It has been in service since 1968; however, some structural repairs were made in 1992. The bridge consists of ten spans. Seven spans are considered the main spans and consist of steel trusses and concrete decks. The other three spans are considered approach spans, which are supported by plate girders. The main span over the river-shipping channel is 375 feet (114 m) long and 89 feet (27 m) wide, and the overall bridge length is 1,795 feet (547 m). There is an estimated 60 feet (18 m) of clearance for shipping on the Hudson River below, which changes with the local tide. Today's replacement cost is estimated to be between $80 and $100 million. The bridge has an HS Inventory load rating of 35 tons, and is inspected annually. The average daily traffic count was 70,787 in 1998 with a 4.5 percent estimated traffic growth during the life of the bridge.
The bridge's design is similar to that of the Interstate 35W bridge in Minneapolis, MN, which collapsed during rush hour on August 1, 2007. This realization by New York State transportation officials prompted full-scale inspections of the state's major highway bridges, including the Patroon Island Bridge. Subsequently, the bridge was deemed safe for the time being, but would need substantial repairs and retrofitting in order to ensure motorist safety, and to extend its useful service life if replacement was found not to be a viable option in the near future.
The bridge's name comes from the former (Lower) Patroon Island that once existed adjacent to the bridge. A patroon was a proprietor of a tract of land in the 17th-century Dutch colony of New Netherland in North America.
Lower Patroon Island on 1927 map (left) and after the bridge was built (right)
Patroon Island Bridge. View shows various structural supports
Patroon Island Bridge, multilane interstate highway bridge carries I-90 over the Hudson River, Albany, New York (Menands Bridge barely visible upstream)