Spatial and temporal analysis of bottleneck flow for the elderly and the young pedestrians under multiple modes

The aging of the population is becoming a global concern. With the increasing number of the elderly, the growing traffic demands are facing greater challenges. The elderly with lower movement ability is more vulnerable to be injured in accidents. Collaborative assistant is an effective way to prevent accidents of falling down for the elderly. In this study, we carried out a series of controlled experiments involving the elderly and the young pedestrians under different modes, including the separate, mixed and synergistic modes. The traffic efficiencies of crowds under different movement modes are compared and their movement characteristics are analyzed. Through the spatial and temporal analysis, it can be found that the primary factor hindering the traffic efficiency of the elderly crowd is the longer time headway. The mean headway distance among homogeneous pedestrians is smaller than that among heterogeneous pedestrians with larger age differences. In addition, the fundamental diagrams under different movement modes are obtained and compared. The findings contribute to a better understanding of the movement for the young assisting the old in the crowded environment. The results have practical applications in the modeling and evacuation management for the public places where the elderly gathered, such as the aged care institutions.