Does affordable housing provide a better life for vulnerable groups? Measuring social equity through public transit accessibility

Affordable housing is a vital measure to alleviate housing pressure for low-income urban populations. However, the lack of comprehensive research on its residents' access to opportunities and services hinders our understanding of actual effectiveness and rationality. In this paper, we establish a equity evaluation system based on Shenzhen's public transit route and station data, operation data, point of interest data, and resident travel survey data. We use improved Shortest Path Faster Algorithm (SPFA) and spatial analysis to build a public transit network that considers transfers. We use an opportunity accumulation model that considers distance decay to calculate the ease with which residents in different locations can access public service facilities, and analyze the distribution balance of social resources. We also analyze whether the actual living needs of different groups are met based on housing type differentiation. Our findings reveal a “high-high clusters” and “low-low clusters” in the spatial distribution of healthcare and education facilities, showing resource scarcity and over-concentration respectively. Affordable housing, despite its potential to address a portion of the housing issues, struggles to provide a convenient living environment due to suboptimal location, making urban villages may be a better choice for low-income groups. The needs of affordable housing residents in the suburbs should be given special attention. Our universally applicable research framework guides improved public resource allocation. It aids in optimizing site selection for affordable housing, enhancing public facilities, and expanding public transit routes, thus addressing vulnerable groups' needs.