Interstate 90 in Washington
Map of Washington with I-90 highlighted in red
|Defined by RCW|
|Maintained by WSDOT|
|Length||297.51 mi (478.80 km)|
|History||Completed in 1993|
|Mountains to Sound Greenway|
|West end||SR 519 in Seattle|
|East end||I-90 at Idaho state line near Liberty Lake|
|Counties||King, Kittitas, Grant, Adams, Lincoln, Spokane|
Interstate 90 (I-90) 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 major north–south 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.
I-90 is the only Interstate to cross the state from west to east, and the only one to connect the state's two largest cities, Seattle and Spokane. It incorporates two of the longest floating bridges in the world, the Lacey V. Murrow Memorial Bridge and the Homer M. Hadley Memorial Bridge, which cross Lake Washington from Seattle to Mercer Island. I-90 crosses the Cascades at Snoqualmie Pass, one of the busiest mountain pass highways in the United States, and uses a series of viaducts and structures to navigate the terrain. The freeway travels across various landscapes, including suburban bedroom communities in the Seattle metropolitan area, forests of the Cascade Range, and the high plains of the Columbia Plateau.
The crossing at Snoqualmie Pass was established as a wagon road in 1867 and incorporated into a cross-state auto trail, known as the Sunset Highway, in the early 1910s. The Sunset Highway was incorporated into the national highway system in 1926 as part of US 10, which I-90 replaced when it was designated in 1957. The first segments of the freeway, located in Spokane and Spokane Valley, opened at around the same time and the state government completed upgrades of US 10 to Interstate standards for most of the route by the late 1970s.
The section of I-90 between Seattle and I-405 in Bellevue was delayed for decades because of environmental concerns and lawsuits by local groups over the freeway's potential impact on nearby neighborhoods. A compromise agreement was reached by the federal, state, and local governments in 1976 to build a second floating bridge across Lake Washington and include extensive parks above tunneled sections of I-90, which were completed in the early 1990s. The new floating bridge opened in 1989 and carried bi-directional traffic while the original floating bridge was renovated. The bridge's center pontoons sank during a November 1990 windstorm due to a contractor error and were rebuilt over the following three years, reopening to traffic on September 12, 1993, marking the completion of the transcontinental highway.
- 1 Route description
- 2 History
- 3 Seattle–Bellevue express lanes
- 4 Exit list
- 5 References
- 6 External links
Interstate 90 is the longest freeway in Washington state, at nearly 298 miles (480 km) in length, and is the only Interstate to traverse the state from west to east across the Cascade Mountains. It is listed as part of the National Highway System, classifying important to the national economy, defense, and mobility, and the state's Highway of Statewide Significance program, recognizing its connection to major communities. A 100-mile (160 km) section of I-90 between Seattle and Thorp named the Mountains to Sound Greenway was designated in 1998 as a National Scenic Byway, in recognition of its scenic views.
I-90 is maintained by the Washington State Department of Transportation (WSDOT), who conduct an annual survey of traffic volume that is expressed in terms of average annual daily traffic (AADT), a measure of traffic volume for any average day of the year. A section of I-90 in Bellevue's Eastgate neighborhood carries a daily average of 150,000 vehicles, making it the highway's busiest. The highway's least busiest section, near SR 21 west of Ritzville, carried 11,000 vehicles in 2016. The freeway has a maximum speed limit of 60 miles per hour (97 km/h) in urban areas, 65 mph (105 km/h) in mountainous areas, and 70 mph (110 km/h) in rural areas. Several proposals to raise the speed limit of the rural section between Vantage and Spokane to 75 mph (121 km/h) have been submitted and denied by the state government due to safety concerns.
