Empirical study of turning and merging of pedestrian streams in T-junction

TL;DR

This study provides a detailed empirical analysis of pedestrian flow dynamics at T-junctions, revealing differences in flow before and after merging, and offers insights for improving safety and design through high-resolution measurements.

Contribution

It presents systematic laboratory experiments and Voronoi-based analysis of pedestrian streams at T-junctions, highlighting flow differences and aiding model calibration.

Findings

Fundamental diagrams differ before and after merging at T-junctions.

Pedestrian velocities are lower before merging at the same density.

Voronoi method yields detailed density and velocity maps for safety analysis.

Abstract

Agent-based models are becoming indispensable tools in building design, safety assessments as well as management of emergency egress. However, reliable calibrations of these models should be mandatory before they are used in practice. To improve the database for model calibration we present results from two experiments at a T-junction and a corner. In such structures the dynamics of pedestrian streams is complex and up to now not studied systematically. To understand it deeply, series of well-controlled laboratory experiments are conducted. The Voronoi method, which is used to analyze the experiments, allows high resolution and small fluctuation in time and space. From the results, it is found that the fundamental diagrams of pedestrian flow in T-junction are not the same before and after merging. At the same density, the velocities of pedestrians before merging are smaller than that after merging. To analyze whether turning or merging of the stream is responsible for this discrepancy, we compare the fundamental diagrams of pedestrian flow in T-junction with the flow at a single corner. The fundamental diagrams of the streams in front and behind the corner agree well and are also in accordance with that from T-junction flow after merging. Besides, space-resolved measurements for the density, velocity profiles are obtained using Voronoi method. These maps offer important information about dangerous spots and thus enable to improve egress management and facility design.