We've all encountered this. I usually cough or spit within earshot of walkers who aren't aware of my approach or who may be deliberately ignoring me. In America, if you simply run straight at the person on your side of the lane (right side, since Americans are inclined to walk as they drive), they will usually move aside or go single-file. I always thank them for moving. If they don't move, I visually edge my body sideways so they know I'm trying to accomodate them as much as they're supposed to be accomodating me. Two things are worse for me than walkers that won't move to the side on a narrow path: People with dogs on a leash who take up the whole path WITH their dog and won't move; and walkers who walk around a track (usually obese women and men) side by side when I want to do some precise speedwork. Walkers on a track have no concept of track etiquette, and they don't know what "Track!" means.