Seattle, Mercer Island, and Bellevue
I-90 begins at the intersection of Edgar Martinez Drive South (part of SR 519) and 4th Avenue South in the SoDo neighborhood south of Downtown Seattle. The interchange is adjacent to Safeco Field, home to the Seattle Mariners baseball team, and includes a pair of ramps to SR 519 and an additional offramp to 4th Avenue South north of Royal Brougham Way and near CenturyLink Field. The ramps converge over the Stadium light rail station adjacent to King County Metro's bus bases and are joined by the bus-only express lane ramps from the Downtown Seattle Transit Tunnel and 5th Avenue in the International District. I-90 travels east through a major interchange with I-5 at the northwest corner of Beacon Hill and passes under the Jose Rizal Bridge.
The freeway wraps around the north end of Beacon Hill and intersects Rainier Avenue at the site of the future Judkins Park light rail station, joined by a multi-use bicycle and pedestrian trail that forms part of the Mountains to Sound Greenway. The express lanes terminate after Rainier Avenue, having been permanently closed for East Link light rail construction, and I-90 travels east into the Mount Baker Tunnel under the Central District. The tunnels, which are listed on the National Register of Historic Places, run under Sam Smith Park and the Mount Baker Ridge neighborhood to Lake Washington, where traffic continues onto a pair of floating bridges. The eastbound lanes are carried by the Lacey V. Murrow Memorial Bridge, while the westbound lanes, multi-use trail, and future light rail tracks are carried by the wider Homer M. Hadley Memorial Bridge. The two floating bridges connect Seattle to the Eastside suburbs and are among the longest in the world, at 5,811 feet (1,771 m) and 6,603 feet (2,013 m) in length, respectively.
From the east end of the bridge, I-90 continues onto Mercer Island and travels under the Mercer Island Lid, a landscaped park built atop a curved section of the freeway between West Mercer Way and 76th Avenue Northeast. I-90 emerges in downtown Mercer Island, adjacent to its future light rail station in the freeway median and a current park and ride. The freeway passes under a smaller lid at Luther Burbank Park and leaves the island on the East Channel Bridge, which crosses a smaller arm of Lake Washington into Bellevue. I-90 travels to the south of Enatai and Beaux Arts Village and intersects Bellevue Way, where light rail tracks will turn north away from the freeway, before crossing the Mercer Slough and its wetlands. After crossing under a disused railroad bridge, slated to be part of the Eastside Rail Corridor trail, I-90 and its short set of collector–distributor lanes meet I-405 in a large stack interchange northwest of the Factoria Mall and the headquarters of T-Mobile US. South of the Bellevue College campus in Eastgate, I-90 intersects 142nd Place Southeast using direct ramps from its high-occupancy vehicle (HOV) lanes. Near the former Bellevue Airfield, I-90 turns southeast to run downhill from Cougar Mountain and along the shore of Lake Sammamish towards Issaquah.
East King, Snoqualmie Pass, and Kittitas
At the south end of Lake Sammamish and northwest of downtown Issaquah, I-90 passes through Lake Sammamish State Park and intersects SR 900. The freeway travels along the north edge of downtown Issaquah, zig-zagging to the south and north to avoid the ridge of Issaquah Highlands and western Tiger Mountain. I-90 leaves Issaquah and enters the heavily forested Issaquah Alps, skirting the north edge of the Tiger Mountain State Forest as it passes Preston. Northeast of Tiger Mountain, the freeway intersects SR 18 and an arterial street connecting to Snoqualmie and Snoqualmie Ridge. I-90 continues southeast past the Snoqualmie Casino to North Bend, where it intersects SR 202. The freeway travels around the southern edge of North Bend and neighboring Tanner in the foothills of Rattlesnake Ridge. I-90 continues southeasterly along the South Fork of the Snoqualmie River into the Snoqualmie National Forest, which also hosts several state parks and campgrounds.
