SR 99 AWV/Holgate to King – Phase 3, Atlantic Street Bypass

Client

Washington State Department of Transportation

Completion Date

2014

Designer

Washington State Department of Transportation

Location

Seattle, Washington

Delivery Method

General Contractor

Division

Northwest

Contract Value

$29 million
Atlantic Street Bypass

The SR 99 AWV Holgate to King Phase 3, Atlantic Street Bypass project is a grade-separated bridge over SR 99 and railroad tracks, establishing a vital link between the Port of Seattle Terminal 46 facility and SR 519.

The project separated train and vehicular traffic, eliminating extended traffic blockages due to train activities that caused delays to freight transportation to and from the Port of Seattle and created congestion that stretched into Seattle city streets onto I-90. The new bridge enhances the efficiency and reliability of freight and general traffic flow in the region, saving up to 20 minutes for freight traffic between the Port and major transportation arteries like I-5 or I-90.

The bridge serves as an essential east/west pedestrian connection, connecting Alaskan Way S. to S. Royal Brougham Way and S. Atlantic Street. The project improved the bicycle and pedestrian path located on the west side of SR 99, between S. Atlantic and S. King streets.

The overpass structure took the form of a three-legged, "h-shaped" bridge design, featuring a 40-foot inside radius. One leg of the bypass structure commenced at the intersection of Alaskan Way S. and S. Atlantic Street, extending northbound to connect with S. Dearborn Street via Alaskan Way S. The second leg commenced at the intersection of Colorado Avenue S. and S. Atlantic Street, concluding at an intersection with the first leg.