Even with safety precautions in place, accidents involving semi-trucks and vehicles often end with catastrophic injuries or death, especially for occupants in smaller passenger cars.
One such safety device is underride guards, which are placed on the back of semi-trailers to prevent vehicles from sliding under the trailer during rear-end crashes.
In recent months, however, their effectiveness has been questioned.
Research conducted by the Insurance Institute for Highway Safety early last year revealed underride guards are prone to failure, even at relatively low speeds.
During the IIHS study, roughly 1,000 crashes (from 2001 to 2003) involving heavy trucks and semi-trailers with and without underride guards were analyzed for patterns.
Findings showed only 22 percent of the crashes didn't involve underride or the impact had minor effect.
But in 23 of the 28 cases where someone in a passenger vehicle died, there was extensive underride damage due to sliding underneath the trailer.
According to the National Highway Traffic Safety Administration, an estimated 423 people in passenger vehicles die every year as a result of crashes into the back of large truck trailers.
Furthermore, more than 5,000 passenger vehicle occupants are injured in such collisions.
Using this initial data, the IIHS conducted crash tests to determine the level of injury at various speeds and what underride guard designs perform best.
Hyundai Translead, Wabash National Corp.
and Vanguard National Trailer Corp.
trailers were tested using a 5-star-safety-rated 2010 Chevrolet Malibu as the passenger vehicle.
In a center-rear impact at 35 mph, the underride guard on the Hyundai Translead trailer bent forward, sheared its attachment bolts and collapsed.
The Wabash trailer withstood the impact and remained in place, making it the strongest trailer of the three tested.
Evaluations were also conducted with overlaps of 50 percent and 30 percent to monitor impact when passenger vehicles crash with only a portion of their front end.
Again, at 35 mph, the Wabash trailer prevented significant underride at a 50 percent impact, but it bent forward at 30 percent and allowed significant underride.
Overall, the tests confirmed even the strongest guards are susceptible to underride, especially when the impact point is away from the center of the guard.
It's also worth noting the 35 mph testing speed is likely lower than the typical pace of passenger vehicles on highways where most semi-trucks travel.
NOTE: As mentioned earlier, accidents involving semi-trucks often lead to horrific injuries and, unfortunately, death.
So a higher standard of insurance coverage is necessary to cover the greater risk truck drivers face.
This increased insurance - as well as the legal regulations surrounding the operation and ownership of semi-trucks - can lead to higher settlements for accident victims.
But a personal injury lawyer is often needed to sort out the unique legal challenges involved with semi-truck crashes.