Regulations

California Air Resources Board Rules

  • Advanced Clean Fleet
    • CARB is accelerating a large-scale transition of zero-emission medium- and heavy-duty vehicles from Classes 2B-8 through implementation of the ‘Advanced Clean Truck (ACT)’ approved in 2020 and ‘Advanced Clean Fleet (ACF)’ regulations approved in 2023.
    • CalCIMA continues engagement with CARB regarding creation of a fleet advisory group to support successful implementation of the ACF regulation is currently in discussion with CARB staff to provide speedy compliance training since there continues to be several outstanding questions. Please reference the attached Conveyor article ‘CARB Approves Advanced Clean Fleet Rule – What to Make of it.’
    • Additionally, CARB will not be immediately enforcing the ACF rule. The agency is awaiting a green light from the U.S. EPA per the Clean Air Act. In the meantime, CARB encourages fleets to comply, or make other fleet specific extension and exemption requests available under the rule.
    • CalCIMA comment letter
    • Conveyor article: CARB Approves Advanced Clean Fleet Rule – What to Make of It.
    • CARB ACF Enforcement Notice
Heavy Duty Inspection and Maintenance
  • CARB's Heavy Duty Inspection and Maintenance Program (HDI/M) goals:
    • To ensure heavy-duty vehicles operating in California are well-maintained and repaired when needed by performing roadside emissions monitoring to screen for potential high-emitting vehicles
    • Requiring fleets to do emissions testing procedures using on-board diagnostics (OBD) data and report data at specified intervals; and
    • Requiring fleets to do compliance verification for freight contractors, seaports, and railyards.
  • Compliance timelines:
    • January 1, 2023: CARB begins high-emitter vehicle screening using roadside emissions monitoring
    • July 1, 2023: Fleets establish reporting accounts in the HD I/M Program database and pay compliance fee
    • January 1, 2024: Fleets begin periodic compliance testing.
  • Exemptions of interest:
    • Zero-emissions vehicles
    • New vehicles with engines certified to the most stringent optional NOx standard for the first four years of the program.
  • Emissions testing:
    • OBD equipped vehicles are required to scan the engine’s OBD data using a CARB-validated OBD test device. Diesel and diesel hybrids with 2013 and newer model year engines have OBD systems. Alternative fuel vehicles 2018 and newer model year engines have OBD systems.
    • Non-OBD vehicles are required to undergo a smoke opacity test (also known as SAE J1667 snap acceleration smoke inspection) and a visual inspection of the vehicles’ emission control equipment.
    • Emissions testing must be performed by a HD I/M tester who has completed CARB free, online HD I/M Tester Training Course and exam. CARB publishes a list of HD I/M testers on their webpage.
  • Emissions testing frequencies:
    • For the first three years of the program all vehicles will have semi-annual compliance deadlines.
    • Three years following the effective date of periodic vehicle emission testing requirements, an OBD-equipped vehicle shall be subject to quarterly compliance deadlines.
  • Reporting:
    • Starting mid-2023, fleets will be required to create accounts in CARB’s HD I/M database, verify the vehicles in their fleets, and pay the first annual compliance fee of $30 for each vehicle. The database will incorporate vehicle data from existing CARB databases and from DMV data. All information will need to be validated and corrected by fleets. - HD I/M compliance certificates will be issued.
  • CARB training:
    • CARB provide training sessions to educate fleets on the HD I/M database.
  • Links