US Route 20

US Route 20 is the longest road in the United States, spanning 3,365 miles (5,415 km). As of 2007, the highway’s eastern terminus is in Boston, Massachusetts, at Kenmore Square, where it meets Route 2. Its western terminus is in Newport, Oregon, at an intersection with U.S. Route 101, within a mile of the Pacific Ocean.
I have seen a small black and white sticker that had:
Route 20 W – IT’S A TRIP – Route 20 E
Does anyone know where I can get one?