A mixed crowd movement model incorporating chasing behavior

Abstract

In recent years, there has been a growing focus on the study of interactive movements within mixed crowds in the field of pedestrian evacuation. This study examines a specific type of interaction within mixed crowd: Group A chases Group B, while Group B needs to evade Group A and complete an evacuation, such as in situations involving attackers and pedestrians during a sudden violent incident. To model these complex movements, a velocity-based model incorporating panic propagation is developed. In this model, pedestrians adjust the magnitude and direction of their velocity by taking into account three key factors: avoidance of the attacker, movement toward the exit, and herd mentality. After a detailed introduction of the model, we first simulated and analyzed the parameters in the model to investigate the impact of various factors on the number of casualties and evacuation time. Subsequently, collective behavior from nature, experimental data, and specific crowd movement data are utilized to compare simulation results and validate the accuracy of the model. Finally, through simulations of single-exit and dual-exit bottleneck scenarios, a comparison of casualties revealed that placing exits at the corners of walls in building designs is more conducive to pedestrian evacuation.