I think it's less about people being selfish (though some certainly are) and more about the metal bubbles that weigh about the same as an adult elephant and mov

I think it's less about people being selfish (though some certainly are) and more about the metal bubbles that weigh about the same as an adult elephant and move at ridiculous velocities, all at the behest of strangers who should (but may not for various reasons) know what they're doing. The amount of cortisol the human body releases in the average driving scenario is enough to make anybody far more irritable and prone to "selfishness" or anger on the road. Unlike on a sidewalk, one mistake on the road can and often does result in fatality and that tends to change one's attitude to something like potential collision.