Motorcycles are less stable and less visible than cars, and they have high performance capabilities.
For these and other reasons, motorcycles are more likely than cars to be in crashes. Helmets decrease the severity of injury, the likelihood of death, and the overall cost of medical care. They're designed to cushion and protect riders' heads from the impact of a crash. Just like safety belts in cars, helmets can't provide total protection against head injury or death, but they do reduce the incidence of both. Motorcycle crash statistics show that helmets are about 29 percent effective in preventing crash fatalities.