I-90 continues in a southern arc around several mountains in the Alpine Lakes Wilderness while following the South Fork of the Snoqualmie River. At the east end of the arc near the Asahel Curtis Picnic Area, the freeway's westbound and eastbound lanes are split by a wide median that includes the Denny Creek Campground. I-90 continues northeast on two high viaducts and ascend to Snoqualmie Pass, the lowest of the state's three major Cascades passes at an elevation of 3,022 feet (921 m). The pass handles 28,000 vehicles (including 6,500 trucks) on an average weekday, making it one of the busiest mountain highways in the United States. I-90 intersects the Pacific Crest Trail and SR 906 at the pass, providing access to the adjacent to the Snoqualmie ski resort. The freeway travels south into Kittitas County and intersects SR 906 Spur at Hyak. I-90 continues south through the Wenatchee National Forest along the eastern shore of Keechelus Lake, under steep cliffs that were cut using controlled blasting. At the south end of the lake, the freeway passes under a 66-foot-long (20 m) arched wildlife bridge, which is the first to be built in Washington state.
While Snoqualmie Pass does not have an annual closure like other passes in the Cascades, it does suffer from vehicle restrictions and occasional days-long shutdowns during the wintertime for avalanche control and clearing collisions. I-90 has several chain-on and chain-off areas on the highway shoulders between North Bend and Cle Elum, including variable-message signage to inform drivers of road conditions. WSDOT estimates that it costs $2–3 million annually to keep Snoqualmie Pass open in the wintertime, which sees an average snowfall of 233 inches (590 cm) and about 120 hours of closures per year.
I-90 continues southeast along the Yakima River to Easton, where it leaves the national forest and is joined by the Palouse to Cascades State Park Trail, part of Iron Horse State Park. The freeway passes several ranches and resort communities, including Suncadia, before reaching Cle Elum. I-90 runs to the south of downtown along the Yakima River and intersects SR 10 east of the city before crossing the river. SR 10 follows the former route of US 10 on the north side of the Yakima River, connecting to SR 903 and SR 970. The two highways continue southeast along the Yakima River and enter the Kittitas Valley near Thorp. I-90 begins a concurrency with US 97 west of Ellensburg, which continues as the freeway travels around the outskirts of the city to an interchange with I-82, which travels south with US 97 along the Yakima River towards Yakima.
Columbia Plateau and Spokane area
I-90 crosses into the Columbia Plateau at the east end of the Kittitas Valley, traveling due east past Olmstead Place State Park and the town of Kittitas. The freeway travels across a series of hills while following the Ryegrass Coulee, including a rest area at Ryegrass Hill near the Wild Horse Wind Farm. I-90 then reaches Vantage, where it travels past the Ginkgo Petrified Forest State Park, one of the largest collections of petrified trees in the world, before crossing the Columbia River on the Vantage Bridge. The bridge ascends up to the cliffs on the western shore of Grant County, where I-90 intersects SR 26 and turns north along the Babcock Bench. The freeway then passes several scenic viewpoints for Lake Wanapum and the Wild Horse Monument, a piece of public art placed atop a hill to the east.
Near Frenchman Coulee and the Gorge Amphitheater, I-90 turns northeast towards George, where it intersects SR 281 and SR 283, providing access to Quincy and Ephrata, respectively. The freeway continues due east across rural Grant County, paralleled by a pair of frontage roads, past several sand dunes, state recreational areas, and the Potholes Reservoir. I-90 reaches Moses Lake by crossing the eponymous lake's western arm and intersecting SR 171, which serves as the city's main street. The freeway then crosses the Pelican Horn and intersects SR 17 before leaving the city, regaining its frontage roads as it continues east across rural Adams County by following several coulees. I-90 intersects the SR 21 east of the Schrag rest area and continues towards Ritzville, where a long concurrency with US 395 begins. The two highways intersect SR 261 and travel northeast along the BNSF railroad, which carries Amtrak's Empire Builder trains, to Sprague Lake in Lincoln County. In Sprague, I-90 intersects SR 23 just south of its junction with SR 231. From Sprague, the freeway passes the Fishtrap Recreation Area and crosses into Spokane County, where it alternates between interchanges with SR 904 and SR 902, which form loops serving Medical Lake and Cheney, respectively.
