When West Seattle’s Terminal 5 was “modernized,” part of the plan was to create a railroad Quiet Zone to reduce – not eliminate – train horns in the area. Originally, it was supposed to be complete before the first modernized berth opened. But instead, three years after that happened, the Quiet Zone is finally officially complete.
Though it’s part of the Northwest Seaport Alliance‘s modernization project, the Quiet Zone’s construction was led by SDOT, the features of which are shown on their map above, and explained here. The work was finished by year’s end; the official Federal Railroad Administration notice happened earlier this month. If you’re wondering why this doesn’t mean an end to train horns, it’s mostly because T-5 isn’t the only facility that railroad traffic serves in the area – as you can see just by traveling along West Marginal Way SW.
P.S. If you’re interested, here’s the federal explanation of Quiet Zones.