The Lake Ontario Parkway runs from Rochester NY to almost Buffalo. It was built I believe in the 30's-40's. Very pretty route, although the road surface is very rough in places. It has the old stone bridges that arch up from either side. The first four bridges that you run into heading west from Rochester, are pretty low. I dont know if they are are listed as a hazard anywhere, but parkway is restricted for larger trucks.
I was completely taken by surprise. They are very well marked in big red letters. The low points of 10'-6" and 11' are on the far sides of the bridge. It was sort of a split second decision. I was traveling at 55 MPH and about 200 yards from the first bridge. I thought okay the Jayco is 11'-6", there were no warning signs at the entrance to the parkway, there were class C RV's traveling on the opposite lanes under same bridges. The top of the arch was much higher (I learned later) is over 12', so I got in the far left lane (middle of bridge) and slowed a bit and zipped through. The thought of the $500 deductible rental policy did cross my mind.
Later at the campground the locals were talking about how those big red letters freak out first time travelers.