common causes of commercial truck accidents

The Federal Motor Carrier Safety Administration (FMCSA) conducted a study on the factors that contribute to large commercial truck crashes. This “Large Truck Crash Causation Study” revealed a few interesting things:

  • Fatigue, alcohol and drug use, and speeding are the top three factors in motor vehicle crashes overall.
  • There are also three “critical events” that can lead to a truck crash: moving out of the lane of travel, losing control of the vehicle, and colliding with another vehicle.
  • Many commercial truck crashes with a smaller vehicle involve errors by the smaller vehicle’s driver, as well.

Below we discuss more about the factors that contribute to commercial truck accidents.

Top 14 Causes of Commercial Truck Accidents

Most truck accidents can be attributed to one or more of the causes below. The more of these factors a single driver has—from intoxication to inattention to a poorly-maintained vehicle—the greater the risk that they’ll be involved in a crash.

Driving Under the Influence

Perhaps the greatest risk to other motorists comes when a commercial truck driver is driving under the influence of alcohol or illegal drugs.

The FMCSA has set forth some strict regulations for the blood-alcohol content (BAC) of commercial truck drivers—while someone driving a passenger vehicle won’t be considered intoxicated until their BAC is 0.08 percent or higher, the threshold for commercial drivers is only 0.04 percent. Additionally, commercial truck drivers are prohibited from consuming alcohol within four hours of driving a company vehicle, regardless of their BAC. Drivers may be randomly tested for illicit drugs, including marijuana, as well.

Unfortunately, not all commercial truck drivers follow these regulations—some may drink alcohol shortly before a trip, while others may use illegal drugs like meth or other amphetamines to stay awake. These reckless actions can put other drivers at risk.


Distracted driving or driver inattention can be incredibly dangerous, whether the distracted driver is piloting a commercial truck or another vehicle. Because large commercial trucks take so much longer to stop or maneuver than smaller vehicles, a commercial truck driver who is distracted can risk rear-ending other vehicles, straying into another lane, or even leaving the roadway entirely.


Even with strict federal hours-of-service regulations for commercial truck drivers, many drivers may find themselves feeling drowsy while behind the wheel.

Currently, commercial drivers are limited to:

  • No more than 11 hours of driving at a time, with a 10-hour break in between shifts
  • No more than 60 hours of driving in one week or 70 hours in an eight-day period

However, drivers who adhere to these regulations can still be at risk of fatigue, and some drivers may feel pressured to violate these regulations—particularly with supply-chain issues still impacting inventory in many parts of the country.

Driving while tired can be just as dangerous as driving while intoxicated—in fact, if you’ve gone 24 hours without sleep, you’ll suffer the same sort of cognitive effects as if you had a blood alcohol content of 0.10 percent. Combining drowsy driving with drugs or alcohol can significantly increase the risk of a crash.


Most major trucking companies use speed limiters (governors) or speed trackers on their company vehicles. However, owner-operated vehicles may not have this technology. Exceeding the speed limit can be dangerous for truck drivers because these vehicles take so long to stop—nearly twice as long as a passenger vehicle, or close to two football fields when traveling 65 miles per hour. If a truck is speeding, even if the driver is able to quickly react to slowed or stopped vehicles, it may not be enough to stop the truck in time.

Interruption of Traffic Flow

When a semi truck is traveling in heavy traffic, it can pose a risk to other vehicles—even if the driver does nothing wrong. When traffic flow is interrupted or another vehicle cuts in front of a truck, the truck driver may not be able to react in time to avoid a collision.

Unfamiliarity With the Road or Route

Some commercial truck drivers handle the same route or set of routes, while others are sent to different places each day. Those who frequently travel on unfamiliar roads may be at a greater risk of an accident, particularly those who are on surface or county roads rather than highways and interstates.

Aggressive Driving

Because truck drivers spend so much time on the road, often traveling long distances while under time pressure, they can be more vulnerable to “road rage” than other drivers. If truck drivers fail to yield the right of way, cut other drivers off, follow too closely, or exceed the speed limit, they risk seriously hurting themselves and anyone caught in the crossfire.

Aggressive drivers of passenger vehicles can also risk collision, as truck drivers aren’t able to quickly maneuver away from a vehicle that is making sudden and unpredictable movements.

Inclement Weather

Weather conditions like rain, sleet, snow, and ice can make roads slick, reduce visibility, and increase commercial trucks’ stopping distance. It’s not uncommon for these road conditions to lead to multi-car pile-ups, often beginning with a commercial truck that wasn’t able to stop in time. Combining inclement weather conditions with distraction, intoxication, or vehicle issues can be a recipe for disaster.

Road Construction

While drivers may not need to worry as much about inclement weather conditions during the summer months, road construction can often more than make up for clear skies and dry roads. Commercial truck drivers who come across tricky road construction may attempt to maneuver around it, only to collide with another vehicle or the median—and drivers who aren’t paying attention when they enter a construction zone may not be able to react to hazards like traffic barrels or construction equipment quickly enough to avoid a collision.

Overloading Cargo

Many semi trucks carry loads that bring the total truck weight to 80 tons or more. Trucks with large loads like these are at a greater risk of tire blowouts or tipping over. And if this large load is being hauled on an open trailer, it can risk sending flying debris to the vehicles behind it, potentially causing injury to other drivers.

Driving While Ill

Commercial truck drivers who are charged with getting cargo from Point A to Point B don’t often have the opportunity to take a sick day—especially if they fall ill while on the road. Drivers who try to work while sick can have slowed reaction times and more fatigue than healthy drivers, risking an accident. What’s more, the federal motor carrier regulations that prohibit driving while tired or while under the influence don’t address driving while ill, which means there’s little incentive for truck drivers to take time off to recover.

Misjudging Other Drivers’ Actions

Because commercial trucks can’t respond to sudden movement as quickly as smaller vehicles, a driver who misjudges the actions of smaller vehicles could be at a higher risk of an accident. If a commercial truck driver assumes that a vehicle will stay in its lane or continue at a certain speed, they may not be prepared to react to a different action.

Brake or Vehicle Malfunction

Although most common causes of truck accidents involve some sort of driver error, there are a few situations in which vehicle problems are to blame. A commercial truck with malfunctioning brakes, a blown tire, an oil leak, or other mechanical problems can pose a major risk to both the truck driver and everyone else on the road.

Inadequate Lighting

Many truck drivers find themselves driving after dark, particularly on cross-country hauls. If the highways or roads are poorly lit, truck drivers may have reduced visibility, increasing the number of blind spots they’re forced to deal with. This can make it much harder for truck drivers to see narrow roads, curves, stop or yield signs, and even other drivers.

What to Do After a Commercial Truck Accident

Commercial truck accidents can be life-altering. If you or a loved one has been injured in a truck accident, it’s important to speak to an experienced truck accident attorney as soon as you can.

At Hale Injury Law, we can help you with your commercial truck accident, contact us now for help!

Insurance companies may reach out to you quickly, even making settlement offers—but it’s in the insurance company’s best interest to settle claims as quickly and cheaply as possible, so any offer may not be enough to compensate you for your injuries. This is why you need an experienced commercial truck accident attorney. Your attorney can fight on your behalf to ensure you get every penny of compensation you deserve.