In a related question, there is some evidence that bike helmets may lead to greater risk taking and thus increase the likelihood of a crash (though bike helmets pretty definitively reduce the risk of head injury should a rider be in a crash).
Your "inescapable conclusion" would probably depend on whether the driver actually perceived the increase in risk. The spike and bubble might, but removing airbags might not.
http://bigthink.com/neurobonkers/the-bike-helmet-paradox
Your "inescapable conclusion" would probably depend on whether the driver actually perceived the increase in risk. The spike and bubble might, but removing airbags might not.