List of Interstate Highways in Washington

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Interstate Highways in Washington
I-5 (WA) Metric.svg   I-90.svg   I-182.svg
Highway markers for Interstate 5, Interstate 90, and Interstate 182
Interstate Highways in Washington.svg
Map of highways in Washington with the Interstates highlighted in red
System information
Length764.26 mi [1]  (1,229.96 km)
FormedJune 29, 1956
Highway names
Interstates Interstate nn (I‑nn)
Business Loops:Business Loop Interstate nn (BL I‑nn)
Business Spurs:Business Spur Interstate nn (BS I‑nn)
System links

The Interstate Highways in Washington are segments of the national Interstate Highway System that lie within the U.S. state of Washington. The system comprises 764 miles (1,230 km) on seven routes that are owned and maintained by the Washington State Department of Transportation (WSDOT); the design standards and numbering across the national system are managed by the Federal Highway Administration (FHWA) and the American Association of State Highway and Transportation Officials (AASHTO).

Contents

Washington has three primary Interstates and four auxiliary routes; the seven routes serve most of the state's major cities. The longest of these is Interstate 90 (I-90), which is 298 miles (480 km) long and connects the state's two largest cities, Seattle and Spokane. I-5 is the only Interstate to span the state from south to north, traveling from the Oregon state line to the Canadian border. The system also includes several business routes that are not maintained or managed by WSDOT, but rather by local governments.

The general plan and federal funding for the Interstate Highway System were approved by the U.S. Congress in the Federal-Aid Highway Act of 1956. The federal plan incorporated elements of the Washington state government's plan for limited access highways, including an urban tollway that was later cancelled. The original allocation of two primary routes and two auxiliary routes was later expanded in the 1960s and 1970s with the addition of I-82 and two more auxiliary routes. The last segment of the Interstate Highway System in Washington, a section of I-90 between Seattle and Bellevue, was completed in 1993. An eighth route, popularly named I-605, has been proposed in several forms since the 1960s but was never submitted for formal approval.

Description

Aerial image of the I-5 and I-90 interchange south of Downtown Seattle Interstate 5 and Interstate 90 interchange, seen from Columbia Center (2022).jpg
Aerial image of the I-5 and I-90 interchange south of Downtown Seattle

All seven Interstate Highways in Washington are legally defined as part of the state highway system, which is maintained and administered by WSDOT. [2] They are all freeways built to Interstate Highway standards, which require full grade separation and control of access via interchanges, design speeds of 50 to 70 miles per hour (80 to 113 km/h), a minimum of two lanes per direction, and widths of at least 12 feet (3.7 m) for lanes and 4 to 10 feet (1.2 to 3.0 m) for the left and right shoulders, respectively. [3] The FHWA is responsible for overseeing these standards and can also approve exceptions. [4] The numbering scheme used to designate the Interstates was developed by AASHTO, an organization composed of the various state departments of transportation in the United States. [3] [5] A set of business routes, which use a modified green Interstate shield, are designated and maintained by local governments instead of WSDOT and do not require approval from the FHWA. [6] [7]

The Interstate Highway System covers about 764 miles (1,230 km) in Washington and consists of three primary routes and four auxiliary routes. [1] [8] They connect the major cities and metropolitan areas of the state, working in concert with the U.S. routes and state routes also maintained by WSDOT. [9] The longest route, I-90, is 298 miles (480 km) and connects the state's two largest cities, Seattle and Spokane; the shortest is I-705 at 1.5 miles (2.4 km). [1] [8] The widest section in the state is on I-5 in Downtown Seattle, which spans 13 lanes and includes a set of reversible express lanes that change direction depending on time of the day. [10] [11] Various sections of the Interstate Highways serving the Seattle and Portland–Vancouver metropolitan areas also have designated lanes for high-occupancy vehicles, buses, and tolled vehicles. [12] The Seattle–Tacoma area ranks third among U.S. metropolitan areas for the number of sections with high-occupancy vehicle lanes. [13] In 2019, Washington's Interstates carried an estimated 17.4 billion vehicle miles traveled, comprising 28 percent of all travel on roads in the state. [14]

History

Construction of I-5 in north Seattle, 1963 Seattle - Interstate 5 under construction, 1963 (46535962192).jpg
Construction of I-5 in north Seattle, 1963

