Truck and Bus Regulation
On-Road Heavy-Duty Diesel Vehicles (In-Use) Regulation

This page last reviewed December 10, 2015

On Road Vehicles


The regulation requires diesel trucks and buses that operate in California to be upgraded to reduce emissions. Newer heavier trucks and buses must meet PM filter requirements beginning January 1, 2012.  Lighter and older heavier trucks must be replaced starting January 1, 2015. By January 1, 2023, nearly all trucks and buses will need to have 2010 model year engines or equivalent.
The regulation applies to nearly all privately and federally owned diesel fueled trucks and buses and to privately and publicly owned school buses with a gross vehicle weight rating (GVWR) greater than 14,000 pounds.  The regulation provides a variety of flexibility options tailored to fleets operating low use vehicles, fleets operating in selected vocations like agricultural and construction, and small fleets of three or fewer trucks.  

For other information about this regulation, other diesel engine regulations, or training programs, please contact an ARB diesel representative at 866-6DIESEL (866-634-3735) or visit the Truck Stop website.  This regulation does not apply to drayage trucks that transport marine containers.

Please sign up to receive email updates at the Truck and Bus Regulation Listserve.

What's New: 

The Truck and Bus Reporting System Now Available for 2016 (December 10, 2015)
  • The Truck and Bus regulation reporting system is now available for fleet owners to report diesel vehicle information for 2016 at no cost. From this site, you can report your company and vehicle information. We encourage fleets to report early, before the January 31, 2016 reporting deadline. If you have previously reported, you can access to your account by using your user name and password.
Lighter Vehicle Compliance Options (September 21, 2015)
Diesel Particulate Filter Evaluation (May 11, 2015)
  • In October 2013, the Board directed staff to investigate stakeholder concerns regarding the cost, reliability, and fire safety of diesel particulate filters in on-road applications. Staff provided an update to the Board in April 2014, and the attached report discusses findings from the completed evaluation.
The Truck and Bus Reporting System Updated for 2015 Compliance Options (December 18, 2014)
  • The Truck and Bus regulation reporting system and the Online Reporting Guide has been updated to include 2015 compliance requirements and options. January 1 of every compliance year, fleet owners that use flexibility options in the regulation must identify which vehicles will use a particular extension and provide any additional information required.  We encourage fleets to report early, before the January 31, 2015 reporting deadline.
Early Access to Economic Hardship and Agricultural Vehicle Extensions  (September 12, 2014)
  • Advisory MSC 14-13 provides early access to the economic hardship extension and compliance options for cattle trucks and other agricultural vehicles.     
Modified Text of the Truck and Bus Regulation is Available for a 15 Day Public Comment Period (June 30, 2014) 
  • The 15-Day Notice of Public Availability of Modified Text is now available. These modifications extend the compliance date for the second truck in the small fleet option, revise the new option for fleets that cannot afford to comply, modify the requirements for cattle livestock trucks, and include other minor modifications. 
Advisory on Early Access to Certain Approved Amendments (June 27, 2014) 
  • The Board approved amendments to the Truck and Bus Regulation at its April 2014 meeting.  An Advisory has been made available to explain how truck and bus owners can plan for and take advantage of recently approved amendments and describes the steps owners that previously claimed good faith efforts must now take to comply. 
Amendments to the Truck and Bus Regulation Planned for April 2014  (March 7, 2014)
  • The Air Resources Board will conduct a public meeting on April 24, 2014, in Sacramento, to discuss proposed amendments to the regulation. A brief summary of the proposed changes and information about the rulemaking are available.

What's New Archive