What Is Jackknifing?

December 6, 2022

Imagine that you're driving to work when you see a fully-loaded tractor-trailer bent at an angle and headed in your direction. With nowhere to go, you brace yourself for impact and hope for the best. This is a terrifying reality for motorists every day in the United States who experience accidents due to jackknifing. Due to its size and weight, a jackknifed semi-truck has the power to cause massive damage to the people and vehicles in its path.

While it may not always be possible to prevent or avoid jackknifing accidents, victims in these incidents have options for seeking justice and financial settlements. To better protect yourself on the road and strengthen the odds that you'll receive fair compensation in the event of an injury, it's important to answer a few essential questions: what is jackknifing, why does it occur, and what harm can it cause? 

Understanding the Term "Jackknifing"

A tractor-trailer is comprised of two parts: the cab and the trailer. These components are meant to operate in alignment, with the trailer following immediately behind the cab. Unfortunately, a situation can occur in which the trailer swings out from the cab and forms a V shape similar to a pocket knife. This is known as truck jackknifing, and it presents a very real threat to the safety of yourself and your vehicle.  

What Causes a Jackknife Accident?

Jackknifing can occur due to a driver's error or poor judgment, particularly in combination with elements outside of human control, such as bad weather. A truck accident case often rests on the driver's liability, so knowing what causes jackknifing can help you better understand whether you have a valid claim for compensation. 


Truck drivers who do not obey the posted speed limit or who do not lower their speed in response to driving and traffic conditions place themselves and other motorists at significant risk. The FMCSA reports that speeding is the most common driver-related factor in truck accidents in the United States. 

When a loaded truck operates at high speed, the driver doesn't have adequate time to react if there is an unexpected obstruction on the roadway. While traveling on the interstate, a truck driver might encounter: 

  • Slowed traffic
  • Fallen objects such as branches and signs
  • Construction zones 
  • Traffic accidents 
  • Pedestrians
  • Stalled vehicles 

Normally, a driver would have time to slow down before reaching the hazard in question. However, even high-quality, well-maintained brakes may not be up to the task of stopping a full-size trailer in a short distance if the driver is going too fast. Rather than stopping, the truck could jackknife, placing everyone in the area in harm's way. 

Driver Fatigue

Truck drivers often face difficult and stressful work conditions that leave them exhausted, and fatigue can contribute to jackknifing. The United States Department of Transportation associates tens of thousands of accidents yearly with drowsy driving. 

Drivers who aren't alert can easily drift across lanes or onto the shoulder and then abruptly hit the brakes when they realize what's happening. As a result of this improper braking, the trailer can jackknife. Likewise, if a sleepy driver swerves the truck, cargo can move dangerously from one side of the trailer to the other. 

Harsh Weather Conditions

Dangerous roads make a jackknifing accident far more likely. Ice, snow, and water can cause slippery roads, making it difficult for the wheels to get traction. If a truck slides, the weight of the load on the trailer and cab can shift, which in turn causes the trailer to become unbalanced. Slick roads are especially dangerous for drivers who: 

  • Do not adjust their speed 
  • Suddenly apply the brakes 
  • Go into a curve too fast

In the worst scenarios, jackknifing a trailer can cause a driver to lose control of the truck entirely. 

Cargo Shifts From Improper Loading

Balance is vital to safely operating a truck, and drivers receive specific training to ensure that they pay close attention to how their loads are distributed. Careless or inexperienced drivers can make critical errors when it comes to loading their trailers. This includes: 

  • Overloading the trailer beyond its weight capacity
  • Neglecting to secure cargo, allowing it to shift during transport 
  • Failing to correctly balance the load, which affects the trailer's center of gravity

In each case, the result can be disastrous. A trailer and cab can become misaligned due to improper loading, causing the trailer to jackknife. 

The Injuries and Damages That Result From Jackknifing

In the United States, a loaded semi-truck can legally weigh up to 80,000 pounds. A truck and trailer of that size can cause catastrophic damage to you and your personal property. The impact of a commercial truck can crush or destroy your vehicle and cause serious or life-threatening harm to you and any passengers in your car. 

Some of the physical injuries that you could experience due to a jackknifing accident include: 

  • Spinal cord injuries
  • Traumatic brain injuries
  • Burns
  • Broken bones 
  • Organ damage

Surviving a jackknifing accident can also have long-lasting psychological effects, such as depression, anxiety, and post-traumatic stress disorder. In the most devastating accidents, jackknifing accidents can also cost human lives. According to data from the Federal Motor Carrier Safety Administration (FMCSA). several thousand jackknife accidents occur annually, and approximately 3.5% of these accidents involve fatal injuries. 

Discuss Your Options With a Truck Accident Attorney

People who experience a jackknifing accident often face substantial financial burdens in the form of medical care, physical therapy, mental health treatment, and home modifications. In an attempt to get help with managing these mounting bills, victims must spend time communicating and negotiating with insurance companies rather than focusing on their recovery. 

An experienced truck accident attorney can help alleviate this stress and ensure you receive the maximum compensation for your expenses and suffering. If you or a loved one has suffered from jackknifing, reach out to the experts at McEldrew Purtell for a free consultation.