South end

Looking for the heart of construction to replace the Alaskan Way Viaduct? Look no further than the massive construction zone to the west of Seattle’s stadiums. This area will change frequently between now and the time the SR 99 tunnel opens in late 2015. Fortunately, with the exception of occasional weekend closures, SR 99 will remain open to traffic throughout construction.

Our interactive simulation shows you how this area will evolve as we continue replacing the viaduct.

Digging deeper

If you’ve driven by the south-end work zone lately, you’ve probably noticed the giant pit we’re digging to the west of the highway. When our work is done, we’ll have what’s called a launch pit - essentially a large hole where the tunnel boring machine will begin its journey underground in summer 2013. Our launch pit fact sheet (597 kb) explains how the pit is being built.

We're also building portions of the tunnel's south portal. It doesn’t look like a portal yet, but trust us – it’s taking shape. Our construction cameras offer a good view of the future northbound SR 99 on-ramp to the tunnel being built near South Royal Brougham Way.  

Truckers rejoice: The South Atlantic Street overpass is coming

Next time you’re stuck waiting for a train on South Atlantic Street, remember this: a solution is under construction now. We broke ground in summer 2012 on a new overpass that will allow traffic to bypass frequent train blockages on Atlantic. This is good news for anyone who uses East Marginal Way South to travel through SODO, and especially good news for truckers who make frequent trips to the nearby Port terminals. Columns for the overpass are now emerging from the ground, and the structure is scheduled to open in late 2013.      

The new SR 99 through SODO

Good news: The southern mile of the viaduct has officially been replaced. Even better news: crews finished one year early and on budget.

Unlike the double-deck viaduct, this new section of SR 99 features twin, side-by-side bridges. As of September 2012, northbound traffic is using the newly completed east-side bridge. Southbound traffic remains on the west-side bridge that was completed in October 2011.

Our south-end SR 99 map (pdf 4 MB) shows you what the new section of highway looks like, and how the area will continue to change as crews build the SR 99 tunnel and a new overpass at South Atlantic Street. Our time-lapse video zips you through 11 months of construction in 2 minutes and 10 seconds, or you can check out how construction looks right now by taking a look at our construction cameras.