Federal Motor Vehicle Safety Standards; Roof Crush Resistance

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This document revises the test procedure in Standard No. 216, Roof Crush Resistance, to make it more suitable to testing vehicles with rounded roofs or vehicles with raised roofs. The test procedure is intended to test the strength of the roof over the front seat occupants by forcing a large flat steel test plate down onto the roof, simulating contact with the ground in rollover crashes. However, when the procedure is followed in testing certain vehicles with rounded roofs (e.g., the Ford Taurus), the test plate is positioned too far back and does not test the roof over the front occupants. In addition, that positioning creates the potential for contact between the front edge of the test plate and the roof. Such contact is undesirable because the front edge can penetrate the roof structure in a way that the ground cannot during rollover crashes. Similarly, for vehicles with raised, irregularly shaped roofs (such as some vans with roof conversions), the initial contact point on the roof may not be above the front occupants, but on the raised rear portion of the roof, behind those occupants. In both of these cases, the positioning of the plate relative to the initial contact point on