The East Link tracks, expected to open in 2023, will connect Seattle to Mercer Island and Bellevue - a big step forward in Sound Transit's advancement of public transportation. This feat is also a landmark move - it will be the first light rail ever in the world to travel over a floating bridge. 

One of the engineers behind the design is John Sleavin. He explains more about the process, what's in store for light rail riders, and what projects he's currently working on. 

See also: 'Never been done': Light rail over I-90 floating bridge is an engineering feat

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