It's safety theatre. Signs don't work, properly-designed roads work. But signs are cheaper and make it possible to continue to live a sprawling life in suburbia, so.
"Fake news" is awkward because it's what you say to discount things you don't like that are actually true. My friends and I all use "fake news" when we're criticizing someone or something, but not to describe actual misleading information. When used earnestly, then, it looks like you're either joking or denying reality.
It's left as an exercise to the reader to figure out why this is.
Ann Arbor is a bit of an outlier in that as far as Michigan cities go, it's relatively bike-friendly. It's still remarkably suburban in most areas, though; good luck biking to a grocery store that isn't out in Pittsfield Township.