California Trucking Rules: Clean Truck Check, AB5 and 55 MPH
The state runs its own emissions testing, engine and labor rules on top of federal ones. Some reach out-of-state trucks, and two of them changed in 2025 and 2026.
California is the only state where an interstate truck faces a separate emissions program on top of federal rules. Diesel trucks rated over 14,000 lb that operate in the state must pass CARB’s Clean Truck Check and have a 2010 or newer engine, and any truck with three or more axles or pulling a trailer is held to 55 mph. Status below is as of November 2026.
Labor law adds another layer: the AB5 employment test changes how carriers can use owner-operators. Each rule has its own scope, so a carrier based in Arizona and a fleet based in Fresno do not face exactly the same list.
What is Clean Truck Check and who has to comply?
Clean Truck Check is the California Air Resources Board’s Heavy-Duty Inspection and Maintenance Regulation. CARB says it covers nearly all diesel and alternative-fuel trucks, buses and other vehicles with a gross vehicle weight rating over 14,000 lb that operate in California, including hybrids, government vehicles and vehicles registered in other states.
Each vehicle has to be reported in CARB’s online system, CTC-VIS, have its annual compliance fee paid and submit passing emissions tests. The main requirements:
| Item | Requirement as of November 2026 |
|---|---|
| Test frequency | Every six months for most vehicles; four times a year for vehicles with on-board diagnostics starting October 2027 |
| Test window | Up to 90 days before each compliance deadline |
| Deadlines, California plates | Set by the DMV registration expiration month, then every six months |
| Deadlines, out-of-state plates | Set by the last digit of the VIN |
| Annual fee | $32.13 per vehicle for 2026 deadlines; $33.12 for deadlines on or after January 1, 2027 |
| Payment | Through CTC-VIS by debit or credit card or eCheck |
| Noncompliance | DMV registration blocks for California vehicles and other enforcement action |
The fee rises each year with the California consumer price index, and CARB posts the next year’s amount by July 1. Details and the testing schedule are on CARB’s Clean Truck Check program page.
Does Clean Truck Check apply to out-of-state trucks?
CARB says yes, but the federal government has declined to back that part. On February 6, 2026, EPA approved the regulation into California’s federally enforceable air plan only for vehicles registered in California. It disapproved the portion that applies to out-of-state and out-of-country vehicles, finding that California had not given adequate assurance that enforcing it is not barred by federal law. The action took effect March 9, 2026, and the text is in the EPA notice in the Federal Register.
EPA also wrote that its decision does not settle whether California may keep enforcing the rule under state law. CARB’s program page, updated in March 2026, still lists out-of-state vehicles as covered. A carrier that sends trucks into California should check each unit’s status in CTC-VIS rather than assume it is exempt.
Which engines does the Truck and Bus Regulation allow?
Since January 1, 2023, CARB’s Truck and Bus Regulation has required diesel vehicles operating in California with a GVWR over 14,000 lb to have a 2010 or newer model year engine and emissions system, with few exceptions. California-registered trucks that do not comply are denied DMV registration.
In practice this rules out pre-2010 diesel trucks for California work, whether they are plated in the state or not. Buyers of used trucks should confirm the engine model year, which can differ from the chassis year. Federal engine standards for new trucks, including the 2027 NOx limits, are covered in our guide to truck emissions rules.
What happened to Advanced Clean Fleets and the drayage rules?
The parts of Advanced Clean Fleets that would have forced private fleets and drayage trucks into zero-emission vehicles are being repealed. The timeline:
- January 13, 2025: CARB withdrew its request for the EPA waiver it needed to enforce Advanced Clean Fleets on drayage, high-priority and federal fleets.
- June 2025: Congress used the Congressional Review Act to revoke EPA’s waivers for CARB’s Advanced Clean Trucks and Omnibus Low-NOx rules. California called the votes illegal.
- June 12, 2025: Governor Newsom’s Executive Order N-27-25; CARB’s drayage page now asks affected fleets to report voluntarily through its TRUCRS system.
- 2025 rulemaking: the CARB board voted to repeal the drayage and high-priority fleet sections and keep the state and local government fleet rules, with a three-year delay in zero-emission purchase requirements.
CARB said the amendments were expected to take effect before January 2027. Its guidance dated June 2026 describes the amended rule as not applying to private fleets.
How does AB5 affect owner-operators in California?
AB5 put the ABC test into California law, and under it a driver is an employee unless the hiring company proves all three parts: the driver is free from its control, the work is outside the usual course of its business, and the driver runs an independently established business. The second part is the hard one for a motor carrier leasing owner-operators to haul freight, because hauling freight is the carrier’s usual business.
The California Trucking Association argued that federal law preempts AB5 for motor carriers. The Ninth Circuit disagreed, and in June 2022 the U.S. Supreme Court declined to hear the case, which let enforcement begin. The law includes a business-to-business exemption with a list of conditions, but whether a lease arrangement qualifies depends on the facts, so carriers and drivers should get advice from a California employment attorney. The cost differences between the two models are laid out in owner-operator vs company driver.
What is the truck speed limit in California, and do meal breaks apply?
California Vehicle Code section 22406 sets a 55 mph maximum for trucks and truck tractors with three or more axles and for any truck or tractor pulling another vehicle, even on highways posted at 65 or 70 mph for cars. Caltrans also requires these vehicles to stay in the lanes designated for them.
California’s meal and rest break rules do not apply to property-carrying drivers who are subject to the federal hours-of-service rules. FMCSA ruled on December 21, 2018 that federal law preempts them for those drivers, and the Ninth Circuit upheld that decision in 2021. Unions and safety groups later asked FMCSA to waive the preemption; FMCSA requested comments in December 2023, and we found no published decision on those petitions as of early November 2026. Drivers who are not subject to the federal hours-of-service rules are outside the preemption.
Bottom line
The Clean Truck Check status of out-of-state trucks is the open question to watch: CARB still lists them as covered, while EPA declined to make that part federally enforceable. Fleets that run into California only occasionally should budget for the $33.12 fee and two tests a year per truck in 2027, and plan for four tests a year on OBD-equipped trucks from October 2027.
FAQ
Do I need Clean Truck Check for a truck that enters California once a year?
CARB’s rule covers vehicles over 14,000 lb operating in the state, with no minimum number of trips. Because EPA disapproved the out-of-state portion for federal purposes, check CARB’s current guidance and your CTC-VIS account before the trip.
Can I run a 2008 truck in California?
Not under the Truck and Bus Regulation, which since 2023 has required 2010 or newer engines for diesel trucks over 14,000 lb, with few exceptions. CARB lists the remaining exemptions on its program pages.
Is the California truck speed limit really 55 mph?
Yes. Under Vehicle Code 22406 a tractor-trailer, or any truck with three or more axles, may not exceed 55 mph on any California highway.
Are drayage trucks still required to go zero-emission?
No. CARB withdrew its waiver request in January 2025 and voted to repeal the drayage requirements of Advanced Clean Fleets. The state and local government fleet rules remain.
