Turn Right? You're Kidding, Right?

So I am on the way to Nyack, and crossing the Tappan Zee Bridge, I see this arrow in the distance, about a quarter of the way across the bridge. I can figure out a lot of things, but this has me stumped. A right turn arrow on the middle of the bridge? Huh? I saw it in the distance, and got my point-and-shoot out of it's pouch, and only had time to snap one photo as the arrow flashed by as we drove across the bridge. I like this photograph a lot because it is incongruous.