Truck Underride Accident Injury Risk May Be Reduced By More Robust Rear Impact Guards: NHTSA

Government highway safety officials proposed a new rule this week, requiring reinforced rear-impact guards on large trucks and semi-trailers, which is designed to reduce the risk of under-ride accidents that cause more than 400 deaths annually. 

A notice of proposed rulemaking (PDF) was issued by the National Highway Traffic Safety Administration (NHTSA) on December 7, which would add two new regulations that require tractor trailers to be equipped with more robust rear impact guards gauged.

The requirements would reduce the risk of severe injury in truck underride accidents that occur at higher speeds, where smaller passenger vehicles may go underneath the trailer. The newly proposed rules will be subject to public comment for up to 60 days after publication in the Federal Register.

The proposed regulations, FMVSS No. 223, addressing the implementation of stronger rear impact guards, and FMVSS No. 224, focusing on full rear impact protection, will expand current safeguards and increase the integrity of the guards to be able to sustain higher velocity impacts.

An underride collision, as described by the NHTSA, are those in which the front end of a vehicle impacts the rear of a larger vehicle, causing the smaller vehicle to slide under the rear-impacted vehicle. The incidents are most common when smaller non-commercial vehicles impacts the rear-end of a tractor trailer at speeds of 30 miles per hour or more. These types of truck underride accidents are extremely dangerous and frequently cause severe head damage or life threatening injuries to the front passengers’ heads and upper torsos.

The NHTSA stated that in excessive underride crashes, there is always passenger compartment intrusion (PCI), as the vehicle slides under the trailer. If the passenger compartment is impacted, it is extremely dangerous and a main cause of fatalities, sometimes even resulting in occupant decapitation. The NHTSA’s data analysis indicated that of the 400 deaths recorded from underride accidents each year, about 125 of them involve passenger compartment intrusion.

“Robust trailer rear impact guards can significantly reduce the risk of death or injury to vehicle occupants in the event of a crash into the rear of a trailer or semitrailer,” NHTSA Administrator Mark Rosekind said in a press release. “We’re always looking at ways to safeguard the motoring public, and today’s announcement moves us forward in our mission.”

Currently there are already rules that require trailers and semi-trailers to be equipped with rear impact guards, which appear as bars hanging down over the back of the trailers. However, current standards only require these bars to be able to sustain impact up to 30 mph. The newly proposed regulations would require the trailers to be equipped with not only larger, more robust guards, but to be able to sustain impact up to 35 mph.

The proposals are expected to result in some increased costs for trucking companies to equip their vehicles accordingly, however many vehicles are already being manufactured with stronger underride protections that may meet the finalized rules’ standards. The agency estimates that it will cost the U.S. fleet of future trailers and semi-trailers a total of about $13 million to meet the new standards.