I-405 - Northbound Peak-Use Shoulder Lane Project, SR 527 to I-5 - Completed April 2017

Project news

  • The new peak-use shoulder lane is 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 built new capacity between State Route 527 and I-5 to help relieve congestion.

The End Result
The primary focus of this project was to build a new northbound peak-use shoulder lane, which has added new capacity for general purpose traffic. The lane extends for about 1.8 miles between SR 527 and I-5.

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

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

Needs & benefits

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


This project was completed in Fall 2017.


Financial Data for PIN 140561W
Funding Source Amount ($ in thousands)

  • Pre-Existing Funds (PEF) - $11,585
  • Total - $11,585

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.


I-405/SR Corridor Communications


I-405 Northbound Peak Use Shoulder Lane Project Map

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