Everything You Need to Know About Underride Crashes

Legally Reviewed by Dale R. Rose on September 24, 2026

An underride crash happens when a passenger vehicle collides with a large truck or trailer and slides partially or fully underneath it, and these crashes are among the most severe collisions on Texas roads because a car’s safety systems, including airbags and crumple zones, are designed for impacts with vehicles closer to its own height. When that safety structure is bypassed, the results are often catastrophic.

At Dale R. Rose, PLLC, we represent people injured in truck and trailer collisions across McKinney, Collin County, and the North Texas communities we serve, including Bonham. With nearly 33 years as a licensed attorney and over 165 first-chair jury trials across 54 Texas counties, Dale R. Rose brings a unique perspective to underride crash cases, having represented both plaintiffs and defendants in trucking litigation over the course of his career.

Understanding Underride Crashes: The Basics

Underride crashes occur when a smaller vehicle collides with a larger truck or trailer and slides underneath it. There are two main types: side underride, where a car slides under the side of a truck, often in the truck’s blind spot, and rear underride, where a car strikes the back of a truck or trailer and slides beneath it.

The severity of these crashes comes from the height mismatch between a car and a truck’s trailer bed. A car’s crumple zones and airbags are engineered to absorb impact from vehicles of a similar height and structure. In an underride collision, the trailer strikes the car above its designed impact zone, often at windshield or roof level, which may bypass those safety features entirely.

How Federal Underride Guard Rules Have Changed

Rear underride guards, the steel bars mounted beneath the back of a trailer, are the primary federal safeguard against rear underride crashes. Federal Motor Vehicle Safety Standard 224 requires most new trailers and semitrailers with a gross vehicle weight rating of 10,000 pounds or more to carry a rear impact guard, and Standard 223 sets the strength and energy-absorption tests that guard must pass. In a final rule published in July 2022, the National Highway Traffic Safety Administration upgraded both standards to align with Canada’s stronger requirements, so that guards on newly manufactured trailers are designed to protect occupants of compact and subcompact cars that strike the rear of a trailer at 35 miles per hour. Guards are certified through laboratory force tests rather than a full vehicle crash test.

The rules do not stop at the factory. Under 49 CFR 393.86, the Federal Motor Carrier Safety Administration requires trailers and semitrailers built on or after January 26, 1998, with a gross vehicle weight rating of 10,000 pounds or more, to keep a rear impact guard that meets the federal standard while the trailer is in service. The regulation also sets placement limits, including a requirement that the bottom of the guard sit no more than 22 inches above the ground, and it exempts certain vehicles, such as pole trailers, low chassis vehicles, and wheels-back vehicles. A guard that is bent, rusted through, missing, or mounted too high may fall short of these requirements.

Side underride guards remain a different story. As of the most recent NHTSA report to Congress, side underride guards are not yet federally required on trailers. The agency has been directed to study their costs, benefits, and feasibility and has indicated it plans further rulemaking, but no side-guard mandate is currently in effect. This regulatory gap is one reason side underride crashes remain especially dangerous and often central to liability disputes.

Legal Considerations and Challenges in Underride Cases

Liability in an underride crash often depends on several overlapping factors: the truck driver’s actions leading up to the collision, whether the trailer’s underride guard met applicable federal standards, whether the guard was properly maintained, and the actions of the car’s driver. Truck drivers and trucking companies must follow federal safety regulations covering vehicle maintenance, driver hours, and inspection requirements, and a violation of those rules may serve as evidence of negligence.

Establishing negligence in an underride case is rarely straightforward. It typically requires a detailed investigation into trucking regulations, maintenance records, and the physical evidence from the crash itself. Poor road conditions, inadequate signage, or malfunctioning truck lights may also play a role and need to be ruled in or out.

Texas Statute of Limitations and Comparative Negligence for Underride Crashes

Texas law places a strict time limit on when an underride crash lawsuit may be filed. Under Tex. Civ. Prac. & Rem. Code § 16.003, most personal injury claims must be filed within two years of the date of the crash, and wrongful death claims generally follow the same two-year window from the date of death. Missing this deadline can permanently bar you from recovering compensation regardless of how strong the underlying evidence may be.

Texas also follows a modified comparative negligence rule, codified in Chapter 33 of the Texas Civil Practice and Remedies Code. If you are found 50% or less at fault for the crash, you may still recover damages, reduced by your percentage of responsibility. If you are found 51% or more at fault, Texas law bars you from recovering anything at all. Because underride crashes often involve disputes over visibility, following distance, and lane position, trucking companies and their insurers frequently raise comparative fault arguments to reduce or eliminate what they owe.

Prevention and Safety Measures

Preventing underride crashes involves both vehicle design and driver awareness. Truck manufacturers continue to explore stronger, more effective rear guards, and federal researchers are actively evaluating side guard designs as part of the NHTSA rulemaking process described above.

Driver education remains just as important. Truck drivers should be trained in safe driving practices, proper vehicle maintenance, and awareness of blind spots around their trailers. Car drivers should maintain a safe following distance from large trucks, avoid lingering in blind spots, and use extra caution when passing.

Evidence That Matters in an Underride Guard Claim

Underride cases often turn on physical evidence that is unique to the trailer, and that evidence can disappear quickly once a trailer is repaired, sold, or put back on the road. Investigators typically want to document the rear guard itself, including whether it bent, sheared off its mounts, or was already damaged before the crash, and whether it carried the required certification label. Measurements of the guard’s height above the ground and its width relative to the trailer can show whether it met the placement limits in the federal rules.

The trailer’s manufacture date matters too, because it determines which version of the federal guard standard applied. Inspection reports, repair invoices, and maintenance logs may reveal whether the trucking company knew about a damaged guard and kept the trailer in use anyway. Federal rules also require retroreflective conspicuity markings on most large trailers, so worn or missing reflective tape and burned-out lights can be relevant when a crash happened at night. Our guide on the steps to prove fault in a Texas truck accident claim explains how this evidence fits into a broader negligence case, and why a prompt preservation letter to the carrier is often one of the first steps.

Who May Share Responsibility in an Underride Crash

More than one party may share responsibility for an underride crash, depending on the facts. The truck driver, the trucking company, a trailer leasing company, or even the manufacturer of the underride guard could potentially bear some responsibility if the evidence supports it. Identifying every potentially responsible party often requires reviewing lease agreements, maintenance records, and inspection history in addition to the physical evidence from the crash. Our related guide on suing a trucking company directly after a commercial vehicle wreck covers this process in more detail, and our overview of evidence used to prove liability in commercial truck accident claims explains how that evidence is gathered and preserved.

Why Choose Dale R. Rose for Your Underride Crash Case?

When facing the aftermath of an underride crash, having experienced legal representation matters. At Dale R. Rose, PLLC, we bring a unique perspective to these cases, with experience representing both plaintiffs and defendants in trucking litigation. That background gives us insight into how trucking companies and their insurers build their defense, and how to counter it.

You work directly with Dale on every aspect of your case, not a rotating team of case managers. For assistance with your underride crash case, reach out through our contact form to request a free consultation.

Frequently Asked Questions About Underride Crashes