New Insights into Pedestrian Flow Through Bottlenecks

TLDR

Capacity estimation for pedestrian facilities is crucial, yet literature methods vary widely and recent data reveal a stepwise increase in flow with width, questioning the specific flow concept. The study experimentally examined unidirectional pedestrian flow through bottlenecks to resolve discrepancies in capacity estimation. The experiment tracked individual velocities, density, and time gaps over time in bottlenecks of different widths. Results show flow increases linearly with width, indicating that current capacity estimates are inadequate, and that jams can form even when incoming flow does not exceed the fundamental diagram’s maximum flow.

Abstract

Capacity estimation is an important tool for the design and dimensioning of pedestrian facilities. The literature contains different procedures and specifications that show considerable differences with respect to the estimated flow values. Moreover, new experimental data indicate a stepwise growth of capacity with width and thus challenge the validity of the specific flow concept. To resolve these differences, we experimentally studied the unidirectional pedestrian flow through bottlenecks under laboratory conditions. The time development of quantities such as individual velocities, density, and individual time gaps in bottlenecks of different widths is presented. The data show a linear growth of flow with width. The comparison of the results with experimental data from other authors indicates that the basic assumption of the capacity estimation for bottlenecks has to be revised. In contrast to most planning guidelines, our main result is that a jam occurs even if the incoming flow does not overstep the capacity defined by the maximum flow according to the fundamental diagram.