The National Highway Traffic Safety Administration has proposed an upgrade Federal Motor Vehicle Safety Standard No. 216 (FMVSS 216) would require that a roof withstand an applied force equal to 2.5 times the vehicle’s weight while maintaining sufficient headroom for an average size adult male. The current standard is 1.5 times the vehicle’s weight.
The new standard also would for the first time extend roof strength standards to vehicles with gross weight ratings up to 10,000 pounds. The current standard applies only to vehicles with ratings up to 6,000 pounds, which means about 44 percent of the SUV and pickup fleets currently are exempt.
To better address fatalities and injuries occurring in roof-involved rollover crashes, NHTSA is proposing a extension of the application of the standard to vehicles with a GVWR of up to 4,536 kilograms (10,000 pounds), and to strengthen the requirements of FMVSS No. 216 by mandating that the vehicle roof structures withstand a force 8 equivalent to 2.5 times the unloaded vehicle weight, and eliminating the 22,240 Newtons (5,000 pounds) force limit for passenger cars. Further, in recognition of the fact that the pre-test distance between the interior surface of the roof and a given occupant’s head varies from vehicle model to vehicle model, NHTSA is proposing to regulate roof strength by requiring that the crush not exceed the available headroom. Under the proposal, this requirement would replace the current limit on test plate movement.
The proposed new limit would prohibit any roof component from contacting the head of seated 50th percentile male dummy when the roof is subjected to a force equivalent to 2.5 times the unloaded vehicle weight.