Sixty three victims of high speed motor vehicle accidents (MVA) who sustained multiple traumatic injuries were identified on admission to a Level I trauma center. A Crash Reconstruction team sent to the scene determined the nature, direction, magnitude of accident forces and the points of body contact with MVA structures. These were correlated with the pattern of patient injuries, their physiologic and therapeutic consequences and complications. In-hospital and posthospital rehabilitation costs, cognitive and physical disabilities and psychosocial problems were related to the crash type and the consequent organ injuries. The data showed that even though the mean Injury Severity Score (ISS= 27±10 F vs. 30±16 L) was not different in the 36 frontal (F) vs. the 19 lateral (L) impact crashes, frontal crashes produced more facial lacerations, lower extremity injuries, shock, sepsis and a higher incidence of pulmonary, cardiac, renal and multiple organ failures than lateral crashes. In contrast, lateral crashes produced a higher incidence of serious brain injury with a lower mean Glasgow Coma Score (GCS) on admission, a higher incidence of chest, lung, heart, liver and kidney injuries and more pelvic fractures than frontal crashes. While survival in F vs. L was not different (83% vs. 84%) both hospital costs and professional charges were greater in F crashes, reflecting a greater complexity of care. In all brain injured patients, even when gross neurologic function returned to normal GCS and Rancho Los Amigos neurologic recovery score levels on discharge, cognitive and expressive brain disabilities were still present. Indeed, 55% of all surviving brain injured patients in this study had some residual speech, language or comprehension defect on discharge from the acute facility. The vulnerability of the brain and thorax in L crashes and the high incidence of lower extremity injuries causing a medical need for extrication in F crashes imply a need for improved MVA safety design standards based on injury reduction criteria.