The Washington State Department of Transportation and Sound Transit has contracted construction company Skanska for Interstate 405 (I-405) corridor improvements.

Under the contract, the company will extend and upgrade 7.2km of the I-405 corridor in Bothell, Washington.

The value of this contract is estimated at around Skr8.8bn ($834m).

As part of the I-405, Brickyard to SR 527 Improvement Project, a dual express toll lane system will be developed from south of the I-405/SR 522 interchange to the I-405/SR 527 intersection.

The scope of this project comprises the development of new lanes, direct access ramps, and interchange, infrastructure in support of the Stride Bus Rapid Transit programme, and new fish passage culverts within the project vicinity.

This project, which is being funded by toll revenue, the Move Ahead Washington package, and Sound Transit, also includes local road upgrades, fish barrier modifications, noise walls, and new stormwater amenities.

The company has entered the contract in its US order bookings for the third quarter of this year.

Construction is scheduled to commence in November this year and conclude in late 2028.

WSDOT I-405/SR 167 programme administrator Lisa Hodgson said: “Our partnership with Sound Transit is crucial for this project. By creating more connections to regional transit service and aligning with Sound Transit’s plans for bus rapid transit, we’re enhancing convenience and accessibility.

“The inclusion of the second express toll lane will provide more opportunity for a faster, reliable trip when you need it, providing a better commute for all lanes.”