I-90 and US 395 continue along the south side of Spokane International Airport and enter the city of Spokane, adding US 2 to the concurrency at an interchange near Sunset Hill. The three highways continue along Garden Springs Creek and the John A. Finch Arboretum to an interchange with US 195, located under several railroad overpasses. The freeway continues across Latah Creek into Downtown Spokane, where it travels on an elevated viaduct along 4th Avenue on the south side of downtown. The freeway passes the city's two hospitals (Deaconess and Sacred Heart) before intersecting Browne and Division streets, which carry US 2 and US 395 north through Spokane. I-90 then intersects SR 290 at the eastern edge of downtown, providing a connection across the Spokane River to the Gonzaga University campus.
The freeway continues east through Spokane's suburban neighborhoods, flanked by a pair of frontage roads that funnel traffic towards local streets at interchanges, and passes the future terminus of the North Spokane Corridor, a major freeway that will carry US 395 when completed. I-90 then enters Spokane Valley near Avista Stadium and the Interstate Fairgrounds. The freeway travels on the north side of the suburban city and intersects SR 27 near the Spokane Valley Mall. I-90 follows the Spokane River and Centennial Trail through Liberty Lake and to the Idaho state line. The freeway then continues across the Spokane River towards Post Falls and Coeur d'Alene.
Early state roads
Snoqualmie Pass was historically used by the indigenous inhabitants of the Puget Sound and Columbia Plateau regions for trade and socializing in the summertime, as it was the lowest pass in the Cascades. The early trails from the pass were used by fur traders and settlers beginning in the 1850s, as it was the only route equipped to handle wagons and livestock. Snoqualmie Pass was later chosen for the region's first major cross-mountain road in the 1860s, having beaten the federal government's favored route over Naches Pass, and a rough wagon road was completed in October 1867 by a group of Seattle businessmen.
The wagon road was popular with settlers and cattle drivers from eastern Washington and was planned to be extended west to the Black River and east to the Yakima Valley using a $2,500 appropriation from the territorial government, but the funds proved insufficient and the project was shelved. The Snoqualmie wagon road was bought out in 1883 by the Seattle and Walla Walla Trail and Wagon Road Company and converted into a toll road to fund maintenance after the federal government declined to fund improvements to the road. The toll scheme was ultimately unsuccessful, as it failed to compete with the Northern Pacific Railway after it built its railroad across Stampede Pass to the south. The toll road was abandoned in 1893 and transferred to King and Klickitat counties, who contracted Denny to maintain and repair the road in 1899 with state money; by that time, sections of the road had deteriorated considerably, but approximately 200 wagons and 1,148 used the Snoqualmie Pass road that summer.
The rise of automobiles after the turn of the 20th century led to the state government funding and supporting new highways across Washington state. Snoqualmie Pass saw its first automobile crossing in 1905, the same year that the state government designated the route as part of State Road 7. State Road 7 began construction between North Bend and Easton in 1907 and became Washington's first trans-Cascades highway. Later that year, state highway commissioner Joseph M. Snow announced plans to extend the Snoqualmie Pass road west to Seattle and east to Spokane and the Idaho state line, using a road through Wenatchee. The cross-state extension was approved by the state legislature in 1909 and commemorated by a 23-day automobile race from New York City to Seattle for that year's Alaska–Yukon–Pacific Exposition; in total, 105 automobiles crossed Snoqualmie Pass in 1909. The racers and a group of Spokane motorists who drove across two years later described the road near Snoqualmie Pass as "impassible" with "treacherous" conditions, leaving much to be improved.
Sunset Highway and national routes
In 1912, the state good roads association endorsed the construction of three trunk highways across the state, including a 400-mile (640 km) route from the Puget Sound to Idaho over Snoqualmie Pass. The state legislature passed an appropriations bill in March 1913 that funded construction of the trunk routes, including a total of $506,834 for the cross-state road, dubbed the "Sunset Highway". Construction of the Sunset Highway through Snoqualmie Pass began in February 1914, with the goal of lowering the crossing of the pass by 117 feet (36 m) under the old wagon road. To extend the highway from Ellensburg to Spokane, the state highway board chose to route the Sunset Highway over a ferry crossing of the Columbia River at Vantage, then north to Wenatchee and Waterville along modern US 2. In Spokane, the Sunset Highway met the Central Washington Highway (State Road 11), which ran southwest through Cheney and Ritzville towards the Tri-Cities. The road across Snoqualmie Pass was mostly complete by September 1914, leading to plans for a formal dedication, but heavy rainfall delayed earthwork along the highway and postponed its use by motorists.
