I ride similarly for errands etc. I have noticed such a similar reaction from drivers. I live in a college town, and most drivers are pretty OK with cyclists -- there is the occasional "use the sidewalk" or close pass w/ horn, but mostly cool people. This past month, since the snows have gotten all wintery, I have also noticed increased agression.<p>I think the cause here may be surprise -- drivers are already nervous about the crappy road conditions, and they can't fathom how a bike is even ridable in winter. They view my riding as extra dangerous (both to me and them) and their stress level increases even more. Such a thing frequently comes out sideways as anger/agression.