Jackknife Truck Accidents in Illinois: Legal Claims

Last Updated: October 24, 2026

A jackknife is the trailer swinging out from the cab. 49 CFR 396.3 requires a motor carrier to systematically inspect, repair, and maintain its vehicles. 49 CFR 393.52 sets the service-brake stopping performance. 49 CFR 571.136 requires electronic stability control on the truck tractors it covers.

A fully loaded tractor-trailer folds in half across three lanes of I-74 during evening rush hour. The trailer swings wide, sweeping up every vehicle in its path. By the time the rig comes to rest, multiple cars are damaged and several people are seriously hurt. That is a jackknife accident, and it is one of the most dangerous events that can happen on an Illinois highway.

What Causes a Truck to Jackknife?

A jackknife occurs when the trailer swings out at an angle from the cab, typically because the drive wheels lose traction. The trailer’s momentum keeps it moving forward while the cab slows or changes direction, and the two pivot at the fifth-wheel coupling. Common triggers include hard braking on wet or icy pavement, excessive speed entering a curve, improperly maintained brake systems, and unbalanced cargo loads that shift the trailer’s center of gravity.

49 CFR 393.52 requires the service brakes, in the loaded condition found on a public highway, to stop the vehicle from 20 miles per hour within the distance in its table. For other property-carrying vehicles and combinations, that service-brake distance is 40 feet. The section measures braking force as the sum of the force at each wheel. It does not require that force to be split proportionally across the axles. 49 CFR 396.3 requires every motor carrier to systematically inspect, repair, and maintain vehicles under its control, and to keep parts and accessories, including the brake equipment in part 393, in safe and proper operating condition. 49 CFR 571.136 requires electronic stability control on truck tractors with a gross vehicle weight rating above 26,000 pounds, with stated exclusions. A described three-axle class manufactured on or after August 1, 2017 must comply, and covered truck tractors manufactured on or after August 1, 2019 must comply.

Who Is Liable for a Jackknife Crash?

Jackknife cases often involve multiple potentially liable parties. The truck driver may be at fault for speeding, following too closely, or braking improperly. The motor carrier may bear responsibility for inadequate driver training, pressure to meet unrealistic delivery schedules, or failure to maintain equipment. In some cases, a third-party maintenance provider or brake manufacturer may share liability if a defective component contributed to the loss of braking control.

Under 735 ILCS 5/2-1116, in a bodily-injury, death, or property-damage action based on negligence, or a product-liability action based on strict tort liability, the plaintiff is barred if the plaintiff’s contributory fault is more than 50 percent of the proximate cause of the injury or damage. If it is not more than 50 percent, damages are reduced in proportion to that fault. In a multi-vehicle jackknife crash, the allocation of fault depends on the evidence. Our guide to truck accident claims in Peoria discusses identifying the responsible parties.

Critical Evidence in Jackknife Cases

Commercial trucks generate a substantial electronic footprint. The engine control module can record speed and braking in the seconds before a crash. 49 CFR 390.15 requires the carrier to keep an accident register for 3 years and to make records and information pertaining to an accident available to an authorized federal or state representative. Section 390.15 does not require the carrier to preserve engine-control-module data. That data can still be overwritten. Hours-of-service logs, whether electronic or paper, reveal whether the driver was fatigued or in violation of driving-time limits. Maintenance records, pre-trip inspection reports, and cargo loading documentation all bear on whether the carrier met its legal obligations.

A spoliation letter sent promptly after the crash puts the carrier and its insurer on notice to preserve all relevant evidence. Waiting too long can mean losing data that would have proven your case. If you suspect evidence has been destroyed, Illinois courts can impose adverse inference instructions telling the jury it may assume the missing evidence was unfavorable to the carrier.

Injuries Common in Jackknife Accidents

Because a jackknifing trailer can sweep across multiple lanes and strike vehicles at high speed, the injuries tend to be severe. Traumatic brain injuries, spinal cord damage, multiple fractures, crush injuries, and internal organ damage are all common. Many jackknife victims face extended hospital stays, multiple surgeries, and long-term rehabilitation. Illinois Pattern Jury Instruction 30.01 tells the jury that, if it finds liability, it must fix the amount of money that will reasonably and fairly compensate the plaintiff for the elements of damages proved by the evidence. The instruction is completed by inserting the elements that have a basis in the evidence. Those elements can include medical expense, lost earnings, pain and suffering, disfigurement, and loss of a normal life when the evidence supports the element used.

What to Do After a Jackknife Truck Accident

The immediate priority is always medical treatment. Beyond that, there are steps that protect your legal interests. Document the scene if you are physically able to do so. Get the truck driver’s name, the name on the side of the trailer, and the carrier’s DOT number. Report the crash to law enforcement so there is an official record. Contact an attorney before giving a recorded statement to any insurance company. Trucking insurers deploy rapid-response teams to crash scenes, and they are not there to help you.

Injured? Get the Help You Deserve.

The attorneys at Parker & Parker offer free, no-obligation consultations. Call 309-673-0069 or schedule online to discuss your case today.

Frequently Asked Questions

Can I sue the trucking company and not just the driver?

Yes. Under the doctrine of respondeat superior, the motor carrier is generally liable for the negligent acts of its drivers committed within the scope of employment. The carrier may also face direct liability for negligent hiring, training, supervision, or maintenance. In many jackknife cases, the carrier’s own failures are more significant than the driver’s.

How long do I have to file a jackknife truck accident lawsuit in Illinois?

735 ILCS 5/13-202 generally requires an action for injury to the person to be commenced within 2 years after the cause of action accrued. A claim against a local public entity, and a claim by a person who was under 18 or under a legal disability, follow different statutes. Engine-control data, driver logs, and dispatch records can be lost well before that filing period ends.

What if the truck driver was not cited by police?

A traffic citation is not required to prove civil liability. Police reports are one piece of evidence, but your attorney can retain accident reconstruction experts, obtain the truck’s electronic data, and review the carrier’s safety record through FMCSA databases to build the liability case independently.

Does insurance cover jackknife accidents?

49 CFR 387.9 sets the minimum public-liability financial responsibility. For a for-hire carrier in interstate or foreign commerce with a gross vehicle weight rating of 10,001 pounds or more, hauling nonhazardous property, the minimum is $750,000. The listed bulk hazardous substances and explosives are $5,000,000. Oil, hazardous waste, and the other listed hazardous materials are $1,000,000. The schedule does not set the limit for every private carrier of ordinary freight. Many large carriers carry $1 million or more. The available coverage is typically much higher than in a standard passenger vehicle case, which reflects the severity of injuries these crashes cause.

Truck accident cases involve complex regulations and multiple liable parties. Peoria personal injury lawyer Robert Parker has the experience to handle these challenging claims.

Need a lawyer? This article is part of our Peoria Truck Accident Lawyer practice area. Call Parker & Parker at 309-673-0069 for a free consultation.

Jackknife Truck Accidents in Illinois: Causes and Legal Claims