California Governor Vetoes Bill Clarifying DUI Liability for Partially Automated Vehicles

On September 27, 2026, California Gov. Gavin Newsom vetoed Assembly Bill 2502 (AB 2502), which sought to explicitly redefine 'drive' under DUI, reckless driving, and vehicular manslaughter statutes to include the use of Level 0-3 driver support features—such as Tesla Autopilot—when a human supervisor is required. The bill passed both chambers with strong support before reaching the governor's desk. Newsom acknowledged the intent to close potential loopholes for impaired drivers relying on semi-autonomous systems but cited drafting issues, including undefined terms like 'driver support features' that could complicate enforcement by requiring courts to assess vehicle software capabilities. The measure was prompted by incidents like a 2018 case of a Tesla driver found passed out on the Bay Bridge with elevated blood alcohol levels, who reportedly claimed Autopilot absolved responsibility. Supporters, including AAA clubs, argued it addressed growing misuse amid misleading marketing of advanced driver-assistance systems (ADAS). Existing California precedent from Mercer v. DMV (1991) already holds that slight volitional movement suffices for DUI charges, and legal analyses confirm Level 2 systems like Autopilot still require active human oversight. Newsom recommended revisiting the issue in 2027 with clearer language aligned to SAE automation standards. The veto aligns with Newsom's broader approach to AV regulation, having signed some bills while rejecting others imposing stricter operator requirements or data mandates on autonomous tech firms.