If you were involved in an accident with a motorcycle rider who was not wearing a helmet, they may be held partly at fault for their injuries. The state of California has some of the most stringent motorcycle safety laws in the country. Motorcyclists in the state are required to wear helmets. If the motorcyclist involved in the accident suffered severe head and neck injuries as a result of the crash, your insurance company will balk at paying them compensation. And it will be easier to defend yourself against any personal injury lawsuits that they launch.