Washington State Route 509 is an approximately 35 mile state highway spanning from WA 99 in Seattle southwest to I-705 in Tacoma. The routing of WA 509 varies from freeway segments, to major surface arterial roadways and even to coastal bluff roads. While certainly not the fast way between Seattle and Tacoma it does serve as a semi-scenic alternate to the topical slog of I-5.
I began my drive on WA 509 heading southbound. With that being the case I approached WA 509 on WA 99 southbound. WA 509 is signed as "To" route via WA 99 as it crosses over the Duwamish Waterway. WA 99 crosses the Duwamish Waterway on the First Avenue South Bridge. The two spans of the First Avenue South Bridge were completed in 1956 and 1998, both are draw spans. Oddly WA 99 traffic is directed to exit on the First Avenue South Bridge while WA 509 continues ahead as a freeway.
The next major junction on WA 509 southbound is at WA 518 near SeaTac International Airport. WA 518 connects SeaTac International Airport and I-5 while WA 509 continues to Normandy Park in addition to Des Moines.
WA 509 becomes a surface route in southern Burien as the freeway segment ends. WA 509 runs on Des Moines Memorial Drive westward where it turns south again on 1st Avenue. This particular segment of WA 509 is incredibly poorly signed and I had to refer to street blades to ensure that I was actually on the highway.
WA 509 straddles Normandy Park and Des Moines on 1st Avenue before turning over Des Moines Creek on 216th Street.
In downtown Des Moines WA 509 runs on Marine View Drive, again there is almost no indication it is a state highway.
WA 509 meets WA 516 at Kent-Des Moines Road. WA 509 technically multiplexes WA 516 east to WA 99 at Pacific Highway.
WA 509 splits away from WA 99 at Dash Point Road in Federal Way.
WA 509 becomes a coastal bluff highway on Dash Point Road. The roadway is curvy but nothing too extreme as it continues westerly to Dash Point State Park.
WA 509 crosses a stream in Dash Point State Park enters Pierce County and the community of Dash Point.
As WA 509 enters the City of Tacoma there is a overlook of Commencement Bay, the Port of Tacoma and downtown Tacoma.
Update 6/1/18: According to thefraze_1020 on AAroads the alignment of WA 509 was shifted onto a multiplex of WA 516 and WA 99 in 1992.
I began my drive on WA 509 heading southbound. With that being the case I approached WA 509 on WA 99 southbound. WA 509 is signed as "To" route via WA 99 as it crosses over the Duwamish Waterway. WA 99 crosses the Duwamish Waterway on the First Avenue South Bridge. The two spans of the First Avenue South Bridge were completed in 1956 and 1998, both are draw spans. Oddly WA 99 traffic is directed to exit on the First Avenue South Bridge while WA 509 continues ahead as a freeway.
The next major junction on WA 509 southbound is at WA 518 near SeaTac International Airport. WA 518 connects SeaTac International Airport and I-5 while WA 509 continues to Normandy Park in addition to Des Moines.
WA 509 becomes a surface route in southern Burien as the freeway segment ends. WA 509 runs on Des Moines Memorial Drive westward where it turns south again on 1st Avenue. This particular segment of WA 509 is incredibly poorly signed and I had to refer to street blades to ensure that I was actually on the highway.
WA 509 straddles Normandy Park and Des Moines on 1st Avenue before turning over Des Moines Creek on 216th Street.
In downtown Des Moines WA 509 runs on Marine View Drive, again there is almost no indication it is a state highway.
WA 509 meets WA 516 at Kent-Des Moines Road. WA 509 technically multiplexes WA 516 east to WA 99 at Pacific Highway.
WA 509 splits away from WA 99 at Dash Point Road in Federal Way.
WA 509 becomes a coastal bluff highway on Dash Point Road. The roadway is curvy but nothing too extreme as it continues westerly to Dash Point State Park.
WA 509 crosses a stream in Dash Point State Park enters Pierce County and the community of Dash Point.
As WA 509 enters the City of Tacoma there is a overlook of Commencement Bay, the Port of Tacoma and downtown Tacoma.
WA 509 continues west along the waters of Commencement Bay where it becomes a freeway again at Port of Tacoma Road.
WA 509 continues west over the Puyallup River and the Thea Foss Waterway on the 21st Street Bridge to a terminus with I-705 in downtown Tacoma.
Before the 1964 Washington State Highway renumbering the route of WA 509 was assigned two different numbers; WA Primary State Highway 1V and 1K. WA Primary State Highway 1V carried traffic from downtown Tacoma to US 99 in Federal Way. WA PSH 1V actually continued along the coastline from Pacific Highway to WA PSH 1K in Des Moines. WA PSH 1K ran from US 99 in Des Moines to US 99 in Seattle. Both WA PSH 1V and 1K were both created in 1937, the map below from 1956 shows them as they were before the 1964 renumbering.
Update 6/1/18: According to thefraze_1020 on AAroads the alignment of WA 509 was shifted onto a multiplex of WA 516 and WA 99 in 1992.
Comments
Is "509" also known as West Seattle Freeway? (Unofficially). And does the roadbed underneath date from BEFORE the Freeways came in?
I'm familiar with many of the 1910s and 1920s historical routes but have overlooked 509 as a Freeway era route entirely.
I don’t remember it being posted next to 99 signs headed south from there to Dash Point Rd except for the section of pre-1992 99/509 Pacific Highway from 16th to Dash Point Rd. Even then it was probably just one sign south of 16th.