2 Line (Sound Transit)

The East Link Extension, also known as the 2 Line, is a future light rail line serving the Eastside region of the Seattle metropolitan area in the U.S. state of Washington. It will be part of Sound Transit's Link light rail system, running 18 miles (29 km) from west to east and serving 12 stations in Downtown Seattle, Mercer Island, Bellevue, and Redmond. The first section of the 2 Line, between South Bellevue and Redmond Technology stations, is scheduled to open on April 27, 2024. It is planned to be followed in 2025 by an extension east to Downtown Redmond and west to Seattle, where it will continue into the Downtown Seattle Transit Tunnel and share stations with the 1 Line through to Lynnwood City Center station.

The East Link project was approved by voters in the 2008 Sound Transit 2 ballot measure, with construction costs projected at $3.7 billion. The line will use the Homer M. Hadley Memorial Bridge, one of the Interstate 90 floating bridges, which was constructed in 1989 with the intent to convert its reversible express lanes to light rail. Early transit plans from the 1960s proposed an Eastside rail system, but preliminary planning on the system did not begin until Sound Transit's formation in the early 1990s.

The proposed alignment of the East Link project was debated by the Bellevue city council in the early 2010s, with members split on two different routes south of Downtown Bellevue; city funding for the downtown segment's tunnel was also debated and ultimately included in the final agreement. The alignment was finalized in 2013, after more than two years of debate, and delayed the beginning of construction to 2016 and the completion of the project from 2021 to 2023. The line will be the world's first railway constructed on a floating bridge and is expected to carry 50,000 daily riders by 2030.