Application of the multi-grid modelling method to pedestrian social group dynamics through a bottleneck

There is a high proportion of social groups in crowds. The influence of social groups on crowd mobility is particularly evident in emergency situations and in confined movement environments. However, studies on the characteristics of social group movement through a bottleneck with different widths are limited. Therefore, the computation and simulation are performed in a corridor with a bottleneck involving individuals and three types of groups (namely two-person, three-person and four-person groups) using a modified multi-grid model. The original multi-grid model is modified by introducing interactions between pedestrians, avoidance behavior and group behavior, and validated by data from a controlled experiment. It is found that the group configuration can be adjusted to the changing scenarios during the passing movement. The movement efficiency and level of walking comfort for pedestrians are significantly improved in wider bottlenecks. Passing efficiency is evidently increased and congestion is reduced, when social groups occupy a large proportion of the crowd in a narrow bottleneck. These numerical findings may provide new insights for analyzing nonlinear pedestrian social group dynamics.