General

Walking fast is not annoying, if you have reason for doing it, like if you're in a hurry because of an emergency or some other important matters. Naturally, if you're in a mall with a friend and you walk faster thus leaving him/her behind that is annoying. It would seem like you don't want to go along with him/her.

I walk fast but that's usually because I just can't wait to get home from a very tiresome day. However, if I am out with friends, walking fast would definitely annoy them. If I had intention of leaving them behind, I shouldn't have invited them in the first place. So, since I walk fast, we usually agree on a tempo that is convenient to both of us.