Phenomenological description of deadlock formation in pedestrian bidirectional flow based on empirical observation

Abstract

.This article presents an empirical investigation for the phenomenon of deadlock formation by analyzing a pedestrian bidirectional flow of a subway station in central Tokyo. Using video images obtained from cameras placed in the station during morning rush hour, the in- and outflow (making up the total flow) resulting in a test section considered were computed. With the use of additional information such as train arrival times, test section density and its flow ratio, the formation of different complex crowd phenomena is analyzed. The information provided by the unsteady flow curves allowed a qualitative and quantitative distinction between free flow, congested flow and deadlock formation. This latter phenomenon could be easily identified based on the shape of the total outflow showing a double peak. Based on the information gained, a flow regime diagram using flow and counter-flow values to distinguish between different flow regimes in bidirectional flow has been derived. In this regard, flow ratio was confirmed as being a relevant parameter to describe bidirectional flow, providing experimental evidence that total flow alone can be misleading. Qualitative and quantitative results obtained in the present study were finally compared with previous literature showing good agreement.