Originally Posted by
gcottay
In my experience staying alert and giving the slower rider plenty of room leaves a fine margin for safety, the call of "On your left" or "Passing" can cause exactly the problems you are trying to avoid, and your mirror is your friend.
^^^
If there is any risk, I'll say something like "Coming by on your left". If there isn't, then I provide all the room required, and say "Hi", "Hey", "Morning", something like that. The "On your left" call can have a derogatory aspect to it, akin to "In yo' face" if you score over someone in basketball, and so I avoid it. I always wave to people riding (or walking) the other direction, but don't expect a response.