SEATTLE, WA — STV joined Sound Transit in celebrating the opening of the Crosslake Connection, delivering the world’s first light rail service to operate on a floating bridge and completing the final segment of the 2 Line across Lake Washington.
The 7‑mile Crosslake Connection travels along Interstate 90 with new stations at Mercer Island and Judkins Park in Washington. The extension directly links Bellevue to Seattle by light rail and connects the 2 Line with the 1 Line, forming a roughly 60‑mile regional light rail network that stretches from Redmond through Seattle to Lynnwood and Federal Way.
STV supported the Crosslake Connection as systems construction management partner, working in collaboration with Mott MacDonald through the Northwest Transit Systems Partners joint venture. STV’s engineers and inspectors oversaw installation and testing of the overhead contact system, signaling, and communications systems, supporting reliable service in a new and unprecedented operating environment and enabling passenger rail operations on the floating I-90 bridge.
“This project pushed light rail into an operating environment no one had solved before,” said Allison Dane Camden, Vice President and Pacific Northwest Area Manager at STV. “Delivering safe, reliable service across a floating bridge required disciplined systems integration and years of testing, and it expands how regions can think about connecting communities across challenging geographies.”
Constructing the first-ever rail infrastructure on a floating bridge required innovative solutions that account for lake movement, weather and long-term durability. Beyond specialized track systems, a first-of-its-kind application of cathodic protection was installed to protect the concrete pontoons and post-tensioned steel anchor cables, preserving the structural integrity of the existing structures and supporting long-term reliability. The work also required careful integration of new tunnel fire and life safety systems with legacy infrastructure, coordinated across multiple jurisdictions.
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The Crosslake Connection expands access to jobs, education, health care, and cultural destinations throughout the region. With the 2 Line fully operational, Sound Transit’s light rail network now spans 63 miles. Trains arrive about every eight minutes at the new stations during peak periods, with the 1 Line and 2 Line providing frequent service through the system’s central corridor.
The opening of the Crosslake Connection completes the expansion of the Link system approved by voters in 2008 as part of the Sound Transit 2 ballot initiative. The 1 Line extension to Federal Way opened in December 2025, following the openings of the 2 Line to downtown Redmond in May 2025; the initial segment of the 2 Line on the Eastside in April 2024; and the 1 Line extension to Lynnwood in August 2024.
