Seattle getting closer to Alaskan Way Viaduct closure

Sep 6, 2018, 5:21 AM | Updated: 5:04 pm
viaduct, tunnel, Highway 99 tunnel...
The SR 99 tunnel. (WSDOT)

We’re getting close to the three weeks of hell that’s expected when the Alaskan Way Viaduct closes for good. That will happen later this year.

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It’s been a very busy few months inside and around the tunnel as Seattle Tunnel Partners prepares to turn the underground passage over to the Washington Department of Transportation. It is unknown exactly when this will happen. What we do know is that crews will eventually shut down the viaduct for three weeks before the tunnel opens, and that is likely before the end of the year.

Status of the viaduct, tunnel

Since I took my last tour a few months ago, the lanes have been finished and striped. There are two 11-foot wide lanes and an 8 foot wide shoulder on both decks. Workers have painted giant stick figures inside the tunnel to show you the closest exit should there be an emergency. There are escape tunnels running parallel to the road decks that you can use to walk or run out of the tunnel. The stick figures show things like an exit 500 feet in this direction, but 150 feet in the other direction.

STP has been testing the 90 safety and operational systems all summer, including the emergency sprinklers should there be a fire and the giant fans that will eliminate the smoke. The state’s Dave Sowers told me earlier this year that this testing will not be rushed.

“The testing, commissioning components that are the balance of this year are the most critical piece of work that we have left to do,” he said. “We’re not going to put live vehicles in this tunnel until it’s absolutely safe.”

During some of that testing last week, pressurized air forced open a door in a maintenance building on the north end of the tunnel. A little drywall came down. No one was injured. That’s still under investigation.

Work has already started on Alaskan Way to move all the northbound traffic from under the viaduct to the west of it. Crews are re-striping and adding new signals in preparation.

Closing the viaduct, opening the tunnel

We will get one month’s warning before the state closes the viaduct and begins the work to tie the tunnel into either end of Highway 99. That tie-in work will take about three weeks, and that’s when we can expect massive disruptions through Seattle. Highway 99 will be closed in both directions between South Lake Union and the stadiums.

There is paving work that needs to be done, intersections that need to be built, ramps that need to built and signals that need to be put-in.

While this is happening, anyone who normally uses the Alaskan Way Viaduct will be forced onto other roads, like I-5 and downtown Seattle surface streets. Again, you will have about a month to prepare for this and come up with plans to get around it. The state is asking the public to adjust travel times, take transit or work from home.

Both lanes of Alaskan Way will be open before this three weeks of traffic hell begins.

As for tolling, the rates will be set next month. Drivers will be able to use the tunnel for free for the first few months before the variable tolls go into effect.

And just a reminder, the tunnel will not have any exits. It is a downtown bypass.


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Seattle getting closer to Alaskan Way Viaduct closure