Even if the storms were below the maximum threshold for failure to occur, Washington State Department of Transportation (WSDOT) would still close the floating bridge to traffic. Additionally, near the end of its lifetime, vibrations induced by storm surges and strong winds were able to compromise the aging drawspan, anchor cables, and pontoons, leading to structural failure in a major storm. The original Evergreen Point Floating Bridge was designed before the implementation of modern earthquake engineering standards, with vulnerabilities in its hollow support structures that could have failed in a major earthquake. The Eastside is also served by the Interstate 90 floating bridges completed in 19, carrying traffic across Mercer Island to and from Bellevue. ĭue to increased traffic generated by rapid growth of the Eastside area, bridge replacement was explored as early as 1969, when building a parallel span was explored and rejected. The original bridge would also close to traffic during sustained wind gusts of 50 miles per hour (80 km/h) or higher for more than 15 minutes. The 7,578-foot-long (2,310 m) floating span consisted of 33 pontoons and cost $24.7 million to construct (equivalent to $209 million in 2022) the bridge carried four lanes of traffic, separated by a curb that was later replaced with a simple Jersey barrier at the center was a drawspan that opened for large vessels traversing the lake. Rosellini, opened on August 28, 1963, carrying the four-lane State Route 520 (at the time designated temporarily as the Evergreen Point branch of Primary State Highway 1 until the 1964 state highway renumbering). The original Evergreen Point Floating Bridge, also named for state governor Albert D. Main article: Evergreen Point Floating Bridge (1963) The bridge opened in April 2016 and replaced another floating bridge of the same name at the site, which was 130 feet (40 m) shorter. The 7,710-foot-long (2,350 m) floating span is the longest floating bridge in the world, as well as the world's widest measuring 116 feet (35 m) at its midpoint. Rosellini Bridge, carries Washington State Route 520 across Lake Washington from Seattle to its eastern suburbs. The Evergreen Point Floating Bridge, also known as the 520 Bridge and officially the Governor Albert D. Washington State Department of Transportation (WSDOT)Įvergreen Point Floating Bridge (1963–2016) Rosellini Evergreen Point Floating Bridge