Something is causing a huge number of Americans to " receive a motor vehicle induced traumatic brain injury every year."
Something like being hit by a car? Pedestrians (70-80K deaths & injuries per year) and cyclists (~50K deaths and injuries per year) are very likely to get TBI in an accident.
I think that if you are inside a car and are wearing a seatbelt the usefulness of a helmet is doubtful.
The cited stat ultimately comes from
As you surmised, the car stat includes everyone related to cars:
...Motor vehicle–traffic includes the following external causes of injury: occupant, motorcyclist, pedal cyclist, pedestrian, other and unspecified person involved in a motor vehicle–tra
A 2006 study showed that “280,000 people in the U.S. receive a motor vehicle induced traumatic brain injury every year” so you would think that wearing a helmet while driving would be commonplace. Race car drivers wear helmets. But since almost no one wears a helmet while driving a regular car, you probably fear that if you wore one you would look silly, attract the notice of the police for driving while weird, or the attention of another driver who took your safety attire as a challenge. (Car drivers are more likely to hit bicyclists who wear helmets.)
The $30+shipping Crasche hat is designed for people who should wear a helmet but don’t. It looks like a ski cap, but contains concealed lightweight protective material. People who have signed up for cryonics, such as myself, would get an especially high expected benefit from using a driving helmet because we very much want our brains to “survive” even a “fatal” crash. I have been using a Crasche hat for about a week.