Single-unit trucks were not exempted from rear underride guard regulation due to science and statistics as NHTSA claims in new Rulemaking. Guards were exempted due to heavy lobbying from the TTMA Truck and Trailer Manufacturers Association which represented the big U.S. Automakers which manufactured most U.S. single-unit trucks.
High speed truck crashes are survivable, claiming otherwise NHTSA is trying to block the public from asking for higher speed guards. Most truck crashes exceed 30 mph and building weak guards such as to the weak Canadian Standard will give the public a false sense of safety such as the fake 1992 standard did. Most trucks already had guards meeting the weak standard so most crashes continued to occur at higher speeds than the guards were designed to handle. Research shows energy absorbing guards can withstand crashes to as much as 50 mph. Extending guards past the end of the truck and rounding ends to deflect vehicles in offset crashes can make very high speed crashes survivable in spite of NHTSA false claims in the rulemaking that high speed crashes are never survivable so we should not try? Studies by VOLVO show extending guards crush depth increases survivable speed.
Fake guards kill and maim and only protect industry from legal responsibility, hence the heavy industry lobbying.
Tell the truth NHTSA!