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SR 99 - S. Holgate Street to S. King Street Viaduct Replacement - Getting around during construction

Replacing a heavily used highway takes years of planning and coordination and a little patience and flexibility from drivers.

WSDOT, King County and the City of Seattle have invested in projects that will help keep people and goods moving through Seattle during construction. You can help out by planning your trips and by considering travel options that will help keep traffic flowing smoothly for everyone.

Know before you go and have a backup plan

You've heard it time and again from us, but knowing traffic conditions before you take your trip is the best way to save time and keep from getting frustrated. This is especially true during construction.

Here are a few tools for you to consider:

Current traffic

Computer iconReal-time conditions on the Alaskan Way Viaduct and many connecting streets can be found on the city of Seattle's Traveler's Information Map.
Real-time conditions on Seattle area freeways can be found on our Seattle Area Traffic Map.

Construction closures

Bridge and roadway construction is underway to replace the viaduct south of S. King Street. A series of lane restrictions began in spring 2011. We have designed the project to keep at least two lanes of traffic on SR 99 open at all times through construction.

Plan your routes ahead of time by getting weekly updates about construction closures in the downtown Seattle and SODO areas. You will also be able to find details about how we're coordinating construction closures with event traffic at Qwest and Safeco fields.


Transit iconWe are working closely with King County Metro to be sure that buses run on time through our construction zone. Visit Metro Online and enter the route number in the box to get timetables, maps and travel alerts for each route.

Pedestrians and bike riders

Bike iconThis project will add new bicycle and pedestrian paths along SR 99 that connect to existing downtown trails. Bicyclists and pedestrians frequently use the nearby surface streets that will be affected by this work. There’s steady foot traffic between the waterfront, stadiums, and local businesses, and Alaskan Way S. is one of the most active bicycle commuting corridors in Seattle. During construction we are committed to maintaining a safe and reliable path for bicyclists and pedestrians who rely on these routes.


Freight iconThe construction zone is in the center of major freight corridors to and from the Port of Seattle and several rail yards. We meet regularly with the Port of Seattle and the trucking industry to help keep freight moving between the waterfront and the SR 99, I-5 and I-90 corridors. Subscribe to email alerts and advisories.

Ways you can help

Van pool iconWSDOT is investing $1.7 million and King County Metro is providing more than $1 million for trip reduction programs. Using extensive research we strategically funded trip reduction programs that will remove trips from SR 99 and key alternate routes during construction. You can help us keep people and goods moving by considering alternatives to driving alone.

Coordinating construction to keep traffic moving; Many interests and values at stake

Keeping traffic moving during construction is one of our top priorities, but we don’t have the luxury of a single top priority for our multifaceted highway construction projects.

While working on the highway, WSDOT and our private sector contractors must:

  • Help keep people and goods moving.
  • Help keep drivers and construction workers safe.
  • Deliver projects on time.
  • Deliver projects within budget.
  • Deliver high quality work.
  • Protect the environment.
  • Coordinate with interest groups like local communities, neighbors, freight, bicyclists, pedestrians, businesses, neighborhood groups and event organizers.
  • Minimize noise, particularly at night when working near neighborhoods or hotels.
  • Coordinate with other agencies like cities, counties, transit agencies, ports and environmental regulators.
  • Coordinate with other state and local transportation construction projects.

Highway construction projects are complex and it’s not easy to meet all of these goals. Our project engineers and contractors are experienced and do their best to find workable solutions to address competing interests. However, meeting all of these goals is a difficult balancing act.