Walking characteristics and collision avoidance strategy in bidirectional pedestrian flow: a study focused on the influence of social groups

Abstract

Abstract The walking characteristics and collision avoidance strategies in bidirectional pedestrian flow with both individuals and groups under three different pedestrian densities were investigated experimentally in the present study. The results showed that pedestrians formed lanes in bidirectional flow, and the lane number basically increased with pedestrian density. In addition, the lane number was positively related to the number of groups in the first row of the two opposite crowds. Compared with the no-group experiments, the walking speed of pedestrians showed less difference in the experiments with groups. The fundamental diagram of the bidirectional pedestrian flow with groups under different pedestrian density conditions was calculated. Three types of collision avoidance strategies, detouring around conflicting pedestrians, passing through the conflicting group in the middle, and group splitting, were summarised based on the experimental results. The statistical results of the three collision avoidance strategies adopted by different size groups under the low, medium, and high pedestrian density conditions were obtained. It was found that the large group was more likely to split into subgroups when they encountered conflicting pedestrians, while the small group was more likely to detour around the conflicting pedestrians. For the same group size, the larger the pedestrian density, the higher the proportion of groups that would choose to split into subgroups during the collision avoidance process.