History
The bridge was opened for commuter traffic on August 28, 1963, after three years of construction. It was built as a four-lane toll bridge to provide easy access from Seattle to Eastside communities such as Bellevue, Kirkland, and Redmond. The total cost of the bridge, in 1961 dollars, was $21 million (at least $127 million in 2011 dollars). To make up for this cost, commuters paid a 35-cent toll in each direction until 1979. The toll booths were then converted into bus stops. The bridge affected many communities on the Eastside. Redmond's population saw a dramatic increase, jumping from less than 1,500 in 1960 to 11,000 in 1970. It was the second floating bridge to cross Lake Washington; the first was the Lake Washington Floating Bridge, built in 1940 as part ofDrawspan opening
The bridge was built with a drawspan in the center that could open for boats too tall to go under the bridge. The bridge opened by raising two steel grids about and moving an adjacent pontoon beneath them. In 1989, an electrical fault caused the drawspan to open during rush hour, causing one death and five injuries. In 2000, a gravel barge struck the bridge.Replacement bridge
Just five years after the bridge opened, a study commissioned by the state legislature was completed to figure out how to provide for the great demand for cross-lake transportation. That study evaluated bridge and tunnel crossings north and south of the bridge. To help provide the political lubrication needed for any plan to go forward, the Trans-Lake Study was commissioned by the State of Washington. The study brought together 47 representatives of public agencies, neighborhoods, businesses, and advocacy interests. In 1997, Myint Lwin, WSDOT's chief bridge engineer, said that even with repairs, the bridge could be expected to last only about twenty more years (until 2017). The bridge needed to be closed to traffic in high winds, and even after a seismic retrofit in 1999, it was at risk of collapse during an earthquake. Due to the weight of various reinforcements over the years, the bridge deck ultimately sat about lower over the water than it did originally. Since the bridge was built in the early 1960s, prior to the implementation of modern earthquake standards, its hollow support structures would have likely failed during a major earthquake. Additionally, vibrations induced by storm surges and strong winds could have compromised the drawspan, anchor cables, and pontoons, subjecting them to structural failure. Even for storms below the maximum threshold for failure to occur, Washington State Department of Transportation (WSDOT) still closed the floating bridge to traffic. The original bridge carried two lanes of traffic in each direction, but did not include emergency shoulders or pedestrian and bicycle crossings. This posed traffic problems since any obstruction caused by car breakdown, wreck or maintenance would result in traffic backups. In 2011, WSDOT broke ground on the replacement bridge. On April 2, 2016, WSDOT held a grand opening ceremony, allowing the public to explore the top deck of the new bridge on the westbound side. The replacement bridge opened to westbound traffic on April 11, 2016, and opened to eastbound traffic on April 25, 2016. The old bridge was permanently closed at 23:00 PDT on April 22, 2016, with demolition completed by the end of 2016. The bridge was removed by spring 2017.Construction
The cost of all improvements to SR-520 between I-5 and I-405, including the new bridge, is forecast to be $4.65 billion. The first of 21 longitudinal pontoons were positioned on August 11, 2012. Each pontoon is long and wide. The pontoons were constructed in Aberdeen by Kiewit Construction. Pontoon construction was plagued by errors and shoddy construction. Reports included workers installing incorrectly sizedTolling
When the bridge opened in 1963, a 35 cent toll was collected to pay off a construction bond. The sole toll plaza was located at the east end of the bridge in Medina and had nine booths. The state government offered discounts to commuters using a ticket book, as well as carpools of two or more people. The toll was retired on June 22, 1979, after the $35 million bond had been paid off 20 years ahead of schedule. More than 213 million vehicles had used the toll bridge and generated $59.6 million in revenue. Tolls were reinstated in December 2011 to fund the original bridge's replacement. Within the first year, traffic levels declined by 30 percent and tolls generated $50 million in gross revenue. To fund the new bridge, in May 2009, Governor Christine Gregoire signed ESHB 2211, which authorized tolling on the SR 520 bridge beginning in 2010. Tolling actually began on December 29, 2011 and has assisted WSDOT in funding the project. The State Transportation Commission has proposed a toll of US$3.59 each way during peak periods. The proposed rates during other hours were to range from $0 to $2.87. All tolling was done automatically with no tollbooths. Tolling for people without " Good to Go" passes is done by license plates. Toll readers were located on gantries at the east highrise, but additional gantries on the east mainland were added to facilitate tolling on the new bridge once opened.See also
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