Semi-trucks and other large commercial vehicles are a common sight on Interstate Highways and in rural areas. Nearly two million semi-trucks are in operation, distributing products throughout the United States and significantly contributing to the economy.

Large trucks are categorized as weighing 10,000 pounds. These trucks can be involved in accidents involving injuries and fatalities. Accidents involving large commercial trucks tend to occur in rural areas or interstate highways. While there are many causes of truck accidents, collision with another vehicle is the most common.

Due to their size and the relatively long time it takes to stop a semi, it is easy to see how the driver of a small passenger car would suffer injuries in a semi crash. Semi-truck accidents happen for all the same reasons as passenger vehicle collisions. Truck drivers are ten times more likely to be the cause of an accident However, some reasons for semi-truck accidents are more common. The following are the most common causes of truck accidents:

Accidents Caused by Truck Driver:

An ambulance at the site of a car wreck, where one car has flipped upside down

Drive or Human Error

Driver error accounts for the highest percentage of semi-truck crashes, making it the most common cause of truck accidents. According to the Federal Motor Carrier Safety Administration (FMCSA), eighty-eight percent of truck related crashes are due to the error of the driver. This can include crashes caused by a speeding driver, a driver who fails to check blind spots before switching lanes, and driver confusion. Some of the mistakes truck drivers can make include anything from negligent driving(e.g., speeding), to distracted driving (e.g., texting), to ​substance use and/or abuse. One more major contributor is driver exhaustion. While truck drivers are called to abide by Hours of Service policies that determine the length of time they can be behind the wheel for a single stretch, several still work prolonged hours and take trips that are long distances. This results in rest deprivation and fatigue, putting them at high risk for errors as well as crashes. 

Overspeeding/ Overtaking

Truck owners usually demand that truck drivers reach certain destinations within a certain time period. This is not always achievable due to many factors, including poor weather conditions and traffic snarl ups in some sections of the road. However, due to the pressure that the drivers are put under to meet these deadlines as well as the risk they face of losing their jobs, the drivers normally drive over the speed limit. Overtaking by these big trucks at break-neck speeds forces oncoming drivers in smaller cars to veer off the road leading to crashes, most of which are fatal. Over-speeding also has the effect of significantly reducing reaction time. When driving at high speeds, drivers may be required to break immediately or suddenly veer into another section of the road. when at high speeds this is not always possible.

Driver Fatigue

Driver fatigue is a serious problem among the trucking industry. While the hours that truck drivers work are dictated and limited by the law, they still often have long hours and demanding schedules. Some truck drivers force themselves to stay awake through long haul drives when they should be taking certain breaks and resting. Plus, truck drivers are often compensated in a way that encourages driving faster and longer than is safe. A truck may then drive in potentially unsafe weather conditions to meet deadlines. This can cause drivers to lose focus, ignore safe driving techniques, and cause crashes. Fatigue is the most common cause of driver error. About 40% of all truck accidents are attributed to fatigue.

Distracted Driver

Inattention and distraction often cause accidents for truckers just as they do for drivers of passenger vehicles. In the course of driving for many hours over long distances, drivers get bored on the road and regularly look for something to keep them occupied. This urge to kill the boredom leads them to do one of several things. Is the driver eating, drinking, daydreaming or sending a text? The most common one is using their phones to read or reply text messages, make phone calls or even visit their favorite social media sites. Changing the car radio station while on the road has also been attributed to distracting drivers, leading to accidents. When on the road in the country, the reception of some radio stations is poor in certain areas. This causes the drivers to reach over to their radios and find a station they can listen to. This happens even when they are on the freeway driving at a high speed. Even a fraction of a second when a driver takes his eyes off the road could be the difference between safety and causing an accident.

Driving Under The Influence

It is illegal in every state to drive under the influence of alcohol or drugs. Many truck drivers have been found guilty of using alcohol and non-medicinal drugs while on the job. Prescription and over-the-counter drugs are a huge issue as they often inhibit the ability of the driver to maneuver such a large vehicle properly. Some only take these substances at stops in towns across the country while others go a step further and carry alcohol and drugs with them while driving. 

Regardless of how they use these substances, their driving becomes impaired and they can easily cause accidents. It is not only illegal drugs that can lead to accidents on the road. Some prescription drugs that the drivers may be using also have the effect of impairing their coordination and judgement, leading to road accidents. Commercial drivers are specifically held to a higher standard than passenger vehicles and the general public. 

They are only allowed a little alcohol in their system due to the fact that the size, weight and force of a semi-truck make them an inherent danger to others on the road. Safety is of the utmost importance to drivers and due to increased risk of semi-trucks causing injury or fatality, they are held to a higher standard. Drivers under the influence can cause severe danger to themselves and everyone else on the road. 

