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I'm sure there is abundant data to back up the author's observation that selfish driving habits are widespread. However, I would like to propose an alternate explanation for our society's deadly driving habits. People are inherently creatures of habit who do things the same way over and over until something dramatic causes them to attempt to change. Couple that to the fact that we allow people to establish their (lifelong) driving habits during their most narcissistic years and we have a formula for deadly roads.
This hypothesis is just barely testable. Find the few hundred people who stopped (or dramatically reduced) their driving for a few years and then started driving class A trucks. I would bet that they are significantly less likely to drive like a typical American than a control group who did not give up driving before training to drive trucks.
Hopefully this will all be moot as we move away from fossil-fool powered wheelchairs towards more sensible transportation options.