Washington State Route 99
State Route 99, also known as the Pacific Highway, is a state highway in the Seattle metropolitan area, part of the U.S. state of Washington. It runs from Fife to Everett, passing through the cities of Federal Way, SeaTac, Seattle, Shoreline, and Lynnwood. The route primarily follows arterial streets, including Aurora Avenue, and has several freeway segments, including the tolled SR 99 Tunnel in Downtown Seattle. SR 99 was officially named the William P. Stewart Memorial Highway by the state legislature in 2016, after a campaign to replace an unofficial moniker honoring Confederate president Jefferson Davis.
SR 99 was originally a section of U.S. Route 99, which was once the state's primary north–south highway before the construction of I-5. US 99 was created in 1926 and replaced earlier local roads that date back to the 1890s and state roads designated as early as 1913. The highway was moved onto the Alaskan Way Viaduct in 1953, replacing a congested stretch through Downtown Seattle, and other sections were built to expressway standards in the 1950s.
US 99 was ultimately replaced by the Tacoma–Everett section of Interstate 5, which opened in stages between 1965 and 1969. The route was decertified in 1969, and SR 99 was created to keep segments of the highway under state control. After decades of crime on some sections of SR 99, various city governments funded projects to beautify the highway and convert it into a boulevard. A section of the highway in Tukwila was transferred to city control in 2004, creating a gap in the route between the interchanges of SR 518 and SR 599.
The Alaskan Way Viaduct was closed on January 11, 2019, and was replaced with a downtown bored tunnel that opened on February 4, 2019. The replacement project was spurred by the 2001 Nisqually earthquake, which damaged the viaduct and left it vulnerable to further damage, as well as city plans to revitalize the Seattle waterfront. The $3 billion megaproject was mired in planning delays for several years before construction began in 2011 with the partial demolition of the viaduct. The tunnel was constructed using Bertha, the world's largest tunnel boring machine at the time of its launch in 2013, which had a two-year halt and completed its bore in 2017. The viaduct was demolished in 2019, leaving room for an expanded park promenade on Alaskan Way that was completed in early 2025.
Route description
SR 99 follows a section of former U.S. Route 99 within the Seattle metropolitan area, from Fife to southern Everett. It is officially designated as the William P. Stewart Memorial Highway, but is commonly known as the Pacific Highway or by one of its local names. The entire highway is listed as part of the National Highway System, a national network of roads identified as important to the national economy, defense, and mobility. A section of the highway from Tukwila to Shoreline is also designated as a Highway of Statewide Significance by the state legislature. The Washington State Department of Transportation estimates that average traffic volumes on SR 99, measured in terms of annual average daily traffic for 2016, range from a minimum of 17,000 vehicles on Everett Mall Way to a maximum of 97,000 at the First Avenue South Bridge in Seattle.Fife to SeaTac
SR 99 begins in Fife as an extension of 54th Avenue East at a partial cloverleaf interchange with Interstate 5. Immediately north of the interchange, SR 99 turns east onto Pacific Highway and passes the Emerald Queen Casino, a gambling and hotel facility operated by the Puyallup Tribe, and a commercial district at the outskirts of Fife. The highway makes a gradual turn to the north, parallel to Interstate 5 and the West Fork of Hylebos Creek, and enters Milton. SR 99 travels north along a ridge and crosses into King County, turning northeast and entering the city of Federal Way. The road cuts through a forested part of the Hylebos basin near West Hylebos Wetlands Park and reaches a commercial district surrounding Kitts Corner.At Kitts Corner, the highway intersects the western section of State Route 18, which continues east to an interchange with I-5 and onto a freeway traveling towards Auburn and Covington. SR 99 continues due north through Federal Way's main commercial strip and passing Celebration Park, The Commons at Federal Way, and Steel Lake. The highway gains a set of high-occupancy vehicle lanes that are also open to right turns into parking lots and side streets. From northern Federal Way to the Redondo area of Des Moines, SR 99 is concurrent with SR 509, which continues southwest to Dash Point State Park and northwest to downtown Des Moines, for.
The two highways pass Saltwater State Park and the former Midway landfill before splitting near Highline College at an intersection with Kent Des Moines Road. SR 99 then enters the city of SeaTac and continues north as International Boulevard, passing a federal detention center and light rail station on the southwest side of Angle Lake. The highway runs along the east side of Seattle–Tacoma International Airport and its expressway, serving the airport's terminals, parking garage, light rail station, and nearby hotels. SR 99 terminates at an interchange with SR 518 in southern Tukwila, near the airport's consolidated rental car facility and the Tukwila light rail station. A section of International Boulevard in Tukwila forms the gap between the two segments of SR 99.
