My son Riley burned to death pinned inside his Honda Civic in a side underride crash in 2015. His death was part of a documented crash pattern that the trucking industry and federal regulators have studied, debated, and ignored since the 1960s.
Side underride crashes happen when a passenger vehicle, cyclist, pedestrian, or motorcyclist goes under the side of a semitrailer. The consequences are often devastating because the trailer frame bypasses the vehicle's safety systems and strikes the occupant space directly. Riley's collision occurred at a shallow angle and a relative speed of about 14.5 mph, lower than speeds at which tested side-guard designs had prevented underride.
The litigation that followed showed how a fatal truck crash can affect the entire transportation chain. The truck driver's insurer and motor carrier settled early. A motor carrier that had served as an unlicensed broker settled after a few months of discovery. The lawsuit against Utility Trailer Manufacturing, a major refrigerated-trailer manufacturer, went to a jury.
Riley's crash was one of roughly 300 deaths and 400 serious injuries that side underride causes each year, with an estimated societal cost of $7.4 billion. In 2023, 5,472 people were killed in crashes involving large trucks, about 30% more than a decade earlier. Seventy percent of those killed were occupants of other vehicles; another 12% were pedestrians, cyclists, or other nonoccupants.
Mistakes happen. Side underride guards, like seat belts and airbags, reduce the severity of consequences regardless of fault.
The cost objection
NHTSA has denied four formal petitions seeking side guards on semitrailers since 1979. The 1979 denial (FR 44:55077-55078) closed with: "If the evidence gathered by the agency indicates that side underride rulemaking could contribute significantly to safety, the agency will commence rulemaking."
The trucking industry's cost objection over whether to require side underride guards on semitrailers has a long history but a thin evidentiary base. In 1969, the industry's trade association told federal regulators that side underride "is not a hazard that warrants some kind of regulatory remedial action."
In 1991, NHTSA declared without evidence that side underride guards were not cost-effective. A 2021 Freedom of Information Act request confirmed the agency held no data or analysis to support that assertion. The industry clings to the same claim in regulatory comments and litigation: guards would be too expensive, add weight, and increase fuel use. Juries are unconvinced.
I tested those assertions.
In my 2026 peer-reviewed cost-benefit analysis, side underride guards produced positive net economic benefits under every modeled scenario, ranging from roughly $137 million to $2.8 billion.
The break-even threshold in my analysis is that modest: guards need to prevent as few as 24 deaths and serious injuries per year to be economically justified. The analysis also excluded litigation, settlements, defense costs, and insurance losses. A side guard with an aerodynamic skirt costs approximately $2,500 per trailer.
For insurers and fleets that bear the litigation costs, the actual break-even is lower still.
What the record shows
Discovery in Riley's case showed that Utility Trailer had known for decades that side underride was a serious hazard but had not designed, built, or tested its own side guard before the lawsuit. The company criticized the Angelwing, a side guard that an independent inventor had already designed, built, and crash-tested without the engineering resources of a major manufacturer, and made no attempt to develop its own solution. Two years before the verdict, IIHS independently crash-tested a side guard at 40 mph and confirmed it prevented underride. Wabash National successfully crash-tested its own design the same year. The jury found Utility negligent and returned an $18.9 million verdict. After the verdict, Utility publicly maintained that it had not negligently designed its semitrailers and argued that side guards would make them more dangerous.
Then, after arguing at trial that side underride guards were impractical, Utility developed and patented one. The company now offers a Side Impact Guard, describing it on its website as evidence of a "long-standing commitment to the safety of every motorist sharing the roadway" and claiming its innovations "set the gold standard for performance and reliability." As of 2026, Utility has delivered nearly 70 semitrailers factory-equipped with the guard.
The technology was never the obstacle.
Nearly every major semitrailer manufacturer now holds a side guard patent. The impracticality argument was an industry position, one the industry's own trade association funded specifically to develop defense strategies against side underride lawsuits, with manufacturers suppressing information from the public under a joint defense agreement.
The costs of inaction
The Utility verdict was not a one-off. Vehicle side underride cases have produced $32.5 million in Georgia for a fatality, $26.1 million in Iowa for a debilitating injury, and $13 million in a second Georgia case. Pedestrian and cyclist cases have produced an $81 million verdict in Utah, $11.5 million in Virginia for a bicyclist, and $8.5 million in New Hampshire for a bicyclist fatality, among others. Many more cases resolve confidentially. These are the hidden costs the industry never mentions when it argues against requiring guards.
The pattern is consistent. When side underride is not addressed before a crash, the costs appear afterward in verdicts, settlements, defense expenses, and rising insurance premiums. The math does not favor waiting.
Those verdicts trace back to a specific, identified crash mechanism with a documented fix. Side underride is not an anomaly. It follows from a design decision, the absence of a guard, that is identifiable, verifiable, and correctable. Insurers are not pricing it as one. Commercial auto insurance has posted 14 consecutive years of underwriting losses. Raising rates does not fix that. Preventing fatal and serious injury from the collisions that generate the claims does.
The insurance decision
Fleets already get underwriting scrutiny for driver safety programs, telematics, dash cameras, maintenance practices, and loss history. Side underride protection is a documented liability exposure that belongs in that same conversation.
Insurers are not encouraging side guard adoption. They should be, through underwriting questions, premium credits, or better retention terms.
Testifying before the Senate Commerce Committee, the American Trucking Associations asked Congress in June 2026 to preempt state tort liability for vehicles that meet federal safety standards, while opposing the side guard mandate that would create the standard preemption requires. The industry wants the litigation exposure eliminated, but opposes the only mechanism that would justify the change. In the meantime, fleets and their insurers absorb the verdicts.
None of this requires waiting for an NHTSA side guard rule. Regulation is not a prerequisite for action.
The Supreme Court recently underscored a related point in a freight-broker liability case, Montgomery v. Caribe Transport II (2026). The unanimous decision recognized that common-law duties and standards of care are part of state safety authority. Justice Kavanaugh wrote that "truck safety is a matter of life and death," and that "Not all truck accidents can be prevented. But some can." He also acknowledged that litigation and insurance costs can be significant even when brokers prevail. The lesson is broader: truck safety decisions become liability decisions.
The question for fleets, insurers, brokers, shippers, and manufacturers is not whether federal regulations will eventually require side guards. It is why the industry keeps defending inaction in court instead of addressing a known hazard. The verdicts have been answering that for years, and the amounts keep adding up.
