Microscopic dynamics of escaping groups through an exit and a corridor

TL;DR

This study investigates how social groups influence evacuation dynamics through an exit and corridor, revealing that strong social bonds can both hinder and improve evacuation efficiency depending on feelings intensity.

Contribution

It extends the Social Force Model to include attractive feelings within groups and analyzes their impact on evacuation performance across different velocities.

Findings

Groups generally worsen evacuation times.

Very strong feelings can lead to faster escapes, called 'Closer-Is-Faster'.

Social groups cause additional slow-downs in corridor movement.

Abstract

This research explores the dynamics of emergency evacuations in the presence of social groups. The investigation was carried out in the context of the basic Social Force Model (SFM). We included attractive feelings between people belonging to the same social group, as proposed in Int. J. Mod. Phys. C 27(6),1-16. We focused on the escaping dynamics through an emergency exit and through a corridor. We confirmed the results appearing in Int. J. Mod. Phys. C 27(6),1-16 for a desired velocity of 4 m/s, but further extended the analysis on the emergency exit to the range 1-8 m/s. We noticed that the presence of groups worsens the evacuation performance. However, very strong feelings can improve the escaping time with respect to moderate feelings. We call this phenomenon "Closer-Is-Faster", in analogy to the "Faster-Is-Slower" effect. The presence of social groups also affects the dynamic within a corridor by introducing an additional slow-down in the moving crowd.