Severe Head and Neck Injuries in NASS Rear Impacts

In this paper the characteristics of rear impact crashes are examined. General information about rear impact collisions is derived from recent data from the National Automotive Sampling System, General Estimates System (NASS/GES) and Fatality Analysis Reporting System (FARS) as reported in the annual National Highway Traffic Safety Administration (NHTSA) Traffic Safety Facts. Additional details about the frequency, severity, type, and cause of injuries to front seat outboard occupants is analyzed using the National Automotive Sampling System, Crashworthiness Data System (NASS/CDS) data from 1997 to 2005. Serious head and neck injuries are focused on for further analysis. Specific cases from the CDS database that meet this classification are examined. Federal Motor Vehicle Safety Standard (FMVSS) 301-R test data is used to analyze occupant, seat, and vehicle kinematics in single impact rear collisions and to look at the occupant rebound velocity. The 301-R analysis found the forward velocity of the dummy's head after rebound was as high at 6 m/sec. Analysis of NASS cases of vehicle-to-vehicle rear crashes found numerous contacts with frontal components even in the absence of a frontal crash. However, the most severe and frequent injuries were attributed to the seat back and head restraint. Severe injuries were observed in seats with and without deformation.