Seattle and Aurora Avenue
SR 99 resumes at the north end of Tukwila International Boulevard and supersedes SR 599, a short freeway connecting to I-5, near the Duwamish River. The freeway travels northwest along the river's west bank through an industrial area that faces Boeing Field. It then enters the city of Seattle and intersects the Des Moines Memorial Drive in the South Park neighborhood before the freeway ends. At an interchange with SR 509, SR 99 turns north and travels across the Duwamish River on the First Avenue South Bridge, a pair of bascule bridges that form a continuation of the SR 509 freeway.At the north end of the bridge, SR 99 turns northwest onto East Marginal Way South and travels through Seattle's industrial neighborhood along the east bank of the Duwamish Waterway. The six-lane street turns north and passes a cement factory before transforming into a four-lane freeway at an interchange with the West Seattle Freeway on the east end of the West Seattle Bridge. SR 99 widens to six lanes, including a northbound bus lane, and passes through the SoDo neighborhood as the dividing line between the Port of Seattle's container ship terminals to the west and industrial businesses to the east beyond a rail terminal. The freeway passes the corporate headquarters of Starbucks and Coast Guard Station Seattle before turning northeast to reach the southern portal of the Alaskan Way Tunnel near Lumen Field and T-Mobile Park. The tunnel portal includes ramps to and from nearby streets, including Dearborn Street, Alaskan Way, and a frontage road along the east side of the highway.
The tunnel travels under Downtown Seattle and carries SR 99 along the central waterfront, running roughly parallel to the former Alaskan Way Viaduct. It is arranged with two stacked decks, carrying two lanes of southbound traffic on the upper deck and two lanes of northbound traffic on the lower deck. SR 99 emerges from the tunnel on the north side of Denny Way and travels onto Aurora Avenue North through the South Lake Union neighborhood, located to the east of the Seattle Center and the Space Needle. Aurora Avenue continues north as a six-lane street with bus lanes and a median barrier that restricts access from side streets to right-in/right-out. The highway runs along the eastern slope of Queen Anne Hill, above the Westlake neighborhood along Lake Union, to the Lake Washington Ship Canal.
File:Aurora Avenue and Bridge Deck 20.jpg|thumb|left|Aurora Avenue with the George Washington Memorial Bridge and the Downtown Seattle skyline in the background|alt=A divided highway seen alongside several buildings, with a city skyline in the background behind a hill.
Aurora Avenue then crosses the ship canal on the George Washington Memorial Bridge, a steel cantilever arch bridge with a clearance of. The bridge has six lanes and no median barrier, which resumes after an interchange with Bridge Way on the north approach, which crosses over the Fremont Troll. The highway continues north through part of Fremont and intersects North 46th Street before entering Woodland Park. SR 99 forms the boundary between Woodland Park to the east and the Woodland Park Zoo to the west and passes under a series of three pedestrian overpasses. The highway turns northeast to follow the shore of Green Lake and passes through the residential districts of Phinney Ridge and Greenwood, where traffic signals replace the medians and right-in/right-out access. SR 99 passes west of the North Seattle College campus in Licton Springs and intersects Northgate Way, a major street that provides access to Northgate Mall. Aurora Avenue then bisects the Evergreen Washelli Memorial Park, the city's largest cemetery, and passes between Haller Lake and Bitter Lake before reaching the northern city boundary at North 145th Street.
Shoreline and Snohomish County
SR 99 enters Shoreline and passes through the city's main commercial district, running parallel to the Interurban Trail. The stretch of Aurora Avenue through Shoreline has a landscaped median, plant buffers for sidewalks, several left-turn pockets, and an overpass for the Interurban Trail. Near Shorewood High School and the Shoreline city hall, the highway is flanked to the east by the Interurban Trail and a park with a preserved section of the original North Trunk Road, which was paved in red bricks. After passing Echo Lake and the Aurora Village shopping center, SR 99 reaches an interchange with SR 104 near the boundary between King and Snohomish counties. The highway intersects SR 104 Spur on the county line itself, which lies south of the interchange.After the interchange, the highway turns northeast and runs through a predominantly commercial area of Edmonds, passing east of the Swedish Medical Center's Edmonds campus and west of Hall Creek and the Interurban Trail. SR 99 continues northeast into Lynnwood and passes the Edmonds College campus before reaching the Crossroads commercial district at a junction with 196th Street Southwest. The highway runs along the city's retail strip and through its international district, which is surrounded by apartments and homes that are set back from SR 99.
Beyond the city limits of Lynnwood, SR 99 enters an unincorporated area near Lake Serene. The highway intersects SR 525 at a partial cloverleaf interchange and crosses Airport Road, which provides access to Paine Field and its passenger terminal. The highway travels north into Everett on Evergreen Way and turns northeast onto Everett Mall Way in the Fairmont neighborhood. SR 99 then passes through several residential subdivisions and reaches the Everett Mall, where it turns north and terminates at the Broadway Interchange. The interchange includes connections to I-5, the Boeing Freeway, and SR 527. The road itself continues north towards Downtown Everett as Broadway.