Video clip of an underride guard test held at the Insurance Institute for Highway Safety research center in Ruckersville, Virginia May 5, 2016.
The new design features a vertical support at each end of horizontal member of the guard. This provides additional strength and helps the guard and trailer absorb much of the energy of the impact.
(Video courtesy of the IIHS)
Read the related article here: Trailer manufacturers meet tougher underride standards