Speed Limit Change on SR 522 Signals Start of Construction on North End of I-405

By Lauren Penning and Julie Moon

Major construction starts this month on the I-405/Brickyard to SR 527 Improvement Project near the SR 522 interchange. This project will add an additional express toll lane in each direction. This means a change from a single express toll lane to a dual express toll lane system to be consistent with the length of I-405. We’ll also build direct access ramps to the express toll lanes and add new Bus Rapid Transit stations and improve connections to regional transit service at both the UW Bothell Station (SR 522) and the park and ride at Canyon Park (SR 527). This project is being built by WSDOT as part of a funding partnership with Sound Transit and will support Sound Transit’s new service with buses arriving every 10 minutes for most of the day.

In 2015, we introduced Express Toll Lanes (ETLs) between Bellevue and Lynnwood. While ETLs helped make trips more reliable for travelers on the north end of the corridor, the section of I-405 between SR 522 and I-5 still experiences heavy traffic, especially during the morning commute. When construction is complete in 2028, the expanded ETL system and new bus service will help keep all vehicles moving efficiently.

Map of I-405 showing the I-405/Brickyard to SR 527 Improvement project area in orange

What to expect when construction starts

We will start this project on the south edge and move north. Our first big change will be to SR 522 between Bothell and Woodinville. First, we will establish the construction work zone and build a new alignment for westbound SR 522. The realignment will allow us to begin construction of the new northbound I-405 on ramp connections from SR 522. There will be lane closures over the course of two weekends.

The scheduled dates for the closures are:

• 10 p.m., Friday, April 12 to 4 a.m., Monday, April 15,
• 10 p.m., Friday, April 19 to 4 a.m., Monday, April 22

During the closure, crews will close one lane of westbound SR 522 and all lanes of eastbound SR 522 near the I-405 interchange. Drivers heading east on SR 522 will follow signed detours via I-405 southbound at Northeast 160th Street. Drivers should be prepared for traffic backups and congestion on SR 522, southbound I-405 and Northeast 160th Street during the closures. After the second closure is complete on Monday, April 22, the speed limit on SR 522 near the interchange will be permanently reduced to 35 MPH.

Map showing the construction zone and the area of speed limit reduction starting April 22

Why is the speed limit on SR 522 changing?

The speed limit is changing during construction to ensure a safe work zone while crews are building improvements in the area. The westbound SR 522 lanes will be shifted over the median next to the eastbound SR 522 lanes, opening space for construction. As drivers travel eastbound out of Bothell, they will maintain the 35 MPH speed limit. As drivers travel westbound towards Bothell, they will need to slow down to 35 MPH as they pass Woodinville and approach the I-405 interchange.

After construction is complete, this project will include three new traffic signals on SR 522 to allow access to the new Stride Bus Rapid Transit (BRT) station and direct access ramps to the ETL system. This work will make access to I-405 in this area more efficient for transit users. We will time the signals so they work together to efficiently manage traffic on SR 522. Our estimates show that the signals will add about one additional minute to SR 522 travel during peak hours.

A map of the final configuration of the SR 522 interchange, with three new traffic signals to allow for access to the new direct access ramps and transit hub. Please note, this is a conceptual design and details are subject to change.

This is a visual rendering showing the design concept of the inline Bus Rapid Transit (BRT) station on I-405 at the Brickyard Park and Ride station. Please note, this is a conceptual design and details are subject to change.

Reliability for all users

WSDOT worked closely with Sound Transit and the City of Bothell to design the new Stride BRT station at the Brickyard Park and Ride in Bothell. Voter-approved Stride BRT service along I-405 as well as the improved connections will serve both the UW Bothell Station (SR 522) and the park and ride at Canyon Park (SR 527). This work will enable BRT vehicles to travel exclusively in the new ETLs between Lynnwood and Bellevue while stopping briefly to pick-up and drop-off passengers without having to leave the highway system. Having dedicated ETL access in the center of the freeway makes travel more efficient.

Proposed design for the I-405/SR 527 interchange. We will build a partial direct access interchange at SR 527 to and from the south connecting to the Canyon Park Park and Ride. Please note, this is a conceptual design and details are subject to change.

Stride BRT S2 Line from Lynnwood to Bellevue with markers
for a new transfer hub at SR 522

Local environmental improvements

We are dedicated to reconnecting streams to improve fish passage and aquatic ecosystems around the state. This project will remove ten fish barriers and create over seven miles of new habitat area. We will also construct new stormwater management and water quality facilities, as well as three new stormwater outfalls on the Sammamish River and North Fork Perry Creek. These improvements will help prevent flooding and pollution.

Preservation and maintenance

From a preservation and maintenance perspective, the project will overlay much of the roadway with new pavement and striping. We also will make repairs to barrier, guardrail, signing, illumination, electrical, ITS, drainage and seismic resiliency throughout the corridor.

What is the project schedule?

We started preparation work last fall and continued throughout the winter. You have probably seen crews conducting field surveys and clearing vegetation and trees. Now we are transitioning to major construction on the project. Check our project website for weekly updates on lane and ramp closures and other updates. This project is scheduled for completion in Spring 2028.

We recognize construction on I-405 is inconvenient and disruptive. We are working to minimize disruptions by providing the latest information so that you “know before you go.” We are steadfast in our commitment to improving the lives of all transportation users along the corridor by reducing congestion and enhancing connectivity, accessibility, safety performance and mobility.

Keep in touch, keep informed

The best way to stay up to date is to follow us @WSDOT_Traffic on Twitter and check our real-time Travel Map to see how things look before you hit the road. You can also subscribe to the weekly Eastside of Lake Washington Transportation newsletter and download our app.

Anyone with questions about this project can call the I-405/SR 167 Program voicemail inbox at 425-456-8585 or email us at i405sr167program@wsdot.wa.gov.