Sub-area equity (SAE) is a favorite whipping boy of transit advocates. If it weren’t for that, they say, we could smuggle those Pierce County dollars up here to create a dense network of rail lines in Seattle! A lot of stuff floating around the legislature this session has sought to do away with it.
While a system focused on dense Seattle neighborhoods has a certain appeal, realistically that kind of plan is a dead duck at the ballot box, for obvious reasons. SAE does force Sound Transit to make some goofy decisions, because it has to spend like crazy in outlying areas to offset the huge capital costs in the core. However, if you look a little past the next ballot measure, SAE will end up working to Seattle’s advantage.
Making the big assumption that something like the most recent workshop proposal gets built, the buildout in Seattle is pretty much done. The Northgate line would probably eventually go out to N. 175th St along the freeway, but that’s relatively cheap, and of more interest to people in Snohomish County. Meanwhile, there are tons of outlying places ST3 can go — to Issaquah, over 520, to Renton, to Tacoma and Everett, etc.
I can picture the ST board, mulling over ST3 and unburdened by SAE, maximizing the investment in the outlying areas, where support for transit is tepid, and banking that earnest Seattle liberals (who are in any case outnumbered) will support it anyway.
SAE would force more investment in Seattle: presumably, in Ballard and West Seattle. With ST2.1 finishing as soon as 2020, we could get service in the Western half of the city by the early 2030s with a little luck.