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Sem-Truck Laying on Side in Grass

Why Trucks Jacknife

Watching a truck lose control is one of the most frightening things that can happen on the highway. But perhaps worse is what happens when a driver overcorrects and makes a bad situation much worse. One example of this is called Jackknifing, where the trailer swings alongside the truck cab, folding like a pocket knife. But why does this happen? Why do trucks jackknife?


Truck jacknife accidents happen when the trailer is moving faster than the truck itself. Trucks and their trailers are supposed to act as a cohesive unit. However, when errors cause the trailer to act independently of the truck, it may slide forward or fishtail. This is especially dangerous for semi-trucks because the hitch is on a hinge.

One of the more common reasons for this phenomenon is when the truck driver brakes too hard, especially in wet conditions. The truck’s brakes lock, but the trailer continues to move forward. When this happens, the trailer is pulling the truck, but it can only do that by swinging on the hinge to get ahead of the cab.

Hydroplaning and locked brakes are by no means the only cause of jackknifing trucks. Some of the other contributing causes include:

  • Unsafe speeding
  • Improper cargo weight distribution
  • Turning (or veering) too quickly
  • Failed brakes
  • Driver error


Semi-truck accidents are much more likely to be catastrophic than other crashes, and jacknife crashes especially are more likely to cause multiple injuries. That’s because the trailer swings across multiple lanes, sideswiping anyone beside the truck as well as in front of the truck.

Additionally, when a jacknife occurs, the trailer is often moving at higher speeds than the truck itself. This, combined with the swiping motion, means that a car moving at the same speed as the truck will often experience much more serious damage than if it was hit from behind by a car traveling the same speed.

Jacknife accidents often cause catastrophic or fatal injuries, and they’re often due to either negligent maintenance or driver error. If you ever find yourself struck by a truck, know that you have a right to pursue damages from those responsible. An attorney on your side can help you explore your options and fight for the damages you need to move forward.

If you’d like to discuss the impact of your crash with an experienced truck accident attorney, don’t hesitate to call upon Maring Williams Law Office. Our firm serves injured parties across North Dakota, Minnesota, and Montana. Send us an email or call us today at (701) 402-6644 for a free consultation.