Modeling and simulation of crowd evacuation with hand holding present

With the increasing density of pedestrians in urban public spaces, safe evacuation under emergencies has become a critical issue in crowd dynamics and urban safety management. Existing evacuation models usually regard pedestrians as independent moving individuals, making it difficult to represent hand-holding behavior, which commonly occurs in real evacuation scenarios. To address this limitation, this paper proposes an extended social force model integrated with a spring–mass–damper mechanism, termed SMD-SFM, to describe the persistent physical connection between hand-holding pedestrians and its influence on surrounding crowd motion. In the proposed model, a hand-holding pair is represented as a mechanically coupled unit with elastic recovery and damping effects, while individual driving forces, pedestrian interactions, and obstacle interactions are jointly considered. Real evacuation video data are processed to extract pedestrian trajectories, and a simulation scenario is constructed based on the observed environment for model validation. The analysis indicates that SMD-SFM can reasonably characterize the constrained movement of hand-holding pedestrians during evacuation and shows that such behavior modifies crowd organization near bottlenecks, thereby impairing passage efficiency. This study provides a mechanically interpretable modeling approach for hand-holding pedestrian behavior in complex evacuation simulations.