(WSB photo: Construction zone just south of southern Highway 99 tunnel portal)

By Tracy Record

West Seattle Blog editor

For the first time in a while, the Alaskan Way Viaduct Replacement Program invited the media into the project zone outside the tunnel – not for a tunnel update, but to talk about two closures.

First one is the one we’ve been reminding you about daily since last weekend – 9 pm tonight until 6 am Sunday, southbound 99 is closing between the south end of the Battery Street Tunnel and the West Seattle Bridge. When it reopens, the stretch just north of the stadium zone will be realigned – a little less curvy, basically; not the final configuration, but closer to it. Here are WSDOT-provided images with the before and after – the U-shaped structure at the top of both views is the Atlantic Street overpass:

This won’t be a major change but it’s important for the project – WSDOT’s viaduct-to-tunnel program boss Dave Sowers explained at the briefing that this is part of getting 99 ready for connections to the tunnel and ramps in the area that will carry non-tunnel-bound 99 users into downtown post-viaduct.

Speaking of which, an update on the big tunnel-to-viaduct closure (likely this fall) was the other part of the briefing, and there’s something new for West Seattle drivers/riders – non-tunnel northbound traffic will be affected beyond the main closure itself. We’ll get into that next but first, here’s our video of the entire briefing and media Q&A in case you’d like to watch/listen for yourself:

The first thing to stress: No, there’s still no date for the three-weeks-or-so viaduct-to-tunnel closure. WSDOT hopes to be able to announce it about a month in advance, and currently expects the contractor Seattle Tunnel Partners will officially hand off the tunnel in late August. Sowers said their biggest goal is to have the tunnel open by Thanksgiving, but it could of course be sooner.

While the three-week closure itself isn’t news – we’ve reported it multiple times before – this is: West Seattleites need to know that even when the three-week closure is over and the tunnel is open, the main pre-tunnel ramp from northbound 99 into downtown – Dearborn Street – will not be ready for up to two MORE weeks. So your main paths into downtown until then will be via the low bridge/Spokane Street, or 1st or 4th or I-5 off the eastbound West Seattle Bridge – if you’re not tunnel-bound, you won’t be able to use NB 99 between here and downtown until Dearborn is ready to go.

WSDOT says it’s of course working with other agencies/services including Metro, the Water Taxi, and SDOT to coordinate planning, but they want you to start preparing too, so they’re starting to sound the alerts now.

Something else new: Viaduct demolition, post-closure, is expected to take about six months. That’s a shorter timeframe than previously mentioned. The contractor Kiewit will start at Columbia Street and at the “Pike hillclimb area.” Some work might even begin before year’s end, if the tunnel really does open by November, according to Sowers.

Though the briefing wasn’t about the tunnel itself, we asked what’s going on underground right now. Sowers said the roadway’s built and much of what’s happening now is testing, testing, testing. The tunnel includes “more than 5,000 different instruments” and they not only have to be tested individually, but project managers have to be sure those systems are “talking to each other.” They’re also striping and installing signs.

WSDOT is continuing to put more information about the project and the viaduct-to-tunnel transition online, with an easy-to-remember website: 99tunnel.com. And watch for word of another short-term closure later this summer like the one that’s set for 9 pm tonight through 6 am Sunday – Sowers said they’re trying to figure out the least-impactful dates.