Sound Transit opens East Link Extension, bringing light rail service across Seattle’s I-90 floating bridge

Recently, Sound Transit’s East Link Extension opened for passenger service, marking the completion of the Crosslake Connection 2 Line. Festivities kicked off at Sam Smith Park near Judkins Station with remarks from local leaders and a ribbon cutting ceremony to commemorate the occasion.

The East Link Extension is part of Sound Transit’s regional system expansion program, crossing Lake Washington and linking Redmond, Bellevue, Mercer Island, and Seattle via the I-90 floating bridge. With 14 miles of electrified light rail and 10 new stations, the extension is designed to move up to 50,000 riders daily with reliable, frequent service.

For over seven years, Mott MacDonald has led Sound Transit’s efforts in rail system construction management, providing project management leadership, contract administration, and technical oversight. The team was instrumental in coordinating complex systems integration to ensure safe, reliable performance under dynamic bridge conditions.

“Seeing the East Link Extension open to passengers is a proud moment for our team,” says Guil Pereira, resident engineer at Mott MacDonald. “Delivering the world’s first light rail line on a floating bridge required remarkable coordination and expertise, and we’re proud to bring faster, more reliable connections for the Puget Sound region.”

Ben Neely, systems construction manager at Sound Transit added, “By embracing collaborative delivery, the project met the complex challenges and delivered a collective achievement for Sound Transit and the region."