I was just talking about this with someone the other day. For me it seems to go in cycles. I will go 3 or 4 days where everyone seems to behave themselves and then all at once I will get honked at, yelled at, told to get off the road. One guy actually slowed down and yelled out his window that he should run me over.
I chalked it up to Michigan drivers. The Motor city is definetly not a bike freindly place. I thought Michigan was the worst since I never had problems like this when I lived and rode in Western New York about 10 years ago. However I see now that it happens all over.
I just can't figure out what makes people so angry especially when your not even in there way.