Spatial accessibility to public electric vehicle charging infrastructure and multi-mechanism process of regional inequity in Greater Bay Area, China

Although existing studies have examined the policy landscape and site distribution of public electric vehicle charging infrastructure (EVCI), they often overlook spatial inequality. Resource allocation at the local level is frequently shaped by broader macro-level policies, leading to uneven distribution and limited access. Importantly, such inequity occurs both within and across regions. Taking Greater Bay Area (GBA) as a case, we aim to investigate the spatial accessibility to public EVCI and its spatial mechanisms. Especially, the study addresses the questions: (1) How to demonstrate the spatial inequality and agglomeration of public EVCI and its accessibility at multi-level spatial scales; (2) How to compare the accessibility and impact mechanisms between different economies; (3) What are the reasons for the inequality in accessibility to public EVCI. Employing Gaussian Two-Step Floating Catchment Area, Dual Machine Learning, and Multi-scalar Geographically Weighted Regression, we find: (1) The charging facilities in the GBA exhibit a pronounced “core-periphery” spatial differentiation. (2) There is a coexistence of “high density but low accessibility” and “low density but high accessibility” phenomena. (3) The impact pathways of natural geographical conditions, socio-economic factors, and the built environment are both scale-dependent and location-specific, forming a complex mechanism that shapes EVCI accessibility. (4) The three regions have formed cross-border supply barriers. This study contributes a novel comparative framework that spans multiple socioeconomic systems and reveals how infrastructure distribution evolves under the “one country, two systems” context. By constructing a three-dimensional and multi-scale explanatory model incorporating natural, economic, and social drivers, we highlight the dynamic interplay between market forces and policy interventions, emphasizing that sophisticated governance is key to steering EVCI development towards equity and integration This research provides valuable insights for future low-altitude transportation and charging infrastructure planning, emphasizing the need for spatially differentiated, demand-responsive strategies in emerging urban mobility systems.