Investigating the effect of stairs on the bidirectional movement of pedestrians

Author: Ye, R., Zhan, Z. H., Chraibi, M., Lian, L. P., Zhang, J., Song, W. G.

Journal: Journal of Statistical Mechanics-Theory and Experiment

Keywords: traffic and crowd dynamics, evacuation dynamics, speed, flow, buildings, Mechanics, Physics

Abstract:

Although bidirectional motion on stairs can be commonly observed for external stairs and in some transportation facilities, a study that aims to investigate pedestrians' walking characteristics under such conditions has never been conducted. In this paper, we perform a controlled experiment to study the bidirectional stair motion with varying flow ratios. It is found that on average, ascending pedestrians walk slower than those descending independent of the flow ratio. At the same density, the average velocity is the smallest for the full bidirectional flow when compared with those in the descending and ascending ones, indicating that the full bidirectional flow is not a simple combination of unidirectional pedestrians. According to the individual time to collision, congestion level and crowd danger, the run when the flow ratio is 0.5 can be considered to be the most critical with a large number of fierce conflicts. Thus, a balanced ascending and descending flow situation should be intentionally avoided for stairs where the bidirectional motion may occur.