Westbound Interstate 90 was scheduled to be reduced to one lane and detoured to the express lanes from May 12-15, allowing the Washington State Department of Transportation (WSDOT) to undertake final light rail preparations.

Crews were set to start re-striping I-90 in preparation for the new HOV lanes opening. Since the primary work involves re-striping roadways, the closure was weather-dependent. It was postponed to this weekend (May 19-22) due to forecasted wet weather.

Starting at 11 p.m. on Friday, May 19, WSDOT will funnel westbound traffic from Bellevue to the center express lanes for construction purposes. The detour will end by 5 a.m. Monday.

All westbound drivers wishing to exit onto Mercer Island must use East Mercer Way.

Unlike recent westbound closures, drivers will not initially have the option to continue through the East Mercer interchange back onto the right lane of I-90, in order to exit at Island Crest Way, until the second day of the closure.

There are no westbound exits from the express lanes. Drivers wishing to reach Seattle from Mercer Island must enter the express lanes at Island Crest Way or 77th Avenue Southeast.

Click here for detour map and exit details, and click here to learn about other scheduled closures.

The directional closures of I-90 have allowed the state to build all-day bus and carpool lanes next to the regular lanes. This work will allow the center I-90 roadway to be dedicated to Sound Transit light rail construction, starting June 3, though a lawsuit initiated by the city of Mercer Island is seeking to delay that. Currently, this is the final full weekend closure of I-90 planned.