Effectiveness of High-Retention Seats in Preventing Fatality: Initial Results and Trends

Abstract

In 1995, new seat specifications were adopted by GM to provide high retention and improve occupant safety in rear crashes. With more than five years of phase-in of high retention (HR) seats, an analysis of FARS was undertaken to determine the initial field performance of HR seats in preventing fatalities. The 1991-2000 FARS was sorted for fatal rear-impacted vehicles. Using a VIN decoder, GM vehicles with HR front seats were sorted from those with baseline (pre-HR) seats. The fatal rear-impacted vehicle crashes were subdivided into several groups for analysis: 1) single-vehicle rear impacts, 2) two-vehicle rear crashes involving light striking vehicles, and 3) two-vehicle crashes involving heavy trucks and tractor-trailers, and multi-vehicle (3+) rear crashes. While more field data is needed to increase confidence in the results, FARS analysis shows that high-retention seats reduce the risk of driver fatalities in single-vehicle rear crashes by 50% (-26%, 80%, ′95% Cl) and driver/RF deaths by 59% (11%, 81%). For two-vehicle rear-impact crashes, high-retention seats reduce the risk of driver death by 54% (-23%, 83%) and driver/RF deaths by 35% (-38%, 70%) when impacted by light vehicles. There is no difference in risk with heavy truck or tractor-trailer impacts or in multi-vehicle (3+ vehicles involved) crashes. The new generation of seats was developed for high retention based on a perimeter seat frame design that allows the occupant to penetrate between the side frames of the seatback giving a yielding performance and pocketing of the pelvis. This increases retention and provides uniform support for the spine. The new generation of seats also includes a higher and more forward placement of the head restraint to reduce neck extension-related injury. That aspect of the seat performance cannot be studied with the FARS data. The initial trends show that high-retention seats are effective in reducing the risk of fatal injury in single vehicle and light vehicle-to-vehicle rear impacts.