SR525 was established during the 1964 state highway renumbering as the successor to Secondary State Highway1D (SSH1D) on Whidbey Island and SSH1I in Mukilteo and Lynnwood, themselves established in 1937. The highway, at its codification in 1970, traversed the north–south length of Whidbey Island and ended at SR536 near Anacortes until it was replaced by SR20 in 1973. SR525 was converted to its present freeway in Lynnwood during the 1980s and widened to four lanes during the late 1990s, including an overpass over SR99. The highway also has a spur route in Mukilteo that has connected SR525 to SR526 via Paine Field Boulevard since it was signed in 2001.
Route description
SR525 and its holding lanes at the former Mukilteo ferry terminal
Every year, the Washington State Department of Transportation (WSDOT) conducts a series of surveys on its highways in the state to measure traffic volume. This is expressed in terms of annual average daily traffic (AADT), which is a measure of traffic volume for any average day of the year. In 2012, WSDOT calculated that the busiest section of SR525 was its southern terminus at I-5 and I-405, serving 61,000 vehicles, while the least busiest section of the highway was at the Mukilteo ferry terminal, serving 5,700 vehicles.[15] SR525 is designated as part of the National Highway System from Lynnwood to the Mukilteo ferry terminal,[16] classifying it as important to the national economy, defense, and mobility.[17] WSDOT designates the entire route of SR525 as a Highway of Statewide Significance,[18] which includes highways that connect major communities in the state of Washington.[19]
History
The Swamp Creek Interchange in Lynnwood, the southern terminus of SR525 and the northern terminus of I-405, viewed from above in 1967. The overpass in the distance is 164th St. SW, where SR 525 was designated at that time.
SR525 was established during the 1964 state highway renumbering and codified in 1970 as the successor to both SSH1D and SSH1I.[2][27] The 62.04-mile (99.84km) highway was extended south and east from Highway 99 to the newly-completed I-5 in February 1965, using 164th Street NE until a new freeway could be constructed.[28][29] The highway was truncated from Anacortes to its present terminus south of Coupeville after SR20 was extended across the state on the North Cascades Highway in 1973.[2] SR525 was re-aligned onto a two-lane freeway between SR99 and the Swamp Creek in the 1980s, extending the route to I-405. The Swamp Creek Interchange itself was completed in November 1984.[30]
WSF ferry routes were added to its respective state highways in 1994,[2] eliminating one of two gaps along the route of SR525, the other being a concurrency with SR99 that was replaced by a partial cloverleaf interchange in 2000 during the widening of the freeway segment in Lynnwood.[31] A spur route, located completely in Mukilteo, was added to SR525 in 2001 along the route of the four-lane Paine Field Boulevard, connecting the main highway to SR526.[2]
The Mukilteo ferry terminal, originally completed in 1957, was replaced by a new facility that opened on December 29, 2020.[32] The new terminal, which includes a waiting area, longer car queues, and a transit center, cost $187million to construct.[33]
In April 2024, Mukilteo mayor Joe Marine floated the idea of renaming Mukilteo Speedway during a work session with the city council to better reflect the city's history; it was axed two months later after it received overwhelming opposition among participants in an online survey and a Facebook post soliciting feedback.[34][35]
SR525 has a 0.86-mile-long (1.38km)spur route on Paine Field Boulevard in Mukilteo that connects the northbound lanes of the Mukilteo Speedway to SR526 eastbound towards Everett and the local Boeing factory.[1] Paine Field Boulevard was constructed as part of compensation for Boeing's expansion of the Everett factory to accommodate the 777 program in the 1990s; a bypass of the 84th Street section of SR526 was selected in lieu of expanding SR525.[36] The new highway was opened in 1999 and signed as SR525 Spur in 2001.[2] It was subsequently widened and improved in 2003 by WSDOT. A proposal to extend Paine Field Boulevard through Japanese Gulch and create a bypass of the Mukilteo ferry terminal has been a part of the city's transportation plan since 2001, but has not been built.[37][38] WSDOT estimated, during its annual AADT survey, that 21,000 vehicles used the highway in 2012.[15]
12Staff (2012). "2012 Annual Traffic Report"(PDF). Washington State Department of Transportation. pp.196–198. Archived from the original(PDF) on December 24, 2013. Retrieved April 22, 2013.
↑Washington State Legislature (March 18, 1937). "Chapter 207: Classification of Public Highways". Session Laws of the State of Washington (1937ed.). Olympia, Washington: Washington State Legislature. pp.995–996. Retrieved April 22, 2013. Secondary State Highway No. 1D; beginning at a junction with Primary State Highway No. 1 in the vicinity southeast of Anacortes, thence southerly by the most feasible route by way of Deception Pass to the vicinity of Columbia Beach in the southern portion of Whidby Island; Secondary State Highway No. 1I; beginning at Everett on Primary State Highway No. 1, thence in a westerly direction by the most feasible route to Mukilteo, thence in a southeasterly direction by the most feasible route to a junction with Primary State Highway No. 1 in the vicinity south of Everett.
12Seattle, 1958(JPG) (Map). 1:250,000. United States Geological Survey. 1958. Retrieved April 22, 2013.
↑"A Year's 'Resume'". Washington Highway News. Vol.9, no.2. Washington State Department of Highways. September 1960. p.35. OCLC29654162. Retrieved April 3, 2022– via WSDOT Library Digital Collections.
↑Prahl, C. G. (December 1, 1965). "Identification of State Highways"(PDF). Washington State Highway Commission, Department of Highways. Archived from the original(PDF) on February 2, 2020. Retrieved April 22, 2013.
↑Staff (1970). "Annual Traffic Report, 1970"(PDF). Washington State Highway Commission, Department of Highways. pp.199–201. Archived from the original(PDF) on October 17, 2013. Retrieved March 24, 2013.
↑"Interchange at mall is nearly completed". The Seattle Times. October 31, 1984. p.F2.
↑Federal Highway Administration (2012). "NBI Structure Number: 0015688A0000000". National Bridge Inventory. Federal Highway Administration.
