Latest updates on the Alaskan Way Viaduct Replacement Program
You may have heard that SR 99 will close for four straight days starting Friday night, Aug. 22. It’s the longest full closure of SR 99 in Seattle since crews demolished the southern mile of the Alaskan Way Viaduct in 2011. While this is probably not welcome news for travelers, it is a sign of progress at the tunnel’s north portal.
The 2011 demolition of the viaduct cleared the way for construction of the tunnel launch pit and the commencement of tunneling. During this … more
Seattle Tunnel Partners, our contractor for the SR 99 Tunnel Project, is remodeling the giant concrete box where they assembled, tested and launched Bertha, the world’s largest tunneling machine.
Fittingly, Bertha’s launch pit is massive – 400 feet long and 80 feet wide. It was 80 feet deep, but it’s a little shallower now due to the remodel, which is turning the pit into part of the future State Route 99.
Remodeling the launch pit isn’t too much … more
Less than three years ago, crews demolished the southern mile of the Alaskan Way Viaduct. When they did, they shifted traffic onto a new section of State Route 99 south of downtown Seattle.
Much of that new section of SR 99 is permanent, but the piece west of the stadiums is temporary. This curving stretch of road takes drivers around the SR 99 tunnel construction site and connects to the remaining section of the viaduct near South King Street. It’s nothing fancy, but it’s … more
Just in time for Bike Month, we opened a new permanent connection between the on-street bike lanes south of South Atlantic Street and the shared-use path from South King Street. Here’s a map that shows the improvements, which include:
A dedicated, 14-foot-wide shared-use path with improved paving.
A separate northbound and southbound path for more efficient navigation.
Signs warning of vehicles crossing the intersection of … more
You may have noticed more construction along State Route 99, just north of the Battery Street Tunnel. That work is part of the SR 99 Tunnel Project, but it has its own name – the North Access Project. It’s also being built under a completely different contract than the one we have with Seattle Tunnel Partners, the contracting team responsible for most of the tunnel work. A map of major contracts within the program can be found here (pdf 1.1 Mb).
Our contractor for the North … more
A few blocks northeast of the Space Needle, crews are building the north portal of the SR 99 tunnel. It’s a huge piece of the overall tunnel project, but it’s largely invisible to the thousands of people that pass by it every day.
About the only place you can see the north portal taking shape is from the viewing deck of the Space Needle because most of the construction is underground, inside a pit that’s every bit as impressive as the launch pit where Bertha, the SR 99 … more
You can’t see much from the surface, but there’s a lot of work happening in the launch pit where tunneling started last summer. Last week, Seattle Tunnel Partners removed the giant steel frame that Bertha, the SR 99 tunneling machine, pushed against to start her drive into the tunnel. The frame is now on its way to be recycled.
Work is also well underway to dismantle the temporary concrete tunnel rings Bertha installed to give her additional leverage at the start of her … more
We're looking forward to opening the tunnel to traffic and demolishing the Alaskan Way Viaduct. It’s the reason we come to work each day. But until we take down the viaduct, it’s our job to protect it and keep it safely open to drivers.
And so this weekend, as they do four times every year, WSDOT crews will inspect the viaduct. They’ll start by closing the structure to traffic on Saturday and Sunday. Then they’ll begin a methodical weekend of work measuring … more
Bertha, the SR 99 tunneling machine, is easily the most recognizable tool being used on the SR 99 Tunnel Project. But she’s not the most important tool.
That distinction belongs to our 1,373-page contract with Seattle Tunnel Partners (STP), the joint venture we hired to design and build the tunnel. The contract can’t bore a tunnel or build the highway within it, but it can perform the project’s most vital function: protecting taxpayers.
On most highway projects, … more
While we’re working with our contractor, Seattle Tunnel Partners (STP), to get Bertha moving again, we’re also doing a significant amount of work elsewhere on the project. In fact, the vast majority of the 300 people who work on the tunnel each day aren’t anywhere near Bertha.
Here are some of the things they’ve been up to:
Building the tunnel’s south portal
It’s hard to tell when you’re driving by on SR 99, but a good portion of the tunnel& … more