Early proposals for a national system of "superhighways" with limited access and grade separation emerged in the 1930s at the behest of the Bureau of Public Roads (BPR; now the FHWA) under the Roosevelt administration. A 1939 BPR report evaluated national corridors for tolled superhighways, including a north–south route on the West Coast terminating at the Canadian border in Washington and an east–west route originating in Seattle to connect the Northern states. [15] [16] The first major expressway with limited access to be built in the state was the Alaskan Way Viaduct in Downtown Seattle, which was announced in 1947 and used federal grants authorized by the Federal-Aid Highway Act of 1944. [17] It opened in 1953 and replaced sections of U.S. Route 99 (US 99), part of the older United States Numbered Highway System. [18] [19]

The Washington State Legislature approved their own plans for a system of limited-access highways in 1947, in response to rising collisions and hazardous conditions on existing state roadways. The legislation authorized planning for a tolled superhighway between Seattle and Tacoma that would later be extended south to Oregon and north to British Columbia as a replacement for US 99. [20] [21] A second bill in 1951 authorized the construction of expressways to replace rural sections of US 99 and US 10 (the east–west trunk), particularly by bypassing small cities, and the program was expanded to cover 2,388 miles (3,843 km) by 1953. [22] [23] In addition to the inter-regional superhighways planned in the 1930s and 1940s, the BPR also surveyed potential urban routes and bypasses that would perform auxiliary functions. [15] [24] These included bypasses of Seattle and Portland, Oregon, the latter of which would also encompass Vancouver, Washington. [25]

The Federal-Aid Highway Act of 1956, signed into law by President Dwight D. Eisenhower on June 29, 1956, formally authorized the creation of the Interstate Highway System and its design standards. It also established a federal commitment to fund 90 percent of construction costs for eligible Interstate projects. [15] In August 1957, the American Association of State Highway Officials (AASHO; now AASHTO) designated the state's two primary routes as I-5 and I-90, replacing US 99 and US 10, respectively. [26] [27] A pair of auxiliary routes were also included in the original Washington allocation and numbered in 1958: I-205, bypassing Portland and Vancouver; and I-405, bypassing Seattle. [28] [29] Washington's third primary route, connecting Ellensburg to Pendleton, Oregon, was authorized by the BPR in October 1957 as part of an addition to the Interstate Highway System. [30] It was numbered I-82 by AASHO in 1958, completing the initial allocation of 726 miles (1,168 km) for Washington. [31] [32] A rejected extension of I-82 across the Cascade Range to Tacoma and Aberdeen, totaling 167 miles (269 km), was submitted by Washington in 1959. [33]

Among the first Interstate projects in Washington to be built with funding from the Federal-Aid Highway Act of 1956 were bypasses of Fort Lewis and Olympia that had already been planned by the state government. [34] They were incorporated into I-5, and in early 1958 the Tacoma project became the first section in the state to use the Interstate shield. [35] I-5 was also the first Interstate to be fully completed in Washington, following the opening of a section between Everett and Marysville on May 14, 1969. [36] The first auxiliary route to be fully completed was I-405, which was opened to traffic between Woodinville and Lynnwood in November 1969. [37] The state government made improvements to the expanding Interstate system in the 1960s and 1970s, building rest areas and scenic overlooks on the primary routes and introducing mileage-based exit numbers in 1973. [38] [39]

The southern section of I-82 between Yakima and Oregon was originally routed away from the Tri-Cities region, where local leaders petitioned for access to the Interstate system. Following a dispute between the states of Washington and Oregon, the FHWA proposed to route I-82 towards the Tri-Cities, which would be directly served by a spur route. [40] The new connector, numbered I-182, was approved in 1969 and fully opened in 1986 alongside the last Washington section of I-82; the highways were delayed by disagreements with local governments and spending cuts during the early 1980s recession. [41] [42] The Washington section of I-205 was completed with the opening of the Glenn L. Jackson Memorial Bridge over the Columbia River in December 1982, a few months before the Oregon section was fully open to traffic. [43] [44] The final Interstate to be added in Washington was I-705, a short spur into Downtown Tacoma, [45] which was approved by the FHWA and AASHTO in 1978 and opened in 1988. [46] [47]

The final section of the Interstate system in Washington, I-90 between Seattle and Bellevue, took over 30 years to plan and construct amid disagreements and litigation over its design and other mitigation. [48] The 7-mile (11 km) section included construction of the Homer M. Hadley Memorial Bridge to supplement the existing Lacey V. Murrow Memorial Bridge (both among the longest floating bridges in the world), expansion of the Mount Baker Tunnel, and a set of lids in Seattle and Mercer Island; its total cost was $1.56 billion (equivalent to $2.87 billion in 2022 dollars), [49] among the most expensive parts of the Interstate system. [48] [50] The FHWA estimated the total cost to construct the Interstate Highway System in the state to be $4.558 billion in 1989 (equivalent to $9.41 billion in 2022 dollars), [49] placing Washington eighth among all states by total cost. [51]

