People who drive are generally very uneducated about how to deal with bikes. I think that is the root of the problem. They think the bikes don't belong. People already become overly agressive behind the wheel and do stuff they normally wouldn't do to other drivers, but add a cyclist to the mix and its 'rider beware.'

I feel your pain in that its not just that Mercedes driver, but a lot of others as well. BTW, you think we have it bad in DC, southern Westchester County NY is in my opinion the worst place to be on a bike. Just far enough out of NYC that people cannot tolerate anything between them and their commute home. Agressive + stressed + yaking on cell phone on winding roads = not nice.