Clean Truck Check Credentialed Tester

Clean Truck Check Testers in California

2,507 CARB-credentialed testers across 509 cities in six freight-corridor regions.

Recommended testers

By region

Top cities

449 more cities — see each region for the full list.

Trucking activity in California

FMCSA MCMIS reports 132,700 active motor carriers registered with operations in California. The Clean Truck Check program reaches the heavy-duty subset that operates in California, which is why this directory exists.

Interstate carriers
104,100
Intrastate carriers
28,600
Hazmat carriers
7,100
Passenger carriers
2,820
Heavy-duty power units
376,500
Medium-duty power units
52,400

Source: FMCSA MCMIS Registration Statistics. Snapshot 2024-10-01. Last fetched 2026-05-18.

CARB Clean Truck Check program status

The California Air Resources Board administers Clean Truck Check as the statewide heavy-duty inspection & maintenance program. Every non-gasoline truck over 14,000 lb GVWR operating in California must comply, regardless of where the carrier is based.

2024 – 2027
2× per year

Two compliance tests per vehicle per year, plus the annual fee paid through CTC-VIS.

2028 onward
4× per year

Quarterly cadence kicks in starting October 2027 for compliance deadlines falling in 2028 and later — four tests per truck per year.

Compliance is filed through CTC-VIS — CARB's vehicle-inspection portal. Tests are performed by CARB-credentialed testers listed on this directory.

Compliance reference →2027 testing changes →CTC-VIS account setup →

Source: CARB Clean Truck Check program page. Cadence dates from CARB rulemaking (Title 17 CCR §§ 2196 et seq.). Rule snapshot 2026-01.