What Are Truck Underride Accidents and Why Are They So Serious?

April 20, 2026

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Large commercial trucks share the road with passenger vehicles every day. While most drivers understand the dangers of driving near these massive vehicles, few realize how catastrophic certain types of truck crashes can be—especially underride accidents.

An underride crash occurs when a smaller vehicle slides underneath the body of a semi-truck or trailer during a collision. Because a passenger vehicle is much lower than the trailer of a tractor-trailer, the car can become trapped beneath the truck while both vehicles continue driving. The resulting impact can have life-altering consequences for the occupants of the smaller vehicle. If you have been hurt in a crash, our skilled truck accident lawyers are here to help.

What Is an Underride Accident?

An underride accident occurs when a passenger vehicle becomes wedged under the side or rear of a large truck. The top of the car may strike the underside of the trailer instead of the truck’s bumper.

Underride crashes typically occur in three scenarios. A rear underride happens when a car crashes into the back of a truck and slides beneath the trailer. A side underride occurs when a vehicle collides with the side of a tractor-trailer, often during a turn or when a truck crosses traffic lanes. Less commonly, a front underride can occur when a truck strikes a smaller vehicle in such a way that the car slides under the front of the truck.

Federal regulations require many commercial trucks to have rear underride guards known as “Mansfield bars.” These bars are designed to prevent smaller vehicles from sliding underneath the truck. However, these guards are not always strong enough to prevent severe injury, and side underride guards are not universally required.

What Makes These Accidents So Serious?

Underride collisions are often far more dangerous than typical vehicle crashes because of the physics involved. When a passenger car crashes into another car, both vehicles are of similar height. Their bumpers, frames, and safety systems work together to absorb much of the impact.

In an underride accident, that alignment does not exist. The front of the smaller vehicle can slide under the truck’s trailer, allowing the trailer to strike the windshield area of the car. This portion of the vehicle offers little protection compared to the reinforced engine compartment or bumper.

The results can be catastrophic. The vehicle’s roof may collapse or be torn away entirely, and airbags may deploy too late to protect occupants effectively. In severe cases, the upper portion of the passenger compartment is crushed.

These accidents also frequently occur at highway speeds, where the impact force is much greater. Because large trucks weigh many times more than passenger vehicles, the smaller vehicle absorbs most of the crash energy. This imbalance increases the likelihood of severe injury or death.

Common Injuries in an Underride Accident

Underride collisions often result in catastrophic or fatal injuries. Victims who survive frequently face long recovery periods and permanent disability. Common injuries include:

  • Traumatic brain injuries
  • Spinal cord injuries
  • Paralysis
  • Neck fractures
  • Internal organ damage
  • Amputations
  • Severe lacerations

The injuries resulting from these accidents can be devastating for most people.

Who Might Be at Fault?

There could be more than one person responsible for these accidents. While most collisions are at least partially the fault of the commercial driver, our attorneys ensure that everyone whose negligence contributed to the crash is held accountable.

The Truck Driver

Truck drivers must operate their vehicles safely and follow traffic laws at all times. If a driver stops abruptly without warning, makes an unsafe turn across traffic, or fails to use proper lighting and signals, they may contribute to an underride collision.

The Trucking Company

Trucking companies are responsible for hiring qualified drivers, maintaining vehicles, and enforcing safety policies. Companies may also be responsible if they knowingly allow unsafe trucks on the road or ignore federal safety regulations.

The Truck Manufacturer

In some cases, the design or construction of the trailer itself may contribute to the severity of an underride crash. If underride guards are defective, improperly installed, or unable to withstand reasonable crash forces, the manufacturer may face product liability claims.

Maintenance Providers

Commercial trucks require regular inspections and maintenance. Third-party maintenance companies that fail to repair safety equipment properly may also be partially responsible for a crash.

Other Drivers

In certain situations, another motorist may be at fault for the accident. For example, a driver who forces a truck to stop suddenly or causes a chain-reaction crash may share responsibility for the events leading to an underride collision.

Discuss Your Underride Accident With Nurenberg Paris Today

The reality about underride accidents is that they are almost always avoidable. When commercial truck drivers pay attention to the other motorists they share the road with, they should be able to avoid having a smaller car trapped beneath their trailer.

These incidents are serious, and the injuries they lead to are often life-changing. We have handled countless claims involving underride accidents and look forward to putting our experience to work for you.

Contact Nurenberg Paris for a free consultation today.

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