SR 99 tunnel

Overview of purpose and need

In February 2001, a 6.8 magnitude earthquake struck near Seattle, causing several foundations of the Alaskan Way Viaduct to shift as much as five inches.  Engineers believe the viaduct would have collapsed had the earthquake lasted a few moments longer. During the next decade, state and local agencies studied more than 90 alternatives to replace the aging viaduct which carried SR 99 through Seattle. In 2009, a bored tunnel was chosen. Building a large single-bored tunnel allowed traffic to continue moving above ground as a tunnel was built below. 

Holgate to King Street Viaduct Replacement - Complete February 2014

Project Overview

The South Holgate to South King Street Viaduct Replacement Project, completed in early 2014, was an early phase of the Alaskan Way Viaduct Replacement Program in Seattle, Washington.

Lane, road closures coming to I-5, SR 548 and Zell Road near Ferndale

As early as May 18, travelers should plan for lane closures on northbound and southbound Interstate 5 for a big environmental improvement project in California Creek, north of Ferndale.

SR 530 project resumes with work at Trafton Creek east of Arlington

Work to build a one-lane bypass on State Route 530 will mark the beginning of a major summer project to improve fish passage under the highway between Arlington and Darrington.

Public invited to virtual open house for SR 520 Overlake access ramp project, May 6-27

The Overlake neighborhood of Redmond is rapidly changing with new residential development and the future Sound Transit Link light rail station. During typical travel conditions, the eastbound State Route 520 off-ramp to 148th Avenue Northeast is slow going with backups and delays during peak travel times.

SR 167 - SR 410 to SR 18 - NB Congestion Management

Project news

  • Travelers will see daytime shoulder closures and overnight lane and ramp closures on northbound SR 167 starting May 24. 
  • A temporary speed limit reduction on SR 167 from 60 mph to 45 mph during nighttime lane closures will be in place from milepost 5.27 to milepost 14.33.
  • This section of SR 167 was identified in the Tacoma/Pierce County HOV Program which inclues a series of projects that build high-occupancy-vehicle (HOV) lanes on I-5, SR 16 and SR 167 in Pierce County.

Plan for US 2 delays during bridge work between Index and Skykomish

On Monday, May 4, contractor crews working for the Washington State Department of Transportation will begin mobilizing for a $4.66 million project to preserve 19 bridges on US 2 between the vicinities of Index and Skykomish.

State ferries extends winter sailing schedules through June 20 due to lower demand

SEATTLE – As part of the state’s response to COVID-19, all state ferries will continue to operate on their winter sailing schedules through at least June 20. Washington State Ferries’ (WSF) spring season, which includes increased service on some routes, was originally scheduled to begin March 29.

State ferries to reduce service in central Puget Sound beginning Sunday, March 29

SEATTLE – Washington State Ferries’ central Puget Sound routes will temporarily move to a reduced service plan as part of the state’s response to COVID-19. These reductions will start at the beginning of the service day Sunday, March 29, and remain in place through at least June 20.

Declining ridership due to COVID-19 brings change to Amtrak Cascades trains

Some Amtrak Cascades service in Washington has been reduced due to COVID-19 and declining ridership

Start of state ferry service to Canada suspended until April 26 due to COVID-19 situation

ANACORTES – Resumption of Washington State Ferries’ service between the U.S. and Canada has been pushed back to at least April 26.

SR 20 North Cascades Highway clearing starts March 23

After assessing snow levels in dozens of avalanche chutes, some stretching more than 2,000 feet above the highway, Washington State Department of Transportation crews will start clearing the State Route 20 North Cascades Highway Monday, March 23.

I-5 - SR 526 - Sign structure and VMS replacements - Complete April 2021

Project news

  • This project was completed in April 2021. No additional closures are scheduled. 
  • This project has been awarded to Northeast Electric.
  • Construction is scheduled to begin in fall 2020.
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  • Follow along on Flickr for progress photos and detour maps.

Feedback wanted from Ferndale and Whatcom County travelers

Taking a short survey could help determine the future of the Interstate 5/Slater Road interchange in Whatcom County. The Legislature has allocated funding from the Connecting Washington transportation package to make improvements to Slater Road from Rural Avenue in Ferndale, through the I-5 interchange to Northwest Drive in Whatcom County.

I-5 - SB Stillaguamish River Bridge - Painting

Project news

  • This project was awarded December 2020 to Southern Road & Bridge, LLC from Tarpon Springs, Florida.
  • Construction work began on April 12, 2021. 
  • Travelers can expect lane shifts and detours beginning Wednesday, June 23, 2021
  • For updates on this and other Snohomish County highway news, sign up for weekly emails.

Needs & Benefits