Group structures facilitate emergency evacuation

Abstract

The motion of pedestrian crowds can be described as if they are subject to "social forces". Grouping, as a common phenomenon in pedestrian behaviors, plays a decisive role in affecting evacuation efficiency. Here we propose two different group evacuation (GE) regimes, namely the leaderless GE and leadership GE, to explore the evacuation dynamics of group-structured pedestrians. Simulation results show that elevating sizes or numbers of these groups can promote evacuation efficiency when individuals all try to move fast, in contrast to the case of small desired velocities. More importantly, with the same group size and group number, leadership GE outperforms leaderless GE, implying the positive effect of adopting appropriate community leaders. We hope that these observations could provide some insight into pedestrians' collective action during the evacuation process.