Pedestrian Protection From almost certain death to less than a 15% risk of life-threatening injuries in a car-to-pedestrian impact at 40 km/h. This is how efficient Autoliv's pedestrian protection system is that includes; the Active Hood and the Pedestrian Protection Airbag (PPA).   Active Hood Autoliv's Active Hood raises instantly when a pedestrian is hit. A sensor system placed in the vehicle's front bumper sends an electrical impuls to two small airbags which lift the rear part of the hood making the pedestrian's head contact a deformable and flexible surface instead of a hard and rigid one. The sensor is so accurate that it can differentiate between a lamp post and a human leg.   With the Active Hood Without the Active Hood   Pedestrian Protection Airbag (PPA) Autoliv has further enhanced its first pedestrian protection system by developing a pair of airbags, one at each windshield pillar. As vehicle hoods tend to become shorter with every new model change, the risk for pedestrians hitting the hard structures around the windshield increases, but this can be prevented by the PPA.     The windshield itself is a deformable surface and this, in combination with a deformable hood and energy absorbing airbags at the side pillars, result in a combination that is both very efficient and comprehensive in terms of addressing the vehicle areas that are most dangerous for the pedestrian.   Full Research Report on Active Hood