In my neck of the woods the common courtesy statement for passing someone is "on your left", as in passing on your left. Well not too long ago (a few weeks) I decide to take the MUP home from work and encountered a woman and her teen daughter who instead of moving off to the right, moved to the left and nearly caused me to crash into them. If it wasn't for me swerving right at nearly the last moment there would have been a pile of bikes and limbs on the trail... in hind sight it's kind of funny, but at the time it wasn't.