When a vehicle smashes into the undercarriage of a semi-truck, it can be one of the worst accidents that ever happens on the road. A smaller vehicle is simply no match for a big rig.

These accidents often involve powerful impacts, crash-related fires, and extreme damage to the smaller vehicle, including having its roof completely sheared off. The occupants inside will be lucky to live through the crash.

With so many semis on the road, it seems like there should be a way to prevent horrific semi-truck underride accidents. So let’s look at why they happen, what could be done to prevent them, and what to do if you ever find yourself in one.

These Catastrophic Accidents Have Many Factors

Safety experts pay close attention to semi-trucks and their accidents on our nation’s roadways. The Insurance Institute for Highway Safety (IIHS) has found that although big rigs are only 4% of vehicles on U.S. roads, they account for 10% of highway deaths.

Severe truck accidents had been declining during the years leading up to 2009, but they’re on the rise ever since. Experts attribute this to many factors, including increased nationwide reliance on truckers for online deliveries, higher expectations for fast delivery, and driver distractions like cell phones.

Underride accidents represent only a fraction of semi-truck accidents, but they’re among the most severe. Here are some of the reasons why.

  • Weights and forces – A semi-trailer can easily weigh 40 tons and when it’s moving at highway speeds, it takes a huge amount of force to stop, turn, or avoid a collision.
  • Visibility – Despite a semi driver’s high vantage point, it’s sometimes hard for them to see small vehicles and those that are traveling in their blind spot. Bad weather and sun brightness can also impact visibility. In addition, other drivers sometimes face visibility issues due to the massive size of the semi-trailer blocking their view.
  • Assumptions – Other drivers often make incorrect assumptions about semi-trucks. They may assume that the truck driver sees them, figure that the driver will yield to them, or make a poor estimate of the time it takes to pass a long semi-trailer.
  • Reaction times and impairment – Semi-trucks already have slow reaction times due to their size, so if a driver is also impaired, this can compound the issue. Anyone on the road may drive distracteddrunkdrugged, or so aggressively that they endanger other drivers.
  • Equipment issues – Although trucks are supposed to be inspected regularly and equipped with reflective lights and tapes, not all truckers or trucking companies follow the rules. Plus, equipment failures happen and a truck may have bad brakes, a punctured tire, or a system breakdown that contributes to a crash.
  • Delivery pressure – Delivery truckers face intense pressure to travel quickly and make it to each destination by the deadline. This can lead to a delivery truck accident due to hazardous behavior like speeding, reckless driving, or drowsiness from long hours on the road.
  • Entrapment – A semi vs. car collision can easily cause a person to become trapped in their vehicle and unable to receive medical attention until vehicles are pulled or cut away. This makes a bad accident even worse.

Is There Any Way to Prevent These Accidents?

Most large semi-trucks that travel highways and interstates already have protective side-bars, rear-guards, and front metal grates. It’s just good sense for trucking companies to have these safety features to minimize damage and prevent insurance claims.

Some safety experts are also calling for required rear underride guards, which prevent other vehicles from sliding under big rigs. Safety tests by the IIHS have shown that although these long, metal guards sometimes bend during powerful impacts, they significantly limit slide-unders and reduce the incidence of death due to underride crashes.

However, so far there have been no widespread mandates for the use of underride guards. And even if there were, some truckers and trucking companies would skirt the rules about installing them.

What to Do if You’re in a Semi-Truck Underride Crash

After an accident that involves a semi-truck, you can take action against the trucker, trucking company, or insurance company. Don’t settle for a lowball offer because an underride accident is likely to leave you with severe bodily injury and huge medical bills, not to mention a crushed car.

A talented truck accident lawyer can be a huge help during this difficult time. At Sally Morin Personal Injury Lawyers, we will take your concerns seriously and get you on the road to a valuable settlement that allows you to rest and recover from the trauma of a crash.

Sally did an amazing job settling my personal injury automobile accident case. I was stopped on the freeway and rear-ended by a texting man in a big truck (don’t text and drive). Aside from the wonderful and unexpected settlement, the best part was that instead of dealing with the slimy insurance settlement case worker (who wanted to show up at my work to verify my injury), I dealt with Sally and her knowledgeable and kind staff. It gave me peace of mind to be able to deal with someone with so much integrity who had my interests in mind.” – Lyssa G.

Experience a serious car and truck accident in San Francisco?

Check out our San Francisco Truck Accident Page to learn more about how the process works.

We Handle Your Accident Claim So You Can Focus on Your Life

After an accident, contact the attorneys at Sally Morin Personal Injury Lawyers. We handle many types of traffic injury claims. We believe you should be able to focus on recovering from your accident while we handle the legal details.

We truly care about the people of California. Contact us today for a free online case evaluation.

Accident Client

“Last March, my partner was struck by a vehicle while crossing the street. During this difficult time of healing, we knew that bills were going to pile up and his was going to be a long process. After looking at multiple law firms, we knew that Sally Morin Personal Injury Lawyers was going to be the best place to work with. Lauren and her team were patient, supportive and caring during his difficult time. His schedule was always busy with work and doctor appointments that his main source of communication was through email. Lauren and her team made it to where he didn’t have to worry about anything but just sending over the paper work he got from the hospital, and other bill collectors involving his incident and they worried about the rest.

Because of all their help my partner Aaron, was able to heal with less worries on his shoulders. By end of December, everything was settled and we were pleased with the results. I’d like to give a huge thank you to Lauren & the Sally Morin team. If you’re looking for a law firm for your incident, I’d definitely look at this law firm.”

We're here to help with your Personal Injury claim

Check out our Personal Injury FAQ Page to learn more about how the process works.

We Handle Your Personal Injury Accident Claim So You Can Focus on Your Life

After an injury, contact the attorneys at Sally Morin Personal Injury Lawyers. We handle many areas of the law, including pedestrian and car accidents that involve speeding. We believe you should be able to focus on recovering while we handle the legal details.

We truly care about the people of San Jose and all of California. Contact us today for a
free online case evaluation.


It is essential to know your rights after a traffic accident so you can protect yourself and the value of your claim.
This guide will help you:

  • 1Know what to do when dealing with insurance claims, police reports and lawyers.
  • 2Avoid making mistakes that undermine the value of your claim
  • 3Put yourself in a position to get the best settlement possible