According to findings for a study completed by the Insurance Institute for Highway Safety (IIHS), results indicate current safety standards for underride bars on semi trailers aren't adequate.
The IIHS has been petitioning to update rear impact guards since February 2011.
While traffic deaths continue, some U.S. trailer manufacturers have looked to increase safety on underride bars with aftermarket options by working with Canadian companies, whose safety standards for rear impact guards are more stringent.
Watch the video (the discussion begins at 2:15) and read more about safety bar regulations.