Under federal law, semi-trucks are required to have rear underride guards. These rails prevent cars from traveling underneath trucks in accidents, potentially saving the lives of drivers. However, there is no such law requiring side guards on trucks.
According to the Insurance Institute for Highway Safety (IIHS), mandating side guards could save hundreds of lives every year in the United States. Statistics from 2015 show that 301 passenger vehicle occupants were killed when their vehicles struck the sides of semi-trucks.
IIHS tested one such side guard, called AngelWing, and the tests were telling. When a midsize car crashed into the side of an AngelWing-equipped semi-truck at 35mph, the front of the car crumpled, but crash test dummies were protected by air bags and seat belts. With the AngelWing removed, the top of the car was sheared off and the car came to rest underneath the truck’s trailer. The crash test dummies were destroyed.
Opposition to a Side Guard Mandate
Trucking industry groups opposed to mandated side guards believe that the resources required to update trucking fleets with side guards would be better spent investing in modern technologies that reduce the risk of semi-truck crashes entirely. The American Trucking Associations noted that there is no widespread agreement among the industry due to trade-offs a mandate would require. For example, side guards require stiffer trailers that can develop cracks in the frame, presenting an entirely new safety risk.