Rules : Truck & Bus

Truck and Bus Regulation

CARB On-Road Heavy-Duty Diesel Vehicle Regulation


The final Truck and Bus Regulation became effective in 2014 after the amendments were approved. This rule is a statewide measure developed to reduce California diesel emissions, including diesel particulate matter (PM) and other pollutants from diesel vehicles.

Truck and Bus Regulation Applicability

  • On-road heavy-duty diesel vehicles over 14,000 GVWR
  • Out-of state vehicles that enter into California
  • Privately and federally owned trucks and buses that operate in California
    Examples: concrete mixer, dump truck, drill rig, water truck, tow truck)

Diesel trucks and buses with a GVWR that is 14,001+lbs must reduce exhaust emissions by meeting particulate matter (PM) filter requirements and upgrading to 2010 model year (MY) or newer engines.