In February 2026, federal lawmakers introduced the Stop Underrides Act 2.0, reigniting a critical national conversation about one of the deadliest — and most preventable — categories of large truck crashes. Underride collisions, where a passenger vehicle slides beneath a commercial truck or trailer, are catastrophically lethal. When federal safety equipment fails or is simply absent, the legal consequences for trucking companies and trailer manufacturers expand dramatically. Understanding underride crash protection federal liability damages has never been more important for victims and their families than it is right now in 2026.
What Is an Underride Crash and Why Does It Keep Killing People in 2026?
An underride crash occurs when a smaller vehicle — a car, SUV, or motorcycle — slides beneath the body of a large commercial truck or trailer during a collision. The roof of the passenger vehicle is sheared off, and occupants suffer catastrophic or fatal injuries. Unlike many truck accident scenarios, underride crashes are particularly deadly because the crumple zones and safety systems engineered into modern passenger vehicles are completely bypassed.
The Insurance Institute for Highway Safety (IIHS) documents between 500 and 600 deaths per year from underride crashes in the United States. What makes that figure even more alarming is a 2024 National Highway Traffic Safety Administration (NHTSA) report finding that side underride fatalities are roughly 80% higher than what official fatal crash databases record — meaning the true death toll from underride collisions is significantly worse than the public has been told. In 2026, those corrected numbers are reshaping how legislators, safety advocates, and courts view this epidemic.
The geometry of these crashes explains why they are so destructive. Rear underrides occur when a vehicle strikes the back of a parked or slow-moving trailer. Side underrides happen when a vehicle slides beneath the side of a trailer — often at intersections when a truck is making a turn. Front underrides, the rarest type, occur when a vehicle slides under the front of a truck. Each category carries extreme injury potential, yet federal law has historically only required protection against one of them.
Federal Safety Standards in 2026: What FMVSS 223 and 224 Actually Require
The regulatory foundation for underride crash protection federal liability damages cases rests on two federal standards: Federal Motor Vehicle Safety Standard (FMVSS) 223 and FMVSS 224. Together, these rules govern rear underride guards on trailers — the steel bars you see hanging beneath the rear of a semi-trailer.
As of July 15, 2024, NHTSA upgraded these standards significantly. Rear underride guards built on or after that date must now protect occupants of compact and subcompact cars striking the rear at 35 mph, up from the previous 30 mph threshold. Per 49 CFR § 571.223 and § 571.224, trailers subject to these rules must have guards that withstand full-overlap, 50% overlap, and 30% overlap impact testing. Any trailer manufactured after the July 15, 2024 effective date that fails these requirements is out of compliance with federal law.
Here is the critical gap that lawmakers are urgently trying to close in 2026: FMVSS 223 and 224 apply only to rear underride protection. There is currently no federal standard requiring side underride guards — even though side underride crashes account for a substantial share of the 500 to 600 annual deaths IIHS has documented. That regulatory void is precisely what the Stop Underrides Act 2.0 is designed to eliminate, and it is also the void that plaintiffs’ attorneys are leveraging in courtrooms across the country right now.
The Stop Underrides Act 2.0: What Congress Is Targeting in 2026
Introduced in February 2026, the Stop Underrides Act 2.0 represents the most ambitious federal legislative push for underride safety in decades. The bill directs the Department of Transportation to finalize a rule within 18 months requiring side underride guards on all new trailers, semitrailers, and single-unit trucks — a category of commercial vehicle that has never been subject to mandatory side guard requirements under federal law.
If enacted and the DOT meets its deadline, mandatory side guard rules could be finalized as early as mid-2027. For victims of crashes occurring in 2026 and beyond, the Act’s introduction already carries legal significance. Courts and juries increasingly treat the absence of side guards as evidence of unreasonable danger, particularly when the safety technology exists, has been proven effective, and was the subject of pending federal legislation at the time of the crash.
The Act also reflects growing congressional recognition that the 2024 NHTSA finding — that side underride deaths are undercounted by approximately 80% — demands an urgent regulatory response. Advocates who have pushed for this legislation for years, including families of underride victims, argue that the corrected fatality numbers make further delay unconscionable. Defense attorneys in trailer manufacturer cases should expect plaintiffs to cite the Stop Underrides Act 2.0 as evidence that the industry has long known side guards are necessary and has resisted them anyway.
Underride Crash Statistics: The Data Behind the Danger
Understanding the scope of the underride crash problem in 2026 requires confronting data that the trucking industry has historically underplayed. The IIHS documents 500 to 600 deaths per year from underride crashes — and that figure is now understood to be a floor, not a ceiling. The 2024 NHTSA report’s finding that side underride fatalities are approximately 80% higher than reported in fatal crash databases means that the actual annual death toll from all underride crash types is almost certainly higher than any figure currently in wide circulation.
Side underride crashes are particularly deadly at intersections, where trucks making left or right turns create a lethal trap for vehicles traveling straight through. Rear underride crashes disproportionately involve parked or slow-moving trailers on highways and rural roads. In both scenarios, the occupant fatality rate is dramatically higher than in other types of truck crashes — which is why verdicts in these cases routinely reach into the tens or hundreds of millions of dollars.
