Off-Road Diesel Regulation
On July 26, 2007, the California Air Resources Board (CARB) adopted the Regulation for In-Use Off-Road Diesel-Fueled Fleets (Off-Road Diesel 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.
The Off-Road Diesel Regulation:
- Imposes limits on idling, requires a written idling policy, and requires a disclosure when selling vehicles;
- Requires all vehicles to be reported to CARB in the online reporting system DOORS and labeled;
- Restricts the adding of older vehicles into fleets starting on January 1, 2014; and
- Requires fleets to reduce their emissions by retiring, replacing, or repowering older engines, or installing Verified Diesel Emission Control Strategies, VDECS (i.e., exhaust retrofits).
The Off-Road Diesel Regulation’s restricts adding vehicles with older tier engines:
- BAN ON ADDING TIER 0 ENGINES – Effective January 1, 2014, a fleet may not add a vehicle with a Tier 0 engine to its fleet.
- BAN ON ADDING TIER 1 ENGINES – Also effective January 1, 2014, for large and medium fleets, and January 1, 2016 for small fleets, a fleet may not add any vehicle with a Tier 1 engine. The engine tier must be Tier 2 or higher.
- BAN ON ADDING TIER 2 ENGINES – Beginning January 1, 2018, for large and medium fleets, and January 1, 2023, for small fleets, a fleet may not add a vehicle with a Tier 2 engine to its fleet. The engine tier must be Tier 3 or higher.
Off-road diesel vehicle owners are required to report their applicable diesel vehicles into DOORS, an online reporting system.
Beginning in 2009, all applicable off-road diesel vehicles were required to be reported to CARB. When a diesel vehicle is reported in DOORS, the engine is assigned a unique EIN. The vehicle must be labeled within 30 days of receiving this EIN. You can learn more about labeling and reporting in DOORS on the DOORS Resources page. This page contains userguides and training videos to help you report in DOORS.
Frequently Asked Questions
View the Regulation FAQ page for documents addressing the most frequently asked questions.
Responsible Official Affirmation of Reporting (ROAR)
Required for large fleets beginning in 2012, for medium fleets beginning in 2016, and for small fleets beginning in 2018. Must be completed and submitted to CARB by March 1st each year annual reporting is required.
The Responsible Official will use this form to designate a person to be responsible for signing the ROAR and/or other forms required under the Off-Road Regulation.
Hour Meter Reading Log for Designated Low-Use Vehicles Operated Inside and Outside of California
Required for large fleets beginning March 1, 2012 for vehicles designated as low-use that operate both inside and outside of California.
Hour Meter Reading Log for Vehicles Designated as Agricultural
Required for large fleets beginning March 1, 2012 for vehicles designated as agricultural (used for agricultural purposes 51-99% of the time).
January 1, 2022 - All fleets must meet emission performance and reporting requirements.
March 1, 2022 - Deadline to complete annual reporting requirements, including the Responsible Official Affirmation of Reporting form.
January 1, 2023 - Small fleets may no longer add a vehicle with a Tier 2 engine to its fleet. The engine tier must be Tier 3 or higher. Medium and large fleets may not add tier 2 engines as of January 1, 2018.