A comparative experimental study on the influence of bottleneck width on evacuation characteristics of pedestrian flow in funnel shape bottleneck and normal bottleneck

Abstract

Previous studies have proposed that increasing bottleneck width help increase evacuation efficiency in normal bottleneck evacuation. However, the effect of funnel shape bottleneck coupled with bottleneck width on evacuation efficiency is still unknown. To improve the understanding of the influence of bottleneck width in funnel shape bottleneck evacuation on the movement characteristics of pedestrians, the funnel shape bottleneck evacuation experiment is carried out in this study. The movement characteristics of pedestrians passing through the funnel shape bottleneck versus the normal bottleneck are compared from the aspects of trajectories, fundamental diagrams, density profiles, speed distribution, flow, time interval, and quiescent time. Logarithmic function fits the relation between density and speed well both for funnel shape bottleneck and for normal bottleneck evacuation. Under the same density, the funnel shape bottleneck allows pedestrians to move faster than the normal bottleneck. For the same bottleneck width, the density in the funnel shape bottleneck is smaller than that in the normal bottleneck. The flow increases linearly with the increasing bottleneck width both in funnel shape bottleneck and in the normal bottleneck. When the bottleneck width is smaller than 1.31 m, the flow of funnel shape bottleneck is higher than that of the normal bottleneck. The funnel shape bottleneck reduces the occurrence and the lasting time of quiescent behaviors. The evacuation time decreases piecewise linearly with the increasing bottleneck width both for the funnel shape bottleneck and the normal bottleneck. The comparisons reveal that the funnel shape bottleneck increases evacuation efficiency under the smaller bottleneck width. The results obtained in this study describe the difference between the funnel shape bottleneck and the normal bottleneck, which is beneficial to safety managers and pedestrian facilities designers.