I generally say something polite (of the "good evening" or "thank you" ilk) to almost everybody I pass (and I announce my passes before I get there for safety reasons), but I figure that crosses the line from polite to creepy if I then try to match their speed. Does that seem about right?

I started doing this because so many people seem to apologize when they get passed, like they're worried that I'm annoyed they're in my way--I really don't want them to feel that way, and I've never had anything worse than being ignored happen when I say "hi" or whatever. I don't mind being ignored, but getting an undeserved apology makes me feel guilty. It's their path/road, too.