建成环境与出行脆弱群体的地铁出行关联机制探究

Transportation equity for mobility-vulnerable groups is an important issue of social equity. As the arterial system of cities, metro systems, due to their advantages of safety, reliability, punctuality, and efficiency, serve as a crucial guarantee for ensuring mobility equity for vulnerable groups, such as the seniors and underage students. The built environment surrounding metro stations, as an important component of urban transportation spaces, not only influences the metro travel behavior of these groups, but also reflects spatial justice through its equal accessibility. However, the mechanisms and pathways by which the built environment affects travel remain unclear. This study focuses on seniors and underage students in Kunming, selecting frequent travelers from both groups based on smart card data from the metro system. By integrating multi-source data, including land use, the study employs a Gradient Boosted Decision Tree (GBDT) model to reveal the complex mechanisms between the built environment around metro stations and the metro travel behavior of these two groups, comparing the differences in impact pathways between them. The results show that: (1) The relationship between the built environment and metro ridership of different groups exhibits four patterns: overall consistency, group diversity, senior group specificity, and student group specificity; (2) Variables such as land use mix, road network density, betweenness centrality, and proximity to intercity transport hubs have a relatively consistent effect on metro ridership across different groups, while the influence of other variables differs significantly; (3) The number of residential communities and land use mix have a consistent relationship with metro ridership across groups, showing a mainly positive nonlinear relationship and an inverted U-shaped relationship, respectively, while the relationships between other variables and metro ridership vary; (4) Compared to traditional linear models, the nonlinear model is more sensitive and can more accurately capture threshold effects. This study deepens the application of spatial justice theory in transportation geography and provides theoretical and empirical support for guiding travel for vulnerable groups and optimizing the built environment around metro stations.