I think the comment about hoping the runner will be predictable is very accurate. I do think that both drivers and runners need to recognize (and some do) that they can see oncoming traffic and make a better decision about passing.

Around here, you never know if the runners and walkers (and cyclists also) will move into a single file line. I've just decided to hold my line, staying straight and not swerving into traffic. It sounds harsh, but the runner(s) can see traffic behind me and I can't.

I also can't think of any reason to be snooty to a runner unless they do something stupid that endangers any of us. Now dog walkers with those expand-o leashes, beware . . . . .