The State of California is currently moving forward with a road usage charge (RUC) demonstration program, creating promising research opportunities to examine the potential social equity implications of a shift from a gas tax to a RUC system in California. RUC . To this aim, this study investigates the relative burden of gas taxes and mileage-based RUC across various sociodemographic and geographic dimensions by examining key trends in road use, vehicle ownership, fuel consumption, use of RUC-related technologies, and attitudes/opinions related to RUC adoption. Expert interviews were...