Enforcement of Clean Truck Check HD I/M Regulation
Enforcement of Clean Truck Check – Heavy-Duty Inspection and Maintenance (HD I/M) Program Regulation:
The Clean Truck Check HD I/M regulation began in January 2023 to ensure polluting, poorly maintained heavy-duty vehicles operating in California are quickly identified and repaired, and to promote a level playing field for businesses that operate compliant vehicles. This webpage is designed to assist vehicle owners, operators, freight contractors, seaports, and railyards to respond to CARB once they are engaged in enforcement actions that may result from inspections, tests, or audits of vehicles, engines, and records.
More about this program
Notice to Submit to Testing (NST) Letter
Responding to a Notice to Submit to Testing letter issued by CARB Enforcement under HD I/M.
