Mobile Source Emissions Reduction Requirements

Through its Mobile Sources Program, the California Air Resources Board (ARB) 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.

The on-road heavy-duty diesel vehicle rule (i.e., truck and bus regulation) 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 (lbs.). School buses owned by private and public entities and federal government owned vehicles are also included in the scope of the rule. By January 1, 2023, nearly all vehicles must have engines certified to the 2010 engine standard or equivalent. The drayage 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, 2023, all applicable vehicles must have engines certified to 2010 standards. The innovative clean transit rule sets emissions reduction standards for new public transit vehicles and requires major transit agencies to purchase only zero emission buses after 2029. The solid waste collection vehicle rule regulates solid waste collection vehicles with a gross vehicle weight rating of 14,000 lbs. 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 the requirements for diesel truck and equipment owners can be found in the ARB Multi-Rule Summary fact sheet. (Reference California Code of Regulations Title 13, 2021-2027)

Point of Contact
Diesel Hotline
California Air Resources Board
Phone: (866) 6DIESEL (634-3735)
8666diesel@arb.ca.gov