Truck Underride Accidents

California Lawyers Who Hold Trucking Companies Accountable

Most cars are built to survive a crash. Safety features like bumpers, crumple zones, and airbags are all designed to absorb the force of an impact before it reaches the people inside. However, those safety measures don’t always protect you in a truck underride accident. When a car slides beneath the rear or side of a tractor-trailer, the trailer’s steel frame strikes the windshield and roof, missing both the bumper and hood entirely. That’s precisely why underride crashes are among the deadliest collisions on California roads, even at speeds that would be survivable in almost any other type of accident.

If you or someone you love was hurt in one of these crashes, you may be facing surgeries, months of recovery, or the unthinkable loss of a family member, all while the trucking company’s insurer works to limit what it pays. The truck accident attorneys at BD&J have recovered more than $3 billion* for injured Californians, and we’re available 24/7 to assist you.

Call (855) 906-3699 today to speak with a California truck underride accidents lawyer in a free, confidential consultation.

Key Takeaways

An underride crash happens when a smaller vehicle slides beneath the rear or side of a large truck or trailer, often causing fatal injuries.
Federal rules require rear underride guards on most new trailers. Since July 2024, new trailers must have guards strong enough to prevent underride intrusions in a 35 mph crash.
There’s currently no federal requirement for side underride guards, even though research shows they could prevent many deaths.
A federal review found about 219 underride deaths per year from 2008 to 2017 and concluded the real number is likely higher because these crashes are underreported.
Liability can extend beyond the truck driver to the trucking company, the trailer or guard manufacturer, and the companies responsible for maintenance.
Most California injury claims must be filed within two years, and claims against public agencies have much shorter deadlines.
BD&J underride truck accident attorneys are here to help. Call for your free consultation at (855) 906-3699.

What Is an Underride Truck Accident?

An underride accident happens when a passenger vehicle, motorcycle, bicycle, or pedestrian ends up partially or fully beneath a large truck. It usually involves a semi-trailer, but box trucks, dump trucks, and other commercial vehicles with high ground clearance can also cause underride accidents.

The main problem is the height difference between vehicles. The bottom of a typical trailer sits well above the bumper of most cars. In a collision, the car’s front end can pass under the trailer until the passenger compartment strikes the trailer’s edge. When that happens, the safety features that protect you in a normal crash are bypassed, leaving you and your passengers vulnerable.

Types of Underride Crashes

Rear Underride Crash

A rear underride crash happens when a vehicle strikes the back of a trailer and slides underneath it. These crashes often occur when:

A truck stops suddenly or slows sharply in traffic.
A truck is stopped on the shoulder or in a travel lane without proper warning.
The trailer’s lights or reflective markings are dirty, damaged, or missing, making it hard to see at night.

Rear underride guards, the metal bars hanging from the back of most trailers, are designed to stop this. When they’re weak, damaged, or missing, they can fail.

Side Underride Crash

A side underride crash happens when a vehicle strikes the side of a trailer, usually between the truck’s rear wheels and the tractor. These crashes are common at intersections and driveways, where a truck is turning or crossing a road and its long trailer blocks the lanes.

Side underride is especially dangerous for motorcyclists, cyclists, and pedestrians, who can be pulled beneath the trailer’s wheels.

Front Underride Crash (Also Known as Override Crash)

In a front underride, a truck strikes a smaller vehicle from behind or head-on and rides up and over it. This is sometimes called an override. These crashes often happen when a truck driver is speeding, distracted, or following too closely in slowing traffic.

Underride Crashes Are Deadly

In an underride crash, the heaviest and most rigid part of a trailer ends up in line with the driver’s and passenger’s head and chest. Upon impact with a trailer, the car’s roof and windshield pillars can collapse, and airbags may deploy too late or not at all because the car’s crash sensors never registered a normal frontal impact.

Research backs up the premise that underride crashes are among the deadliest. The Insurance Institute for Highway Safety (IIHS) estimates that about 15% of fatal crashes between large trucks and passenger vehicles involved the rear of the truck, with a majority produced in underride situations. IIHS testing has also shown that many rear guards meet federal standards yet still buckle or break away in a crash, especially when a car strikes the guard’s outer edge instead of hitting it head-on.

If an underride crash turned your life upside down, you don’t have to face the trucking company alone. Call BD&J at (855) 906-3699.

