Sound Transit previews plans for keeping light rail service moving as construction crews tie in East Link light rail extension

Carefully choreographed service will keep trains running during early 2020 construction to connect the Eastside to the system

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Sound Transit today previewed construction plans for early 2020 that will connect the existing light rail system in downtown Seattle to Mercer Island, Bellevue and Redmond, with service beginning in 2023. Under tightly choreographed operations, Link will continue serving riders over an approximately 10-week construction period at International District/Chinatown Station.

During the process to connect East Link to the transit tunnel—known as Connect 2020—Sound Transit will close one platform of International District/Chinatown Station at a time for construction. During the construction period, riders will experience reduced frequency and reduced peak-hour capacity. However, Sound Transit will mitigate the reduced frequency by operating all four-car trains.

“We had two options: close the line for several weeks during construction, or continue to serve our 80,000 daily riders over a slightly longer construction period. We choose to keep service running at the highest level conditions will allow,” said Sound Transit CEO Peter Rogoff. “We’ve devised a plan that will keep riders moving. This unavoidably disruptive period is the inconvenience we all must face so we can enjoy the extraordinary convenience of traveling to ten new light rail stations across the Eastside in 2023.  By scheduling this construction during our slowest weeks for light rail ridership, we aim to inconvenience the fewest number of riders possible.”

How will single-tracking work?
Construction will occur at International District/Chinatown Station over 10 weeks between January and mid-March 2020. Link will essentially operate as two lines, both terminating at Pioneer Square Station. Southbound trains originating at Husky Stadium will travel to Pioneer Square and then reverse direction to head back north on the same track. Similarly, northbound trains originating at Angle Lake will travel to Pioneer Square and then reverse direction to head back south on the same track. Riders continuing northward or southward through Pioneer Square Station will need to change to a waiting train on the opposite track, crossing a temporary center platform that Sound Transit will construct this year. During the construction period trains on both segments will operate at a frequency of 12 minutes in each direction and will be timed to meet at Pioneer Square.

The transfer at Pioneer Square enables higher frequency service than would otherwise be possible with the limited number of locations where trains can switch tracks. Four-car trains arriving every 12 minutes compares to current operations where a mix of three- or two-car trains arrive every 6 minutes during peak hours; mid-day and weekend service where three-car trains arrive every 10 or 15 minutes; and weekday evening service where two-car trains arrive every 10 or 15 minutes.

Click here for animation of how single-tracking will work.

“Our region successfully weathered the SR-99 viaduct closure in preparation for the opening of the new SR-99 tunnel. While Connect 2020 will also be disruptive, careful planning and patience will minimize the inconvenience,” Rogoff said. “By doing this work now before Northgate Link opens in 2021, we will avoid disrupting more riders. The eastward connection we establish will transform many thousands of commutes as trains reach the Eastside in 2023 and thousands more in 2024, when trains reach Lynnwood, Federal Way and downtown Redmond.”

During the single-tracking period, there will also be three weekends—one in early January, one in February and a third in March—when the International District Station will need to fully close. During these closures, light rail will operate between Angle Lake and Stadium stations and between Westlake and the University of Washington stations. Sound Transit will operate buses on surface streets between the SODO and Westlake light rail stations in place of light rail service. Sound Transit will communicate more specific service information after the agency finalizes the construction schedule.

Sound Transit will deploy staff ambassadors and temporary signage during single-track operations to help guide customers to correct platforms.

Sound Transit has begun a public information campaign to educate riders and the Chinatown-International District community about the short-term delays and crowding that will result during this construction. When all tunnel and related construction work is complete, the tunnel will be ready to provide congestion-free service to thousands more riders each day across an expanding light rail system that will include destinations to the Eastside and up and down the I-5 corridor.

Connect 2020 work will not affect bus service, since the downtown transit tunnel will convert to rail-only operations on March 23, 2019. As long planned, buses are leaving the tunnel due to Washington State Convention Center construction and to enable light rail expansion across the region. To keep buses moving, Sound Transit, King County Metro and the City of Seattle are investing $30 million in surface-street transit pathways and other improvements that will be in place by March.

While single-tracking operations will not begin until next January, riders will start noticing early work soon after buses come out of the tunnel this March. Sound Transit will begin constructing a turn-back track at the International District/Chinatown Station this summer, and the temporary center platform at Pioneer Square in October. Other potential improvements this year will involve repair and maintenance activities to upgrade tunnel systems to current operating standards. Examples of this work include seismic upgrades, installing mid-car platform barriers, and removing bus-only infrastructure. Crews will complete most of this work during the day and the work will not affect service.

Connecting East Link to the downtown tunnel will require approximately 10 weeks of around-the-clock heavy construction. Work will include shifting tracks in the tunnel’s south portal (at the International District/Chinatown Station) to accommodate East Link trains that will exit and enter the tunnel from the center trackway on Interstate 90. Tracks need to move west to connect with the new tracks and switches. In other areas, tracks need to be adjusted to accommodate switches for special track work. Sound Transit will also update the signal system.

Sound Transit is simultaneously working to extend light rail north, south, east and west, opening new stations every few years to form a 116-mile regional system by 2041. Northgate Link in 2021 will be followed by service to Mercer Island, Bellevue and Redmond’s Overlake community in 2023. Additional extensions to Shoreline, Mountlake Terrace, Lynnwood, Kent/Des Moines, Federal Way and downtown Redmond are planned in 2024. Further light rail extensions are scheduled to reach West Seattle, Fife and Tacoma in 2030; Ballard and South Lake Union in 2035; Paine Field and Everett in 2036; and South Kirkland and Issaquah in 2041.

The agency is also working on further investments including but not limited to expansions of Sounder South service and bus rapid transit service in 2024 along the north, east and south sides of Lake Washington. More information is available at