An outer beltway for the Seattle metropolitan area, bypassing I-405 and several Eastside suburbs, has been proposed under the unofficial moniker of "I-605" several times since the 1960s. [52] The state government has never formally applied for its addition to the Interstate Highway System, but it was tentatively designated as State Route 605 (SR 605) by the legislature. [53] [54] Proposals to build a north–south freeway near Lake Sammamish were defeated in 1968, but the idea was revived in 1998 as an extension of SR 18 through the Snoqualmie Valley. [55] A 2004 study commissioned by the state legislature determined that an outer beltway would not be feasible to construct due to its high costs as well as opposition from local residents and environmental groups. [56]

Primary Interstates

List of Primary Interstate Highways in Washington
NumberLength (mi) [1] Length (km)Southern or western terminusNorthern or eastern terminusFormedRemovedNotes
I-5.svg I-5 276.62445.18 I-5 at Oregon state line in Vancouver Hwy 99 at Canadian border in Blaine 01957-08-141957 [26] currentMain north–south corridor in Western Washington; completed in 1969. [36] Officially designated the Purple Heart Trail since 2013. [57]
I-82.svg I-82 132.57213.35 I-90  / US 97 in Ellensburg I-82  / US 395 at Oregon state line near Plymouth 01957-10-171957 [30] currentServes the Yakima Valley and Tri-Cities regions and was completed in 1986. [42]
I-90.svg I-90 297.51478.80 SR 519 in Seattle I-90 at Idaho state line near Liberty Lake 01957-08-141957 [26] currentMain east–west corridor in Washington and the longest Interstate, completed in 1993. [48] Officially designated the American Veterans Memorial Highway since 1991. [58]
1.000 mi = 1.609 km; 1.000 km = 0.621 mi

Auxiliary Interstates

List of Auxiliary Interstate Highways in Washington
NumberLength (mi) [1] Length (km)Southern or western terminusNorthern or eastern terminusFormedRemovedNotes
I-182.svg I-182 15.1924.45 I-82  / US 12 near Richland US 12 in Pasco 01969-06-231969 [41] currentI-182 is a spur that serves the Tri-Cities area and was completed in 1986. [42]
I-205.svg I-205 10.5717.01 I-205 at Oregon state line near Vancouver I-5 in Salmon Creek 01958-01-011958 [29] currentI-205 is a loop that bypasses Portland, Oregon, and Vancouver, Washington; its Washington section was completed in 1982 and the entire highway opened in 1983. [44]
I-405.svg I-405 30.3048.76 I-5  / SR 518 in Tukwila I-5  / SR 525 in Lynnwood 01958-01-011958 [29] currentI-405 is a loop that bypasses Seattle to serve the Eastside and was completed in 1969. [37]
I-705.svg I-705 1.502.41 I-5  / SR 7 in Tacoma Schuster Parkway in Tacoma01978-01-011978 [46] currentI-705 is a spur that serves Downtown Tacoma and was completed in 1988. [47]
1.000 mi = 1.609 km; 1.000 km = 0.621 mi

See also

Related Research Articles

<span class="mw-page-title-main">Interstate 82</span> Interstate in Washington and Oregon

Interstate 82 (I-82) is an Interstate Highway in the Pacific Northwest region of the United States that travels through parts of Washington and Oregon. It runs 144 miles (232 km) from its northwestern terminus at I-90 in Ellensburg, Washington, to its southeastern terminus at I-84 in Hermiston, Oregon. The highway passes through Yakima and the Tri-Cities, and is also part of the link between Seattle and Salt Lake City, Utah. I-82 travels concurrently with U.S. Route 97 (US 97) between Ellensburg and Union Gap; US 12 from Yakima to the Tri-Cities; and US 395 from Kennewick to Umatilla, Oregon.

<span class="mw-page-title-main">Interstate 705</span> Interstate highway in Tacoma, Washington

Interstate 705 (I-705), also known as the Tacoma Spur, is a short Interstate Highway in Tacoma, Washington, United States. It is a spur route of I-5 that connects the freeway to Downtown Tacoma, Tacoma's waterfront, North Tacoma, and the Tacoma Dome. I-705 was completed in 1988 and is one of the newest portions of the Interstate Highway System in Washington.

