It isn’t always a pleasant thought, but at some point, people might need to escape a building you have designed. Whether from fires, earthquakes, or other catastrophes, the safe egress of inhabitants is something architects need to thinking about during design.
Can you model human behavior and the panic response sufficiently? How can you design your buildings to ensure the safety of the maximum number of people?
Panic Is a Normal Response to Threat
Unfortunately, panic is a normal response to threats. Panic allows us to move faster than we normally would, but it also causes pushing and behaviors that can slow down the exit of the crowd.
While it seems like the best response would be to calm a panicked crowed, this is not a stable strategy. Part of the changes to the brain during a panic response are to encourage selfish actions and not cooperative ones.
Interestingly, several studies have found that the number of people has an impact on the effect of the panic. In smaller crowds of under 100 people, panic actually helps people get out faster. In larger crowds, panic can slow down how quickly people can get out.
Maximize Output Victim Flow
Since the solution to saving as many lives as possible is not to ask a panicked crowd to calm down, what other solutions are there? Several researchers have been working on developing architectural standards for optimizing survival.
Most of the research has been on maximizing output victim flow. In 2003 researchers with the Chalmers University of Technology in Sweden, used a model previously developed by Helbing, Farkas, and Vicsek in 2000 to find answers. This model developed by Helbing et al. is different from previous ones in that it was oriented towards self-driven many-particle systems as opposed to fluid modeling.
In the 2000 study, the authors discovered that putting a column near the exit in an asymmetrical position greatly improved the victim flow. The researchers on the 2003 study wanted to expand that kind of thinking to understand what is happening.
They found that what was happening was a “waiting room” effect. This “waiting room” can be created by including columns or angled walls in front of the exit. “This creates a region for a new -but smaller- ‘room’, which, having less pedestrians in it, makes it easier for them to leave.” The research shows that with this simple change the victim flow rate is doubled than that of an empty room with a single exit door.
A model developed in 2013 went a step further by including a calculation for the rate of possible injuries based on the building layout and the evacuation speed. The researchers concluded that the “building layout can be optimized to increase the safety of a crowd with an initial distribution.”
The model will need a rigorous tuning process to make it useful for architects and safety officials. The researchers hope that eventually their study will help change the conventional egress building code to a more efficient alterative.