Experimental study of crowd evacuation dynamics considering the effects of different obstacles

The geometry, spatial arrangement, and dimensional parameters of obstacles significantly impact crowd evacuation efficiency and movement behavior. This study investigated the influence of obstacle configuration on crowd evacuation dynamics via controlled experiments, using high-resolution video tracking and entropy analysis to quantify evacuation time, trajectory, velocity, regional density, and behavioral disorder. Results show that obstacles generally prolong total evacuation time, with double cylindrical obstacles causing the most significant increase (20 %) and vertical plate obstacles the smallest (7.5 %). The average evacuation time reaches a minimum when obstacles are placed 1.0 m from the exit. Individual instantaneous velocity exhibits a typical four-phase characteristic: initial acceleration, deceleration, stable fluctuation, and final growth. Obstacles have a dual effect on evacuation behavior: obstacles enhance the psychological motivation of the initial evacuation response, and the initial speed increases from 0.35 m / s to 0.50–0.80 m / s; the obstacle suppresses the stable physical movement speed, and the stable speed decreases from 0.4 m / s to 0.3 m / s. Plate obstacles significantly reduced the density of the exit area, effectively avoiding the accumulation of lethal stress. In contrast, cylindrical obstacles exacerbated the “edge effect.” Vertical plate obstacles optimize evacuation order, reducing entropy by 63.1 %. These results deepen the understanding of crowd evacuation dynamics and provide important data support for optimizing evacuation strategies and balancing evacuation time and safety.