An active bolster is integrated within a seat for a transportation vehicle by covering an inner inflatable bladder with an outer cushion layer to provide a seating support surface. Seating loads are borne on the support surface from the weight of an occupant by elastic deformation of the bladder. When a vehicle crash event is detected, at least a portion of the bladder is inflated to extend a seat surface to protect the occupant. Size and weight of the seat are reduced as a result of the bladder contributing significantly to the normal cushioning of the seat in everyday usage.