Last Thursday, the Sound Transit Board was briefed about progress on East Link and the related Downtown Redmond Link Extension. East Link construction has been well underway for a few months, with visible progress from Mercer Island to Overlake, while the Downtown Redmond extension is still in early design and is awaiting the publication of supplemental environmental documents.
For the Downtown Redmond extension, Sound Transit plans to release a request for proposals (RFP) in October that will kickstart the selection process for the project’s design-build contract. Similar to the contract used to build South 200th/Angle Lake, the design of the stations and construction of the entire project will be left to a single contractor and would compress part of the planning timeline. Sound Transit expects to have development agreements with the City of Redmond, King County, and WSDOT in place by early next year. The 3.4-mile Downtown Redmond extension is expected to begin construction sometime next year and open in 2024, with two stations and 1,400 total parking spaces.
Meanwhile on the other sections of East Link, Sound Transit has over 1,000 tradespeople and workers who are actively involved in construction and is still trending on schedule for a mid-2023 opening.
Excavation of the 2,000-foot tunnel under Downtown Bellevue is about 90 percent complete and is expected to break-through at the north end later this month. The tunnel, unlike University and Northgate Link, is being dug using conventional excavators and cutters instead of a tunnel-boring machine due to its short length and to prevent potential disruptions.
All of the elevated guideway piers between 120th and 130th streets in Bel-Red have been finished, while work is still underway in southern Bellevue and at the crossing of I-405 in downtown. Overlake Village Station’s retention vault has been completed with assistance from the City of Redmond, and excavation at Redmond Technology Center Station is still in progress.
On Mercer Island, the first sections of track for East Link are being welded together into 560- and 800-foot-long “strings” on Interstate 90. The tracks will be stored in the former I-90 express lanes while awaiting future installation, which is still a few years away.