Assessing the Hierarchical Diversity of Public Transportation Considering Connectivity and Its Implication on Regional Sustainability

Given a decreasing and aging population, there is a growing need to establish convenient public transportation systems that offer a variety of transportation modes seamlessly connected to one another. This study attempts to develop an index to assess the hierarchical diversity of public transportation, drawing an analogy between public transportation networks and ecosystems. By considering both hierarchical (meta-physical) and physical connections among respective modes, which are aspects that have not been addressed in previous studies, this study aims to enhance the spatial resolution of the analysis units in the index. The diversity indices were applied to the northern Osaka area in Japan as the study site. The results show a correlation between the diversity index, population, and public transportation modal share. We then discuss the influence of hierarchical diversity on the sustainability of public transportation systems and regional development.