Road to Zero Safety Priority Statement

Truck Underride


UnderrideTruck underride arises from the structural mismatch between large commercial motor vehicles (CMVs) and smaller passenger vehicles. Commercial trucks sit higher off the ground than
passenger vehicles chiefly due to the much larger tire size trucks require to carry large cargo loads.
This height mismatch can result in underride crashes in which a smaller passenger vehicle travels under
the body of a truck when a crash occurs. In 2016, there were 204 occupant fatalities in passenger vehicles in crashes involving large truck(s) where the passenger vehicle experienced an underride.  However, underride fatalities may be underreported.


To view the full Truck Underride Priority Statement, click here.

Current Situation:


Rear underride guard protection has been a federal requirement for semi-trailers
since 1952, though the requirement did not contain explicit strength standards, only dimensional requirements. In 1996, rear underride guard standards were published setting explicit requirements for guard strength and size on semi-trailers, but these current standards can be strengthened. In 2015, NHTSA issued a notice of proposed rulemaking to strengthen rear underride guards to prevent underrides by cars travelling at up to 35 miles per hour but has taken no action since then.The National Transportation Safety Board has recommended that NHTSA develop rear and side underride guard standards for single unit trucks as well.



The Insurance Institute for Highway Safety (IIHS) has highlighted the insufficiencies of
current US regulation as well as the upgrade proposed by NHTSA in 2015 by conducting extensive crash testing of rear underride guards at 35 mi/h. A guard designed to the existing standard failed in a center impact, while several guards designed to meet the proposed standards failed in tests where there
was not full horizontal overlap between the trailer and passenger vehicle. Many trailer manufacturers have made voluntary changes to their rear guard designs in order to improve performance in the tests.
This demonstrates that improved safety is feasible, but regulation may be needed to ensure the improvements are extended throughout the trailer fleet. While some manufacturers are equipping their trailers with their improved guard design as standard equipment, others continue to fit their older designs as standard while offering the improved guards as options for their customers. No single-unit trucks are known to have a rear underride guard that would meet the existing or proposed standards for semi-trailers.


Supporters of Road to Zero Coalition Priority Statement on Truck Underride:



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