Are Underride Guards a Safety Concern?

white semi truck with underride guards

The Advisory Committee on Underride Protections, led by the National Highway Traffic Safety Administration (NHTSA), is dedicated to exploring ways to diminish underride crashes. Truck safety advocates are pushing for a mandatory side underride guard rule to prevent vehicles from sliding beneath tractor-trailers during collisions. However, some committee members have expressed concerns about potential unintended consequences associated with implementing side underride guards.

Jeff Bennett, representing motor vehicle engineers, discussed rear underride guards, highlighting worries that side underride guards might rebound cars into traffic, causing multi-vehicle accidents.

“All the trailer rear impact guards that passed the 30% offset crash test caused the crash car to spin out of its lane of traffic,” Bennett said. “And where I come from, there are always cars in the other lanes.”

Doug Smith, the lone truck driver representative on the committee and an OOIDA board member, also voiced similar concerns.

“Rebound accidents are an important consideration,” Smith said. “The design is based on not kicking cars back into traffic, so that is an important consideration and not something to be dismissed.”

Supporters of mandatory side underride guards within the committee argue that other technological mandates could mitigate the guards’ limitations. Lee Jackson, the committee’s chairperson and a crash investigator, emphasized that underride guards would be more effective when combined with mandated automatic emergency braking systems.

“Nobody expects for there to be a 70 mph impact and for the occupants to walk away unscathed,” Jackson said. “That’s just not realistic, but that’s why I’ve said numerous times we have to have a good rear guard and a good side guard that work in concert with automatic braking.”

The existing regulations outline requirements for rear impact guards on trailers, but there are no federal regulations for side underride guards. NHTSA estimates that a nationwide mandate for side underride guards on all trailers and semitrailers could save 17.2 lives annually, resulting in safety benefits of up to $166 million.

However, the annual cost of this mandate is projected to be up to $1.2 billion, with the cost per equivalent life saved ranging from $73.5 million to $103.7 million. The analysis did not consider effects on port and loading dock operations, freight capacity, or infrastructure modifications.

The committee, currently divided on the side underride guard mandate, is working towards consensus recommendations for NHTSA to reduce underride crashes and fatalities. The definition of consensus itself sparked debate during the last meeting, with proponents of the mandate advocating for a simple majority, while opponents insisted on at least 75% agreement. Ultimately, the committee decided, through a simple majority vote, that a simple majority constitutes a consensus.

 

 

Source: Land Line