 1990, Sorensen co-authored a report, Communication of Emergency Public Warnings, which lays out the rules for communicating hazards to the public. Warnings, he said, needed to include information about the hazard, its location, what action people should take, when they need to do it, and the source of the warning.

Their style should be specific, consistent, certain (if something is not fully known, it should be stated), clear, and accurate. Often, several organizations will make a joint announcement. By banding together, they not only enhance one another's credibility, but also ensure everyone is on the same page.

They must also act quickly, even if it means acting on incomplete information, says Fugate. "You have only a couple of minutes at the start of each event," he warns. "The public won't sit around if they know something will kill or incapacitate them. They will react before we have all the information. We're going to have to plan for that."

Understand the limits of shelter-in-place. "A large chemical release could envelop an area so fast, all you can do is shelter in place," says Fugate. Closing down ventilation systems and duct-taping windows will keep harmful chemicals out of the interior rooms of a building or home. It may also keep people from evacuating into even worse danger, such as a chemical plume moving their way.

Yet Sorensen sees limits to this strategy. "For certain events, such as a short-duration release of hazardous materials or a chemical weapon, sheltering in place might work extremely well," he explains. This is especially true for homes built since 1970, when energy conservation measures began to produce more airtight new homes. Older homes are more difficult to secure, no matter how much duct tape residents use.

"What shelter-in-place won't work for is a long-duration plume that lasts over 2 or 3 hours," Sorensen continues. "It doesn't matter how air-tight your house or apartment is, eventually the exposure inside will equal the exposure outside, even if the concentration is lower. You could buy extra time and safety by having a safe room and taping and sealing it, but its effectiveness varies with room characteristics and how well people seal it off."

Practice together. "The best advantage that hurricane states have over other states is that the communications between our responder organizations are tested and exercised on a regular basis," says Fugate. "If the relationships are not already built on exercise and training, the communications are too complicated and the decisions come too fast.

"We also run a lot of games in the state that emphasize the unified command structure. If it's a biological hazard, the health professionals lead. If it's hazmat, the chemical team makes the decision. If it's a bomb, it's law enforcement. If you tried to push all those decisions on one individual, it would overwhelm him."

Despite the practical advice, most experts concede that a WMD evacuation would be incredibly difficult to manage. While emergency planners and responders can train and practice together, any local evacuation will hinge on two largely unknown factors: the ability of officials to discern the nature of the threat and communicate an action plan within minutes; and the ability of ordinary citizens to follow that plan.

No one knows how this will play out until it happens. Moreover, most experts provide unsettling answers when asked about civilian readiness to evacuate or take shelter in a WMD emergency.

Still, by starting to think through infrastructure issues now, emergency planers can begin to at least begin to get their arms around the problem.

For More Information
Oak Ridge National Laboratory's Emergency Management Center, led by John Sorensen, has compiled an outstanding collection of publications on topics ranging from emergency warning systems and evacuate vs. shelter decisions to decontamination and respiratory protection in an emergency. Find it at www.emc.ornl.gov.

FEMA's Emergency Management Guide For Business & Industry provides useful information on evacuating tall buildings and industrial facilities. It is at www.fema.gov/library/biz1.shtm.

Hide comments


  • Allowed HTML tags: <em> <strong> <blockquote> <br> <p>

Plain text

  • No HTML tags allowed.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.