Yes, if you see or hear the runner coming - not the situation I am talking about (though your advice is very poor and likely to increase reactivity, not decrease it.)
Dogs don't automatically know what the word 'calm' means and forcing them to sit, preventing movement by holding the collar etc can dramatically increase the chances of them feeling bad about such a situation in the future.
As an 'emergency strategy' to avoid accident, yes of course - but as a training plan, no, absolutely not.
As for 'don't give rewards before he has exhibited the behaviour you want...' well.. tell me you don't know the difference between operant conditioning and classical conditioning without telling me.......
Btw, your dog is not protecting you. He's protecting himself. If he is aware of your vulnerability, it is only in the sense that by being trapped, on a lead, with you, it makes him more vulnerable too. What you are doing is waiting for him to guess the correct response, and probably causing him to suppress behaviour/emotion rather than actively changing emotion which would then change behaviour.
Back to the topic in hand...
Who gets to determine how much space to pass - I'd like it if people left a good few feet between me and them, because if I turn suddenly and I have no choice but to do so sometimes (I can't see behind me, and I can't turn my head to see all Ill see is my headrest), I would suddenly be taking up an extra two feet of the pavement as my chair is longer than it is wide.
If you've decided I only need a foot spare, and I turn to see whats coming up behind me, you're going flying over my foot rests and splat into the pavement - if you're walking you can probably side step but if you're running, the chances are you won't.
However, I agree that if passing with enough space and walking, theres no need to call out or let someone know you're passing. I don't believe I said there was, as I was talking about runners, not walkers, and people passing close, not people passing with plenty of room.
As ever, people do like to twist others wording ...