Covering All the Bases: Domain Expansion and Typologies of Subnational Electric Vehicle Policies in the United States

ABSTRACT Electric vehicles (EVs) are a key strategy for reducing transportation greenhouse gas emissions. State and local EV policies in the United States often extend beyond the transportation sector, impacting other policy subsystems and creating complex policy structures. This study combines descriptive and summative measures with text analysis to track the composition and evolution of subnational EV policy actions over nearly three decades, spanning a range of policy domains. First, we categorize these actions using labels from an existing policy typology framework. Next, we expand the framework to contextualize the emergent policy domains within subnational EV actions. Our findings demonstrate that state and local EV policies have transcended typical policy domains, now encompassing a broader range of policy areas and design considerations. This research contributes to the policy studies literature by expanding our understanding of how subnational actions might span multiple domains, especially in the context of complex problems. We also contribute to the scholarship on transportation, technology, and environmental policy by highlighting the subnational EV policies' increasingly complex and interconnected nature. By analyzing the interplay between policy domains and typologies, this study offers valuable insights for policymakers aiming to design more effective and holistic strategies for sustainability policy.