<span class="mw-page-title-main">Washington State Route 99</span> Highway in the Seattle metropolitan area, Washington, U.S.

State Route 99 (SR 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 49 miles (79 km) 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.

<span class="mw-page-title-main">Washington State Route 16</span> State highway in the U.S. state of Washington

State Route 16 (SR 16) is a 27.16-mile-long (43.71 km) state highway in the U.S. state of Washington, connecting Pierce and Kitsap counties. The highway, signed as east–west, begins at an interchange with Interstate 5 (I-5) in Tacoma and travels through the city as a freeway towards the Tacoma Narrows. SR 16 crosses the narrows onto the Kitsap Peninsula on the partially tolled Tacoma Narrows Bridge and continues through Gig Harbor and Port Orchard before the freeway ends in Gorst. The designation ends at an intersection with SR 3 southwest of the beginning of its freeway through Bremerton and Poulsbo. SR 16 is designated as a Strategic Highway Network (STRAHNET) corridor within the National Highway System as the main thoroughfare connecting Tacoma to Naval Base Kitsap and a part of the Highways of Statewide Significance program.

<span class="mw-page-title-main">Washington State Route 526</span> Highway in Washington

State Route 526 (SR 526), also known as the Boeing Freeway, is a state highway in Snohomish County, Washington, United States. The east–west highway travels 4.52 miles (7.27 km) and connects SR 525 in Mukilteo to Interstate 5 (I-5) in southern Everett. The highway serves the Boeing Everett Factory and Paine Field; it also serves as a main route to the city of Mukilteo and the state-run ferry to Whidbey Island.

<span class="mw-page-title-main">Washington State Route 509</span> Highway in Washington

State Route 509 (SR 509) is a 35.17-mile-long (56.60 km) state highway in the U.S. state of Washington, connecting Tacoma in Pierce County to Seattle in King County. The highway travels north from Interstate 705 (I-705) in Tacoma to SR 99 south of downtown Seattle. It serves cities along the Puget Sound and west of Seattle–Tacoma International Airport in south King County, including Federal Way, Des Moines, and Burien. SR 509 is part of the National Highway System and is a limited-access highway near the Port of Tacoma and from Burien to its northern terminus in Seattle.

<span class="mw-page-title-main">Interstate 405 (Washington)</span> Interstate highway bypassing Seattle, Washington, U.S.

Interstate 405 (I-405) is a north–south auxiliary Interstate Highway serving the Seattle region of Washington, United States. It bypasses Seattle east of Lake Washington, traveling through the Eastside area of King and Snohomish counties, providing an alternate route to I-5. The 30-mile (48 km) freeway serves the cities of Renton, Bellevue, Kirkland, and Bothell. I-405 terminates at I-5 in Tukwila and Lynnwood, and also intersects several major highways, including SR 167, I-90, SR 520, and SR 522.

<span class="mw-page-title-main">Washington State Route 18</span> Highway in Washington

State Route 18 (SR 18) is a 28.41-mile-long (45.72 km) state highway in the U.S. state of Washington, serving southeastern King County. The highway travels northeast, primarily as a controlled-access freeway, from an intersection with SR 99 and an interchange with Interstate 5 (I-5) in Federal Way through the cities of Auburn, Kent, Covington, and Maple Valley. SR 18 becomes a two-lane rural highway near Tiger Mountain as it approaches its eastern terminus, an interchange with I-90 near the cities of Snoqualmie and North Bend.

The Washington State Department of Transportation is a governmental agency that constructs, maintains, and regulates the use of transportation infrastructure in the U.S. state of Washington. Established in 1905, it is led by a secretary and overseen by the governor. WSDOT is responsible for more than 20,000 lane-miles of roadway, nearly 3,000 vehicular bridges and 524 other structures. This infrastructure includes rail lines, state highways, state ferries and state airports.

<span class="mw-page-title-main">Interstate 605 (Washington)</span> Never-built Interstate highway in Washington

Interstate 605 (I-605) is the popular moniker given to several proposals for a new auxiliary Interstate Highway bypassing I-5 and I-405 in the U.S. state of Washington. Proposals have been heard from since the 1960s, including highways connecting from I-5 all the way to the Canada–US border, and some just between I-5 and I-90. The Washington State Department of Transportation (WSDOT) has no projects designated I-605 at this time. However, some I-605 proposals have included State Route 18, which has been partially constructed as a freeway.

