I get off the road for snow plows. I want them to do their job, and I don't want the plow path to weave out away from the side of the road so that they can pass other vehicles.
I get out of the way of plows when I'm driving a car too. It only makes sense to allow those who are trying to make the road more navigable to do their jobs. If there's a plow around, I want to be BEHIND it, not in front.
I will agree that the close pass and the "get off the road" comment were inappropriate. But before that, the cyclist (and, IMHO, the cars) should have gotten out of the way of the plow.
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Work: the 8 hours that separates bike rides.