Sound Transit reports continued progress on testing for the East Link Extension’s floating bridge segment, marking another major step toward linking Seattle and the Eastside via light rail across the I-90 bridge. Full service on the East Link Extension (2 Line) is expected to begin in early 2026.
The agency confirmed that the first powered train crossed the floating bridge overnight on Sept. 8–9 using a single-car train. Since then, testing has expanded to a four-car train operating at full speed, reaching roughly 55 miles per hour.
Crews have also been conducting live-wire testing to assess the power system that supplies electricity to the trains, along with ongoing work on signals, traction power and communications equipment.
Sound Transit says substantial progress has been made in systems testing overall. While work will continue through the end of the year, most of the remaining tests can now occur at night. This shift frees up the alignment during daytime hours for final construction items, including track repairs, work on the dual blocks supporting the track approaches to the bridge and remaining concrete activities.
Project officials note that day-to-day activity on the bridge will vary. Some days, the public may see trains or crews on the structure; on other days, testing and coordination may be happening behind the scenes.
Preparation work extends beyond the floating bridge as well. In downtown Seattle and other parts of the system, riders on the Link 1 Line may notice additional trains as Sound Transit tests future four-minute headways between downtown Seattle and Lynnwood.
Later this month, during select morning and evening peak periods, an out-of-service, single-car 2 Line train will occasionally “interline” between 1 Line trains from International District/Chinatown Station to Lynnwood City Center Station. These trials will continue for several weeks as operators practice doubling current service levels. Passenger service will remain every eight minutes during peak hours.
Sound Transit also advises riders to expect weekend closures on the 1 Line in December. The closures will allow installation of advanced signaling technology in the downtown tunnel, supporting more frequent and reliable service in the future.
Once completed, the 2 Line will provide a direct light rail connection between Seattle and the Eastside over the I-90 floating bridge and will serve the Operations and Maintenance Facility East in Bellevue, helping expand system capacity.
The first segment of the 2 Line opened in April 2024, operating between South Bellevue and Redmond Technology stations with stops at East Main, Bellevue Downtown, Wilburton, Spring District/130th and Overlake Village. Two additional stations; Marymoor Village and Downtown Redmond, opened on May 10, 2025, as part of the Downtown Redmond Link Extension.