<span class="mw-page-title-main">Washington State Route 167</span> Highway in Washington

State Route 167 (SR 167) is a state highway in the Seattle metropolitan area of Washington state. It is commonly known as the Valley Freeway and serves the Green River Valley from Tacoma to Renton, primarily as a four-lane freeway. The 28-mile (45 km) highway begins in Tacoma at an interchange with Interstate 5 (I-5) and travels southeast to Puyallup as an undivided road. It then turns northeast onto a freeway and passes through interchanges with SR 512 in Puyallup and SR 410 in Sumner, continuing north through Auburn and Kent. After an interchange with I-405 in Renton, it terminates at an intersection with SR 900.

<span class="mw-page-title-main">Washington State Route 512</span> Highway in Washington

State Route 512 (SR 512) is a suburban state-maintained freeway in Pierce County, Washington, United States. It travels 12 miles (19 km) from west to east, connecting Interstate 5 (I-5) in Lakewood to SR 7 in Parkland and SR 167 in Puyallup. The freeway travels north–south through Puyallup, concurrent with SR 161.

<span class="mw-page-title-main">Washington State Route 7</span> State highway in Lewis and Pierce counties

State Route 7 (SR 7) is a state highway in Lewis and Pierce counties, located in the U.S. state of Washington. The 58.60-mile (94.31 km) long roadway begins at U.S. Route 12 (US 12) in Morton and continues north to intersect several other state highways to Tacoma, where it ends at an interchange with Interstate 5 (I-5) and I-705. The road has several names, such as Second Street in Morton, the Mountain Highway in rural areas, Pacific Avenue in Spanaway, Parkland and Tacoma and 38th Street in Tacoma. Near the end of the highway there is a short freeway that has been proposed to be extended south parallel to an already existing railroad, owned by Tacoma Rail, which serves as the median of the short freeway.

<span class="mw-page-title-main">Washington State Route 161</span> Washington state highway in Pierce and King counties

State Route 161 (SR 161) is a 36.25-mile-long (58.34 km) state highway serving Pierce and King counties in the U.S. state of Washington. The highway begins at SR 7 southwest of Eatonville and travels north as Meridian Avenue to Puyallup, becoming concurrent with SR 512 and SR 167. SR 161 continues northwest as the Enchanted Parkway to end at an intersection with SR 18 in Federal Way, west of Interstate 5 (I-5). The highway serves the communities of Graham and South Hill before reaching Puyallup and the communities of Edgewood, Milton, and Lakeland South before reaching Federal Way.

<span class="mw-page-title-main">Interstate 90 in Washington</span> Interstate highway in Washington

Interstate 90 (I-90), designated as the American Veterans Memorial Highway, is a transcontinental Interstate Highway that runs from Seattle, Washington, to Boston, Massachusetts. It crosses Washington state from west to east, traveling 298 miles (480 km) from Seattle across the Cascade Mountains and into Eastern Washington, reaching the Idaho state line east of Spokane. I-90 intersects several of the state's other major highways, including I-5 in Seattle, I-82 and U.S. Route 97 (US 97) near Ellensburg, and US 395 and US 2 in Spokane.

<span class="mw-page-title-main">Interstate 5 in Washington</span> Interstate highway in Washington

Interstate 5 (I-5) is an Interstate Highway on the West Coast of the United States that serves as the region's primary north–south route. It spans 277 miles (446 km) across the state of Washington, from the Oregon state border at Vancouver, through the Puget Sound region, to the Canadian border at Blaine. Within the Seattle metropolitan area, the freeway connects the cities of Tacoma, Seattle, and Everett.

<span class="mw-page-title-main">Washington State Route 223</span> Highway in Washington

State Route 223 (SR 223) is a 3.81-mile (6.13 km) long state highway located entirely in Yakima County, Washington, United States. It has served the role of connecting the city of Granger to the county seat, Yakima via Interstate 82 and to SR 22 since its establishment in 1967, serving between 4,000 and 8,500 cars per day on average in 2009.

<span class="mw-page-title-main">Point Defiance Bypass</span> Rail line in Pierce County, Washington, United States

The Point Defiance Bypass is a 14.5-mile-long (23.3 km) rail line between the cities of DuPont and Tacoma in Pierce County, Washington. It was originally built by the Northern Pacific Railway – the Tacoma–Lakewood segment in 1874 as part of the Prairie Line, and the Lakewood–DuPont section in 1891. Passenger service on the lines declined after the 1914 completion of a flatter route along Puget Sound, and ended entirely in 1956.

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