Qualitative and quantitative hybrid analysis of heterogeneous crowds involving individuals with diverse types of disabilities passing through bottleneck

Abstract

This paper presents a series of controlled experiments involving a heterogeneous disabled group composed of individuals with various types of disabilities and normal pedestrians passing through a bottleneck. A hybrid qualitative-quantitative analysis was applied to examine the movement characteristics. The disabilities include physical impairment, lower limb impairment, visual impairment, hearing impairment, mental impairment and intellectual impairments. Qualitatively, typical phenomena of the interaction between the visually and hearing-impaired individuals, and spatial features around the wheelchair users can be observed through the video recordings. Qualitatively, the path length ratio (PLR) and entropy of trajectories for different disabled are calculated and compared. With regard to the typical phenomenon, the Cross-Correlation Function (CCF) was quantified to measures the similarity between the interaction, including “shoulder guide” cooperative movement of the visual disabled and interacting with each other of the hearing disabled. The results show that the speeds of visually impaired individuals and their guides are strongly correlated both temporally and spatially.

Further, the fundamental diagram of the heterogeneous crowds with various types of disabilities was quantified. The heterogeneous group exhibits slightly higher speeds compared to the elderly group at the same density. Due to the high heterogeneity within the crowd, it is challenging to achieve a stable state at the exit. The impact of heterogeneity on traffic efficiency is assessed through cumulative passage times, flow, and flow rates. It is demonstrated that the traffic efficiency of the heterogeneous group is lower than that of the elderly group and the building code standards. Various parameters such as passage time, actual speed, effective speed, instantaneous speed, stagnation time, and acceleration are calculated to analyze the impact of disability types on pedestrian passage efficiency. Factors contributing to the reduced traffic efficiency of the heterogeneous group are analyzed from temporal and spatial perspectives. Wheelchair users experience more pronounced stoppages due to their larger space requirements. Additionally, the reaction time and the collision avoidance behaviors of pedestrians in the heterogeneous group lead to longer exit intervals. This results in a relatively dispersed concentration of crowd density within the experimental space. These findings underscore the importance of enhancing crowd management and optimizing traffic designs for heterogeneous groups with various types of disabilities for ensuring their mobility and safety. The results provide reliable data support for transportation modifications and guidelines for the development of evacuation models, as well as the formulation of management strategies for heterogeneous populations.