The legal significance of these statistics in 2026 is substantial. When a plaintiff’s attorney presents a jury with evidence that federal regulators have known about a dangerous gap in underride protection for years, that the technology to prevent these deaths exists and is affordable, and that Congress itself has now formally declared the problem requires legislative correction, the foundation for punitive damages becomes considerably stronger. Jurors in 2026 are not sympathetic to trucking companies or trailer manufacturers that have profited while resisting safety improvements that could have saved lives.
How Trailer Manufacturer Liability Works When Guards Fail
One of the most important developments in underride crash litigation over the past several years is the broadening of defendant targets beyond the trucking company operating the vehicle. Trailer manufacturers — the companies that design and build the semi-trailers involved in these crashes — are increasingly being named as defendants, and the results have been staggering.
On September 5, 2024, a St. Louis City jury rendered a $462 million verdict against trailer manufacturer Wabash National Corporation for the deaths of two young fathers in an underride crash. The verdict sent a clear message to the trailer manufacturing industry: designing and selling trailers without adequate underride protection, in the face of known risks and available solutions, will be treated as conduct warranting massive financial consequences. As of 2026, that verdict stands as one of the largest in the history of truck crash litigation and is being closely watched by plaintiff attorneys and defense counsel nationwide.
In April 2026, the Iowa Supreme Court affirmed a $26.1 million judgment arising from a catastrophic underride crash that left victim Margaret McQuillen with a traumatic brain injury. The Iowa decision reinforces that state courts across the country are willing to hold defendants fully accountable for underride crash injuries — not just fatalities — when the evidence shows that compliant guards or available safety improvements would have prevented the harm.
Manufacturer liability in underride cases typically rests on one or more of the following theories: defective design, failure to warn, negligence per se based on FMVSS violations, and — increasingly — evidence that the manufacturer knew about underride dangers and actively resisted safety improvements for economic reasons. That last theory is particularly powerful in cases involving trailers built after the July 15, 2024 FMVSS upgrade, where any rear guard falling below the 35 mph protection threshold is a straightforward regulatory violation.
Calculating Settlement Value in Underride Crash Cases: The Multiplier Effect
Underride crash cases consistently produce some of the highest verdicts and settlements in all of personal injury litigation. Several compounding factors drive exceptional damages in these cases, and understanding how they interact is essential for victims evaluating their legal options in 2026.
Severity of injury. Underride crashes produce catastrophic outcomes almost by definition. Traumatic brain injuries, decapitation, full-roof intrusion injuries, spinal cord damage, and death are common results. Economic damages — including lifetime medical care, lost earnings, and rehabilitation costs — in serious survival cases routinely reach seven figures before a single dollar of non-economic damages is added.
Federal regulatory violations. When a trailer’s rear guard fails to meet the post-July 2024 FMVSS 223/224 standards, or when a side underride occurs on a trailer with no guard at all, plaintiffs have a powerful tool: negligence per se. A defendant who violated a federal safety standard designed to protect the class of people the plaintiff belongs to is presumed negligent in most jurisdictions. This dramatically simplifies liability and shifts the litigation focus to damages.
Corporate knowledge and resistance. The $462 million Wabash National verdict illustrates what happens when juries learn that a defendant knew about the danger, had access to solutions, and chose not to implement them. Internal documents, engineering records, and lobbying history are all discoverable in product liability cases. When those records show years of resistance to side guard technology that has been proven to save lives, punitive damages become a realistic component of any verdict.
Legislative context. In 2026, the Stop Underrides Act 2.0’s introduction gives plaintiff attorneys an additional narrative tool: the federal government itself has declared that side guards are necessary and has directed the DOT to mandate them. That congressional finding, presented to a jury alongside evidence that the defendant chose not to install available side guards, is a compelling argument for both compensatory and punitive damages.
Settlement values in underride cases involving federal violations, serious injuries, and corporate misconduct evidence routinely range from several million dollars into the tens or hundreds of millions. Each case is fact-specific, but the trajectory of verdicts like Wabash National and the Iowa McQuillen judgment makes clear that defendants and their insurers take these cases seriously — and that victims who pursue them aggressively are often rewarded for doing so.
What Victims and Families Should Do Right Now in 2026
If you or a family member has been injured or killed in an underride crash involving a commercial truck or trailer, the steps you take in the days and weeks immediately following the crash can determine whether your case achieves its full potential value. In 2026, the legal landscape strongly favors informed, proactive victims.
Preserve evidence immediately. Underride crashes involve complex physical evidence: the trailer itself, the passenger vehicle, skid marks, debris patterns, and electronic data from the truck’s event data recorder and electronic logging device. Trucking companies are required to preserve this data after a serious crash, but that obligation is not always honored voluntarily. An experienced truck accident attorney can issue a litigation hold letter within hours of being retained, putting the defendant on formal notice that destruction of evidence will be treated as spoliation.
