The math behind a gas-tax-funded road system in a ZEV state.
California's 59¢/gallon gas tax — the highest in the nation — funds about 80% of the state's road and highway repairs. It generated $7.8 billion in 2023.
Under the 2035 ZEV mandate, 100% of new vehicle sales must be zero emission. The Legislative Analyst projects gas tax revenue falls roughly 64% by 2035 if the state hits its climate targets. EV owners currently pay a flat $118 Road Improvement Fee on registration — about a third of what an average gas-car driver pays at the pump.
There is no mileage tax in effect. None is currently scheduled.
SB 339 (2021). Authorized the road charge pilot program with real fee collection, replacing earlier mock-invoice studies.
AB 1421 (Jan 2026). Does not create a tax. It extends the Road Usage Charge Technical Advisory Committee from a January 2027 sunset to January 2035 — a study extension, not an implementation.
A formal recommendation set is expected in 2027. The earliest plausible legislative vote on a binding proposal is 2028+, with a mandatory rollout, if it happens, likely in the 2030s. Hawaii's path from authorizing legislation to its mandatory 2028 EV start took about five years.
At the pilot rate of 2.5¢/mile, vs. what an equivalent gas-car driver pays today.
Note: Average California driver ~11,400 mi/yr (FHWA). Gas-car estimate assumes ~25 mpg at 59¢/gal. EV current fee is the $118 Road Improvement Fee on registration.
Per-mile rates among states with RUC programs or pilots.
Hawaii is the only state with a mandatory RUC scheduled — EVs by 2028, all light vehicles by 2033. Oregon, Utah, and Virginia are voluntary.
What the funding gap, the proposal, and the pushback actually look like.
Gas tax funds ~80% of CA road repairs and brought in $7.8B in 2023. With the 2035 ZEV mandate, the legislative analyst projects revenue falls 64% by 2035. The math is not contested.
AB 1421 (passed Jan 2026) extends the Road Usage Charge Technical Advisory Committee to 2035. It does not create a tax. A formal proposal isn't expected until 2027 at earliest.
Caltrans tested 2.5¢/mile flat for light-duty (or fuel-economy variable) from Aug 2024 to Jan 2025. Real fees collected, gas-tax credits returned. Three reporting options offered, with and without GPS.
Plug-in device (with or without GPS), automaker telematics, or monthly odometer photo. The non-GPS options exist but data retention rules, audit trails, and access policies are not yet drafted.
A flat per-mile fee falls hardest on long-distance drivers — typically Central Valley, Inland Empire, and rural commuters who live far from job centers. Progressive design is possible but unspecified.
Any state mileage tax is almost certainly reimbursable on top of the 72.5¢/mile IRS rate under §2802. Mobile workforces — outside sales, home health, field service, construction — absorb the cost.
The discourse has stable inaccuracies on both sides.
The funding problem is real and not ideologically contestable — some replacement is coming. The mainstream proposal (~2.5¢/mile, replacing the gas tax) would leave the average gas-car driver roughly where they are today and meaningfully increase what EV drivers pay. The most-circulated criticisms (30¢/mile, imminent, double tax) are factually wrong as proposed.
The honest debate is over four unsolved questions: (1) Will the rate actually stay revenue-neutral over time? (2) How is the rural long-distance driver protected? (3) Who controls the location data, and for how long? (4) How does a state RUC reconcile with a future federal one? This is policy that's probably defensible in the abstract and very easy to implement badly.