I’m at Atlanta-Hartsfield on a busy Thursday evening, and my goal is to walk a few dozen yards from Simply Books across the “A” concourse’s main hallway to the Chick-Fil-A. It’s a short but not a trivial journey — the wide hallway is packed from edge to edge with a swiftly moving river of thousands of travelers headed both left and right. It reminds me of that chaotic moment between classes in high school when everyone rushing to get to their next class before the bell rings, although with less flirting and more grim expressions.

Closest to me a thick stream of people is headed to the right, toward Gate 34, and beyond that a counterstream has set up headed in the opposite direction toward Gate 1. Drawing on experience in whitewater kayaking, I ease into the flow moving to my right and ferry across the current, crossing diagonally as… More…