Arch formation-based congestion alleviation for crowd evacuation

Abstract

Congestion in pedestrian crowds is a critical issue for evacuation management. This paper presents an approach based on arch formation to alleviate congestion formed by crowds gathering at a bottleneck. In this approach, analyzing a specific self-organized motion pattern, namely, arch formation, the position of the arch formation has a great influence on congestion alleviation. Specifically, an arch formation at an outer position is beneficial for congestion alleviation because it is unstable and collapses easily. The symmetrically placed obstacles, which have a similar role as anti-slide piles, are used to change the position of the arch formation in a crowd. The spacing between the symmetrically placed obstacles is an important parameter for adjusting an arch formation. We present a modified model that originates from the soil mechanics in civil engineering to calculate the proper spacing between the symmetrically placed obstacles. This model analyzes the static attributes of an arch formation and improves the spacing calculation. The proper spacing between symmetrically placed obstacles can alleviate congestion and increase evacuation efficiency. In this paper, the social force model is used to conduct an evacuation simulation, and the simulation results illustrate the effectiveness of the proposed approach.