Skip Top Navigation

I-405 - Northbound Peak-Use Shoulder Lane Project, SR 527 to I-5

Construction phase
I-405 Northbound Peak Use Shoulder Lane Project Map View larger image. 

Peak Use Shoulder Lane Map -Thumbnail 
View larger image. The new peak-use shoulder lane will extend about 1.8 miles between SR 527 and I-5, as shown in this visualization.


October 2017

The new peak-use shoulder lane is now open to traffic during the afternoon commute.

Why is WSDOT building this project?
Northbound Interstate 405 experiences heavy congestion, especially in the Bothell area during the afternoon commute. With funding from I-405 toll revenue, the Washington State Department of Transportation plans to build new capacity between State Route 527 and I-5 to help relieve congestion.

The End Result

The primary focus of this project is building a new northbound peak-use shoulder lane, which will add new capacity for general purpose traffic. The new lane will extend for about 1.8 miles between SR 527 and I-5.

WSDOT will also construct one new noise wall along northbound I-405.

Overhead lane control signs will display whether the peak-use shoulder lane is open to traffic. The lane will generally be open to traffic during the peak afternoon commute. Vehicles over 10,000 gross vehicle weight will be prohibited from using the lane, with the exception of buses.

Project Benefits

By building more capacity to handle the large volumes of traffic entering I-405 from SR 527, we expect to improve congestion that travelers are experiencing, especially in the area near the SR 522 interchange, where I-405 has less capacity.

The I-405 project office is evaluating additional longer-term projects to provide benefits in the area between SR 522 and I-5.

What is the project timeline?
Contract awarded: November 2016  to Graham Contracting Ltd. 

Construction start: January 2017 
Preliminary tree removal: January 2017
Open to traffic: Spring 2017
Bulk of tree Removal: Spring 2017
Noise wall construction: Spring 2017

Financial Information

Financial Data for PIN 140561W
Funding Source Amount ($ in thousands)
2003 Gas Tax (Nickel Funding) $1,510
2005 Gas Tax (TPA) $0
Pre-Existing Funds (PEF) $10,085
CWA $0
Total $11,595

How can I get more information?
For more information about peak-use shoulder lanes around the region, check out the peak-use shoulder lane resource page.

Craig Smiley, I-405 Public Information

Chun-Ho Chen, Project Engineer

back to top