This story appeared in the December 2001 issue of Planning, a national magazine for professional planners.
Danger! Coastal states get ready for a really rainy day -- by cranking up their evacuation plans.
By Terry Plowman
Hurricane Floyd's September 1999 assault on the southeastern U.S. was a major wake-up call for emergency management officials.
Almost 600 miles wide, and swirling with 130-mph winds and relentless rain, Floyd forced nearly three million people to join the largest evacuation in U.S. history. And it sent this sobering message to the coastal states: You had best take a look at your evacuation plans.
Although no deaths directly resulted, tens of thousands of evacuees suffered through near-gridlock as they tried to flee Hurricane Floyd. Trips that normally would have taken an hour or two took 16 hours or more.
In Florida, an estimated two million people left their homes, "causing an enormous strain on the carrying capacity of evacuation routes," according to a post-Floyd report that described the event as a "worst-case scenario."
Unprecedented traffic flowed northward, flooding into Georgia and the Carolinas, whose own citizens were trying to flee the impending storm. Floyd blew ashore near Cape Fear, North Carolina, with 110-mph winds, then dumped 15 inches of rain in 12 hours, causing post-evacuation flooding on a scale never before seen in the region.
A year earlier, Hurricane Georges had delivered a similar wake-up call to states along the Gulf Coast. Predicted to make landfall at New Orleans (pop. 1.3 million), one of the largest metropolitan areas on the Gulf, Georges forced an evacuation that was the largest in U.S. history until Floyd.
Georges ultimately came ashore near Biloxi, Mississippi, but not before about half a million people evacuated from around New Orleans. About 15,000 took refuge in the concourses of the Superdome stadium, in schools, and in other public buildings. Fearing that late evacuees would be trapped on the highway, police eventually closed Interstate 10, the main evacuation route, effectively sealing remaining inhabitants in the city.
Hurricanes Georges and Floyd were "watershed events" that made evacuation planning efforts urgent along the entire Gulf and Atlantic coasts, says Brian Wolshon, a researcher and professor at Louisiana State University's new Hurricane Center. "Georges got the attention of the Gulf states, but Floyd really got the attention of federal agencies," Wolshon says.
The evacuation problems caused by Georges and Floyd were so widespread that they prompted emergency management planners from Texas to the mid-Atlantic to look for ways to improve evacuation traffic flow, leading them to a number of new tools, both high- and low-tech, that they hope will make future evacuations more efficient and safer.
At the heart of the evacuation problem is the fact that the population of coastal counties from Texas to Maine has increased by about 20 million in the past 30 years -- to more than 80 million now -- and it continues to grow at a faster rate than the nation as a whole. "Our coastal populations are exploding, but our road infrastructure to support evacuation of those populations has not," Wolshon says.
The magnitude of the challenge facing evacuation planners is obvious in Florida -- geographically a sitting duck for hurricanes, with more than seven million residents living five miles or less from its coastline. Southwest Florida, southeast Florida, and the Florida Keys were three of the top five problem areas identified in a 1992 evacuation study done by Post, Buckley, Schuh & Jernigan Inc., a leading consulting firm in the field. (The other two were southeast Louisiana and the Delaware-Maryland-Virginia peninsula.) The report warned that a major hurricane could force all three of Florida's problem areas to evacuate concurrently.
A Florida Hurricane Task Force Report, commissioned in 1999 after Hurricane Floyd, notes that peninsular residents cannot evacuate to safe inland havens because no point in the state is more than 100 miles from the Gulf of Mexico or the Atlantic Ocean. (Residents of the Florida Panhandle could evacuate to neighboring inland states.) The report warns that "even if there were inland sites to evacuate to, Florida's infrastructure has not kept pace with its rapid growth, which is a limiting factor in our overall evacuation strategy."
And there's another factor here: A lull in hurricane activity over the past several decades may make new residents complacent. Between 1970 and 1994, a average of five hurricanes a year formed in the Atlantic Basin, but the period since then has been the most active period on record, with an average of eight hurricanes a year. Weather experts, such as the renowned hurricane forecaster William Gray of Colorado State University, believe the Atlantic Basin is entering a period of greater storm activity.
