An empirical investigation on social group evacuation dynamics in multi-exit evacuation scenarios

As a common form of evacuation, social groups play an essential role in shaping crowd dynamics. However, the exit choice behaviour of social groups in complex scenarios has not been fully investigated yet. In this study, we conducted a series of experiments considering various arrangements and numbers of available exits, as well as different social group sizes. Our findings reveal social group dynamics on various levels. At the tactical level, participants exhibit diverse preference patterns depending on both the size of their group and the number of available exits, and the impacts of exit properties vary with contexts at the operational level, crowds with social groups display distinct movement phases: initial acceleration, deceleration near exits due to high density, and post-exit re-acceleration. Exit placement influences high-density distributions, with longer walls hosting exits leading to more elongated queues. Furthermore, our analysis revealed pronounced asymmetries in the density distributions across multiple exit scenarios, indicating that proximity to the exits significantly influenced individuals' exit choices. Our work expands the dataset on social group evacuation dynamics in emergencies and deepens the understanding of how social group dynamics shape crowd behaviour.