Hmm.. Well I think if a guy came up to me randomly in the street I probably would be a little like Okaaay who is this guy. But its never happened to me lol and I think if your genuine it would probably go your way. I mean why not go speak to someone spontaniously. You never know who you could meet. Go for it what's the worst that could happen? I know ask them for directions then ask them to take you there haha, like a café and invite them for coffee to say thanks for showing you the way :P