The Raquette Lake Road bridge was built in the early 20th century and consisted of an earth-filled, concrete arch structure supported on timber piles. Narrow width and poor sightlines effectively reduced it to a one-lane bridge. Short spans of the arches and exposed footings allowed beavers to easily dam the inlet, requiring regular maintenance to clear the waterway opening. The bridge’s poor geometrics, hydraulics, and physical condition necessitated complete replacement. RBA was contracted to perform final design for both the highway and bridge portions of the project. Due to the close proximity of state-regulated wetlands to the roadway embankment, the bridge was replaced without significantly shifting the alignment of it or of the highway. One lane of signalized, alternating, one-way traffic was maintained during construction. The design required a minimum clearance under the bridge for canoeists who use the area as a launching point. The profile at the bridge was thus raised (since the new bridge structure depth was greater than the existing depth) to accommodate canoeists. Concrete crib walls were installed parallel to the roadway to keep embankments of the raised roadway out of the wetlands, and lightweight fill materials were used to reduce loads to the subgrade, as existing soil conditions required. A two-span-continuous steel bridge design was chosen in order to limit structure depth and to limit loads to the piles.