"The East Coast and Caribbean have been very lucky the last 25 years as they've developed," Gray says. "They've become spoiled by this downturn in hurricanes. This luck isn't likely to last."
Tech to the rescue
Tackling the evacuation problem requires "the marriage of emergency management with intelligent transportation system technology," says Donald Lewis, AICP, an evacuation studies expert with Post, Buckley, Schuh & Jernigan Inc.
With the sponsorship of the Federal Emergency Management Agency and the Federal Highway Administration, PBS&J has developed the latest high-tech tool for emergency managers: the Evacuation Traffic Information System (ETIS). ETIS is a computer modeling system that helps emergency management officials predict traffic flow and congestion points using data such as level of storm threat, expected evacuation participation rates, tourist occupancy, route closings, and real-time traffic counts, if available. The program uses this information and its built-in data from hurricane evacuation studies to predict traffic volumes across a wide geographic area, displaying the information on an interactive map.
In August, the U.S. Department of Transportation tested ETIS in an exercise that included states from Louisiana to North Carolina. As officials from FEMA, the Army Corps of Engineers, the Federal Highway Administration, and other agencies looked on, simulated hurricane data was sent to state emergency operations centers, which used ETIS to manage a hypothetical evacuation involving several states. The test included six different scenarios, simulating both Gulf of Mexico and Atlantic Ocean hurricanes.
Bill Massey, FEMA's hurricane program manager, said participants were pleased with the experience they gained in the exercise. "You will see a vastly different, coordinated effort [during the next major hurricane]," he said.
ETIS isn't the first high-tech tool for emergency managers. The SLOSH computer model (for Sea-Lake Overland Surges from Hurricanes) has been used for years to calculate where flooding will occur under various storm conditions, and Hurrevac continues to be the standard for tracking hurricanes, predicting clearance times, and assisting in evacuation decisions.
Emergency managers also use a low-tech tool: regional coordination. "Evacuation has always been planned at the local level, county by county, but because of the growth of coastal populations, evacuation is now a regional event," says LSU's Brian Wolshon.
Floyd caused "huge out-of-county and out-of-state evacuee movements, and multiple states loading onto a limited road network," said FEMA's post-Floyd Southeast U.S. Hurricane Evacuation Study. This massive movement of evacuees inspired various regional alliances.
One such offspring of Floyd was the Evacuation Liaison Team, an idea based on FEMA's Hurricane Liaison Team, based at the National Hurricane Center in Miami. Created to improve the flow of traffic information between the many agencies and states affected by a storm, the Evacuation Liaison Team includes representatives of FEMA, the U.S. Department of Transportation, and the Army Corps of Engineers. The evacuation liaison team will operate from FEMA's Atlanta Regional Operations Center.
Such coordinated efforts have now become common. For example:
* Florida has developed formal procedures to coordinate multi-county evacuations. These procedures include the designation of inland "host counties" that will open shelters for evacuees from coastal counties.
* Delaware, Maryland, and Virginia have formed the Delmarva Emergency Task Force to improve evacuation traffic flow between the states on that vulnerable peninsula.
* The Georgia Emergency Management Agency has created an interstate coordinator position to facilitate communications with neighboring states.
Hurricane Floyd also inspired planners to take a new look at a little-used evacuation scheme: reverse laning of major highways, also called "contraflow." Reverse laning allows evacuating vehicles to use lanes normally used by coast-bound traffic, in effect making a dual-direction highway one way.
The concept had few advocates in the emergency management field until recently. Problems included the possibility of head-on collisions, the large numbers of personnel needed to set up traffic cones and direct evacuees, and the bottleneck created where the reverse laning ends.
"Before Floyd, many states said, "This is impossible; we're not going to do it,'" says PBS&J's Don Lewis. "Now states are much more willing to plan for unusual traffic patterns [such as reverse laning]."
After Floyd, the state of Florida identified seven highways that can support reverse laning, and it has begun training police and making the necessary roadway modifications. However, the state's hurricane task force emphasizes that reverse laning is a drastic step that "must be used only as a last resort when the conditions are dire."
