A meta-synthesis of experimental studies of pedestrian movement in single-file flow

The single-file pedestrian flow experiment is a simplified system for investigating the fundamental walking characteristics of pedestrians and their dependence on various individual factors. Despite numerous experimental studies emerging in recent years, a comprehensive review and meta-analysis of the literature is lacking. Abundant research results and findings have not been thoroughly compared and examined in a unified manner. To address this gap, this paper comprehensively gathers existing experimental studies and compared the basic characteristics of pedestrian walking in a single-file flow, highlighting consistencies, inconsistencies, and controversies across different studies. Furthermore, this review emphasizes the need for future investigations to address theoretical inconsistencies and controversies. Specifically, we suggest more efforts in single-file flow experiments should be made for the open-boundary scenarios and the high-density conditions for normal and emergency conditions. Additionally, we recommend that future studies should also consider the effects of distractions, diverse age composition and disabilities on pedestrian walking characteristics as these factors are less examined in existing single-file flow experiments. Furthermore, we suggest that future studies should continue to reveal the underlying mechanism that governs the speed-headway relations of pedestrians and develop a universal standard form of the fundamental diagram. Finally, we propose the development of a hybrid model in the future that integrates behavioural rules, motion dynamics, and stepping locomotion to simulate single-file pedestrian movement from a microscopic to a macroscopic level. Addressing these gaps will lead to a more comprehensive understanding of single-file pedestrian flow and improve the design and management of pedestrian-traffic environments, ultimately enhancing pedestrian mobility and safety.