Underride Risks for Motorcyclists, Cyclists, and Pedestrians

Side underride is a serious danger for people who aren’t protected by a car. A truck making a right turn can sweep across a bike lane or crosswalk, and without a side guard, a rider or pedestrian can be pulled beneath the trailer’s rear wheels.

If you were hurt while riding or walking, our motorcycle accident, bicycle accident, and pedestrian accident attorneys can help.

Injured by a truck while riding or walking? BD&J represents motorcyclists, cyclists, and pedestrians across California. Call (855) 906-3699 for a free consultation.

Common Injuries in Underride Accidents

Because underride crashes strike the passenger compartment at head and chest height, the injuries are often severe:

Traumatic brain injuries. These range from concussions to severe injuries that permanently affect memory, movement, and personality.
Spinal cord and neck injuries. Some cause partial or complete paralysis.
Facial and skull fractures. These injuries often require reconstructive surgery.
Crush injuries and amputations. They happen when the passenger compartment collapses.
Chest and internal injuries. Damage to the lungs, heart, and other organs can be life-threatening.
Deep cuts and eye injuries. Shattered glass and torn metal cause many of them.

Many of these are catastrophic injuries that require lifelong care. Tragically, many underride crashes are fatal. When a loved one dies, surviving family members may be able to file a wrongful death claim.

How Common Are Underride Crashes?

Underride crashes are more common than official numbers suggest. A U.S. Government Accountability Office (GAO) report found an average of about 219 underride deaths involving large trucks each year from 2008 through 2017. GAO also concluded that these deaths are likely underreported.

That matters for your case. If the police report doesn’t describe your crash as an underride, it doesn’t mean it wasn’t one. Your attorney may need to use photos, vehicle damage, and expert analysis to show what really happened.

What Causes Truck Underride Accidents?

Underride crashes rarely come down to a single mistake. Common causes include:

Sudden stops. Trucks that brake hard without warning give following drivers little time to react.
Improperly stopped trucks. Federal rules require truck drivers who stop on a highway or shoulder to turn on their hazard flashers and put out warning devices. When drivers skip those steps, especially at night, trailers can be nearly invisible.
Poor visibility. Trailers are required to carry reflective tape and working lights. When tape is faded, dirty, or missing, or lights are broken, other drivers may not see the trailer until it’s too late.
Turning and crossing trucks. A truck making a wide turn or pulling across multiple lanes from a driveway can block the road with the side of its trailer.
Driver error. Fatigued driving, distracted driving, and drunk driving all increase the risk of sudden stops, missed turns, and following too closely.
Weak, damaged, or missing guards. A guard that’s rusted, bent from an earlier impact, or poorly repaired may fail even in a low-speed crash.

Underride Guard Requirements and the Law

Rear Underride Guards

Federal safety standards have required rear impact guards on most new trailers since the late 1990s. In 2022, the National Highway Traffic Safety Administration (NHTSA) upgraded those standards. New trailers and semi-trailers weighing 10,000 pounds or more must now have rear guards strong enough to prevent passenger compartment intrusion when a car hits them at 35 mph, up from the old 30 mph standard. Manufacturers had to comply by July 15, 2024.

The federal rules also changed how guards are checked. Motor carriers must now include rear impact guards in each truck’s required annual inspection. Before that change, a trailer could pass its annual inspection with a missing or damaged guard.

Side Underride Guards

There’s currently no federal requirement for side underride guards on trailers. That’s despite a 2023 NHTSA proposal that attributes 409 serious passenger injuries to side underride accidents.

In February 2026, the Stop Underrides Act 2.0 was introduced in Congress to require side guards on new trailers, semi-trailers, and single-unit trucks. As of this writing, it hasn’t become law.

Truck Guards Are Crucial for Your Claim

Safety regulations can become powerful evidence. In California, violating a safety law or regulation can create a presumption of negligence when the violation caused the kind of harm the rule was meant to prevent. For example:

A trucking company that skipped rear guard inspections may be held responsible for a failed guard.
A driver who stopped on a highway without warning devices may be held responsible for a nighttime rear underride.
If a guard was poorly designed or built, the manufacturer may be liable under California’s product defect laws, even if the truck driver did nothing wrong.

