Even though Congress recently overturned rules like the Advanced Clean Trucks mandate and the Low NOx Omnibus regulation, big rig operators driving through California remain under strict environmental scrutiny. The Clean Truck Check program, enforced by the California Air Resources Board (CARB), is still fully in effect—and the penalties for noncompliance are steep.

This program requires all diesel or alternative-fuel trucks over 14,000 pounds to register in the CTC-VIS system, pay an annual fee (currently $31.18), and pass emissions tests twice a year. Starting in October 2027, trucks with 2013 model engines or newer will be required to undergo four onboard diagnostics (OBD) tests per year.

Failing to comply can be costly: fines range from $1,000 to $10,000 per truck per day, and violators may face DMV registration holds—making it illegal to operate the truck in the state.

Additionally, California Highway Patrol and CARB conduct roadside inspections using license plate scanners and Remote Emissions Monitoring Devices (REMDs). If a truck is flagged as a potential polluter, the owner will be given 30 days to complete an emissions test or face further penalties.

Tampering with emission control systems is a serious offense, with potential fines of up to $37,500 per violation.

In short, truckers operating in the Golden State must stay current with emissions tests and registration fees to avoid major consequences—and keep rolling without interruption.