State and federal governments rely on fuel taxes to help build and maintain roads, bridges, and other transportation infrastructure. The federal gasoline tax has not been increased since 1993 and inflation, improvements in fuel efficiency, and an increasing share of electric vehicles on the road have created a revenue shortfall from fuel taxes in the Highway Trust Fund.

Many states have begun conducting pilot programs for a road user charge, or mileage-based user fee, which would impose a fee per mile for drivers rather than a charge per gallon of fuel. Benefits of this system are that it is not sensitive to changes in drivetrain technology to electric vehicles, can be designed to be less regressive than a gasoline tax, and can be easily adjusted for inflation. However, implementing a new tax would have challenges. This policy brief summarizes findings and policy implications from University of California, Davis research that assessed the administration of the gasoline tax, including collection and distribution of revenues, to determine what barriers and opportunities might exist for a road user charge funding mechanism.

Key words: policy, funding, planning