Semi Trucks Need This Device To Prevent Your Car From Getting Squished In A Crash

Cheryl and Christopher Jensen, CONTRIBUTOR We report on auto tech and consumer and safety issues 

When the Insurance Institute for Highway Safety crashed cars into the rear of tractor-trailers back in 2011, it found that having strong underride guards on the rears of those semis were effective in keeping cars from sliding underneath the semi.

Underride guards are a kind of metal bumper that hangs from the back of a high-riding semi to stop a smaller vehicle from sliding underneath in a rear-end crash.

Without a strong underride guard or with no guard, a car that rear-ends a semi keeps going and slides underneath the truck, shearing off the roof and resulting in a crash that would likely be fatal to the people in the car. Decapitation is a serious threat in these crashes.

Now the IIHS has released the results of crash tests done to evaluate how effective side underride guards might be in preventing side underride crashes.

The verdict? The new tests show that side underride guards have the potential to save lives, according to the IIHS.  

“We think a mandate for side underride guards on large trucks has merit, especially as crash deaths continue to rise on our roads,” said David Zuby, IIHS executive vice president, and chief research officer, in a written statement.

This morning Jackie Gillan, president of Advocates for Highway and Auto Safety (Advocates) issued a statement in support, which read: "These are crucial safety protections because frequently in side underride crashes, the front seat occupants are killed when the vehicle goes under a truck and shears off the top of the vehicle."

It said requiring side underride guards on semis a "practical and commonsense" solution.

Advocates said that preventing cars from sliding underneath the side of semitrailer trucks in crashes has been one of its top priorities for years because of the numbers.

In 2015, 1,542 people were killed in two-vehicle crashes between a passenger vehicle and a tractor-trailer. Of those, 301 were killed when their vehicle struck the side of a tractor-trailer and 292 died when their vehicle struck the rear of the semi. Because of gaps in fatality data, it’s impossible to know how many of the crashes involved underride, but IIHS researchers estimate it’s about half.

In addition to these figures, Advocates noted that the cost to society from crashes involving commercial motor vehicles has been estimated to be $112 billion in 2014, which is the most recent year for which this data is available.

This is the first time that IIHS has conducted these side underride guard crash tests. It performed two tests both at 35 miles per hour with a midsize car striking the center of a 53-foot-long trailer. One test was done with an AngelWing side underride protection device from Airflow Deflector Inc.; one was done with a fiberglass side skirt, which is intended to improve aerodynamics, not to prevent underride.

With the AngelWing, the guard bent but kept the car from sliding underneath the trailer.

In the test with the fiberglass side skirt, the car ran into the side of the trailer and kept going, shearing off part of the roof. IIHS said that in a real-world crash injuries to the people in the vehicle would likely be fatal.

Federal law requires large trucks to have rear underride guards, not side guards. But while these underride guards must meet federal safety standards, initial IIHS crash tests found that many rear guards were weak and could buckle or break off in a crash.

IIHS conducted its first tests of rear underride guards in 2011 with three semis.

In that test, Adrian Lund, IIHS president, was quoted in a statement saying: "Damage to the cars in some of these tests was so devastating that it's hard to watch the footage without wincing. If these had been real-world crashes, there would be no survivors."

Two years later, in 2013, IIHS then performed more tests, this time of eight semis; these eight manufacturers comprise 80% of the heavy truck market.

In those tests the rear underride guards of eight semis were put through three rear-crash scenarios. When the full width of the car’s front end hit the center of the guard, the easiest of the tests, all eight guards prevented underride. In the second test when 50% of the car’s front end hit the trailer, seven of the eight guards prevented underride. However, when 30% of the front end of the car hit the guard at its outermost edge, the toughest test, only one semi, the Manac, passed.

And then this March IIHS issued its first TOUGHGUARD awards, which recognize rear underride guards that are designed to prevent a range of these deadly underride crashes.

The TOUGHGARD winners have rear guards that prevent a midsize car from underriding in all three test scenarios and this time five of the eight semis passed all three tests: Great Dane, Manac, Stoughton, Vanguard and Wabash.

This means that between 2013 and 2017 four more companies reworked their rear underride guards to make them stronger to pass the IIHS tests, even though IIHS has absolutely no regulatory authority, only the power of publicity. Regulatory authority rests with the federal government.

After conducting its initial tests in 2011, IIHS petitioned the National Highway Safety Administration to upgrade its federal safety standard for rear underride guards. It is now 2017 and the agency has not changed the standard, although it has proposed changes.

Maybe using the power of publicity, especially if it threatens to be bad, will get the job done at least for rear underride guards. It will be more difficult with side underride guards since those are not even mandated at this point.

Advocates' statement noted that last week more than 60 families whose loved ones have been killed or seriously injured in truck crashes went to Washington, D.C. to lobby Congress and the U.S. Department of Transportation, urging action on overdue advances in truck safety.

Two issues they asked officials to take action on were mandating side underride guards and improving rear underride guards because the current standard was issued nearly 20 years ago (in 1998) and is "weak and ineffective."