Effect of directional distribution on stairway capacity at a suburban railway station

Abstract

Flow condition on undivided stairways becomes more acute during heavy inflow of pedestrian under restricted space. The study of pedestrian movement under such conditions is inevitable for understanding overall operation at a railway station. Limited studies have been reported in the past considering pedestrian movement under different flow and direction of movement under controlled conditions. Nevertheless, to this end, this study aims at investigating the effect of bidirectional pedestrian movement on capacity of undivided stairways located inside railway transit stations, where pedestrians face heavy opposing flow particularly during arrival of train. For this purpose, analysis has been carried out to comprehend the influence of directional distribution of pedestrian flow on walking speed and hence, also on capacity of an undivided stairway, taking a case of Dadar railway station in Mumbai, India. Collected data-sets were used for developing fundamental macroscopic speed-flow relationships. Based on directional distribution ratio, available space for individual direction was determined through acquisition of coordinates based on the geometry of stairways considered for this study. Study results show that unbalanced distribution ratio reduces the average walking speed in individual direction as well as capacity of the stairway. The effect of bidirectional movement is found to be more significant, when distribution ratio decreases from 0.6 in descending direction, making ascending flow more dominant. At this ratio (downward 0.6 and upward 0.4), it is observed that descending flow is reasonably influenced due to movement of opposing minor flow (upward) indicating certain levels of bidirectional as well as unidirectional conflicts between two streams; resulting into highest difference in the walking speed of both directions (mainly due to higher speeds in downward direction); which offers maximum capacity. Methodology developed through this study and the results obtained can be useful for optimizing the pedestrian flow on a given undivided stairway coupled together with planning of other alternative pedestrian facilities at railway stations.