Underride cases often involve federal regulations, product design, and multiple insurance policies. Talk to a BD&J truck accident attorney about your options at (855) 906-3699.

Who Can Be Held Liable for an Underride Accident?

Underride cases often involve more potential defendants than a typical crash. Depending on the facts, responsible parties may include:

The truck driver. A driver who stopped improperly, turned unsafely, or drove while tired or distracted may be at fault.
The trucking company. Carriers are responsible for training drivers, maintaining equipment, and inspecting rear guards every year. In fact, the company behind the driver often shares the blame.
The trailer owner or leasing company. Trailers are often owned by a different company than the one operating the truck, and the owner may be responsible for the guard’s condition.
The trailer or guard manufacturer. A guard that was defectively designed or built, or that failed well below its rated strength, may support a product liability claim.
Maintenance and repair shops. A shop that repaired a damaged guard incorrectly, or signed off on an inspection it didn’t perform, may share liability.
Shippers and loaders. Cargo that’s loaded improperly can affect how a truck stops and handles.
Other drivers. Another motorist who cut you off or forced you toward the truck may also be at fault.

It’s common for the trucking company’s insurer to argue that you’re to blame for driving into the truck. California’s comparative negligence rules mean that even if you share some responsibility, you can still recover compensation, reduced by your share of fault. And if a properly working guard would have prevented your most serious injuries, the parties responsible for that guard can still be held accountable.

Important Evidence in an Underride Case

Underride cases are won or lost on physical evidence, and much of it can disappear within days. Your legal team at BD&J will work quickly to secure:

The trailer and rear guard. Measurements, photos, and the guard’s certification label can show whether it met federal standards and how it failed.
Your vehicle. Damage to your car’s roof, pillars, and windshield helps experts show how far it traveled under the trailer.
Lighting and reflective tape. The condition of the trailer’s lights and reflective markings can show whether you had a fair chance to see it.
The truck’s black box. Electronic data can show the truck’s speed, braking, and location in the moments before the crash.
Dashcam and surveillance video. Many trucks carry cameras, and nearby businesses may have footage.
Inspection and maintenance records. These can show whether the guard was inspected, damaged, or repaired before the crash.
Driver logs. Hours of Service records can reveal whether fatigue played a role.
Witness statements. Other drivers may have seen the truck stop, turn, or sit unlit on the shoulder.

Avoiding common mistakes after a truck accident can make a real difference in protecting this evidence.

Evidence in underride cases can be repaired, scrapped, or lost quickly. Call BD&J at (855) 906-3699 so we can start protecting it today.

Compensation After an Underride Accident

Every case is different, but a successful underride claim may help you recover:

Medical costs. This includes current and future expenses, such as surgeries, hospital stays, rehabilitation, and in-home care.
Lost income. This covers lost wages and reduced earning capacity if you can’t return to your job.
Pain and suffering. This includes emotional distress and loss of enjoyment of life.
Vehicle and property damage. This means repairing or replacing what was damaged in the crash.
Wrongful death damages. Families may recover funeral costs, lost financial support, and the loss of a loved one’s love and companionship.
Punitive damages. In rare cases involving malice, oppression, or fraud, courts may award punitive damages, such as when a company knowingly kept a dangerous trailer on the road.

Insurance companies often make quick, low offers after serious crashes. Before you accept anything, talk to an attorney who can calculate what your claim is really worth, including the costs you’ll face years from now.

How Long Do You Have to File an Underride Accident Claim?

In most cases, California gives you two years from the date of the crash to file a personal injury lawsuit. Wrongful death claims generally must be filed within two years of the death. If a public agency is involved, such as a government-owned truck or a dangerous road condition that was neglected by the municipality, you usually must file a written claim within six months before you can sue.

Because underride cases depend so heavily on physical evidence, waiting can hurt your case long before any legal deadline arrives. The sooner your attorney starts investigating, the more evidence can be preserved.

Don’t let critical evidence disappear. Call BD&J at (855) 906-3699 to get started on your claim today.

