Occupant’s protection requires two design considerations: 1) reduction of decelerations on the occupant (restrained by a belt) by intentional deformability of the structure; 2) limitation of passenger’s compartment deformation to avoid passenger crushing. It is thought that the second trend should have basic importance. It is necessary to ensure a minimum space called “survival space.” This is also necessary in the event of severe crashes.A survey is made of structure deformations due to longitudinal, transversal and vertical loads dynamically or statically applied on trucks cabs and car passenger’s compartments. A high-power static test rig permitting the study of structure is described. Orientative values of the survival space are proposed for truck cabs and car passenger’s compartments.