Jackknife truck crashes in Indiana: causes and who is at fault

A jackknife happens when the tractor and trailer fold toward each other, like a pocketknife closing. The trailer can swing across several lanes, roll, or sweep vehicles into barriers. Because a jackknifing semi can block an entire interstate in seconds, these crashes often involve several vehicles and serious injuries.

Who is at fault in a jackknife truck crash in Indiana?

Fault in a jackknife crash usually turns on why the truck lost control: speed too fast for conditions, following too closely, hard braking, brake or equipment problems, or a poorly balanced load. The driver and motor carrier are often responsible, and a loader, repair shop, or other company may share fault under Indiana’s comparative fault rules.

What causes a semi to jackknife?

A jackknife usually starts when the drive wheels or trailer wheels lose traction and the trailer keeps moving while the tractor slows or turns. Common contributing factors include:

• Speed too fast for conditions. Indiana law prohibits driving faster than is reasonable and prudent for the conditions, including weather and road hazards (IC 9-21-5-1). Rain, snow, ice, and lake-effect squalls in Northwest Indiana all call for slower speeds.
• Following too closely. A loaded truck needs much more distance to stop than a car. When traffic slows suddenly, a driver who is too close may brake hard and lose control. Indiana law prohibits following more closely than is reasonable and prudent (IC 9-21-8-14).
• Hard braking or braking in a curve. Sudden braking, especially while turning or on a downgrade, can lock wheels and start a skid.
• Brake and equipment problems. Out-of-adjustment brakes, worn tires, or a malfunctioning anti-lock system can make a skid more likely. Federal rules require carriers to systematically inspect, repair, and maintain their vehicles (49 CFR 396.3).
• Empty or lightly loaded trailers. A light trailer has less weight on its tires and can lose traction more easily.
• Shifting or poorly balanced cargo. A load that is not properly distributed and secured can affect stability. Federal cargo rules require cargo to be secured so it does not shift in a way that hurts the vehicle’s stability or handling (49 CFR 393.100).
• Fatigue and distraction. A tired or distracted driver reacts late and brakes harder. See FMCSA hours-of-service rules.

Who may be responsible for a jackknife crash?

Weather is not an excuse by itself. Truck drivers are expected to adjust speed and following distance for conditions. Depending on the facts, responsibility may be shared by:

• The truck driver, for speed, following distance, braking, distraction, or fatigue.
• The motor carrier, which is generally responsible for an employee driver on the job and can also be responsible for its own choices, such as unrealistic schedules, poor training, or skipped maintenance.
• The shipper or loading company, if a trailer it loaded and sealed was overweight or badly balanced.
• A maintenance shop or parts manufacturer, if faulty brake work or a defective component contributed.
• A freight broker, in some cases, if it carelessly selected an unsafe carrier. In May 2026 the U.S. Supreme Court held that federal law does not preempt these negligent-selection claims against brokers (Montgomery v. Caribe Transport II, LLC).
• Other drivers, if someone cut off the truck or caused the chain reaction.

More on this: who can be liable in an Indiana truck crash.

What evidence matters in a jackknife case?

• Engine control module (ECM) data, which may record speed, braking, and throttle in the moments before the crash.
• Electronic logging device (ELD) records showing hours driven and duty status.
• Forward-facing and driver-facing camera video, if the truck had them.
• Inspection and maintenance records for brakes, tires, and the anti-lock system, including the driver’s inspection reports.
• The bill of lading and load records showing what was in the trailer, how much it weighed, and who loaded it.
• Scene evidence: tire marks, gouges, the final resting position of the tractor and trailer, and weather data.
• The police crash report and any post-crash truck inspection.

Some of this data is kept only for limited periods or can be overwritten, so a preservation letter should go out early. See truck black box and ELD evidence.

What happens when a jackknife causes a multi-vehicle crash?

When a jackknife blocks an interstate, several vehicles may be involved, and each driver’s insurer may point at someone else. Indiana uses modified comparative fault: your damages are reduced by your share of fault, and you cannot recover if your fault is greater than the combined fault of everyone else (IC 34-51-2-5 and 34-51-2-6). Defendants can also ask a jury to assign fault to a “nonparty” who was not sued, which is why identifying every responsible company early matters.

What injuries and damages can a jackknife crash cause?

Jackknife crashes often involve side impacts, rollovers, and underride, which can cause brain injuries, spinal injuries, fractures, and death. Depending on the facts, an injured person may seek medical expenses, lost income, pain and suffering, and other losses. When a crash is fatal, Indiana’s wrongful death statutes control who may bring the claim.

Hurt in a jackknife or multi-vehicle truck crash in Indiana? Call 1-800-265-9881 or send the free case review form.

General information only—not legal advice. Laws change and every case is different; deadlines can be shorter in some situations. Prior results do not guarantee a similar outcome.