This diagram takes the existing Sound Transit Link Light Rail network, adds in the planned expansions, and then adds in a series of speculative extensions. These include an extension up into Ballard, another down to Burien from West Seattle, and separating the lines south of Seattle into one that goes to Renton (following part of the existing corridor) and a more efficient corridor south towards the airport. It’s not as ambitious as the Seattle Subway group’s proposals, but perhaps a bit more workable in the next few decades. This also includes major expansions to the Tacoma light rail network.

I’m originally from the Seattle area, so I’ve been following Sound Transit’s development, and found this to be a fun imaginative project.