We were at Glimmerglass SP about a month ago, and went to Cooperstown then South to I-88. In Cooperstown, there was a "narrow road" sign just South of Main St. on Chestnut (which is hwy 28). This was a large, orange, temporary sign advising vehicles wider than 8' 6" to take a detour. It was the type of sign you usually see advising of road construction. It faced the South bound traffic. It indicated the detour was 5.x miles ahead, best I remember, which would put the narrow road between Cooperstown and I-88. However, we pulled our fifth wheel that way, and never saw a problem or any type construction. So, the sign was either old and had not been taken down, or was new and the construction had not begun yet.
