On the morning of March 28, 2026, a Sound Transit light rail train pulled out of the International District/Chinatown station in downtown Seattle, dipped into the trench alongside Interstate 90, and did something no light rail train had ever done before: it floated. Gliding across the reversible center lanes of the Homer M. Hadley Memorial Bridge, the train carried its first revenue passengers over Lake Washington on a bridge that sits on the water rather than above it. Eight minutes later, it stopped at Mercer Island — an island city of about 25,000 people that had never had a rail station in its history. A few minutes after that, it climbed out of the corridor and rolled into downtown Bellevue.
It is difficult to overstate how long people in the Puget Sound region have been waiting for that ride. Voters first approved cross-lake rail in November 2008 under the Sound Transit 2 (ST2) ballot measure. The Hadley Bridge itself was designed with rail in mind and opened in 1989. The oldest strand of the story goes back to 1968, when the region's first attempt at rapid transit — the Forward Thrust ballot measure — proposed a rail line across Lake Washington and was rejected by voters. Fifty-eight years later, the ride finally exists.
The World's First Light Rail on a Floating Bridge
The engineering headline is genuinely a first. The 2 Line is the world's first light rail line to operate on a floating pontoon bridge. Floating bridges are a Seattle specialty — the region has more of them than anywhere else on Earth, because Lake Washington is deep, soft-bottomed, and inconveniently placed between the region's two biggest cities — but running steel-wheel rail across one had never been attempted at revenue scale.
A Bridge Built for a Train That Took 37 Years to Arrive
The Homer M. Hadley Memorial Bridge is the middle span of the three-bridge I-90 complex. When it opened in 1989, its reversible center lanes were pre-engineered for eventual rail conversion, following the 1976 I-90 Memorandum of Agreement that designated the corridor's center roadway for future transit use. The people who signed that agreement in the mid-1970s and the engineers who detailed the bridge in the 1980s were, in effect, sending a package forward in time. It took 37 years from the bridge's opening to the first revenue train.
The Plinth Problem
Getting rail onto a floating structure is not the same as bolting track to a normal bridge deck. Because pontoons flex, twist, and rise and fall with the lake, the track sits on precisely engineered concrete plinths that isolate the rails from the bridge's movement. When crews began inspecting the plinths installed during earlier bridge work, they discovered in 2019 and 2020 that the units were out of specification and would have to be replaced in place, on an active floating bridge, in a working freeway corridor. That single discovery added roughly five years to the Crosslake Connection schedule and a substantial share of the project's cost overrun. It is a useful reminder that the last mile of a megaproject often isn't the tunnel or the political fight — it's a tolerance problem on a component nobody outside the engineering room has ever heard of.
What the Ride Actually Feels Like
Passengers get a genuinely unusual transit experience. The train drops into the I-90 corridor east of downtown Seattle, threads under the Mount Baker Ridge tunnel, and then emerges onto the bridge with open lake on both sides — the Seattle skyline receding to the west, Mercer Island straight ahead, the Cascades on the eastern horizon on clear days. For a rider who has spent years staring at brake lights on I-90, the view alone reframes the trip.
What the Full 2 Line Actually Connects
With the Crosslake Connection open, the 2 Line runs 33 miles (53 km) end to end, from Lynnwood City Center in Snohomish County to Downtown Redmond on the Eastside. That's a suburban-to-suburban run that crosses three counties' worth of geography and, for the first time, links Seattle (population ~750,000) and Bellevue (~150,000), its largest suburb, by rail.
The Two New Stations
The March 28 opening added two stations to complete the east-west link:
- Judkins Park, on the eastern edge of Seattle's Central District, with a walkable connection to the First Hill Streetcar
- Mercer Island, the first light rail station the island has ever had
The Eastside segment from South Bellevue to Redmond Technology — 10 stations across 14 miles of the East Link Extension — had actually opened first, on April 27, 2024, and ran as an isolated line while the plinth work continued. Downtown Redmond was added in May 2025. The March 2026 Crosslake Connection is what finally stitched the two halves together into a single 2 Line.
One-Seat Rides That Didn't Exist Before
The most immediate change for riders is a set of trips that used to require a bus, a transfer, or a car:
- Lynnwood to Microsoft's Redmond campus — a direct suburban-to-tech commute across the top of the region
- University District to Downtown Bellevue without a transfer
- Capitol Hill to Mercer Island, linking Seattle's densest walkable neighborhood to a previously transit-isolated suburb
- Anywhere on the 1 Line into the Eastside via the shared downtown Seattle tunnel stations
Rail vs. the I-90 Slog
The I-90 corridor carries roughly 200,000 vehicles per day according to WSDOT, and is one of the most reliably congested stretches of freeway in the Pacific Northwest. Against that baseline, the rail numbers are striking:
- International District to Mercer Island: about 8–10 minutes by train, versus 20–40+ minutes driving
- Seattle to Downtown Bellevue: about 25 minutes by train, versus 30–60+ minutes in peak traffic
- Seattle to Redmond Technology: about 35–40 minutes by train, versus 45–75 minutes driving
Those are not marginal improvements; they are the kind of gap that changes commute decisions and directly speak to the role of public transportation in reducing traffic congestion.
