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

News & project updates


May 24, 2017


The northbound shoulder lanes opened to the public on April 24!

Why did WSDOT build this project?


Northbound I-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.

What peak shoulder use looks like

I-405 Peak Shoulder Use Visualization

The end result


This project's primary focus was building a new northbound peak use shoulder lane, which adds new capacity for general purpose traffic. The new lane extends 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 display whether the peak use shoulder lane is open to traffic. The lane is generally open to traffic during the peak afternoon commute (3 to 7 p.m.). Vehicles over 10,000 gross vehicle weight are prohibited from using the lane, with the exception of buses.

Project vicnity

I-405 Peak Shoulder Use Vicinity Map

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
Open to traffic: Spring 2017

Learn more on WSDOT's website.
Updated May 24, 2017