CRASH3 based computer programs model a vehicle structure as a homogeneous body. Crush stiffness coefficients determined from full-overlap crash tests, when used in these computer programs allow for an accurate reconstruction of collisions where the accident damage profiles are full-overlap. The structures of vehicles, however, might not be purely homogeneous in their crush response. How accurately do crush stiffness coefficients that were determined from full-overlap crash tests represent the crush response of that same vehicle in a partial-overlap/offset frontal collision? Before this question can be answered a method needs to be developed for determining crush stiffness coefficients from partial-overlap/offset frontal test collisions. These crush stiffness coefficients then could be used in a comparative analysis of the crush response of vehicles tested in both full-overlap and partial-overlap/offset frontal collisions.A method is set forth that allows for the determination of crush stiffness coefficients from tests involving partial-overlap/offset frontal collisions with a fixed deformable barrier. This method is extended to tests involving side impacts with movable barriers.