answer:Because 99.9% of the time it is mindless and thoughtless work, just going with the flow of traffic, little to stimulate the mind. So people listen to the radio, they check the phone, they read a book, they eat a hamburger or a taco. My first accident when I was 19 I was a distracted driver, using the cigarette lighter to light a smoke. Looked up and the pick up in front of me had stopped. Bam.