Enforcement-Clean Truck Check Clean Truck Check (HD I/M)AboutNewsResources Vehicle Owner InformationFact Sheets, Guides & VideosInstructional Videos (CTC-VIS)EnforcementCredentialed Testers & Testing DevicesReferee ProgramTesting Device Vendor Information Subscribe Contact Clean Truck Check (HD I/M) Email hdim@arb.ca.gov Phone (866) 634-3735 For statistics regarding the enforcement of Clean Truck Check please see Enforcement Data - Clean Truck Check