What Is the Biggest Risk 18-Wheelers Pose to Other Drivers?

Dangers of 18-WheelersIt comes as no surprise that there are dangers associated with sharing the roadway with a vehicle twenty times the size of your own. If you have ever skidded over ice or hydroplaned through water, you know how hard it can be to regain control over your car or SUV. Imagine trying to do that with a tractor trailer. Smaller vehicles in the way are like marbles waiting to be ejected inside a pinball machine. It is not a good place to be.

The biggest risk associated with driving around 18-wheelers is the potential for becoming the victim of an override or underride truck accident when one of these large commercial vehicles loses control. Today, we discuss the difference between these two collisions and what you can do to protect yourself.

What is an underride accident?

Underride crashes occur when passenger vehicles go partially or completely underneath the back trailer of a commercial semi-truck. In this type of accident, the smaller vehicle often only stops moving forward once the uppermost area of the vehicle – the cab – connects with the lower edge of the trailer. This edge can act like a blade, shearing through metal like butter, killing every occupant in the vehicle. Frequently, death is the result of traumatic brain injuries and decapitation.

Occupants who survive may suffer from:

  • Spinal cord injuries
  • Lacerations
  • Internal organ damage
  • Crush injuries
  • Traumatic amputation
  • Permanent disfigurement

Vehicles that are lower to the ground are particularly high risk for these types of accidents. SUVs and taller pickup trucks that sit up higher are less likely to slide under the edge of the trailer than for the body of their vehicle to make contact with it, which can still cause a devastating accident depending upon the speed and circumstances.

What is an override accident?

Underride accidents occur when a passenger car rear-ends a truck. However, in an override accident, the truck is the vehicle that makes initial contact by rear-ending the passenger vehicle. If an override accident occurs, the commercial truck rolls up and over the back of the smaller automobile, which can crush the vehicle and its occupants. These collisions are usually fatal for passenger car occupants, causing many of the same injuries as underride collisions.

Dos and don’ts for sharing the road with large trucks?

While everyone is supposed to take care to prevent negligence on their part on the road, because of the risk of override and underride accidents, you must be prepared to protect yourself. For your own safety, assume that the responsibility is all on you and follow these rules:


  • Let trucks have the right of way by slowing down.
  • Drive at a safe speed.
  • Adjust your speed according to weather conditions.
  • Be aware of traffic signals and road conditions.
  • Slow down when being passed by a big rig.
  • Use your turn signals.
  • Maintain a constant speed when passing, watch the truck’s tires to see if they’re approaching the lane line, and make sure the front of the truck is visible in your rear-view mirror before moving in front of the truck.
  • Leave space in between you and 18-wheelers when stopped or moving uphill.
  • Use low-beam headlights when following large trucks at night to avoid blinding the driver.
  • Remember that large trucks take longer to pass and that you want a clear path before doing so.
  • Be cautious when passing trucks that are pulling a trailer, which could become unsteady and swing in your lane.


  • Change lanes abruptly.
  • Cut off commercial trucks because they do not have the ability to stop short.
  • Tailgate a truck; you may not be visible if you’re too close.
  • Do not try to squeeze into the space next to a semi-truck when it’s making a turn, because it could hit you or cause an override collision.
  • Position your car in between two or more large trucks, as they may not see you when changing lanes.

Determining fault in an underride or override accident must begin with an investigation. One of these accidents can be caused by poor weather, low visibility, a fatigued truck driver, another distracted motor vehicle driver, speeding, reckless driving or following too closely. Driver error is the most common factor involved in both types of accidents. Identifying the cause of the accident could mean the difference between victims or their loved ones having the ability to seek financial compensation or undergoing a lifetime of financial hardship due to costly medical care.

If you or a loved one has been injured in an override or underride truck accident, you need an experienced legal team on your side. The dedicated Huntsville personal injury lawyers at Martin & Helms are ready to help. To schedule your free consultation in our Huntsville or Decatur office, please call 256.539.1990 or we invite you to reach out to us through our contact form to tell us your story. Proudly serving Madison, Athens, and all of North Alabama.