The California Air Resources Board is suspending enforcement of its greenhouse-gas emission standards for trailers for at least two years. The Golden State-specific rules were scheduled to go into effect on Jan. 1.

CARB stated in its Dec. 3 announcement that “this suspension of enforcement will, at a minimum, be in effect for model year 2020 and 2021 trailers manufactured before January 1, 2022.” The agency noted that it will provide at least six months’ written notice before it does begin enforcing the GHG trailer standards.

The enforcement delay was driven largely by the fact that as of Dec. 3, only one trailer OEM had been certified by the state as meeting the CARB standards, Act Research pointed out in an advisory. Without that certification, trailer makers would have not been authorized to sell within California any trailers manufactured after Jan. 1, 2020.

“Given the lack of certified trailers, trailer sales within California would have been significantly impacted,” stated Act Research. “Once the stock of available trailers produced before 1/1/20 was sold, there would be no new certified units available for sale within the state.”

Along with the lack of progress by trailer builders to meet the deadline, CARB cited as a related factor the legal challenge to the federal trailer GHG rules put up in 2017 by the Truck Trailer Manufacturers Association, which has stalled and prevented federal enforcement of those requirements.

Per CARB, the 2020 standards are “intended to make trailers more efficient and lower the greenhouse gas emissions associated with their use.” Affected trailer types include box-type (dry van and refrigerated van trailers of all lengths), flatbed, and tank trailers as well as container chassis. 

The California standards largely align with the stalled federal GHG rules for trailers. CARB has stated that the GHG trailer rules “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.”

CARB noted that, in the meantime, it 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.

The agency said that effort on its part “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 Jan. 1, 2022.”