Failing To Secure Loads

Whatever product the truck is carrying, it is crucial that said product is carefully packed and secured so weight is evenly distributed across the truck. Failure to properly distribute the weight can make it more likely that a truck will get into an accident. This is especially true when turning or trying to stop. When a product is not properly tied down or stored on a flyer, it can potentially fly off the trailer onto the road into the path of another vehicle causing a potential road hazard or car accident. 

Low Filled Liquid Loads

Many trucks transport liquids like gas and oil. These trucks were designed to hold a certain amount of liquids before they are full. It can be dangerous to keep the truck partially full, the liquids can splash around in the trailer and in turn cause the truck to sway back and forth with turns and changes in speed. Further, if a liquid makes a sudden movement, a driver could lose control and cause an accident. 

Rear End Crashes

A rear end crash is one of the deadliest types of crashes. This type of crash can occur when a semi-truck driver fails to stop or slow their vehicle in time to prevent a crash with a car in front of them. The truck strikes in the rear, often with significant force. A car is not capable of taking this heavy of an impact and will likely crumble. All vehicle occupants are at risk for injuries in the event of a rear-end crash. Backseat passengers in these situations have a more particularly high risk of injury. 

Lack Of Training

There is a high demand for truck drivers and sometimes, the trucking companies do not often do enough to train or work on their drivers’ skills. This in turn can lead to dangerous and severe accidents, especially since trucks are so heavy and large. Before truck drivers can be allowed to drive huge commercial vehicles on public roads, they are required to put in a certain threshold of training hours and to meet certain minimum requirements. However, not all truck drivers adhere to these guidelines. What you get is a poorly trained truck driver with little experience behind the wheel.

Lack Of Maintenance

Trucking companies are required by law to maintain their vehicles and keep them in a condition that ensures safety. However, because there are costs and time involved in maintaining semi-trucks, this cuts into profits in making deliveries. Likewise, truck owners are required by law to see to it that their trucks are in top condition before hitting the road. However, they do not normally do this due to the costs involved and time it takes to maintain the trucks – time they could use to make deliveries. Poorly maintained trucks being driven by poorly trained drivers is one of the biggest causes of truck accidents.


According to the National Highway Safety Administration, at least 29% of truck accidents involve brake failure. This can be due to faulty inspection, lack of maintenance, condensation or overheating. The federal government requires truck companies and drivers to stay on top of their brake conditions at all times. More than one party can be liable for brake failure. Manufacturers and designers can also be responsible. Poorly maintained trucks are one of the biggest causes of truck accidents.


Another common problem found in large truck accidents involves its tires. With so much riding on them, it is of the utmost importance that they are always performing safely. Flaws in design, poor maintenance, and lack of proper inspection can cause tire blowouts, which can cause serious destruction. 

Not Caused by Driver:

A large truck missing the front of its hood after being in a car wreck

Issues With The Road Or Highway

Truckers invest a lot of time traveling down strange roadways, usually at night. When roadways are not kept in excellent upkeep, or when there are barriers on them, they can possibly trigger accidents. If a trucker encounters climate problems on these roadways(snow, heavy rainfall, etc.), the risk of an accident increases. Also the most mindful driver can not entirely prevent the risk of being associated with a truck crash.

Vehicle Malfunctions

Problems with the truck itself can often cause accidents and crashes. Mechanical failures can happen when there is a faulty design or installment of truck components, such as when brakes fail to run effectively. Trucks must also be loaded and kept effectively. Failing to do so can result in rollovers, jackknifing, and also various other dangerous scenarios that place various other motorists in danger.

Accidents Caused By Passenger Vehicles:

firefighters pulling an injured man from a fiery car

The Federal Motor Carrier Safety Administration (FMCSA) provides a Safety section with tips and resources for commercial truck drivers and other motorists. Common unsafe acts committed by car drivers in the vicinity of large trucks, which often result in truck accidents include:

  • Driving in the "No-Zones" -- the areas behind and beside a commercial truck where the truck driver has limited or zero visibility.
  • Changing lanes abruptly in front of a truck.
  • Maneuvering to the right of a truck that is making a right turn.
  • Misjudging an approaching truck's speed at an intersection, and making a left turn in front of the truck.
  • Merging improperly into traffic, causing a truck to maneuver or brake quickly.
  • Failure to slow down or speed up when a truck begins to change lanes or merge.
  • Unsafe passing, particularly passing with insufficient headway.
  • Passing a truck, then being blown out of position by air turbulence or cross-wind.
  • Pulling into traffic from the roadside in front of a truck without accelerating sufficiently.
  • Driving between large trucks.
  • Abandoning a vehicle in a travel lane, or failing to get a disabled vehicle completely off the highway and onto the shoulder.


Truck Accidents