Bob Collins, Florida's hurricane program manager, points out that reverse laning isn't a panacea. "You need a good plan for how you're going to disperse traffic at the end of the contraflow, or you just end up moving your bottleneck inland," he says.
Wolshon notes that reverse laning is also problematic because limited-access highways are designed for travel in one direction only. Signs, signals, off ramps, and merge lanes aren't functional for vehicles going in the opposite direction.
More states sign on
Despite the challenges, several states have embraced reverse laning. Georgia has been at the forefront, with a plan that is considered a model for other states. Forced by the 1996 Olympics to think outside the box, Georgia was ready when Floyd came up the coast, according to Gary McConnell, director of the state's Emergency Management Agency.
The state implemented reverse laning on a large scale, using it to evacuate a majority of the 350,000 people who left Georgia's coast. All four lanes of Interstate 16 were made westbound for about 80 miles, from Savannah to U.S. 1.
"We were always skittish about using [reverse laning]," says Bryant Poole, assistant state maintenance engineer. "We wondered if it would work. But now that we've done it, we wouldn't hesitate to use it again."
Georgia has since extended its reverse-laning plan to 125 miles, from Savannah to Dublin. It is installing mechanical arms that can be lowered to block access ramps, and it is installing crossovers designed to smooth the transition back to normal traffic flow.
South Carolina also reversed traffic during Floyd, but it did so under the gun. Without a formal plan, the state decided to use all four lanes of Interstate 26 out of Charleston. Building crossovers during the storm to send traffic to eastbound lanes, emergency crews were able to reverse traffic all the way to Columbia, almost 100 miles away. South Carolina has since developed and practiced a formal plan for reverse-laning I-26.
Maryland has been using reverse laning since 1985. Its plan, covering a 10-mile stretch of two-lane highway, has been implemented twice: for Hurricane Gloria in 1985 and for Hurricane Emily in 1993.
Mike Augustyniak, New Jersey's hurricane program manager, says his state recognizes that reverse laning could buy more time for emergency managers, who always have to contend with forecast error: The farther away a hurricane, the harder it is to predict its track. If it takes 36 hours to evacuate New Jersey's Cape May County, the evacuation would have to begin when a hurricane is off South Carolina, but at that point a storm track forecast could be off by more than 100 miles. By planning for reverse laning of major evacuation routes, the state hopes to reduce clearance times so it can base an evacuation order on a later, more accurate forecast, Augustyniak says.
Almost every Gulf and Atlantic Coast state now has a reverse-laning plan for worst-case scenarios, such as a fast-moving Category 4 or 5 hurricane:
* Louisiana could make Interstate 10 one-way eastbound out of the east side of New Orleans and one-way westbound out of the west side. One factor that makes the plan practical is that 25 miles of the westbound section is over water, so there are no entrance ramps to close for that stretch.
* Texas is developing a plan to make I-37 one-way from Corpus Christi to San Antonio, a route that suffered major gridlock during Hurricane Bret in 1999.
* North Carolina has a plan, developed after suffering near gridlock during Hurricane Floyd, to reverse-lane I-40 from Wilmington to I-95, a distance of about 90 miles.
* Virginia can reverse-lane 85 miles of I-64 from Hampton Roads to just east of Richmond. As in other states, the plan had been discussed before Hurricane Floyd, but was adopted and rehearsed after the storm.
Although reverse-laning plans are getting more attention, they are still considered a last resort to be used only in a crisis. In addition to developing such plans, emergency managers are working on two other less radical approaches to surviving a hurricane: sheltering and public information.
Where to go, how to get there
Evacuation, sheltering, and public information are intrinsically linked. If residents can go to local shelters, they needn't undertake long-distance evacuation. If residents have clear information about an impending risk, they may not have to leave their homes at all.
Emergency managers used to worry that too few people would respond to evacuation warnings; now they worry about too many people hitting the road unnecessarily. This over-response by people not in threatened areas -- called "shadow evacuation" by hurricane experts -- was one reason the Hurricane Floyd evacuation was so large. In Florida, various studies showed that 1.3 million people were at risk, but more than two million evacuated.
