Over the weekend of June 3 and 4, the Washington State Department of Transportation (WSDOT) will undertake final preparations for light rail construction, involving overnight directional closures.

Before opening newly-painted eastrbound and westbound high occupancy vehicle (HOV) lanes to drivers, a final test of the Mount Baker and Mercer Island tunnel operations systems is needed, which will require two 12-hour closures of Interstate 90.

From 9 p.m. Friday to 9 a.m. Saturday, eastbound I-90 will reduced to a single lane near Rainier Avenue. Eastbound traffic will be rerouted to the express lanes. Traffic diversions will be similar to prior eastbound closures.

From 9 p.m. Saturday to 9 a.m. Sunday, westbound I-90 will be reduced to a single lane near Bellevue Way. Westbound traffic will be rerouted to the express lanes. Traffic diversions will be similar to prior westbound closures.

After these closures are complete on the morning of June 4, all-day bus and carpool lanes will open, and the Center Roadway Express Lanes will be closed permanently for Sound Transit light rail construction.

Drivers are directed to the city’s resources webpage for helpful commuter information.