Dear Dumb Runner,
My running route is in an area where a lot of people walk, for exercise and transportation. And I find that I sometimes startle my fellow pedestrians without meaning to. Just this afternoon, I think I scared the heck out of a lady when I ran up behind her. Is there some sort of signal I should be giving people to say, "Hey, I'm here and I'm running up behind you but I am just a non-threatening runner?"—Amy, Louisville, KY
In these situations, I advise taking a two-pronged approach. (Note that actual prongs aren't used, for legal and ethical reasons.)
Here is what you can do to avoid scaring the crap out of innocent bystanders as you pass them—or at least to scare as little crap out of them as possible.
1. Give the bystander as wide a berth as you can. The closer you are to someone as you pass, the scarier it is, for obvious reasons.
2. Make noise. Doesn't matter what kind. You could cough, or clear your throat, or simply say, "Hello there!" or "Good morning/afternoon/evening!" Personally I'm a fan of shuffling and scuffing my feet. Usually that's enough to prompt them to look around and see me. Whatever you do, do it from a decent enough distance. Waiting until you're five feet away to blurt out "Good morning!" sort of defeats the purpose.
Of course, if the innocent bystander is wearing earbuds or zoned out while staring at his or her phone, or both, that's a different story. All you can do in those cases is pass as widely as you can and hope for the best. Good luck!