Spatial accessibility research of public facilities considering the intensity of human activities: an analysis based on tertiary hospitals in Shenzhen, China

Abstract Evaluating and optimizing the accessibility of public facilities is a crucial task in urban planning and resource allocation. However, existing studies seldom consider the impact of human activity intensity on spatial accessibility, which leads to the calculation results being inconsistent with the actual situation. This study introduced floating vehicle and mobile phone signaling data, which used to represent the intensity of human activities in various time periods and age groups, and used an improved Gaussian two-step floating catchment area (Ga2SFCA) method to carry out accessibility analysis of public facilities. An analysis based on tertiary hospitals in Shenzhen, China, was performed, and the results indicate that: (1) Significant spatial disparities persist, with central districts such as Futian, Nanshan, and Luohu demonstrating higher accessibility, while peripheral areas like northern Bao’an and Longgang remain underserved; (2) Accessibility varies notably across time periods, declining during peak traffic hours and improving during off-peak periods, highlighting the influence of commuting dynamics; (3) Age-based inequalities in access are evident, with adolescents and older adults experiencing the greatest disparities due to limited mobility and centralized healthcare resources. This study underscores the importance of incorporating real-time spatiotemporal data and population heterogeneity into accessibility evaluations and provides evidence-based guidance for optimizing medical facility planning and transport infrastructure development in rapidly urbanizing cities.