Imagine you are walking alone on the sidewalk of a residential street, and a large dog comes running toward you. It does not look aggressive, but it is also showing no fear. What might be an appropriate course of action.
Because you are in a residential area, it is likely that the dog is someone's lost pet. If you are comfortable around dogs, it would be good to allow the dog to come close enough to you that you can see whether it has a collar and tags, and if so, to contact the owner listed on the tags. If the dog has no identification, it might be best to call animal control. And of course, be wary of signs of aggression, including any symptoms of rabies.