there have been successful attempts to promote the sale of ski helmets. Again, results have been less than impressive, with great increases in helmet use yielding no reduction in fatalities, and with most injury reduction confined to lacerations, contusions, and minor concussions, as opposed to more serious head injuries. There have been rare campaigns for motoring helmets. Unfortunately, just as people greatly overestimate the traumatic brain injury danger of bicycling, they greatly underestimate the risk of motoring, which remains the largest source of traumatic brain injury in the developed world, despite the protective effects of seatbelts and airbags. See also Cerebral contusion Concussion Diffuse axonal injury Intracranial hemorrhage Traumatic brain injury References Neurotrauma