Setting the Record Straight: “Too Rigid” Underride Guards is a Myth

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I would like to do what I can to make a bridge between those who study truck safety issues, the trucking industry, and the regulators. It seems to me that it would help if we would all take a deep breath, not get defensive, and work really hard to understand all of the factors involved in “truck safety” and make sure that the roads are as safe as possible.

Specifically, I would like to do my part in clearing up some possible confusion about underride guards on large trucks. Two aspects: the impact of rigidity and the type of trucks which need to have them.

In the fall of 2013, I read an article online written by an investigative reporter about the inadequacy of current standards for underride guards. It included some quotes from the trucking industry and one in particular caught my attention and—because of what happened in our crash—caused me consternation. It didn’t make sense:

— Response from trucking, trailer industries

If the NHTSA creates new standards, it could be expensive for the trucking and trailer industries, and some argue tougher guards are not even the answer.

‘This type of accident usually involves serious driver error, so the Truck Trailer Manufacturers Association notes first that the rules already in place to prevent these accidents must be followed, including regulations against speeding or driving while impaired or distracted,’ said Jeff Sims, TTMA president, in an emailed statement to WRTV. ‘Proper maintenance of vehicle lighting equipment is also critical, both for passenger vehicle headlights and trailer tail lights and reflective tape.”‘

Sims argued that more rigid guards could lead to more deaths and more significant injuries.

‘A neck strain could become a neck fracture as a result,’ said Sims.” http://www2.thedenverchannel.com/web/kmgh/news/underride-guards-metal-barriers-on-back-of-large-trucks-often-fail-to-protect-drivers

(Truck Trailer Manufacturers Association Statement referred to in that report: http://media.theindychannel.com/docs/ttma_statement.pdf)

While that may have been true at one time, it definitely no longer is the case. Due to advances in technology, cars have become much more crash-worthy, i.e.,  they are better able to absorb the energy of a crash and protect the passengers.

Notice—in direct contrast to the  quote above—what the Insurance Institute for Highway Safety (IIHS) said in their March 2011 Status Report on underride guards (written two years prior to that 2013 quote from the trucking industry):

“Meanwhile, the passenger vehicle fleet has changed dramatically since NHTSA wrote the standards. Regulators then were concerned that ‘overly rigid guards could result in passenger compartment forces that would increase the risk of occupant injuries even in the absence of underride.’ The agency also recognized the need for balancing energy absorption with guard strength because ‘the more the guard yields, the farther the colliding vehicle travels and the greater likelihood of passenger compartment intrusion.’

The Institute’s latest analysis indicates that guards too weak to adequately mitigate underride are a bigger problem than overly stiff guards.http://www.iihs.org/iihs/sr/statusreport/article/46/2/2

Another IIHS report describes it this way:

“Underride crashes can be catastrophic for people in passenger vehicles that run into the backs of heavy trucks. The steel guards on the backs of big rigs are supposed to stop smaller vehicles from sliding underneath trailers, but a new Institute analysis of real-world crashes indicates that too often rear guards intended to prevent underride buckle or break away from their trailers — with deadly consequences. To understand how this happens, the Institute ran a series of crash tests and discovered that guards meeting federal safety standards can fail in relatively low-speed crashes….

Cars’ front-end structures are designed to manage a tremendous amount of crash energy in a way that minimizes injuries for their occupants,’ says Adrian Lund, Institute president. ‘Hitting the back of a large truck is a game changer. You might be riding in a vehicle that earns top marks in frontal crash tests, but if the truck’s underride guard fails — or isn’t there at all — your chances of walking away from even a relatively low-speed crash aren’t good.‘” http://www.iihs.org/iihs/sr/statusreport/article/46/2/1

Another area of concern is that the current federal standards allow for certain types of large trucks to be exempt from these underride regulations. IIHS has indicated that this is a big mistake.

“Many of the cases of severe underride involved trucks and trailers exempt from underride-related safety standards. More than half of the trucks in the study weren’t required to have guards, although many had them anyway. The two largest exempt groups were trailers with rear wheels set very close to the back of the trailer and straight trucks (single-unit trucks with a cab and cargo body on one chassis). Dump trucks represented a particularly hazardous category of straight truck. They accounted for about one-third of the straight trucks but half of all the straight truck crashes involving severe or catastrophic underride.” http://www.iihs.org/iihs/sr/statusreport/article/46/2/1

How much of the opposition to change in safety standards is due to a misunderstanding of the factors involved? It is very distressing to me that somebody could die as a result.

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