Originally Posted by livedarklions

I agree with all of that. I'm entirely basing my statements about OP's failure to announce on OP's own version of events. Nowhere have I stated that I thought doing a UTurn without looking was at all acceptable. If the Uturner had asked "who's at fault", my answer would still be you should have looked and OP should have announced. I think we are in total agreement.

I use "passing on your left" BTW, the addition of the verb seems to clarify it. "On your left" is slightly ambiguous.

Weirdly, when repeated "passing on your left" produces no response, as sometimes happens, a "HELL--LO!" will usually get people to move. I can't fathom the psychology, and only know that it can work because I got frustrated enough to do the sarcastic method.

I don't ride on sidewalks so I really can't compare