if it's a narrow space I do, like on a rail trail, etc. mostly for safety reasons. one the road is another thing altogether. but the funny thing is yesterday a guy passed me and said nothing. I was surprised he didn't even say hello, but I got over it. later in the day I past a couple and as I dashed off ahead of them I heard the woman politely say "on your left" as a reminder that would be a nice courtesy.