In September 2020, the U.S. Court of Appeals for the D.C. Circuit granted the request for a stay of the January 1, 2021 implementation date for National Highway Traffic Safety Administration’s (NHTSA) trailer requirements. The NHTSA’s trailer requirements, a portion of the federal medium-duty and heavy-duty fuel efficiency and greenhouse gas (GHG) emissions standards known as Phase 2, mandates new trailers apply technologies such as low rolling resistance tires and aerodynamic devices to improve fuel efficiency. Given the stay on NHTSA’s trailer requirements, the requirements will not take effect on January 1, 2021 unless the D.C Circuit issues a merit ruling on the case prior to January. In 2017, the D.C Circuit placed a stay on EPA’s Phase 2 trailer requirements.
The stay was requested by the Truck Trailer Manufacturers Association (TTMA). The court case, TTMA v. EPA, et al., was first filed in 2016 but was held in abeyance (temporary suspension) for years while EPA and NHTSA reconsidered the rule’s requirements. However, in late 2019 the agencies had not concluded their administrative reviews of the rule. As a result, TTMA requested the court restart the case in December 2019, citing the looming January 2021 deadline for the NHTSA rule to take effect.
The TTMA case argues that EPA lacks statutory authority to regulate trailers under the Clean Air Act because trailers do not have engines and therefore should not be regulated as “motor vehicles” as defined by the Clean Air Act. The Department of Justice argues that the tractor-trailer combination is designed to operate as a single unit and therefore trailers qualify to be regulated.
California Air Resources Board (CARB) also adopted Phase 2 GHG trailer standards identical to the EPA GHG trailer standards except that California standards were start with the 2020 model year. In December 2019, CARB announced that it would “suspend its enforcement” of the California GHG trailer standards for a period of at least 2 calendar years (2020 and 2021). California cites the uncertainty around the litigation as the reason for the suspension.
For more background, please see https://www.mema.org/trailer-manufacturers-proceed-phase-2-trailer-greenhouse-gas-lawsuit