In-Use Off-Road Diesel Vehicle Regulation
This page last reviewed March 18, 2014
On July 26, 2007, the Air Resources Board (ARB) adopted a regulation to reduce diesel particulate matter (PM) and oxides of nitrogen (NOx) emissions from in-use (existing) off-road heavy-duty diesel vehicles in California. Such vehicles are used in construction, mining, and industrial operations. The regulatory language and information on reporting and compliance tools can be accessed by clicking the quick links buttons above. For more information, please contact the Diesel Hotline.
What's New?:Posted March 18, 2014
- Fleet Average Calculator for Large Fleets has been updated and expanded.
The fleet average calculator for large fleets has been expanded to
include all compliance years out to January 1, 2023, and is available here.
The calculator has also been updated with additional features to better
aid large fleet owners in planning out their compliance strategies.
The User Guide has been updated as well to reflect the changes to the calculator, and fleet owners are advised to read it before making use of the calculator.
- U.S. EPA authorization granted. ARB has
received authorization from the United States Environmental Protection
Agency (U.S. EPA) to enforce the In-Use Off-Road Diesel Vehicle
Regulation, including the regulation’s performance requirements, such
as turnover requirements and restrictions on adding older, dirtier Tier
0 and 1 vehicles. Enforcement of the restrictions on adding Tier
0 and 1 vehicles will begin January 1, 2014. Enforcement of the
first fleet average requirements for large fleets (> 5,000 total
fleet horsepower) will begin on July 1, 2014. Regulatory Advisory 13-25 discusses further how ARB staff will proceed with the enforcement of
- Video of the Off-Road Regulation Compliance Training (Course 504) is now available. Not able to attend a class but still have questions about the Off-Road Regulation and how to comply? A video of the recorded class presentation is now available.
- The revised Fleet Average Calculator for
large fleets is now available.
The calculator is
for the large fleet January 1, 2014 compliance date only, and can be
Fleet owners utilizing the calculator are advised to first read the revised User Guide in order to familiarize themselves with the calculator.
The Fleet Average Calculator is an Excel spreadsheet designed to assist fleet owners in calculating their Fleet Average Index and Fleet Average Targets, based on the equipment model year and horsepower input. The calculator allows fleets to experiment with different turnover, repower, and retrofit strategies to plan for compliance with the in-use off-road diesel vehicle regulation.
- March 1, 2013 deadline for ROARs and locking
some data in DOORS.
By March 1, 2013,
large fleets must submit a signed Responsible Official Affirmation of
Reporting (ROAR) to ARB. By the same date, large fleets must designate
appropriate vehicles as low-use for 2012, and submit hour meter
Also, as of March 1, 2013, fleets will no longer have the ability to use the "Oops Unsell", or "Oops Restore" features for vehicles and engines removed in 2012. Similarly, fleets will no longer be able to move vehicles among fleets in their DOORS account using the "Reassign Vehicle" function, nor to change how their fleet portions are aggregated using the "Aggregate Fleet" function. Fleets under common ownership or control must decide now if/how they want to apportion themselves, and ensure that parent fleets are reported properly.
Please see the Knowledge Center for more information; in particular, see the FAQs, "ROAR," "Fleet Portions," and "Fleet Size - Private Fleets," and the DOORS user guides, " How to Report Fleet Portions or Multiple Fleets" and "Reassign Vehicles."
- ARB staff is offering Course 504: In-Use Off-Road Diesel Vehicle Regulation Training at various locations throughout California on September 19, 2012, through November 6, 2012. This class will provide an overview of the Off-Road regulation, including the applicability, requirements, and the Diesel Off-Road Online Reporting System (DOORS). ARB staff will also be available after the class to answer individual questions. For more information on this class, including how to register, please see the course #504 website.
- Many two-engine vehicles that were designed
to be driven on-road are subject to the Off-Road Regulation and must be
more information see Regulatory
Effective January 1, 2013, all in-use off-road vehicles will be required to have both sides of their vehicles labeled with Equipment Identification Numbers (EINs), and Captive Attainment Area Fleets will be required to label their off-road vehicles with EINs that are white with a green background. For more information see Regulatory Advisory 12-08.
- By March
1, 2012, large fleets (those with off-road vehicles totaling over 5,000
horsepower and state and federal fleets) are required to submit a
Responsible Official Affirmation of Reporting (ROAR) to ARB. The ROAR
is a signed statement affirming that the information reported is
accurate. Beginning in 2012 for large fleets, 2016 for medium fleets,
and 2018 for small fleets, the In-Use Off-Road Diesel Vehicle
Regulation requires fleets to annually update and affirm their
In addition to the ROAR, the annual update must include reporting of engine hour meter readings for low-use vehicles and vehicles used for more than half their annual operating hours for agricultural operations. For more information on reporting low-use vehicles, see the Low-Use Vehicles DOORS user guide. The log for reporting hours for agricultural operations vehicles is available here and within DOORS.
