Both directions of the Highway 520 bridge will close this weekend, from Montlake Boulevard to the 92nd Avenue Northeast interchange east of Lake Washington, for ongoing work on the replacement highway.

The shutdown begins at 11 p.m. Friday, and lanes reopen at 5 a.m. Monday.

Drivers will be able to use Highway 520 for the short distance between Interstate 5 and the Montlake interchange, for access to the University of Washington and local neighborhoods. But the walk-bike trail will be closed near the lake.

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Crews this weekend will relocate and pave a temporary eastbound onramp from Montlake toward the bridge. That shift will open up work space to install two columns that will help support a lid over 520 at Montlake that will include landscaping and bus lanes.

The Washington State Department of Transportation (WSDOT) says it will also replace an overhead sign bracket that crosses all six lanes. The sign was damaged by a subcontractor’s boom truck last year, causing some electronics to malfunction, said project spokesperson Steve Peer.


The Bellevue Fire Department will conduct training exercises on empty portions of the bridge, Peer said.

The work is part of the $455 million Montlake Project phase of a $4.6 billion, approximately 20-year program to construct a new Highway 520. Earlier work included building the world’s longest floating bridge at 7,710 feet across Lake Washington.

Contractors are building a new fixed-bridge segment for traffic from Seattle toward the lake, as well as a larger Montlake interchange, to be completed in 2024.