Standing at a height of above Manhasset Bay and measuring in length, the Manhasset Viaduct is the highest bridge on the entire LIRR network. The viaduct uses a steel stringer bridge design and is one of two
King Bridge Company-built railway viaducts still in operation as of 2025 – the other being the
Short Line Viaduct near
Cleveland, Ohio. The Manhasset Viaduct is a critical component of the infrastructure on the LIRR's Port Washington Branch. Its construction enabled the railroad line to traverse the Manhasset Valley and Manhasset Bay: due to the surrounding area's geographical and topographical characteristics, the LIRR could not extend the line into Manhasset and
Port Washington – both communities being located across the valley, on the Cow Neck Peninsula – without it building a viaduct over it and the bay. The viaduct also passes over two major roads – one on each end: East Shore Road (at its west end) and Bayview Avenue (at its east end). == History ==