blue-board
n.— «Travelers along Interstate 57 are subjected to food, fuel and lodging signage, along with tourist attractions. Following years of paperwork and waiting, signs are being installed at the Exit 71 mile marker, also known as the Benton-Christopher exit, that will feature some of the best the area has to offer. “We originally applied for the attraction signs—or blue-boards as they are called—five years ago.”» —“Wheels of progress turning: Attraction signs on the horizon” by Mona Sandefur Benton Evening News (Illinois) Feb. 11, 2008. (source: Double-Tongued Dictionary)