In passenger car-to-pedestrian impacts head and leg injuries account for the largest number of severe injuries (AIS 3+). US data from 2005 confirmed this but when studying LTV (Light Truck Vehicle) type of vehicles;​ thorax injuries replaced leg injuries at 2nd place for AIS 3+ injuries. For passenger cars the hood edge contributed to very few injuries, while in the LTV vehicles it was the main contributor for both lower extremity as well as thorax injuries. It is likely that the lower extremity injuries mainly consist of pelvic injuries, and that the hood edge (also called bonnet leading edge or BLE) of large Sport Utility Vehicles (SUV) produce more thorax injuries while lower SUV hood edges produce more pelvic injuries.

The recent development of pre-crash sensors has opened up new possibilities for pedestrian protection. Reversible solutions can be used as well as airbags in the very front of the car, where time is too short when using a bumper contact sensor.

In this study a bonnet leading edge airbag was developed to mitigate pelvis and thorax injuries for an SUV. The airbag was designed using mathematical simulations with the goal to decrease the upper legform requirements below the threshold levels of EuroNCAP. A physical prototype was produced which was tested and further developed using side impact dummies at a test speed of 40 km/h where pelvic and thoracic loadings were in focus. To do this a dummy test method was developed based on field data. The field data showed that the injury pattern of car occupants in near-side crashes is similar to that of pedestrians impacted by SUVs.

In simulations the BLE airbag proved able to pass the tough EuroNCAP requirements with the upper legform impactor. In full-scale tests the airbag decreased the risk of chest and pelvis injuries considerably, with the largest reductions in the chest and abdomen area.