Sound Transit Set to Launch Long-Awaited Cross-Lake Light Rail Service in March 2026

Published: February 17, 2026

SEATTLE — For the first time in the region’s modern transit era, Sound Transit light rail trains will soon carry passengers directly across Lake Washington, linking Seattle and the Eastside with a one-seat ride and completing a major missing piece of the system’s buildout.

Sound Transit announced in late January that the agency’s new “Crosslake Connection” will open for passenger service on Saturday, March 28, 2026—a milestone that will allow Link’s 2 Line to run across the I-90 floating bridge and connect into the 1 Line at International District/Chinatown Station.

Sound Transit F59PHI #908 is laying over at Freight House Square in Tacoma on a rainy Saturday July 21, 2007. Doug Kroll photo.

A “final link” across the lake

The cross-lake segment is more than a new stretch of track—it effectively stitches together what has, until now, been a largely Eastside-focused 2 Line into a regional network riders can use to reach Seattle and beyond.

According to Sound Transit, opening day will mark the debut of the 2 Line’s last major component: the portion of the East Link Extension that crosses Lake Washington via I-90 and brings two new stations online—Mercer Island and Judkins Park—while enabling full connectivity between lines.

From a rider’s perspective, the change is straightforward: a trip that previously required a transfer to buses (or a drive) over the lake becomes a rail trip—more predictable, less dependent on bridge traffic, and better integrated with the rest of the region’s Link spine.

Why this project is unique: light rail on a floating bridge

East Link’s cross-lake crossing is not a typical bridge-and-rails project. The I-90 span over Lake Washington is a floating bridge—one of the engineering realities that makes transportation in the Seattle area both iconic and complicated. Sound Transit and its partners have had to develop specialized approaches for running rail across a structure that moves with wind, waves, and temperature.

Outside engineering and infrastructure partners have described this as a world-first application—light rail operating on a floating bridge—and Sound Transit has documented the project’s testing and readiness activities as the March start date approached.

In the months leading up to the January announcement, Sound Transit also highlighted progress on testing—an important step for any new rail segment, and especially critical for one that must operate reliably in challenging conditions on a floating structure.

What changes March 28: the 2 Line becomes truly regional

Sound Transit’s January news release framed March 28 as the moment the 2 Line becomes fully integrated—crossing Lake Washington and connecting with the 1 Line at International District/Chinatown Station. That junction is key, because it turns Eastside rail into a system riders can use to reach destinations across the broader Link map.

Just as important are the new stations included in the remaining segment. Sound Transit has emphasized Mercer Island and Judkins Park as major additions, bringing rail access to dense neighborhoods and creating new options for commuters and event travel alike.

In practical terms, the opening will:

Provide a rail alternative to I-90 travel across the lake
Expand access to jobs and institutions on both sides of Lake Washington
Improve transit resilience during major events, traffic surges, and roadway incidents
Strengthen the “spine” effect of Link by making the 2 Line a true companion corridor to the 1 Line

A Brief History

Sound Transit—formally the Central Puget Sound Regional Transit Authority—was created to plan, build, and operate high-capacity transit across the fast-growing central Puget Sound region. The agency’s roots go back to the 1990s, when voters approved a long-term vision for regionwide transit investment.

Sound Transit’s own history notes that a voter-approved plan in 1996—“Sound Move”—authorized the taxes that launched the agency’s first wave of projects, spanning what would become a three-part family of services: Link light rail, Sounder commuter rail, and ST Express bus service.

The agency’s first operational service arrived soon after: Sound Transit notes that ST Express buses launched in September 1999, offering regional peak and all-day express routes while rail projects advanced through planning and construction.

Over time, Link became the signature mode—expanding in stages and building a backbone through the region’s densest corridors. Today, Sound Transit’s system identity is built around:

Link light rail (the growing rapid-transit network)
Sounder (commuter rail on existing freight rail corridors)
ST Express (regional bus routes feeding key hubs and bridging gaps)

How East Link fits into the bigger picture

The East Link Extension—now culminating in the Crosslake Connection—has long been envisioned as the rail bridge between Seattle and the Eastside’s major employment and residential centers. Sound Transit’s East Link project updates describe the Crosslake Connection as the “final component” of the 2 Line project, underscoring how central the lake crossing is to the corridor’s usefulness.

In a region where Lake Washington is both a defining geographic feature and a daily bottleneck, a rail crossing creates something the area has historically lacked: a fixed-guideway transit connection that isn’t at the mercy of peak-hour congestion. And because it ties directly into the existing 1 Line, the cross-lake connection also helps Link function less like separate projects and more like a single network.

Moving ahead

With opening day set, attention turns to the details that matter most to riders: final service patterns, schedule frequency, connections at key transfer points, and how quickly the new segment becomes “normal” in daily life.

Sound Transit has positioned March 28 as a generational turning point—completing the 2 Line and creating a seamless cross-lake light rail connection between Seattle and the Eastside.

For a region built around water crossings, bridges, and constrained corridors, the Crosslake Connection is poised to become a defining piece of infrastructure: a train ride across a floating bridge—turning one of the area’s biggest geographic barriers into a direct transit link.