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Mobile Source Emissions Reduction Requirements

Through its Mobile Sources Program, the California Air Resources Board has developed programs and policies to reduce emissions from on-road heavy-duty diesel vehicles through the installation of verified diesel emission control strategies (VDECS) and vehicle replacements.

An on-road heavy-duty diesel vehicle rule requires the retrofit and replacement of nearly all privately owned vehicles operated in California with a gross vehicle weight rating (GVWR) greater than 14,000 pounds. School buses owned by private and public entities and federal government owned vehicles are also included in the scope of the rule. The requirements phase in the installation of VDECS on certain heavier in-use vehicles beginning January 1, 2012, and require the replacement of older vehicles starting January 1, 2015. By January 1, 2023, nearly all vehicles must have engines certified to the 2010 engine standard or equivalent. A drayage/port truck rule regulates heavy-duty diesel-fueled vehicles that transport cargo to and from California's ports and intermodal rail facilities. The rule requires that certain drayage trucks be equipped with VDECS and that all applicable vehicles have engines certified to the 2007 emissions standards by January 1, 2014. A public transit agency fleet rule regulates public transit fleets and sets emissions reduction standards for new transit vehicles. A solid waste collection vehicle rule regulates solid waste collection vehicles with a gross vehicle weight rating of 14,000 pounds or more that operate on diesel fuel, have 1960 through 2006 engine models, and collect waste for a fee. The fleet rule for public agencies and utilities requires fleets to install VDECS on vehicles or purchase vehicles that run on alternative fuels or use advanced technologies to achieve emissions requirements by specified implementation dates.

A summary of Requirements for Diesel Truck and Equipment Owners can be found in the Multi-Rule Summary Fact Sheet. (Reference California Code of Regulations Title 13, 2021-2027)