Current standard
Semi-Annual Testing
Most heavy-duty vehicles must complete emissions testing twice a year.
2 tests across a compliance year
The California Air Resources Board (CARB) requires emissions testing for certain vehicles to meet air quality standards. Here is exactly who needs it, how often, and how each test works.
Reference guide3 min read
Vehicle test report
CTC-VISNext test due: in 6 months
Illustrative report - we file yours through CTC-VIS.
Diesel and alternative fuel vehicles with a Gross Vehicle Weight Rating (GVWR) over 14,000 pounds must undergo emissions testing as part of CARB's Clean Truck Check program.
Frequency depends on your vehicle class — and it is about to change for OBD-equipped vehicles.
Most heavy-duty vehicles must complete emissions testing twice a year.
2 tests across a compliance year
Some vehicles, like specific agricultural vehicles and California-registered motorhomes, may qualify for annual testing.
1 test across a compliance year
Vehicles equipped with On-Board Diagnostics (OBD) systems will transition to quarterly emissions testing, ensuring real-time compliance monitoring.
4 tests across a compliance year
Which procedure applies depends on whether your vehicle has an On-Board Diagnostics system.
For vehicles with OBD systems, emissions data is collected directly from the onboard computer. This ensures that emissions controls are functioning correctly.
For older vehicles without OBD systems, a smoke opacity test measures the density of exhaust smoke. This test evaluates the level of particulate emissions.
Failing to meet testing requirements can result in fines, registration holds, and other enforcement actions. Ensure compliance to avoid disruptions to vehicle operations.
Fines and penalties
Monetary penalties issued by CARB
Registration holds
The DMV can block your vehicle registration
Enforcement actions
Disruptions to your vehicle operations
New filings, renewals, vehicle additions and 5-Day Pass requests.
Browse servicesDeadlines, documents, fees - the answers truckers ask us for most.
Read the FAQsNot sure what applies to your vehicle? Ask us before you file.
Contact usPrefer to talk it through? (800) 213-0491