I am not a dog owner nor do I dislike dogs, I am however like most here, I don't think enough emphasis is placed on the owners behaving. There is an almost universal regulation about the length of leashes, in our area it is 6' and it must be sturdy in construction. I do not know of a National Park that does not have the same or a similar rule. Why do people have those silly 35' retractable leases at all? Sorry, rant over.
I do think that non dog owners and even dog owners need to learn good manners in approaching other folks dogs. I always ask permission to approach and try to shrink down from my normal 6'2" stance, so as not to intimidate the dog. The folks I've met sometime question my actions but appreciate my answers.