Panic contagion and the evacuation dynamics

TL;DR

This paper models panic contagion in crowds, revealing two distinct evacuation patterns influenced by stress levels, and quantifies these patterns using topological parameters, with insights into how panic spread diminishes when danger subsides.

Contribution

It introduces a novel simulation of panic contagion within the Social Force Model, identifying two evacuation schemes and quantifying their patterns through topological analysis.

Findings

Two distinct evacuation schemes based on panic stress levels.

Quantitative topological parameters characterize evacuation patterns.

Panic spread diminishes when the danger source ceases.

Abstract

Panic may spread over a crowd in a similar fashion as contagious diseases do in social groups. People no exposed to a panic source may express fear, alerting others of imminent danger. This social mechanism initiates an evacuation process, while affecting the way people try to escape. We examined real life situations of panic contagion and reproduced these situations in the context of the Social Force Model. We arrived to the conclusion that two evacuation schemes may appear, according to the \textit{stress} of the panic contagion. Both schemes exhibit different evacuation patterns and are qualitatively visible in the available real life recordings of crowded events. We were able to quantify these patterns through topological parameters. We further investigated how the panic spreading gradually stops if the source of danger ceases.