Southbound I-5 off-ramps to Mercer Street in Seattle closing four consecutive weekends starting Sept. 8

Closure includes express lanes off-ramp to Mercer Street

SEATTLE – Travelers heading to Seattle’s South Lake Union area will soon need to prepare for four consecutive weekend closures of the southbound Interstate 5 off-ramps to Mercer Street.

Contractor crews working for the Washington State Department of Transportation will close both the mainline and express-lane off-ramps to Mercer Street beginning at 10 p.m. Friday until 5 a.m. Monday the weekends of Sept. 8-11, Sept. 22-25, and Sept. 29-Oct. 2.

The weekend closure for Sept. 15-18 is now a 21-hour closure scheduled to begin at 10 p.m. Friday, Sept. 15 until 7 p.m. Saturday, Sept. 16.

The Sept. 29 - Oct. 2 weekend closure is postponed. A new date will be announced soon.

During the closures, crews will repave sections of the roadway, perform utility and drainage work, and continue building a new retaining wall. These closures help keep the project on schedule for spring 2024 completion.

This work is part of the SR 520/I-5 Express Lanes Connection Project.

Stay up to date

Some of the closures are weather-dependent. The public will be notified of any changes to the schedule on the SR 520 Construction Corner webpage. People can also get real-time traffic information from the WSDOT app or by calling or texting the 24-hour hotline at 206-316-2559.

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