California Air Resources Board

California Phase 2 trailer standards take effect for all trailer manufacturers in 2020. The standards are intended to make trailers more efficient and lower the greenhouse gas emissions associated with their use. Affected trailer types include box-type trailers (dry van and refrigerated van trailers of all lengths), flat bed trailers, tank trailers, and container chassis. The trailer standards can be met through aerodynamic improvements, low rolling resistance tires, tire pressure systems (Tire Pressure Monitoring System/Automatic Tire Inflation System), and/or weight reduction.  Beginning January 1, 2020, trailer manufacturers must certify to California standards and receive an Executive Order from CARB to legally sell trailers in California. However, please see the enforcement advisory #295 below.

Meetings and Workshops 

Current Standards, Test Procedures, and Regulatory Documents

Section 95663, Title 17, California Code of Regulations contains California's greenhouse gas emission standards for on-road heavy-duty vehicles including trailers, and the following test procedures, as incorporated by reference.

California Greenhouse Gas Exhaust Emission Standards and Test Procedures for 2014 and Subsequent Model Heavy‑Duty Vehicles amended December 19, 2018 

Certification Forms and Guidance

Mail-Out to trailer manufacturers February 20, 2019: Mail-Out # ECARS 19-01

New! Advisory # 295 (December 3, 2019):  Enforcement of California Phase 2 GHG Trailer Requirements

Application Process

Manufacturers need to send the following documents to CARB before submitting first certification application:

• Letter of Intent (updated 11/08/2019)
• Authorized Contact Information Form 
• U.S. EPA Manufacturer Code: For step by step instructions on how to register for the code on U.S. EPA's website, please follow these instructions.

Once the preliminary steps are completed, manufacturers will then complete the certification application package:

• CARB Trailer Certification Application (updated 09/05/2019). To download the application, right click the link and select the "Save...As" option to save the file to your computer. 
  • Trailer Certification Application Guidance Document (updated 06/26/2019): Step-by-step walk through of how to fill out the application
• Supporting Documents
  • Statement of Compliance
  • Tire report and tire data CSV submission file  (updated 11/21/2019)  
    • Tire Document Requirements  (new 11/21/2019)
  • Labeling, warranty, and maintenance statement instructions (updated 09/26/2019)
  • Any other applicable supporting documentation. Examples could include, but may not be limited to, aerodynamic test data and off-cycle technology test data.

Additional Resources 

• Helpful Tips for Trailer Certification
• Compliance Verification Calculator (updated 04/29/2019)
• Pre-Approval Aero Devices
• Executive Orders (EO) for Heavy-Duty Highway Trailers

Please email certification documents to: TrailerCert@arb.ca.gov.

More Information

Contact trailer certification staff.