Local Information

SR 520 construction ramping up in Seattle

Tuesday, October 7, 2014 - 16:42

Ian Sterling, WSDOT Communications, 206-819-7230 (mobile)

New west approach bridge will link floating bridge with Montlake

SEATTLE – Construction of a new, safer State Route 520 is kicking into high gear this week in Seattle’s Montlake neighborhood and on Foster Island along the west shore of Lake Washington.

Contractor crews for the Washington State Department of Transportation are beginning to move in heavy equipment and remove trees and vegetation, as needed, along a strip of Foster Island in preparation for building the West Approach Bridge North. One of the crews’ first tasks on the island and adjoining waterways is to build a work platform from which they’ll construct the permanent SR 520 approach bridge.

In a nearby staging area along the west edge of the Washington Park Arboretum, work is underway to place field trailers and other construction equipment. Also, at the former site of the Museum of History and Industry just north of SR 520, crews are preparing to demolish the building later this year. The demolition will make way for additional staging operations and, eventually, creation of a water-detention pond where stormwater runoff from the highway will be naturally filtered and treated.

“This is the launch of major construction activity along the highway’s Seattle corridor,” said Julie Meredith, WSDOT administrator for the SR 520 Bridge Replacement and HOV Program. “The new bridge will be able to withstand larger earthquakes and addresses a vulnerable link in the SR 520 corridor.”

This month crews also expect to begin pile installation for the approximately one-mile-long work platform and will begin removal of the R.H. Thomson “Ramps to Nowhere” in the Arboretum.

Replanting trees and vegetation
Crews will remove trees and vegetation within WSDOT’s right of way on Foster Island as needed to make room for the new West Approach Bridge North and work platform. Most of the trees being removed on the island are nonnative ashes and willows, which will be replaced with native conifers, shrubs and groundcovers.

More than 400 trees and 22,000 shrubs will be planted within the project area when construction is completed in mid-2017. Orange fencing will be placed near protected trees to ensure they are not damaged during construction.

The 1.2-mile-long, fixed-column West Approach Bridge North, mostly built on piers over water, will connect the new SR 520 floating bridge now under construction with the highway’s Montlake Boulevard interchange in Seattle.

When completed, the approach structure will carry three westbound lanes of traffic from the new floating bridge to Montlake. The new West Approach Bridge North, built to modern seismic codes, also will extend a new, cross-lake bicycle and pedestrian path from Montlake to Bellevue.

More information on West Approach Bridge North construction can be found on the SR 520 Bridge Replacement and HOV Program website. Also, a short online video provides an overview of the project. For information on road closures associated with SR 520 construction, please visit the SR 520 Orange Page and follow us on Twitter: @wsdot_520.

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