Washington State Route 509

State Route 509 is a state highway in the U.S. state of Washington. It extends just over 35 miles (56.6 km) from Tacoma in the south to Seattle in the north.

Route description

Originating at Interstate 705 in Tacoma, it travels over a cable-stayed bridge as a four-lane limited access highway east towards Fife before turning northward, skirting the Tacoma tideflats and rounding Brown's Point to Dash Point State Park. Entering King County it winds on top of the bluff along the south shore of Poverty Bay through Federal Way until connecting with State Route 99. It then follows SR 99 and State Route 516 into Des Moines and Normandy Park. It continues north as a four-lane freeway, skirting the western edge of the Seattle-Tacoma International Airport and intersecting State Route 518 in Burien. The route descends to the Duwamish River and terminates in the Industrial District south of downtown Seattle, where it rejoins State Route 99.

Proposed extension

A proposal to link SR 509 directly to I-5 south of Sea-Tac Airport is expected to relieve congestion by attracting much truck traffic to the more direct route. The project will also include adding extra lanes to the section of I-5 that is south of the SR 509 interchange to accommodate additional traffic.

Major intersections

References

External links

• Highways of Washington State
• Project page for the proposed SR 509 expansions