Sound Transit opened the world’s first floating light rail bridge across Lake Washington on March 28, connecting the agency’s two lines into a unified system for the first time ever.

For years, Seattle’s light rail system had been divided by the lake, with Line 1 connecting Lynnwood and Federal Way, and Line 2 connecting Bellevue and downtown Redmond. With the opening of the new bridge alongside Interstate 90, Line 2 now extends to downtown Seattle and Lynnwood. The extension of Line 2 along the same route as Line 1 between downtown Seattle and Lynnwood also doubles frequency at 14 stations in the busiest part of the system (one train every four minutes during peak hours).

The floating bridge was constructed in 1989. The part used by the rail line was once reversible express lanes for the adjacent highway. The first trains ran over the bridge in September 2025. Along with the bridge, Sound Transit also opened two new stations at Judkins Park and Mercer Island. 

—Justin Franz