Head injury reduction potential of integrated pedestrian protection systems based on accident and experimental data: benefit of combining passive and active systems

The aim of this study was to investigate the potential pedestrian head injury reduction from passive and active protection systems compared to an integrated system. The GIDAS database was queried from 1999 to 2013 for severely (AIS3+) head injured pedestrians when struck by car fronts. This resulted in 68 cases. To estimate the protecting performance, headform tests to different impact locations in the hood, A‐pillar and lower windshield areas were performed on cars with and without deployable hood and airbags. The active protection system was an autonomous braking system, which was activated one second prior to impact if the pedestrian was visible to a forward‐looking sensor. The integrated system was a direct combination of the passive and active protection systems. Case by case the effect from each of the active, passive and integrated systems was estimated. The individual active (AEB) and passive (deployable hood and windshield airbag) pedestrian protection systems were effective to reduce severe head injury, but combining the two systems was more effective than either of the two systems alone, with 32‐42% higher integrated effectiveness than the best single system. Even for the most advanced single system there was a benefit to combine into an integrated system.