But even without the shadow evacuees, most states lack enough shelter space. Florida, for one, found a deficit of more than 1.5 million shelter spaces during its post-Floyd studies. For those without shelter, "the only alternative is evacuation across county, regional, and even state lines," said the state's Hurricane Floyd report.
Most states have taken a two-fold approach to solving the shelter-shortage problem: increasing shelter space and discouraging evacuation by those not at risk.
Increasing shelter space is not easy, as emergency managers want shelters to meet the strict guidelines established by the American Red Cross. Such shelters must be able to withstand high winds and be situated outside Category 4 storm-surge zones and the 500-year floodplain. (The Red Cross will issue a revised version of its shelter standards by the end of this year, according to Luis Garcia, the organization's evacuation planner.)
But even with these strict standards, states have increased shelter space by requiring new public buildings to meet the standards, by retrofitting existing buildings, and by searching out appropriate facilities that had not been on previous shelter lists.
Public information may have gotten less emphasis before Hurricane Floyd, but emergency managers now see it as crucial. It can improve traffic flow by keeping evacuees informed about road conditions and shelter availability, and it can reduce shadow evacuation by delivering clear messages about who should leave.
"Behavioral studies show that people will tolerate traffic delays if they are better informed," says Florida's Bob Collins. "We don't want people driving blind. We need to tell them where shelters are available and give them useful traffic information."
Emergency managers say they want everyone in storm-surge areas, such as barrier islands, to evacuate. But their advice to those not at risk of flooding is "if you won't drown, hunker down," says Collins. "We tell them that the worst-built house is better than the best-built car in a hurricane," Collins says.
Officials in the Tampa Bay area annually distribute more than a million copies of a full-color map that shows evacuation zones based on storm-surge areas. In addition, researchers are using a form of radar called LIDAR (for Light Detection and Ranging) to compile land elevation maps that are more accurate than the standard topographic maps used to calculate storm-surge zones. The accuracy of these maps can help evacuation officials fine-tune which areas need to be evacuated, and can reduce the overall number of evacuees. LIDAR mapping has allowed officials in Broward County, Florida, for example, to revise the county's evacuation zones, reducing by 125,000 the number of residents they would advise to evacuate in a Category 4 or 5 hurricane.
Evacuation planners are also proposing alternatives for those left behind.
Emergency managers are identifying shelters for use by those who are unable or unwilling to leave a threatened area, or those evacuees about to be overtaken by a fast-approaching storm. Appropriately named "refuges of last resort," these shelters may not be optimum, but they are still safer than a vehicle or a vulnerable building. Refuges of last resort are usually near evacuation routes.
In addition, some experts are suggesting that residents of hurricane areas adopt a concept familiar to those in tornado zones: the "safe room." A safe room -- something as simple as a reinforced closet -- would provide protection against high winds, though not storm surges.
Those who like to think big might be intrigued by the "community haven" idea proposed for New Orleans by Walter Maestri, director of emergency preparedness for Jefferson Parish, Louisiana, and Joseph Suhayda, of LSU's Hurricane Center. With at least 100,000 residents who have no vehicles, the below-sea-level city faces a disaster of epic proportions if a hurricane were to make a direct hit there.
Maestri and Suhayda have proposed the construction of a series of 30-foot-tall steel walls on tracks that could be rolled out to enclose a six- to 12-square-mile area of the city, where those left behind could take refuge. Maestri says the idea, which he estimates would cost $10 million to $15 million, has been the subject of "substantive discussion" among emergency planners and other officials. "Some people love the idea and some ask if we've lost our minds," Maestri says.
The best-laid plans
Despite human efforts, evacuations remain like an equation with one variable that is always unknown: exactly where a hurricane will strike. Officials can be reasonably sure about all sorts of data -- storm direction and speed, previous hurricane tracks, population figures, evacuation route capacities. They continue to develop new tools, like ETIS, that put computers to the task. But where a hurricane will make landfall is always nature's wild card.
Most evacuation planners are philosophical about that. They'd agree with Jesse St. Amant, director of emergency preparedness for the vulnerable Plaquemines Parish, Louisiana, who says, "We plan for the worst case. If anything less happens, we should be able to handle it."
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