The first Sound Transit Link light rail vehicle crossed the I-90 floating bridge under its own power, enabling the start of a series of tests to prepare for the opening of the full 2 Line in early 2026. 

The move marks a historic milestone for both the agency and transit industry — the first time in the world that trains under power are operating across a floating bridge.

Sound Transit’s Link Testing

A single train crossed the Homer M. Hadley bridge several times at increasing speeds, from approximately five miles per hour up to the full operating speed of 55 mph. 

The test was conducted overnight so that crews could observe and document expected electrical arcing, typical in this phase of testing, between the overhead power wires and the light rail vehicle.

Live wire and signal testing are part of the system integration testing program, which will be completed over the next few months.

Testing will continue between the Mercer Island and Judkins Park stations intermittently throughout the coming weeks.