Question for Runners

On the MonkeyMartian blog, there is a discussion of runners on the side of the road.

Now, I'm certainly not a runner, plus I don't know much about how traffic laws apply, so I have no opinion about where people should run. However, I do have a question.

The road to my neighborhood is popular for both cycling and running. In fact, the Purdue Crew team jogs to and from their practices at the Fort. When I'm in my car and I come up upon an oncoming runner in my lane, what should I expect from the runner?

It's easy when I am behind a cyclist. I just have to slow down until it is safe to pass. No big deal.

When I meet the runner, no amount of slowing down will prevent a problem if one of us doesn't move. (If one train leaves Chicago going west at 60MPH and another leaves Seattle going east at 70MPH, there's going to be a big collision somewhere in Wyoming!) If I can't pass because of oncoming traffic, should I stop? Or should I expect the runner to jump into the grass.

I don't know. Can someone help me with this?

(BTW, I really don't want any arguments or flames in the comments about who has the right to the road. I'm just trying to be civil and safe.)