Planning for a Mass Evacuation: Contraflow, Katrina, and Gustav

Noted EMS (emergency medical services) leader W. Michelle Spencer has described all emergency responses as efforts to “impose order on chaos.” That blanket statement holds true for everyone involved in those responses from the front-line first responder to the most senior national emergency-management official. There are, of course, varying degrees of chaos – but there are very few events or incidents quite as chaotic as the evacuation of an entire city only a day or two before a looming natural disaster – such as this year’s Hurricane Gustav, which, although almost comparable in strength to Hurricane Katrina in 2005, was not nearly as destructive.

In that context, it is important to remember that hurricanes and other natural disasters actually start with chaos (and sometimes, if the disaster is an earthquake or a tsunami, with little or no warning). No matter what type of disaster it is, though, the evacuation of a major city is no small thing and by its nature can lead to additional chaos. It is easy to look at bumper-to-bumper traffic on an interstate where the speed limit is 65 mph and see a failure – of either emergency management or of the response effort — but an evacuation is not a day trip out of the city.

The most important component of the television picture viewed by the American people during Hurricane Gustav was not the many miles of bumper-to-bumper traffic on the road but that the traffic was moving. Louisiana state police took many steps to keep it moving, slowly perhaps but also surely, and almost without incident.

For anyone who has ever wanted to drive down a highway “the wrong way,” contraflow provides a golden opportunity. Simply put, contraflow refers to the use of all travel lanes of a highway, regardless of their normally posted direction of travel, to speed up traffic. During Hurricane Gustav, this meant that evacuees from New Orleans and the surrounding area not only would travel north from the hurricane, in the highway’s usual northbound lanes, but also north in the southbound lanes as well, effectively doubling the evacuation capacity of the highway.

It Might Look Simple, But It Isn’t

The contraflow plan sounds and looks simple; however, it was no small feat to put it in place. One of the major difficulties in the implementation of a contraflow plan is that there will still be people who want to go south and, therefore, may try to use the highway as marked. Just as the person who drives the wrong way on the highway during a normal day is a hazard to the other drivers on that highway, the driver getting on the highway “the right way” becomes a hazard during a contraflow evacuation.

Controlling access to the highway is therefore a critical part of an effective, and safe, contraflow plan. According to Doug Cain of the Louisiana State Police, the state had two plans in place, before Gustav made landfall, involving the possible contraflow use of the state’s highways to evacuate specific sections of the Louisiana coastline: a Southeast plan, which includes New Orleans; and a Southwest plan.

To implement those plans, however, it was calculated beforehand, would take 900 law-enforcement officers for the Southeast plan and 300 officers for the Southwest plan. Those officers would be and are drawn from the state police, county/parish sheriff’s offices, local agencies, and Louisiana’s Department of Transportation and Development. Not incidentally, Hurricane Gustav was the first time that both plans have been used simultaneously.

Whether contraflow is used or not, keeping the traffic moving is still the key to operational success. There are numerous reasons why traffic has to stop, even on a normal day. Once stopped, though, an at least partial blockage starts – and spreads quickly to adjacent lanes of travel because of people either slowing down to look at the cause of the delay or attempting to change lanes.

In Louisiana, fixed- and rotor-wing aircraft were used to spot trouble as early as possible during the Gustav evacuation. Once identified, such traffic-slowing difficulties as a disabled vehicle were quickly dealt with, both to keep traffic moving and to provide for those evacuees who were stranded because of the disabled vehicle. In addition, extra road patrols were used to keep traffic moving and clear trouble spots.

Two final points to remember about mass-evacuation situations: (1) Anyone and everyone who can evacuate under their own power should do so, but it is the responsibility of the emergency manager to ensure that they can do so both safely and quickly; (2) Although it takes fewer resources for a person to self-evacuate than to be moved by the emergency-management system, it still requires at least some expenditure of resources to make it possible.

Joseph Cahill
Joseph Cahill

Joseph Cahill is the director of medicolegal investigations for the Massachusetts Office of the Chief Medical Examiner. He previously served as exercise and training coordinator for the Massachusetts Department of Public Health and as emergency planner in the Westchester County (N.Y.) Office of Emergency Management. He also served for five years as citywide advanced life support (ALS) coordinator for the FDNY – Bureau of EMS. Before that, he was the department’s Division 6 ALS coordinator, covering the South Bronx and Harlem. He also served on the faculty of the Westchester County Community College’s paramedic program and has been a frequent guest lecturer for the U.S. Secret Service, the FDNY EMS Academy, and Montefiore Hospital.



No tags to display


Translate »