Impacts of new metro lines on the activity space of older people

With declining physical health, older people face increasing travel difficulties and shrinking activity spaces, negatively impacting their well-being and raising significant equity concerns. Metro offers a promising solution to enhance the mobility of older people and expand their activity spaces. This study assesses the causal impact of new metro lines on older people’s activity spaces, using the opening of Shanghai Metro Line 15 as a natural experiment. We track activity spaces of different age groups at a grid cell level over time using a large-scale mobile phone dataset and employ difference-in-differences models to evaluate Line 15′s impact. The results show that Line 15 has expanded the activity spaces for all age groups, with older adults benefiting more than the younger groups, thus enhancing transport equality. Our findings provide evidence highlighting the significant role of metro systems in enhancing older people’s mobility, offering valuable insights for policymakers in planning age-friendly cities.