People drive aggressively in Boulder. Road rage has gotten worse in the last few years as Boulder has become increasingly crowded. There are aggressive drivers, though, and then there are complete douchebags. Cutting into someone's lane early might be a shitty move, but moving into someone's lane without even looking and coming within inches of smashing the hell out of the car in the next lane makes you a monumental asshole.
Take a look at the king of the pricks right here:
Of course, I could be wrong. I might be giving him too much credit. He might just be a simple shithead, someone incapable of having enough thought or presence of mind or the balls to qualify himself as a cunt, a prick or an asshole.