Driving peeves.

Why is it that some well educated folk leave their brains at home when they drive?
Don't they know that holding an infant on their lap in the front passenger seat is a death sentence? Don't they care that cutting across 4 lanes at high speed, then skimming across the chevrons at the exit is dangerous? Or that leaving a slippered foot dangling off the motorbike pedal is asking for 5 toes and maybe the whole foot to be chopped off? Or that cars come with indicators so that you can do just that, indicate your intentions so that drivers behind you can anticipate your move? Or that slowing down way before the traffic lights so that they don't have to stop is selfish?
And the list could go on and on, as do the drivers and their brainless driving habits.
I think it is pure selfishness, really. What other possible explanation is there?