In a unanimous opinion authored by Justice Nielsen, the court held that the district court erred by applying a policy-balancing test to negate a broad statutory duty to operate safe equipment on roadways. The court also found that the lower court improperly excluded expert testimony on underride crash dangers and injury prevention.
The case stems from a collision in Parley's Canyon involving a Volkswagen Jetta driven by Raul Lopez and carrying passenger Emilio Martinez-Arroyo. Lopez, traveling at approximately sixty miles per hour, struck the rear of a utility trailer owned by Ron J. Peterson Construction, Inc. The trailer, which was hauling a large forklift, lacked underride protection. The Jetta's passenger compartment slid beneath the trailer, killing both occupants instantly.
Martinez-Arroyo's widow, Yesneiri Maldonado-Velasquez, sued RJP for negligence. She argued the company operated its equipment unreasonably and that the absence of underride guards made the crash far deadlier than it needed to be.
The district court had granted summary judgment on the enhanced-injury claim, ruling that RJP had no duty to upgrade the trailer beyond minimum federal safety standards. The court reasoned that Utah Code section 41-6a-206, which states that federal motor carrier regulations supersede conflicting state provisions, precluded any higher state-law obligation.
The Utah Supreme Court rejected that interpretation. Surveying the four strains of federal preemption, the court concluded that the Federal Motor Carrier Safety Regulations establish only a conflict preemption scheme and are explicitly "minimum standards" that do not bar states from imposing more stringent requirements so long as compliance with both is possible.
Justice Nielsen, citing decisions from the Fourth and Sixth Circuits and a Northern District of Indiana ruling, wrote that federal regulations in this area function as a floor rather than a ceiling. "State law can impose a level of duty exceeding federal motor carrier regulations because it is possible to adhere to such a standard without making it impossible to comply with that federal floor," the court said.
The court also criticized the district court's use of the Jeffs policy analysis framework. Justice Nielsen wrote that the Jeffs factors are necessary only when a party seeks to establish a previously unrecognized duty for a category of cases, and do not apply when a plaintiff invokes a categorical duty already recognized under Utah law. The court pointed to Utah Code section 41-6a-1601(1)(a)(i), which forbids operating a vehicle in an unsafe condition that may endanger any person.
RJP argued that any error was harmless because the jury ultimately found the company bore no fault for the collision. The court rejected that argument, noting the jury reached its verdict without hearing the excluded expert testimony. "This additional evidence of RJP's alleged negligence may affect a jury's assessment of, well, RJP's negligence," the court wrote.
The case returns to the Third District Court in Summit County, where District Judge Richard E. Mrazik had presided, for a new trial. The Supreme Court heard oral argument on December 8, 2025, and issued its opinion on April 16, 2026.