US$834 million for Seattle area highway widening

A US$834 million highway widening project is underway for the Seattle area.
Road Structures / June 17, 2024 59 seconds Read
By MJ Woof
Work is underway for a highway widening project close to Seattle, WA

Work is underway for the US$834 million I-405/Brickyard to SR 527 Improvement Project in Washington State, close to Seattle. Construction is being carried out by Skanska, which was awarded the package of works by the Washington State Department of Transportation (WSDOT).

The project involves upgrading the 7.2km stretch of I-405 running through Bothell, with the work due for completion in 2028. AECOM is partnering with Skanska as the lead designer for the project.

Improvements will include increased express toll lane (ETL) capacity and direct access to state highways. This includes building one new express toll lane in each direction between south of SR 522 and SR 527 (extending the existing dual express toll lane system), widening I-405 through the SR 522 interchange, and building direct access ramps to the express toll lanes at SR 522, and a partial direct access interchange at SR 527 to and from the south connecting to the Canyon Park Park and Ride.

There will also be improved connections to regional transit service at both the UW Bothell Station (SR 522) and the park and ride at Canyon Park (SR 527) and add a new transit-only Bus Rapid Transit (BRT) station to connect to Sound Transit’s BRT service along the I-405 corridor, boosting connections to the existing park and ride.

The project includes sustainability measures including six new fish passages, designed to improve fish migration. New culverts are located adjacent to existing ones to minimise disruption to the ecosystem.

The work will improve transport in the Seattle area. For drivers on SR 522, the speed limit near the I-405 interchange is 56km/h (35mph). This speed limit change will ensure safety for both drivers and construction crews through the work zone and accommodate the future traffic configuration.

The I-405/Brickyard to SR 527 Improvement Project will include three new traffic signals on SR 522. These will allow access for regional transit services to a new Stride Bus Rapid Transit (BRT) stop and direct access in and out of the Express Toll Lanes (ETL) system for transit and ETL users. The signals will be operated by WSDOT and timed to work together to make sure traffic is flowing smoothly.

For more information on companies in this article