The Third Lake Washington Bridge, officially the Homer M. Hadley Memorial Bridge, is a floating bridge in the Seattle metropolitan area of the U.S. state of Washington. It is one of the Interstate 90 floating bridges, carrying the westbound lanes of Interstate 90 across Lake Washington between Mercer Island and Seattle. The floating bridge is the fifth-longest of its kind in the world, at 5,811 feet (1,772 m). History A third floating bridge on Lake Washington was proposed in the 1950s during construction of the Evergreen Point Floating Bridge to the north. After several locations were considered, a span parallel to the existing Lake Washington Floating Bridge (now the Lacey V. Murrow Memorial Bridge) was chosen in the 1960s. The first pontoon for the new bridge was floated from Everett to Lake Washington in September 1983. The bridge opened in 1989 and is named for Homer More Hadley, who designed the bridge's companion span, the parallel Lacey V. Murrow Memorial Bridge. Hadley also designed the McMillin Bridge in Pierce County. It originally carried bidirectional traffic while the older Murrow Bridge underwent extensive renovations. On November 25, 1990, sections of the Murrow Bridge sank during a windstorm that flooded several pontoons; the sinking sections also severed 13 of the 58 anchor cables of the Hadley Bridge, which remained closed for several days. Following the reopening of the Lacey V. Murrow Memorial Bridge, two reversible high-occupancy vehicle (HOV) lanes were set up on the Hadley Bridge to accommodate the traffic flow between Seattle and the suburban Eastside (westbound in the morning, eastbound in the evenings). The lanes were opened to all Mercer Island commuters, including single-occupant vehicles, per a 1978 agreement negotiated by the city government. The reversible lanes were planned to be converted for light rail use at a future date, but design issues prevented a simple conversion from being feasible. Sound Transit and the Washington State Department of Transportation added HOV lanes to the bridge's westbound lanes in 2017. This preceded construction of the East Link light rail line from downtown Seattle to Bellevue and Redmond, which will use the former reversible express lanes. When East Link, scheduled to be completed in 2023, begins operation, it will be the first permanent railroad on a floating bridge. The light rail line will employ a set of floating spans for tracks on the transition between pontoons and the fixed spans. The Maxau