BENEFITS OF THE INFLATABLE TUBULAR STRUCTURE AN INVESTIGATION ON THE CASUALTY ABATEMENT CAPABILITY OF THE BMW HEAD PROTECTION SYSTEM HPS 986169

Beginning in model year 1997, BMW introduced an innovative head protection system HPS called the Inflatable Tubular Structure (HPS). Tests indicate that the system dramatically reduces the severity of head impacts in side crashes.

This investigation is an evaluation of casualty abatement benefits that are derived from applying injury measures based on the HPS test results to the population in US National Accident Sampling System (NASS/CDS). The results of component and vehicle crash tests are summarized. The procedures for estimating benefits are described along with the benefits in terms of injuries mitigated, maximum injuries to occupants mitigated, and fatalities prevented.

The calculated benefits of the HPS in reducing fatalities and the most serious injuries to front seat occupants of passenger cars are:

The impact mitigation benefits were derived from reducing injuries from head impacts to the following components: A & B pillars, side rails, window frames & glass, and window-pillar interfaces. Approximately 51% of the reductions in fatalities were attributable to the mitigation of head impacts with these components. The remaining 49% of the fatality reductions were associated with mitigation of exterior contacts and prevention of ejection through side windows.

According to the US National Accident Sampling System, the population injured in tow-away motor vehicle crashes suffers an average of about 3 injuries per person. The accounting system used in the tables above does not give credit for injury reduction when the injury is not the most severe of all injuries suffered by an injured person. If the less severe injuries are considered, there is a much larger opportunity for injury reduction. When considering all injuries, the injury reductions for the HPS system are:

The benefits cited are over and above the benefits offered by other safety systems. These systems include: frontal air bags, side air bags, FMVSS 214 side impact protection, and FMVSS 201 head protection for the vehicle roof and headers.