The men I know are pretty sweet, I've interacted with some seriously rude women, and I've experienced road rage myself. There's something about getting behind the wheel of a car that makes a lot of people angry!
I think that men are often more rude than women because they can be--they're generally bigger and more often in positions of power. When I read the sci-fi book, "The Power," in which that dynamic is switched, I was disappointed at first to find the women in charge behaving just as badly as men do today. But then I realized that's probably realistic. Power corrupts.