Order-disorder transition in multidirectional crowds

• 成果类型: Article
• 署名作者: Bacik, Karol A.; Sobota, Grzegorz; Bacik, Bogdan S.; Rogers, Tim
• 署名单位: Massachusetts Institute of Technology (MIT); University of Bath
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-9224
• DOI: 10.1073/pnas.2420697122
• 发表日期: 2025-03-24
• 关键词: dynamics

摘要

One of the archetypal examples of active flows is a busy concourse crossed by people moving in different directions according to their personal destinations. When the crowd is isotropic-comprising individuals moving in all different directions-the collective motion is disordered. In contrast, if it is possible to identify two dominant directions of motion, for example in a corridor, the crowd spontaneously organizes into contraflowing lanes or stripes. In this article, we characterize the physics of the transition between these two distinct phases by using a synergy of theoretical analysis, numerical simulations, and stylized experiments. We develop a hydrodynamic theory for collisional flows of heterogeneous populations, and we analyze the stability of the disordered configuration. We identify an order-disorder transition occurring as population heterogeneity exceeds a theoretical threshold determined by the collision avoidance maneuvers of the crowd. Our prediction for the onset of pedestrian ordering is consistent with results of agent-based simulations and controlled experiments with human crowds.