Charging ahead unfairly: An examination of temporal shifts in electric vehicle supply equipment accessibility across California’s communities

With the expansion of electric vehicle (EV) use, it has become increasingly important to ensure that public electric vehicle supply equipment (EVSE) meets growing demand and is accessible to everyone in need. Yet a meaningful assessment of how communities have benefited from EVSE expansion requires a lens that goes beyond static snapshots of EVSE accessibility. In this study, we conduct a longitudinal analysis over the past decade (2014–2024) to uncover how public charging infrastructure has evolved and how accessibility has shifted over time in the State of California. We examine EVSE accessibility across communities using a mixture of descriptive and statistical methods. A core feature of our analysis is that we examine changes in accessibility over time using a generalized additive model (GAM) with time-varying effects. Our findings suggest that accessibility patterns across California’s communities have varied according to three distinct stages in EVSE deployment: early deployment and planning, accelerated expansion, and coordinated growth. The GAM analysis identifies a clear temporal shift in relative EVSE accessibility levels across income groups: lower-income locations exhibited relative advantages prior to 2017, but higher-income locations became increasingly advantaged during the accelerated expansion phase in later years. Majority Black locations maintained above-average accessibility but experiencing a gradual decline over time, while majority Hispanic locations remained consistently below average throughout the study period. These time-varying findings enhance understanding of how disparities unfold across deployment stages and motivate more adaptive, stage-aware EVSE policy design.