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Update - Dec 03, 2019 - CARB Notice (Download)

Latest CARB Info - Link



On October 25, 2016, the U.S. EPA (EPA) and the National Highway Traffic Safety Administration (NHTSA) finalized a regulation that established federal greenhouse gas (GHG) emissions standards and fuel economy standards from medium-and heavy-duty engines and vehicles.  U.S. EPA’s and NHTSA’s regulations are collectively referred to as the federal Phase 2 GHG regulation.  CARB staff collaborated with EPA and NHTSA staff in developing the federal GHG emission standards in order to ensure that the federal standards and subsequently adopted California standards would allow affected manufacturers to build a single set of engines and vehicles to serve the entire nation.  

Federal GHG Emission Requirements for New Trailers 
The federal Phase 2 GHG regulation established federal GHG emission standards and fuel economy requirements for new box-type trailers and certain non-box trailers hauled by heavy-duty tractors on the nation’s highways.  Those requirements include performance standards for box-type trailers, which manufacturers can meet by equipping such trailers with aerodynamic features that reduce aerodynamic drag, low rolling-resistance (LRR) tires, tire pressure monitoring systems, and weight reduction measures.  The requirements specify design standards for non-box trailers that only require those trailers to be equipped with LRR tires and tire pressure monitoring systems.   

California GHG Emission Requirements for New Trailers 
On September 27, 2018, CARB approved for adoption the California Phase 2 GHG regulation.  That regulation largely aligns California’s GHG emission standards and test procedures with the federal Phase 2 GHG emission standards and test procedures, and, as previously discussed, provides nationwide consistency for engine and vehicle manufacturers.  The California Phase 2 GHG regulation establishes requirements for 2020 and later model year new trailers sold in California that are largely identical to the federal GHG emission standards for trailers. California Code of Regulations (Cal. Code Regs., title 17, §§ 95663(c) and (d).  

Litigation Challenging Federal GHG Trailer Requirements 

Subsequent to the adoption of the federal Phase 2 GHG regulation, an association representing trailer manufacturers, the Truck Trailer Manufacturers Association 

(TTMA), filed a petition for review with the U.S. Court of Appeals for the District of Columbia Circuit challenging the federal Phase 2 GHG regulation on the grounds that, inter alia, it is in excess of the agencies’ statutory authority.  On October 27, 2017, the court granted TTMA a stay of EPA’s trailer standards.  Consequently, EPA is currently precluded from enforcing the federal Phase 2 GHG regulation’s requirements applicable to trailers.  The court also put the case in abeyance, pending EPA and NHTSA’s reconsideration of their respective trailer standards.  Neither agency has initiated a reconsideration proceeding at this time.  One of the main issues in the case is whether trailers are “new motor vehicles” that EPA may regulate under the Clean Air Act. 

In light of the uncertainty presented by the aforementioned circumstances, including the stay of the federal standards, the current abeyance in the D.C. Circuit litigation, the delay in reconsideration by the federal agencies, the uncertainty concerning the characterization of trailers as new motor vehicles under the Clean Air Act, and the imminence of the January 1, 2020 effective date of the California trailer standards, CARB is notifying affected entities that it will suspend its enforcement of the California GHG trailer standards (Cal. Code Regs, tit. 17 §§ 95663(c) and (d)) for a period of at least two years (calendar years 2020 and 2021). This suspension of enforcement will, at a minimum, be in effect for model year 2020 and 2021 trailers manufactured before January 1, 2022.  CARB will provide regulated  entities at least six (6) months written notice before it commences enforcing the GHG trailer standards.   

CARB Will Continue to Process and Approve Applications to Certify 2020 and Subsequent Model Year Trailers  
CARB will continue to administer the California GHG trailer regulation on a voluntary basis, including processing and approving applications to certify 2020 and subsequent model year trailers, which will assist both trailer and equipment manufacturers seeking to comply with the trailer requirements in future model years and entities seeking to purchase new 2020 and subsequent model year California certified trailers.  CARB will not, however, enforce the standards for model year 2020 and 2021 trailers manufactured before January 1, 2022. 
For information regarding this advisory, please contact Jeremiah Bearden at (916) 229-0877 or via email at jeremiah.bearden@arb.ca.gov.  

Update - Feb 20, 2019 - CARB Notice (Download)

On June 19, the proposed Phase 2 GHG rulemaking was announced. The 1,329 page document covers both tractors and trailers for the first time. It is a joint proposed GHG stand- ard between EPA and NHTSA to improve the fuel efficiency of medium and heavy duty vehicles effective model year 2018 and beyond. This new Phase 2 program is estimated to cut emissions by 1 billion metric tons, conserve 1.8 billion barrels of oil, and lower fuel costs by over $170 billion over the lifetime of the vehicles covered.

The five primary greenhouse gases in the earth’s atmosphere are: water vapor, carbon dioxide, methane, nitrous oxide and ozone.

The new Phase 2 GHG rulemaking is divided into four regulatory categories:

  • Tractors
  • Trailer
  • Heavy-duty pick- up trucks and vans
  • Vocational vehicles (buses, refuse, concrete, etc.)

There are also separate standards for engines.

Trailers are recognized in the standard as an integral part of the tractor-trailer vehicle that significantly contributes to the emissions and fuel consumption of the tractor. The new proposed rule spells out cost-effective trailer technologies that can offer significant carbon dioxide and fuel use reductions for the vehicle. These technologies include: aerodynamic devices, low rolling resistance tires*, automatic tire inflation systems* and lightweight components.

*Non-box trailers (including platform/flatbed, tank, container chassis and other specialty trailers) would be required to use lower rolling resistance tires and automatic tire inflation systems

Trailers have been broken into five categories:

  • Highway box trailer shorter than 50’
  • Highway box trailer longer than 50’
  • Highway box refrigerated trailers longer than 50’
  • Highway box refrigerated trailers shorter than 50’
  • Non-box highway trailers

EPA/NHTSA has published an updated Greenhouse Gas Emissions Model for this Phase 2 rulemaking called the GEM model. It is a tractor-trailer computer vehicle simulation tool to determine if vehicles will meet the new standards. This new GEM program can be down- loaded at http://www.epa.gov/otaq/climate/gem.htm.