If an imminent side impact is detected, PRE-SAFE® Impulse Side moves the driver or front passenger to the centre of the vehicle. The restraint system, which absorbs the initial impact, uses air chambers in the side bolsters of the seat backrests. If the vehicle sensors report that a side collision is unavoidable, the air chambers inflate in fractions of a second, shifting the passenger to the side with a light push. The occupant is therefore further away from the door. At the same time, the difference in speed between the vehicle and the occupant is decreased so as to reduce subsequent contact with the door trim.