Experimental study on pedestrians’ uni- and bi-directional movement on staircases under emergency conditions

Abstract

Staircases are main vertical evacuation passages in multi-story buildings characterized by different pedestrian flow from horizontal passages, such as corridors. Experiments were conducted to investigate crowd ascending and descending dynamics with different numbers of pedestrians in both uni- and bidirectional scenarios. Evacuation processes were recorded by video cameras and velocity sensors, and movement parameters were extracted from the recordings. Typical evacuation features on the staircase such as overtaking behavior, queuing behavior, repelling behavior, and packed and staggered motion mode are observed. The study explores velocity on the staircase as well as the fundamental diagram of velocity–density relationship. Experimental results show that ascending pedestrians could move upwards faster than descending pedestrians under emergency conditions. The stair landing can provide a wide and flat place for pedestrians to accelerate in unidirectional evacuation cases, but has a negative effect on evacuation velocity in bidirectional flow. The distribution of velocity in bidirectional evacuation is more convergent than in the unidirectional scenario. The study findings enrich evacuation modeling and improve the assessment of the pedestrians’ performance on staircases.