California Assembly Bill 1421 extends the state’s Road Usage Charge Technical Advisory Committee and its voluntary pilot program through January 1, 2035. Without the bill, both were set to expire on January 1, 2027. AB 1421 does not create a mileage tax, raise any fee, or require drivers to do anything different. It keeps a study alive for another eight years.1Digital Democracy. AB 1421: Vehicles: Road Usage Charge Technical Advisory Committee
What the Bill Actually Does
The bill does one concrete thing: it moves the sunset date on California’s road usage charge provisions from January 1, 2027, to January 1, 2035. Existing law already requires the Chair of the California Transportation Commission, working with the Secretary of Transportation, to convene a Technical Advisory Committee that guides development and evaluation of a mileage-based revenue pilot. Separate existing law requires the Transportation Agency, in consultation with the commission, to run that pilot. AB 1421 leaves both structures untouched. It just gives them more time.1Digital Democracy. AB 1421: Vehicles: Road Usage Charge Technical Advisory Committee
Does This Mean California Drivers Pay a Per-Mile Fee Now?
No. AB 1421 imposes no new tax and no new fee. Participation in the pilot is voluntary, and no per-mile charge applies outside that testing framework. If you don’t sign up for the pilot, nothing about your driving costs changes because of this bill. The gas tax continues to work the way it always has.
Why California Keeps Studying a Mileage-Based Charge
California funds a large share of its road work through per-gallon taxes on gasoline and diesel. As more drivers move to electric vehicles and high-efficiency hybrids, per-gallon revenue drops while the roads absorb the same use. A road usage charge would tax miles driven instead of fuel burned, so every driver contributes regardless of what powers the vehicle. California has one of the highest EV adoption rates in the country, which makes the revenue gap sharper here than in most states.
What the Pilot Is Testing
The pilot has tested several ways to measure miles: annual odometer readings, GPS-based reporting, and third-party devices that plug into a vehicle’s diagnostic port. Each method trades off accuracy, convenience, and privacy differently. A flat odometer-based fee is simplest but can’t separate California miles from out-of-state miles. GPS can draw that line but raises concerns about the government seeing where people drive. Sorting through those trade-offs is much of the committee’s work, and it is a major reason the program was granted more time.
What the Technical Advisory Committee Can and Cannot Do
The committee is advisory. It studies how mileage-based fees could work, reviews pilot results, and makes recommendations. It has no authority to impose a charge. Any move from the gas tax to a per-mile fee would require separate legislation, with its own hearings and public debate.1Digital Democracy. AB 1421: Vehicles: Road Usage Charge Technical Advisory Committee
What Would Have to Happen Before Any Real Charge
The pilot would need to produce a workable model, the legislature would need to pass a separate bill adopting it, and lawmakers would almost certainly pair any new per-mile fee with a reduction or elimination of the existing gas tax to avoid charging drivers twice for the same miles. That decision is years away. AB 1421 simply keeps the option on the table by keeping the research going until 2035.