Underride protection systems can be installed at the rear, front and sides of a truck and the rear and sides of a trailer. A Rear Underrun Protection System (RUPS) is a rigid assembly hanging down from trailer's chassis, which is intended to provide some protection for passenger cars which collide with the rear of the trailer. Public awareness of this safeguard was increased in the aftermath of the accident that killed actress Jayne Mansfield on 29 June 1967, when the car she was in hit the rear of a tractor-trailer, causing fatal head trauma. After her death, the NHTSA recommended requiring a rear underride guard, also known as a "Mansfield bar", an "ICC bar", or a "DOT bumper".