Also by March 1, 2012, nearly all on-road vehicles with two diesel engines must be reported and are subject to the In-Use Off-Road Diesel Vehicle Regulation. Further information concerning this new requirement is available in Regulatory Advisory 12-02-B.
Posted January 30, 2012
- On March
1, 2012, large fleets (those with off-road vehicles totaling over
5,000 horsepower) are required to submit a Responsible
Affirmation of Reporting (ROAR) to ARB. The ROAR
is a signed
statement affirming that the fleet information reported is accurate and
that the fleet is in compliance. Beginning in 2012 for large fleets,
2016 for medium fleets, and 2018 for small fleets, fleets must annually
update and affirm their reporting information is correct.
Log into your DOORS account and choose the button labeled "ROAR Forms" to print out the ROAR form, sign, and mail or email it to the ARB.
Posted December 22, 2011
- Final Amended Off-Road Diesel Vehicle Regulation. On December 14, 2011, the Office of Administrative Law approved amendments to the regulations for In-Use Off-Road Diesel-Fueled Fleets (Off-Road regulation) and Large Spark-Ignition Engine Fleet Requirements (LSI Fleet regulation). The amendments became effective on that same day, December 14, 2011. For more information on the amendments to both regulations, please see the website for this rulemaking here.
Posted November 10, 2011
- Final Rulemaking Package for the Amendments to the Off-Road and LSI Fleet Regulations. Staff have posted the Final Rulemaking Package for the amendments to the Off-Road and LSI Fleet regulations. The package was filed with the Office of Administrative Law (OAL) on October 28, 2011, and OAL has until December 14, 2011 to make a determination. The package includes the Final Statement of Reasons which includes ARB's responses to all comments received on the Off-Road and LSI Fleet regulations during the public comment periods.
Posted September 30, 2011
- Advisory on the Delay or Suspension of the Installation of Particulate Matter (PM) Filters. MSC Mail-Out 11-29 has been posted to address compliance when a manufacturer of a verified diesel PM filter suspends sales and installations of a PM filter, or requires its removal for a particular engine family.
Posted March 29, 2011
- 2011 Large Fleet Reporting and Compliance Certification. ARB will not be enforcing the off-road regulation large fleet reporting and compliance certification deadline this year. The first large fleet annual reporting date and due date for a signed statement affirming compliance will instead be March 1, 2012. However, we encourage fleets to double check that their DOORS data is accurate. Also, the requirements to report added vehicles to ARB within 30 days, to label vehicles with Equipment Identification Numbers (EINs), and to limit idling to 5-minutes or less, remain in effect and are being enforced.
- A fact sheet summarizing the December 2010 amendments now available. A fact sheet summarizing the December 2010 amendments to the In-Use Off-road Diesel Vehicle Regulation is now available here.
Posted January 12, 2011
- Attachment B to Draft Resolution now
available. At the December 17, 2010 Board Hearing, Air
Resources Board staff distributed a draft 15-day modified regulation
order as Attachment
B to the draft resolution. Staff will finalize the draft
regulation order per the direction of the board as soon as possible,
including adding a compliance option to allow on-road and off-road
vehicles that have been retrofit to count towards the compliance
requirements of either regulation. Staff will then make it available to
the public for a supplemental written comment period of at least 15
days in accordance with section 11346.8 of the Government Code.
Staff's proposal will incorporate into the Off-Road and Truck and Bus regulation so long as the actions taken under this option do not result in the loss of emission benefits in any given year.
Posted November 4, 2010
- Public Meeting on Emissions Inventories for Trucks, Buses, and Off-Road Equipment. The Air Resources Board will conduct a public meeting on November 18, 2010, to hear a report on updates to emissions inventories for trucks, buses, and off-road equipment prior to considering amendments to the Truck and Bus and the off-road regulations at a hearing scheduled in December 2010. This informational item for the November meeting focuses only on the emissions inventory activity and emissions data and methods, and not the proposed regulatory amendments which will be considered in December. Comments on the emission inventory used to support the proposed amendments to the Truck and Bus and Off-Road regulations may be submitted here.
Posted October 28, 2010
- Regulatory Documents for Proposed Amendments to the In-Use Off-Road Diesel Vehicle and Large Spark Ignition Fleet Regulations. The Air Resources Board will conduct a public hearing on December 16 or 17, 2010, in Sacramento, to discuss proposed amendments to on-road and off-road regulations to reduce emissions from diesel vehicles. Specifically, the Board will consider proposed amendments to the In-Use Off-Road Diesel Vehicle and Large Spark Ignition Fleet Regulations. The public hearing notice and staff report have been posted on the Rulemaking Activity web page. ARB staff has posted additional supporting documentation at the AB 1085 Compliance web page. A fact sheet summarizing the proposed amendments to the In-Use Off-road Diesel Vehicle Regulation is also available here.