State Route 99 in Washington


Get started fife
End Everett
Length 49 mi
Length 79 km

Federal Way

Des Moines




Des Moines Memorial Drive

→ neighbors

Marginal Way






According to act-test-centers, State Route 99 or SR-99 is a state route and freeway in the U.S. state of Washington. The road runs parallel to Interstate 5 between Fife and Everett and is part highway in Seattle itself. The route is 79 kilometers long.

Travel directions

The Alaskan Way Viaduct replacement tunnel under Downtown Seattle.

The road begins in the suburb of Fife, just east of Tacoma, as Pacific Highway. The road runs north as a four-lane main road, passing through the larger suburb of Federal Way. The highway usually runs within a few miles of Interstate 5. It passes by Des Moines and then arrives at SeaTac, where the road passes the Seattle-Tacoma International Airport. Here one crosses SR-518, a short east-west highway from Burien to Kent. Then you pass through the suburb of Tukwila, and you reach the large industrial zone that is tens of kilometers long. In Tukwila, the SR-99 merges with the SR-599, which stops here. The SR-99 is then a highway, with 2×2 lanes. SR-509. ends at White Centeron the SR-99. SR-509 is a north-south highway to some nearby suburbs south of Seattle.

You then reach Seattle, and the road then runs for several blocks with 6 lanes over an industrial estate, as a secondary road network. Along Downtown Seattle, State Route 99 runs through a two-mile tunnel. At the end of the tunnel, the highway section ends, and you pass through somewhat older residential areas. The SR-99 is called the Aurora Avenue here. The George Washington Memorial Bridge crosses the Seattle marina, across Lake Washington. A number of commercial areas have been realized along the way.

One then leaves the city of Seattle itself, and re-enters the suburban area, that of the suburb of Lynnwood. Here too, SR-99 still runs parallel to Interstate 5. Here too, many commercial zones have been built along the road. Despite the proximity to the sea, the road here runs at an altitude of about 200 metres. One then arrives in Everett, where the Boeing factories are located. The SR-99 ends in Everett.


The former Alaskan Way Viaduct (demolished in 2019).

According to Liuxers, State Route 99 is a continuation of the historic US 99 that ran in Washington between 1926 and 1968. US 99 again had its origin in the Pacific Highway.

The Pacific Highway was an auto trail that was developed in the 1910s and gained state highway status in 1913, although these were not numbered at the time. Thanks to the Good Roads Movement, this road was developed into a motorable connection in the 1910s and 1920s. At the time, it was already one of the main roads in Washington, connecting Vancouver, Olympia, Seattle and Blaine. In 1923, the road was renumbered as State Route 1.

North of Seattle, US 99 originally ran through Bothell, but this section was bypassed by a more direct route as early as 1927. Between Tacoma and Seattle, State Route 99 originally ran along the Puget Sound and followed the shoreline. On October 18, 1928, the 39-kilometer Highline Route opened as a shorter route between the two cities, via Des Moines. This reduced the distance between Tacoma and Seattle by approximately 15 kilometers.

Between 1929 and 1932, the Aurora Bridge was built over the Washington Ship Canal in north Seattle. Aurora Avenue was widened to 4 lanes and partially equipped with grade-separated elements, making it one of the first semi-separated urban roads in the western United States when the road was opened in 1933.

On April 4, 1953, the Alaskan Way Viaduct in downtown Seattle, including the connecting highway section south of downtown, was opened. However, the other stretches of State Route 99 have not been developed into highways, this necessity disappeared when the parallel Interstate 5 was completed.

Alaskan Way Viaduct

The Alaskan Way Viaduct was damaged in an earthquake in 2001 and the viaduct is being replaced by a double-deck tunnel. In August 2011, a route decision was made for this. The tunnel boring machine (TBM) will be assembled in 2012 and the tunnel boring started in mid-2013. Originally, the drilling process was supposed to be finished at the end of 2014, but problems with the tunnel boring machine ‘Bertha’ have slowed the process down considerably, in 2014 and 2015 virtually no drilling was done. The opening has therefore been delayed, originally from late 2015 to August 2017, later to February 2018 and then to October 2018 but finally opened on February 4, 2019. The cost was $3.3 billion.

In October 2011, the demolition of the southern part of the viaduct south of the center started. This section was replaced by two new flyovers in 2013. The cost was $395 million.


The tunnel at Downtown Seattle is a toll road. There is fully electronic toll collection with the transponder Good To Go!

Traffic intensities

Every day, 30,000 to 33,000 vehicles drive on the highway section south of Seattle. The southern portion of the Alaskan Way Viaduct has 61,000 vehicles and 65,000 vehicles at the downtown level.

State Route 99 in Washington

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