MI light rail opening is projected for later in 2026

Riders will have to wait deeper into 2026 for East Link light rail service to arrive at Mercer Island’s station.

In May of this year, Sound Transit listed the opening timeframe for local activity as early 2026. According to its System Expansion Monthly Status Report, trains are now projected to begin darting across the Interstate 90 floating bridge from the Island to Judkins Park station in Seattle and back by May 31, 2026.

“That’s kind of a conservative target that we need to provide for sort of tracking purposes to the FTA (Federal Transit Administration) and others as just sort of a milestone or a last possible date that we could open,” said Rachelle Cunningham, Sound Transit’s public information officer. “We certainly hope to and expect to (open by then) — we’re working hard toward opening sooner than that.”

Sound Transit crews are nearing a wrap-up on the first phase of testing involving system integration, and then the pre-revenue operations phase will occur. The final stage will be simulated service to set the stage for the opening.

During the system integration phase, workers will be inside the trains and ensuring that the vehicle communicates with the track, and the signaling and power systems are functioning together. In the pre-revenue phase, operators will become familiar with the system, drive the trains and ensure that everything’s running smoothly.

A pair of light rail crossings between Seattle and Mercer Island have already taken place. During the early morning hours of Sept. 8-9 of this year, a powered light rail vehicle traversed a floating bridge for the first time worldwide. On May 21 of this year, Sound Transit pushed a test train across the bridge.

Cunningham said these haven’t been delays regarding the push of the 2026 opening date.

“Things are going as expected. We’ve been doing the system integration testing,” she said, adding that the testing includes measuring the cathodic protection system that protects the bridge from long-term damage that could be caused by a stray current. “It’s something that they take some time to do.”

Due to issues that arose in 2022 with the cast-in-place concrete plinths that support the tracks, the original projected East Link opening of mid-2023 was delayed, according to a previous Reporter story. The construction challenges also caused delays in the opening of other cities’ routes.

The Mercer Island Station will be one of the segments of the 14-mile East Link Extension Project. The MI Station platform level distance is marked at 380 linear feet between the 77th Avenue Southeast entrance and the 80th Avenue Southeast entrance. Users will descend 27-foot staircases to the rail platform, as reported in a Reporter tour on May 1, 2023.

A previous Reporter story noted that the city of Mercer Island’s recent Town Center projects are or have been concentrated on crosswalks, sidewalk construction, ADA-accessible curb ramps, street lighting, traffic signals and parking. The new commuter parking facility on Southeast 27th Street and Sunset Highway features 35 parking stalls, bike racks, bike lockers and fresh landscaping. The improvements are focused on helping pedestrians get to and from the light rail station safely and more efficiently throughout the Town Center.

As the testing continues, Cunningham said it’s cool to see the trains crossing the bridge and streaking through the Seattle area.

Over the last few years, Sound Transit has been in regular communications with the city of Mercer Island on how things have been going with light rail.

“Obviously a new station there in Mercer Island is a big deal for folks there and really everywhere,” said Cunningham, adding that when the time comes, they can all celebrate the opening together.

A message from the city of Mercer Island to the Reporter said that officials have been in contact with Sound Transit regarding the light rail opening, and the city’s public safety personnel have been preparing and are ready when the station and line opens.