How To Navigate the Aftermath of a Truck Underride Accident

If you or a loved one has been in an underride crash, these steps can protect your health and your claim:

Call 911 immediately. Underride crashes often trap occupants, so tell dispatchers a car is under a truck so the right rescue crews respond.
Get medical care, even if you feel okay. Head and neck injuries from underride crashes may not show symptoms right away.
Photograph the back and side of the trailer. If it’s safe, capture the rear guard, any damage or rust, and the reflective tape and lights.
Note whether the truck had its hazard lights on. If the truck was stopped, record whether flashers or warning triangles were in place.
Get the truck’s identifying information. Photograph the DOT number, license plates, trailer number, and company name on the cab and trailer.
Don’t let your car be scrapped. Your vehicle is key evidence, so tell your insurer and the tow yard not to salvage or crush it until your attorney has inspected it.
Avoid recorded statements. Don’t give a recorded statement to the trucking company or its insurer before you speak with a lawyer.
Contact a truck accident attorney quickly. An attorney can send preservation letters that legally require the trucking company to keep the trailer, guard, and black box data.

The trucking company is already building its defense. Start building yours today. Call BD&J at (855) 906-3699 or complete our online form for a free case review.

How BD&J Handles Underride Accident Cases

Underride cases require a legal team that understands trucking regulations, vehicle engineering, and product liability. When you work with BD&J, our attorneys:

Move quickly to preserve evidence. We send preservation letters to the trucking company, trailer owner, and tow yards so the trailer and guard aren’t repaired or destroyed.
Work with engineers and reconstruction experts. They analyze how your vehicle went under the trailer and whether a properly built guard would have stopped it.
Investigate every responsible party. That includes trailer manufacturers and maintenance providers, not just the driver.
Handle the insurance companies. We take over communication so you can focus on your recovery.
Prepare every case for trial. Our attorneys are members and leaders of the American Board of Trial Advocates and the Consumer Attorneys of California, and we’re ready to go to court if the insurer won’t offer a fair settlement.

Learn more about BD&J and our commitment to injured Californians.

Frequently Asked Questions About Underride Accidents

Who Is Liable for a Truck Underride Accident?

Liability may fall on the truck driver, the trucking company, the trailer owner, a maintenance shop, or the manufacturer of the trailer or guard. An attorney can investigate which parties share responsibility in your case.

Can I Sue the Manufacturer of the Trailer or Underride Guard?

Yes, if the guard or trailer was defectively designed or built, you may have a product liability claim against the manufacturer. These claims can apply even if the truck driver wasn’t at fault.

Are Side Underride Guards Required in California?

No, there’s currently no federal requirement for side underride guards on trailers, and the Stop Underrides Act 2.0 introduced in 2026 has not become law. Rear underride guards are required on most new trailers.

Does a Missing Side Guard Help My Case?

A missing side guard may help your case. It isn’t a violation on its own, but in some cases it can support a product liability claim if a safer, practical design was available.

How Does Comparative Fault Affect My Compensation?

Under California’s comparative negligence rules, your compensation is reduced by your percentage of fault, but it isn’t eliminated. For example, if you’re found 20% at fault, you could still recover 80% of your damages.

What if I Rear-Ended the Truck?

You may still have a claim, especially if the truck stopped improperly, lacked working lights or reflective tape, or had a weak or damaged rear guard. Rear-ending a truck doesn’t automatically make you fully responsible for your injuries.

How Long Do I Have to File an Underride Accident Claim in California?

Most personal injury claims must be filed within two years of the crash, and wrongful death claims generally within two years of the death. Claims against a public agency usually require a written claim within six months.

Why Should I Act Quickly if the Deadline Is Two Years Away?

The trailer, guard, and black box data can be repaired, replaced, or overwritten long before the deadline. Contacting an attorney early gives them time to preserve that evidence.

What Evidence Proves an Underride Accident Case?

Key evidence includes the trailer’s rear or side guard, your vehicle, the truck’s black box data, lighting and reflective tape, and inspection and maintenance records. Photos, video, and witness statements also help show what happened.

Why Shouldn’t I Let the Insurance Company Scrap My Car?

Your car shows how far it traveled beneath the trailer and where the impact occurred. If it’s crushed or sold for salvage, that evidence may be lost for good.

Talk to a California Truck Underride Accident Lawyer Today

An underride crash can change your life in an instant, and the companies responsible have teams of lawyers working to limit what they pay. You deserve a team fighting just as hard for you. Contact BD&J at (855) 906-3699 or complete our online form to schedule your free, confidential consultation.