Eighteen Years From Ballot to Ribbon
The path from a "yes" vote to a running train ran through nearly two decades of politics, litigation, and construction.
The Bellevue Tunnel Fight
The most contentious stretch of the story was between roughly 2011 and 2013, when Sound Transit and the City of Bellevue fought over the downtown alignment. Local developer Kemper Freeman led an aggressive opposition campaign, at least two lawsuits were filed, and the city council pushed for an expensive downtown tunnel rather than an elevated alignment. The final deal, reached in April 2013, kept the tunnel but had Bellevue contribute directly toward the cost — a rare case of a suburban city paying to shape its own rail project. That tunnel is now the reason downtown Bellevue riders exit into the middle of the office district rather than at its edge, and it is a substantial share of why the project ran over budget.
A Timeline in Milestones
- 1968 & 1970: Forward Thrust ballot measures for regional rail — including a Lake Washington crossing — fail at the polls
- 1976: The I-90 Memorandum of Agreement reserves the center lanes for future transit
- 1989: The Homer M. Hadley Memorial Bridge opens, pre-engineered for rail
- 2004: East Link is added to Sound Transit's long-range plan
- November 2008: ST2 passes; East Link is authorized
- April 2013: Bellevue alignment finalized after litigation
- 2015–2016: Construction begins
- 2019–2020: Plinth defects discovered; timeline slips
- April 27, 2024: Eastside-only segment opens
- May 2025: Downtown Redmond extension opens
- March 28, 2026: Crosslake Connection opens; full 2 Line in service
The originally projected completion was 2021. The actual opening was roughly five years late on the crossing itself. The final cost landed in the $3.7–4+ billion range, against a voter-approved ST2 budget of about $3.7 billion for the East Link Extension — the single largest project in the ST2 program. Overruns tracked closely to the two hardest problems: the downtown Bellevue tunnel and the floating-bridge plinth replacement.
The Region This Line Is Actually Building
A new rail line is worth what the land use around it becomes. On that front, the Eastside is unusually far along.
Bellevue, BelRed, and the Spring District
Downtown Bellevue is in the middle of a transit-oriented development wave measured in billions of dollars of new office and residential construction — much of it explicitly timed to rail arrival. The BelRed corridor, a designated urban growth area running between Bellevue and Overlake, is systematically replacing auto-oriented strip retail with dense mixed-use blocks. The Spring District, built around its namesake station, is essentially a from-scratch urban neighborhood — an unusual example of a station-first development pattern in a US suburb. It is the sort of pattern that other regions have been trying to encourage for years and is one of the clearest local echoes of the land-use lessons from Denver's light rail expansion and the broader relationship between transit and urban development.
Mercer Island's Tradeoffs
The story is not uniformly celebratory. Mercer Island residents lost the exclusive HOV access they had long enjoyed on I-90's center lanes, and the city spent years negotiating mitigation with Sound Transit. Those tradeoffs are worth naming; they are also the kind of conflict that shows up whenever a shared freeway right-of-way gets reallocated. Seattle's broader experience with equitable station-area planning — including debates around equitable transit-oriented development along Link light rail — is directly relevant here.
The Tech-Employer Corridor
Redmond Technology Station sits a 5–10 minute walk from Microsoft's main campus, home to roughly 60,000 employees per company filings. Downtown Bellevue, four stations to the west, hosts significant offices for Amazon, Google, and Meta. This is the first time the region's two largest tech-employer concentrations have been on the same rail line, and it is a natural test case for the economic benefits of transit investments.
What Comes Next: ST3 and Beyond
The 2 Line's opening effectively completes the Sound Transit 2 light rail program. University Link (2016), Northgate Link (2021), and Lynnwood Link (2024) are all in service; East Link/2 Line (2024–2026) closes the ST2 chapter.
ST3 Is Now the Story
Voters approved Sound Transit 3 in November 2016 to fund the next generation of expansion: extensions to West Seattle and Ballard, Federal Way to Tacoma (see the Federal Way Link Extension opening), an Issaquah line that will connect back into the 2 Line at South Bellevue, and a further reach into Everett. ST3 is a bigger, more expensive, and more politically contested program than ST2, and the region's ability to deliver it on any reasonable schedule is now the open question.
Nearer-Term Milestones
Sound Transit projects 50,000 daily riders by 2030 for the full 2 Line, on top of roughly 100,000 peak daily riders currently on the 1 Line. The next visible milestone is the Pinehurst infill station between Northgate and Roosevelt on the shared 1/2 corridor, scheduled to open in late 2026. Sound Transit also announced a suspension of 2 Line service between South Bellevue and International District/Chinatown for maintenance beginning July 26, 2026 — an early sign that operating a novel piece of infrastructure will require ongoing attention. First-of-a-kind engineering does not stop being first-of-a-kind after opening day.
Conclusion
For a region defined for generations by its two lakes and its car dependency, a floating light rail crossing is more than a line opening. It is a physical answer to a question that was first asked at the ballot box in 1968 and finally answered, in steel and concrete and pontoons, in the spring of 2026.