I have discovered a trick that has helped Buster a few times...Normally when he starts his barking I try and correct or distract or do something...anything LOL
What I have been doing is joining the other dog and owner in a walk. Of course you need cooperative owners to do this....but when I approach, they keep walking with their dog, I catch up to them and we walk...by then Buster is focused on "walking" and not barking. As long as the other dog doesn't react, we do quite well. Once Buster has settled into a nice walk, the dogs are allowed to sniff and meet. It helps if Buster has already had a good 15-20 minute before so some of his energy has been exhausted.
Not sure if I explained that right...... but hope it helps.