California Regulations to Reduce Heavy-Duty Vehicle Emissions

On December 12, 2008, the California Air Resources Board (ARB) adopted two regulations to reduce greenhouse gas emissions from heavy-duty vehicles. One regulation requires diesel-powered trucks, buses, and shuttles to install exhaust filters by 2014 and requires that engines older than the 2010 model year be replaced by 2022. Vehicles have three options for compliance with this regulation: using a compliance schedule, in which vehicle compliance dates depend on the engine model year; a fleet percentage system, in which an incremental percentage of fleets must meet NOx and Particulate Matter (PM) standards each year; or a fleet average system, in which averaged fleet NOx and PM levels must be lowered over time. Several vehicles are exempted, including limited-use and low-mileage vehicles, and small fleets have options for delayed compliance.

The second regulation requires that heavy-duty tractors and trailers over 53 feet meet certain efficiency criteria developed by the U.S. EPA, including using aerodynamic trailer skirts, mirrors, cab extenders, and other tractor additions, as well as using tires that meet U.S. EPA fuel savings standards.

The ARB has stated that several funding options will be available to ease the financial burden of these regulations. Funding options from other statutes will be available. The ARB estimates that the diesel regulation will reduce diesel emissions 68 percent and reduce NOx emissions 25 percent by 2014.

Press Release
Statewide Bus and Truck Regulation
Heavy-duty Vehicle GHG Reduction Measure