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Digging into Data About Getting Out

THE EVACUATION OF the World Trade Center’s Twin Towers on 9-11 has provided a trove of information for researchers studying building evacuations. The latest effort to glean new lessons from that tragic event was undertaken by U.K. fire safety engineering expert Ed Galea, who spearheaded a three-and-a-half-year project called HEED (High-rise Evacuation Evaluation Database).

The HEED project, which wrapped up last year, was funded by a £1.6 million (about $2.2 million) grant from the U.K. Engineering and Physical Sciences Research Council—the equivalent of the U.S. National Science Foundation. The project was a collaborative effort of the universities of Greenwich, Liverpool, and Ulster. The University of Greenwich’s Fire Safety Engineering Group, of which Galea is the founding director, was the principal investigator.

The researchers collected interviews from 271 survivors of the Twin Towers attack—average people rather than first responders. The work generated 6,000 pages of firsthand accounts, providing a window into the survivors’ experiences as they tried to leave the buildings. The resulting database is searchable, but it is available only to researchers, engineers, and regulators.

Data collected during the HEED project is being used to identify strengths and weaknesses in evacuation modeling technology. One objective is to use the information to improve behavioral algorithms for high-rise building-evacuation models.

Review of the data is ongoing, but some preliminary analysis has been done. For example, Galea and his group found that more than half the WTC occupants stayed to carry out tasks before evacuating and that response times were between five and eight minutes, which was much longer than building engineers predicted they would be.

Physical data about survivors (like height and weight, for example) were also collected and used in the models. Using this information, Galea found that the number of the people in the stairwell, given the space each would take, slowed the evacuation.

Some in the evacuation community had speculated that evacuation speeds were slower than expected because of the obesity epidemic in America, but the data did not support that theory. Galea conducted interviews of evacuees from the World Trade Center. Of those he interviewed, the majority were either overweight or obese. However, after studying the travel speeds of evacuees, Galea found that obese people moved just as quickly as those of normal weight.

Galea is now involved in a new project, a multicountry effort that will examine the role of culture on emergency evacuation behavior. As part of this project, which is called the BeSeCu (Behavior, Security, and Culture) project, a group of European researchers and end-users from seven organizations in five countries is conducting interviews of survivors of such emergencies as domestic fires, the terrorist bombings in the London Underground, and various natural disasters.

Cultural groups within the participating countries—Germany, the United Kingdom, Spain, Sweden, Poland, Turkey, and the Czech Republic—will be compared. In addition, the group will conduct and study full-scale building evacuations in three European countries. “What we’re trying to find out is if people from different cultures behave significantly differently in evacuation situations,” Galea says.

Led by Silke Schmidt, a professor at the Institute of Psychology at Germany’s Ernst-Moritz-Arndt University of Greifswald, and funded by the European Commission, BeSeCu is still in its first phase. While researchers have been conducting interviews for 10 months, very little analysis has been done.

Both Schmidt and Galea agree on the importance of discovering the role of culture. Architects and engineers design buildings around the world, and most of the data used to create computer models for those designs are derived from the United States and the United Kingdom, Galea says. “Is that data applicable to Saudi Arabia, to Japan, to Turkey, and the assumption is that it is, but is that a good assumption to make?” he asks.