Truck Underride Accident Cases

Underride accidents occur when a passenger vehicle slides beneath a truck's trailer, often shearing off the roof and killing or catastrophically injuring occupants. Federal law requires underride guards, but many trucking companies fail to maintain them.

What Is an Underride Accident?

An underride accident happens when a passenger vehicle slides beneath the raised body of a commercial truck trailer. Because most trailers sit 4 or more feet off the ground — higher than the crumple zones and windshields of standard cars — the vehicle cabin is sheared or crushed.

There are three types of underride accidents:

  • → Rear underride: A vehicle rams into the back of a stopped or slow-moving trailer
  • → Side underride: A vehicle slides under the side of a trailer — often when a truck turns or changes lanes
  • → Front underride: A vehicle slides under the front of a truck cab — rare but catastrophic

Federal Underride Guard Requirements

The FMCSA mandates rear underride guards (also called ICC bars or DOT bars) on trailers under 49 CFR Part 393. These guards must:

  • → Be installed on all trailers manufactured after January 26, 1998
  • → Have sufficient strength to resist crash forces
  • → Be no more than 22 inches from the ground
  • → Span at least 3/4 of the trailer width

Critically: The federal standard does not require side underride guards, despite evidence showing their effectiveness. This regulatory gap is an ongoing issue in trucking safety advocacy.

Common Causes and Liability

Missing or defective underride guards: If a guard was absent, damaged, or not properly maintained, the trucking company may face per se liability for the FMCSA violation.
Inadequate rear lighting: Trailers parked or stopped on roads without proper reflectors or lights create invisible hazards at night.
Sudden stops: Trucks that stop abruptly without warning give trailing vehicles no time to react.
Improper lane changes: Side underride accidents often happen when a truck merges into a lane occupied by a passenger vehicle.
Guard manufacturer defects: If the guard met compliance standards but failed in a low-speed crash, the manufacturer may bear product liability.

Why You Need a Specialist Attorney

Underride cases require investigation of:

  • The guard's compliance with FMCSA standards
  • Maintenance and inspection records
  • Trailer lighting and reflector condition at time of crash
  • Accident reconstruction to determine whether a compliant guard would have prevented the underride
  • Expert engineering testimony on guard performance

The trucking company's insurer will investigate immediately after the crash. You need an attorney equally fast.

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Step 1 of 4 — Accident Details

Act Immediately

The condition of the underride guard at the time of the accident must be documented before repair or replacement. Request an immediate investigation.

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