Unfortunately even the most friendly of dogs will pick up your vibes if you show that you are fearful of it. This does not mean that it will bite you, but it will be wary of you and and probably make you even more nervous. Why not drop the neighbours a little note before you even get there, and explain the situation, this would be much more likely to get them on side than turning up and demanding that they keep the dog away from you.
It is a fact of life that at some time you will probably meet this dog on your way in or out, and I think it will make your life very difficult if you do not try to do something about it.
I also hope for your son's sake you are not transferring your fear of animals to him, as loving and caring for a pet is one of the best ways of teaching children to respect all forms of life, especially other humans.