Assessing Spatiotemporal Variations in EV Charging Access and Implications for Infrastructure Equity

Abstract: Understanding EV charging accessibility, or the ability to access charging infrastructure, has critical implications for both individual mobility and community equity. However, existing studies often overlook temporally varying factors such as traffic conditions and station availability, leading to inaccuracies in accessibility assessments. This study addresses this gap by introducing a framework that evaluates accessibility to multi-tier EV charging stations, accounting for both spatial and temporal variations, using Origin-Destination (O-D) traffic data at the census block level, and assesses its impact on horizontal and vertical equity. Implemented in a major urban area, we apply the Gaussian two-step floating catchment area method for accessibility quantification and utilize real-time travel data to capture dynamic conditions. Our analysis uncovers: (i) significant temporal fluctuations in EV charging accessibility, especially during peak traffic periods, with notable effects on both horizontal and vertical equity due to varying travel times and station availability; (ii) larger disparities in higher-capacity charging station accessibility compared to lower-capacity ones; (iii) greater horizontal equity in census blocks with higher personal vehicle ownership and higher vertical equity in areas with improved charging station distribution. These findings highlight the need for targeted expansion of EV charging infrastructure, equity-focused station deployment in underserved areas, and the integration of equity considerations in future EV infrastructure planning and policy development.