> Yet, lethal TBIs are more likely to come from motor vehicle accidents than from bicycle accidents.
Is that per mile, per minute, or per lethal TBI? Also, is a collision between a bicycle and a motor vehicle a motor vehicle accident or a bicycle accident?
Of course, bike helmets protect against more than just brain injury. They also protect against road abrasion of some portion of the head, which is not usually a factor for car occupants, except if they're ejected or they're in a car that rolls over and doesn't have an roof or an effective roll bar.
Bike helmets are much lower expense and hassle than car helmets (which are mostly motorcycle helmets) and neck restraints, etc. If it's a public use bike system, especially the leave anywhere bikes, the expense and hassle gets overwelming, and helmets for customers of a pedal cab would be similar.
I've got a bike helmet with integrated lighting, which adds functionality and is kind of neat, although it was much more expensive than a good enough helmet.