3.3.2 Movable Deformable Barrier and Test Procedure

The MDB defined in FMVSS 214 was designed to be representative of the mass and size of U.S. vehicles. The angle of impact represents the most common side crash. The relative longitudinal and lateral speed of the MDB and target vehicle is considered the threshold for serious injury in actual crashes [9 pg.IIIA-44]. At the time of issuance of the dynamic portion of FMVSS 214 for passenger cars, NHTSA analyzed industry data in order to evaluate the European MDB and test procedure. Using data generated by the American Automobile Manufacturers Association (AAMA), the agency concluded that the variability of the European procedure and barrier in conjunction with EUROSID-1 was slightly higher than NHTSA's procedure and barrier with SID [9, pg.IIIA-84]. This result was for a single barrier face designed by EEVC and made of urethane foam.

Crash tests performed by Volkswagen AG showed 25 percent and 67 percent lower TTI(d) than the U.S. barrier for two different European barrier designs. These tests were performed using SID and indicate the European barrier produced a less severe result. NHTSA also examined testing performed by Transport Canada using the EEVC designed European barrier and procedure, which gave more severe results than the U.S. barrier and procedure. NHTSA concluded that this was due to the foam EEVC barrier disintegrating upon impact. Clearly, the performance based method of specifying the EU barrier stiffness lead to conflicting results in crash tests.