What leads to jackknife accidents?


When the attached trailer of a truck suddenly swings out at an angle from the truck’s cab, that’s called a “jackknife” accident because it resembles the motion of a folding knife.

Given the size, weight and speed of the average truck, and the potential for a chain-reaction accident among nearby vehicles, it’s no wonder that these are among some of the most devastating of wrecks. There were 4,842 fatal jackknife crashes, for example, in 2020 alone.

The causes are numerous

A jackknife accident doesn’t happen in a vacuum, and it can be related to more than one thing. Some of the primary causes include:

  • Loss of traction: When the wheels of either the truck’s cab or its trailer lose traction, that can result in skidding or sliding. The loss of traction can be due to anything from bald tires to wet roads.
  • Sudden braking: Hard braking, especially when the trailer’s wheels lock up, can cause a truck’s trailer to swing out of alignment with its cab very rapidly.
  • Oversteering: If a driver overcorrects while trying to regain control of their truck after a skid or a slide, it can cause the trailer to swing out to the side.
  • High speeds and sharp turns: Making sharp turns at high speeds can cause a truck’s trailer to swing out wide due to the momentum of its load and the laws of physics. The faster the vehicle is moving, the greater the risk of the trailer swinging out during a turn.
  • Uneven loads: Proper weight distribution of a trailer’s load is essential for stability. If more weight is concentrated toward the rear of the trailer, it can increase the likelihood of a jackknife accident.
  • Mechanical failures: Malfunctions in the braking system, suspension or other components of either the cab or the trailer can lead to a loss of control over the vehicle. This is particularly common if there’s a mismatch in the braking power between the truck’s cab and trailer.
  • Bad weather: Adverse weather conditions such as rain, ice, sleet or strong winds can reduce traction and stability, making it more likely for a jackknife to occur.

Preventing jackknife accidents involves proper driver training, adjusting speeds for the driving conditions, maintaining proper following distances and making sure that vehicles are properly loaded and maintained. When these things don’t happen and people suffer harm as a result, the victims of jackknife accidents and their loved ones have every right to expect fair compensation for their losses.