Rear underride guards are required
Most trailers must have a rear guard under 49 CFR § 393.86. The guard must meet strength and dimension standards. We inspect whether it was compliant, corroded, or damaged before the crash.
Severe semi-truck crash types
Underride & Jackknife Accident Lawyer in Tyler
Underride and jackknife crashes are among the most devastating collisions on East Texas highways. The injuries are severe, and the evidence is often in the truck's own maintenance and black-box records.
Where these crashes happen
- I-20Rear-end and lane-change underrides
- Loop 323Wide-turn and jackknife ramps
- US 69High-speed rear-end exposures
- Wet weatherBrake-lock jackknife risk
Underride crashes
When a car goes under the trailer.
Underride crashes are devastating because the trailer's flat bed is at windshield height. Federal rules require rear guards, but they are not always strong enough, and side guards are not required at all.
Side underride guards are not required
Despite safety recommendations, federal rules do not mandate side guards. That does not excuse a carrier from driving safely or from choosing trailers that are unreasonably dangerous for the roads they use.
A failed guard turns a crash into a catastrophe
When a guard is weak or missing, a passenger car can slide beneath the trailer. The impact strikes the windshield and occupant compartment at head height.
Jackknife crashes
When the trailer folds.
A jackknife is almost always a loss-of-control event caused by brake imbalance, light trailer loading, or speed too fast for the road conditions.
Brakes out of adjustment
If the trailer brakes lock before the tractor brakes, the trailer swings out. Brake imbalance and deferred maintenance are common findings.
Empty or light trailers
A lightly loaded trailer has less traction. Hard braking on a wet or uneven surface can cause the trailer to break traction and fold.
Speed too fast for conditions
Entry speed into a curve, ramp, or emergency stop is the single biggest contributor. The black box usually proves it.
Evidence
What we demand after an underride or jackknife.
These crashes are won on physical evidence and electronic data. This is the list that goes into the preservation letter.
Preservation letter6 items
- Rear underride guard inspectionWas it compliant, corroded, previously damaged or repaired?
- Trailer and tractor photographsGeometry of the impact, guard deformation, and final rest positions.
- ECM / black box downloadSpeed, braking, and throttle in the seconds before the crash.
- Brake inspection and maintenance recordsAdjustment, wear, and prior out-of-service orders.
- Driver and witness statementsWhat the driver did, what other motorists saw, and the road conditions.
- Roadway evidenceSkid marks, gouge marks, and debris that reconstruct the sequence.
Free case review
The guard condition and the black box do not wait.
Tractors are repaired and trailers are sold. A preservation letter is what keeps the evidence you need from being destroyed.
No fee unless we win · Consultations are free and confidential
Straight answers
Underride and jackknife questions, answered.
What is an underride crash?
An underride happens when a smaller vehicle slides beneath the trailer or side of a semi-truck. Because the trailer bed is higher than the car's hood, the car's passenger compartment takes the impact, often at windshield level. Rear underride guards are designed to stop this, but they do not always work.
Why do jackknife crashes happen?
A jackknife occurs when the trailer swings out and folds toward the tractor, usually because the trailer brakes locked or the driver braked too hard for conditions. Contributing factors include brakes out of adjustment, empty or light trailers, wet roads, and excessive speed.
Are underride guards required on all trucks?
Rear underride guards are required on most trailers under 49 CFR § 393.86. Side underride guards are not federally required in the United States, although they are recommended by safety advocates and are required in some other countries. A missing or defective rear guard can be strong evidence of negligence.
Who is liable in an underride or jackknife crash?
The driver, the motor carrier, the trailer owner, and sometimes a maintenance contractor or parts manufacturer can all be liable. In underride cases, the guard's designer or installer may also be a defendant. The specific evidence, photographs, guard condition, and ECM data, usually decides who is responsible.
If you were hurt in an underride or jackknife crash on I-20, Loop 323 or US 69, speak with a Tyler truck accident lawyer before the tractor is repaired and the black-box data is overwritten. The first call is free and there is no fee unless we win.