Japan is another world. When I was traveling there, I remember seeing dots on the highways so as to space your interval with the car in front of you. Another person in my group started laughing because that would be ignored in the US but the guy driving was confused and couldn't fathom not following that rule. He was like, "why wouldn't you do that?"
EDIT: I meant that this isn't just a US problem. There are way too many selfish people worldwide, and they are one of the many reasons we still haven't made proper steps to avoid an ecological disaster. I don't really get the downvotes.
They have those dots on the road in some parts of PA, specifically around Lancaster. Some people follow the 2 dot rule there, but most I've seen do not.