Effectiveness of High-Retention Seats in Preventing Fatality: Initial Results and Trends 2003-01-1351

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% CI) 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.