Preventing congestion in crowd dynamics caused by reversing flow

TL;DR

This paper presents an agent-based model to simulate crowd behavior in a corridor with a suddenly closed gate, analyzing how reversing flow can cause dangerous congestion and offering safety recommendations.

Contribution

It introduces a novel microscopic model capturing dynamic crowd reactions to unexpected gate closure and reversing flow in confined spaces.

Findings

Reversing flow can lead to dangerous counter-flows and congestion.

Certain crowd behavior parameters significantly impact flow stability.

Practical safety suggestions for mass event organizers are provided.

Abstract

In this paper we devise a microscopic (agent-based) mathematical model for reproducing crowd behaviour in a specific scenario: a number of pedestrians, consisting of numerous social groups, flow along a corridor until a gate located at the end of the corridor closes. People are not informed about the closure of the gate and perceive the blockage observing dynamically the local crowd conditions. Once people become aware of the new conditions, they stop and then decide either to stay, waiting for reopening, or to go back and leave the corridor for ever. People going back hit against newly incoming people who are not yet aware of the blockage or have already decided to stay. This creates a dangerous counter-flow which can easily lead to accidents. We run several numerical simulations varying parameters which control the crowd behaviour, in order to understand the factors which have the greatest impact on the dynamics. We conclude with some useful suggestions directed to the organizers of mass events.