The completed Sunset Highway was briefly opened for traffic on October 1, 1914, before closing for the winter season. It reopened to traffic on June 20, 1915, and the highway was formally dedicated at the summit of Snoqualmie Pass on July 1, 1915, by a party of 400 motorists led by Governor Ernest Lister and Seattle Mayor Hiram Gill. Lister compared the highway's opening to the arrival of the transcontinental railroads and called the completion of the Sunset Highway the more important achievement for the state. In 1919, the state government rerouted the Sunset Highway between Ellensburg and Wenatchee, proposing a new branch through Blewett Pass in lieu of the ferry crossing at Vantage, which became part of the North Central Highway. The Blewett Pass highway was completed in May 1922, replacing a more dangerous wagon road across the pass. Portions of the Sunset Highway remained graded but unpaved until funds from the Federal Aid Road Act of 1916 were used to pave a gravel surface; some sections in King County were also upgraded with concrete pavement.
The Sunset Highway was renumbered to State Road 2, as part of a statewide reorganization of the highway system in 1923; the Vantage segment was retained as part of North Central Highway, renumbered as State Road 7, and the Ritzville–Spokane highway became part of State Road 11. The Sunset Highway became part of two transcontinental auto trails in the late 1920s: the National Park to Park Highway and the Yellowstone Trail, which was rerouted away from the Inland Empire Highway in 1925. The federal government established its own national highway system in 1926, designating the Sunset Highway as part of U.S. Route 10 (US 10), a transcontinental highway between Seattle and Detroit, Michigan. At the time, the 348-mile-long (560 km) Sunset Highway had 256 miles (412 km) with gravel paving, 70 miles (110 km) with cement pavement, 7 miles (11 km) with macadam, 6 miles (9.7 km) with bricks, and 4 miles (6.4 km) with asphalt concrete; only 3 miles (4.8 km) of the highway remained without any sort of pavement beyond graded dirt.
The state highway department continued work near the Snoqualmie and Blewett pasess, including the staging of snow removal vehicles to allow for all-winter passage beginning in 1930–31 and a 12.4-mile-long (20.0 km) segment near Snoqualmie Pass being completely paved in 1933. The year-round access to Snoqualmie Pass led to a rise in local skiing, especially at the ski area operated by the Seattle city government. By the end of the decade, the entire Sunset Highway was paved with either asphalt or concrete. The state highway system was restructured once again in 1937, leading to the creation of primary and secondary highway designations. State Road 2 became Primary State Highway 2 (PSH 2), still retaining its concurrency with US 10; similar carryovers followed for State Road 7 and State Road 11, which became PSH 7 and PSH 11, respectively. A new highway, PSH 18, was created and ran from PSH 7 at Burke near Quincy and through Moses Lake to PSH 11 and US 395 in Ritzville. US 10 was rerouted onto the new Burke–Ritzville highway and a section of PSH 7 between Thorp and Burke, incorporating the original Vantage Bridge, in the early 1940s.[year needed] The old alignment through Wenatchee, Coulee City, and Davenport, along with a new segment across Stevens Pass to Everett, was designated as US 10 Alternate in the early 1940s.[year needed] US 10 Alternate itself was usurped by the extension of US 2 from Sandpoint, Idaho, to Everett in 1946.
