The panel denied a petition for review brought by the People of the State of California and California officials seeking review of the determination of the Federal Motor Carrier Safety Administration (“FMCSA”) that California’s meal and rest break (“MRB”) rules, as applied to drivers of passenger-carrying commercial motor vehicles, were preempted.

The Motor Carrier Safety Act (“MCSA”) requires the Secretary of Transportation to review State laws and regulations on commercial motor vehicle safety, and gives the Secretary express power to preempt State law. In 2020, the FMSCA determined that California’s MRB rules, as applied in this case, were regulations “on commercial motor vehicle safety” that were “additional to or more stringent than” the federal hours-of-service (“HOS”) regulations under 49 U.S.C. 3114. The FMSCA determined that the MRB rules were preempted because they did not provide any reasonable safety benefit beyond the safety benefit already provided by the federal HOS regulations, were incompatible with federal regulations, and imposed an unreasonable burden on interstate commerce.

The panel held that petitioners’ contention that California’s MRB rules were beyond the scope of the FMSCA’s preemption authority was precluded by the holding in International Brotherhood of Teamsters, Local 2785 v. Federal Motor Carrier Safety Administration, 986 F.3d 841 (9th Cir. 2021), cert. denied, 142 S. Ct. 93 (2021) (“Teamsters”). The panel also rejected petitioners’ argument that the FMSCA may not preempt California’s mid-shift break rules for drivers of passenger-carrying commercial motor vehicles because the agency itself has not promulgated such regulations. Petitioners read Teamsters too narrowly. Finally, the panel rejected petitioners’ argument that the FMSCA acted arbitrarily and capriciously in determining that California’s MRB rules would cause an unreasonable burden on interstate commerce. The record supports the FMSCA’s conclusion that California’s MRB rules impose a significant operational burden upon operators of passenger-carrying commercial motor vehicles. This conclusion was sufficient to justify the agency’s decision to preempt California’s MRB rules.

https://cdn.ca9.uscourts.gov/datastore/opinions/2026/06/04/20-70706.pdf