What Is A Mansfield Bar On A Truck

A Mansfield bar on a truck or semi-trailer is a rear underride guard designed to help stop a passenger vehicle from travelling underneath the trailer in a rear-end collision. It is typically a strong horizontal structure mounted below the rear edge of the trailer. Underride crashes can be exceptionally dangerous because the trailer may penetrate the passenger compartment above the car’s bumper and other crash structures. The device is also called a rear impact guard, underride guard or, informally, an ICC bumper. The “Mansfield bar” name is associated with actress Jayne Mansfield, who was killed in 1967 when the vehicle she was travelling in collided with the rear of a tractor-trailer. Modern federal safety standards regulate rear impact guards on many trailers. In truck-accident investigations, the condition, dimensions and performance of an underride guard can become important evidence, particularly when determining whether the trailer complied with applicable safety requirements and how the collision caused the occupants’ injuries.