The impact of spatial redundancy and merging conflicts on crowd movement patterns: An empirical study

Modern urbanization has led to increased crowd gatherings, heightening crowd safety risks in public infrastructure. To enhance safety management, investigating crowd flow patterns in typical building structures is crucial. Merging scenarios are frequently scrutinized as dangerous bottlenecks prone to severe crowd accidents. Extensive research on corridor structural design and merging patterns’ effects on merging flows has attempted high-density designs to ensure the emergence of merging phenomena, while few studies have focused on the effect of redundant space on pedestrian decision-making processes. Spatial redundancy is a relative concept, determined jointly by the available space within the corridor and the number of pedestrians. Under high spatial redundancy, pedestrian decisions are less constrained by spatial pressure, enabling more behavioral emergence and helping to more comprehensively understand pedestrian decision-making processes, which has important research significance. To address this, we conducted a controlled crowd experiment featuring corridors with two main-corridor widths and three merging angles, examining pedestrian flows under two regimes: with and without merging. We observed that a layered-flow pattern with low inter-stream coupling emerged under high spatial redundancy, whereas an interwoven-flow pattern with pronounced trajectory overlap appeared under low spatial redundancy. Additionally, merging induced anticipatory avoidance phenomena, with trajectories shifting significantly toward one side. Density and speed analyses revealed that high spatial redundancy design in the merging area reduces density aggregation effects caused by merging, thereby effectively enhancing traffic efficiency. These findings offer new insights into pedestrian movement strategies and provide an empirical basis for optimizing corridor design and calibrating crowd simulation models.