Identify all defendants. Do not assume the trucking company is the only responsible party. The trailer manufacturer, the company that leased the trailer, the shipper who loaded the cargo, and the maintenance contractor who last serviced the underride guard may all share liability. In cases involving rear guards built after July 15, 2024, determining whether the guard meets the upgraded 35 mph FMVSS standard is an early and critical task. In cases involving side underrides, the absence of any guard at all — combined with the legislative and regulatory record showing the industry has resisted side guards for years — opens the door to manufacturer liability.
Consult an attorney with specific underride crash experience. Underride crash litigation in 2026 requires mastery of FMVSS 223 and 224, familiarity with the Stop Underrides Act 2.0 and its legislative history, access to expert witnesses in trailer engineering and accident reconstruction, and experience litigating against well-funded trucking industry defendants. General personal injury experience is not sufficient. The Wabash National verdict and the Iowa Supreme Court’s McQuillen decision were the product of years of aggressive, specialized litigation — and your case deserves the same level of commitment.
Act before statutes of limitations expire. Most states impose a two- or three-year statute of limitations on personal injury and wrongful death claims, but the clock starts running at the time of the crash — not when you retain an attorney. Waiting too long can permanently eliminate your right to compensation, regardless of how strong your case would otherwise be. In 2026, with verdicts reaching into the hundreds of millions and federal legislation explicitly acknowledging the danger these crashes pose, there has never been a better time to pursue justice aggressively and without delay.
Frequently Asked Questions About Underride Crash Protection and Federal Liability
What federal law currently governs underride crash protection on commercial trailers?
The primary federal standards governing rear underride protection are FMVSS 223 and FMVSS 224, codified at 49 CFR § 571.223 and § 571.224. As of July 15, 2024, trailers must have rear guards capable of protecting occupants of compact and subcompact cars in impacts at 35 mph — up from the prior 30 mph threshold — across full-overlap, 50% overlap, and 30% overlap test configurations. There is currently no federal standard requiring side underride guards, though the Stop Underrides Act 2.0, introduced in February 2026, directs the Department of Transportation to finalize such a rule within 18 months.
Can I sue a trailer manufacturer — not just the trucking company — after an underride crash?
Yes. Trailer manufacturers are proper defendants in underride crash cases under both product liability and negligence theories. The September 2024 $462 million verdict against Wabash National Corporation in St. Louis and the April 2026 Iowa Supreme Court affirmance of the $26.1 million McQuillen judgment are prominent examples of courts holding trailer manufacturers fully accountable for underride crash injuries and deaths. If the trailer’s design was defective, if the manufacturer failed to incorporate available safety technology, or if the guard violated FMVSS standards, the manufacturer may bear significant liability alongside — or even instead of — the trucking company.
How does a federal safety violation increase my settlement value in an underride case?
A federal safety violation — such as a rear guard that fails the post-July 2024 FMVSS 35 mph standard, or the complete absence of any underride guard where one is required — triggers the doctrine of negligence per se in most jurisdictions. Under this doctrine, a defendant who violated a federal safety regulation designed to protect people in the plaintiff’s position is presumed to have been negligent, removing a major contested issue from the case. This shifts litigation focus to causation and damages, and it significantly strengthens the argument for punitive damages when combined with evidence that the defendant knew about the risk and chose not to address it.
What is the Stop Underrides Act 2.0 and how does it affect my claim right now?
The Stop Underrides Act 2.0, introduced in February 2026, directs the Department of Transportation to finalize a rule within 18 months requiring side underride guards on all new trailers, semitrailers, and single-unit trucks. While the bill has not yet been enacted into law and no final DOT rule exists as of 2026, its introduction carries immediate legal significance. Courts and juries in 2026 are being presented with the Act as evidence that Congress itself has recognized the danger of side underride crashes and declared that mandatory guards are necessary. That legislative acknowledgment, combined with the 2024 NHTSA finding that side underride deaths are undercounted by approximately 80%, makes a powerful argument that trailer manufacturers and trucking companies operating without side guards are behaving unreasonably — and that damages should reflect that unreasonableness.
What types of injuries typically occur in underride crashes, and how do they affect damages?
Underride crashes produce some of the most catastrophic injury profiles in all of vehicle collision litigation. Because the roof of the passenger vehicle is typically sheared off or severely intruded upon, occupants suffer traumatic brain injuries, severe facial and head trauma, spinal cord injuries, amputations, and death at rates far exceeding other crash types. Survivors frequently require lifetime medical care, extensive rehabilitation, and significant accommodations for permanent disability. These injury profiles drive exceptional economic damages — lifetime care costs, lost earning capacity, home modification, and vocational rehabilitation — before a single dollar of non-economic damages for pain, suffering, and loss of enjoyment of life is added. In wrongful death cases, the loss of future earnings and the grief suffered by surviving family members add further layers of compensable harm. The combination of catastrophic injuries and clear federal safety violations is why underride crash verdicts and settlements in 2026 routinely reach into the tens or hundreds of millions of dollars.
Marcus Holloway is a commercial truck accident claims specialist with deep expertise in FMCSA regulations, trucking company liability, and high-value settlement negotiations across the United States. Marcus is not an attorney, and the information provided is for educational purposes only.