DOT May Mandate Side Underride Guards on Trailers

Weight of Guards = Less Freight You Could Haul

The National Highway Traffic Safety Administration (NHTSA) recently sent an advance notice of proposed rulemaking (ANPRM) on side underride guards to the White House Office of Management and Budget. OMB must approve it before the ANPRM is published in the Federal Register and available for public comment.

What’s the purpose of mandating side underride guards? Congress voted to require side underride guards to protect motorists when their passenger car hits a truck trailer or semitrailer from the side. During debate, the discussion focused on test crashes at 35 mph. At that level of impact, side underride guards are clearly not the “lateral protective devices,” common in Europe, meant to prevent pedestrians and cyclists from entering the space under a truck trailer. Lightweight airflow deflectors to improve fuel efficiency – known as “trailer skirts” – also do not meet side underride guard standards.  

While side underride guards may improve safety, a key downside is that the devices are heavy. One manufacturer of side underride guards advertises that its devices would add 450-800 pounds, depending on the type of trailer or semitrailer. That would be a reduction of 450-800 pounds in the net weight a truck combination could carry. It would also mean an increase of 450-800 pounds a truck tractor would be required to pull, no matter the amount of cargo on board the trailer. Unknown at this time is how side underride guards would work with the wide variety of trailers in trucking – would the guards flex as flatbed trailers must flex under load? Would the guards allow access to pipes and valves on tank trailers? And would guards be required on all trailers or only on newly manufactured units?

Whether you own, lease, or just pull someone else’s trailers, the upcoming NHTSA side underride guard proposal could change the equipment you know. ICSA will keep you informed as this measure moves ahead.