I've lived in Boston's Metrowest area for seven years now (!) and, as such, spend an inordinate amount of time on Route 9.
So you'd think that i'd have seen it all, but yesterday as I was - surprise! - stuck in traffic, I looked over and noticed a small sign in the median announcing that I was on the "Ted Williams Highway."
Wikipedia tells me that "In Framingham, Route 9 is officially the "Ted Williams Highway", named after the Red Sox sports legend Ted Williams, who sported that number."
Massachusetts specializes in random signs like this. When I was living in Brighton, every other intersection was a "square" named after some random person. What's your favorite example of a random sign?