Restraint Survival Distance (RSD), a quantity used for determining potential occupant survival in a motor vehicle collision, is derived. The RSD depends upon the vehicle crash response, available occupant stroking distance (taking compartment intrusion into account) and assumptions regarding ideal restraint system performance. RSD calculations were performed for 17 passenger cars which were subjected to 30 mph barrier crash tests. The RSD values were compared with measured dummy responses. Similarities and differences between actual crashsurvivability levels achieved with existing restraint systems and potential crashsurvivability levels achievable with ideal restraint system characteristics were explored.