Valley residents who commute to Seattle should brace for major backups on Interstate 90, starting Friday night.

At 9:30 p.m. on Friday, July 18, WSDOT contractor crews will close all but one lane of westbound I-90, just before Bellevue Way Southeast, for seven days.

The work will replace the two expansion joints on the East Channel Bridge.

WSDOT has created animated traffic maps here to illustrate the lane closures.

In stage one, crews will close the three left lanes of westbound I-90 between I-405 and Bellevue Way Southeast. Westbound I-90 will narrow down to just one lane at Bellevue Way Southeast and widen to three lanes just before the East Channel Bridge. The Bellevue Way HOV on-ramp to westbound I-90 will be closed around-the-clock. All drivers will use the general purpose on-ramp.

The southbound I-405 ramp to westbound I-90 will be closed around-the-clock. All drivers will use the general purpose on-ramp.

In stage two, the three right lanes will be closed between I-405 and Bellevue Way Southeast. Westbound I-90 will remain just one lane near Bellevue Way Southeast and widen to three lanes just before the East Channel Bridge. The Bellevue Way general purpose on-ramp to westbound I-90 will be closed around-the-clock. The southbound I-405 HOV ramp to westbound I-90 will be closed around-the-clock. All I-90 lanes and ramps are scheduled to reopen by 5 a.m. Friday, July 25. However, WSDOT is offering a financial incentive to Mowat Construction to reopen all lanes early. WSDOT expects significant backups and delays and suggests travelers attempt to avoid any unnecessary travel during this time period.