A second alternate route was established in the 1940s[year needed] after the opening of the Lake Washington Floating Bridge between Seattle and Mercer Island. US 10 previously traveled between Seattle and Issaquah via the south side of the lake, passing through Renton and crossing the Issaquah Alps. The terminus of US 10 remained at the intersection of Airport Way and 4th Avenue South (carrying US 99) between King Street and Union stations, the city's main railroad terminals. The floating bridge was conceived by engineers in the 1930s as a replacement for the automobile ferries on the lake and was opened on July 2, 1940, after one year of construction. The bridge, which initially had a toll of 25 cents, reduced the drive to the pass by 14 miles (23 km) and encouraged new suburban development on the Eastside that grew in the following decades. A new section of US 10 between Issaquah and North Bend was also constructed the following year, bypassing the towns of Fall City and Snoqualmie. Upgrades to the Snoqualmie Pass section of the highway began in 1950, expanding the road to four lanes and constructing two snowsheds to protect motorists from avalanches. The $8.25 million project was completed in 1958.
Interstate designation and construction
The federal government endorsed proposals for a transcontinental system of "superhighways" that were transmitted by the Roosevelt administration and the Bureau of Public Roads (BPR) to Congress in the late 1930s. In its 1939 report, the BPR proposed that one of the country's main toll highways run from Seattle across the northern Great Plains to Minneapolis and Chicago. Similar bills introduced by congressmen of the time proposed a transcontinental route across the northern U.S. originating in Seattle, with its eastern terminus as far as New York City or Boston. The toll roads concept was rejected, but the idea of transcontinental "superhighways" was further developed by an appointed committee into the 1944 Interregional Highways system plan, which included a route following the Sunset Highway from Seattle to Spokane and continuing along US 10 through to the Great Lakes region.
The Federal-Aid Highway Act of 1956, signed into law by President Dwight D. Eisenhower on June 29, 1956, formally authorized the creation and funding of the Interstate Highway System. The Seattle–Spokane corridor was designated as part of "Interstate 90", which continued east to Chicago and Boston, superseding US 10 through the northwestern United States. The first section to be completed under Interstate standards was a five-mile (8 km) section through Spokane Valley from Havana Street to Pines Road, which opened on November 16, 1956, and was credited with reducing the city's rate of collisions and had no fatal collisions until late 1958. The state government received $59.5 million in federal appropriations for 1957 to construct its first Interstate sections, including freeway bypasses of cities along US 10.
The Spokane Valley segment was extended east to Greenacres in November 1957 and west to Spokane in 1958, terminating near the end of a proposed elevated freeway. It was extended 3.2 miles (5.1 km) further east to Liberty Lake in October 1964, stopping near the Idaho state line. The $5 million section from Burke Junction (near present-day George) to Moses Lake was opened in June 1958 and was later extended 25 miles (40 km) to the Vantage Bridge, which was reconstructed in 1962 due to the reservoir created by the Wanapum Dam. A 7-mile (11 km) section from Ritzville to Tokio opened in November 1959 and cost $3.8 million to construct. In October 1959, the state government completed construction of a divided highway spanning 22 miles (35 km) across Snoqualmie Pass to Easton, finishing the last section of four-lane highway between Seattle and Snoqualmie Pass. A 4-mile (6.4 km) extension from Easton to Cle Elum was dedicated by Governor Roselini on September 30, 1964.
Spokane freeway construction
Planning for the east–west freeway through Downtown Spokane began in the mid-1940s, with city leaders undecided on a specific route but generally favoring a southerly bypass of the central business district. Among the options were a replacement of Riverside Avenue on the north side of downtown and an alignment along the edge of South Hill or through the hill via a tunnel. The routing debate was hotly contested among the public, attracting opinions from various public organizations and 500 members of the public during one hearing at the Spokane Coliseum, and a route along 4th and 5th avenues was chosen by the state highway commission in March 1958. The South Hill routing was deemed the most practical and least costly (at $33 million) and was submitted to the Bureau of Public Roads, despite opposition from the Deaconess Hospital, which was located 75 feet (23 m) from the proposed freeway. The hospital filed suit in 1963 and won an injunction to halt construction, but the case was overturned by the Washington Supreme Court in 1965. Construction of the Spokane Freeway began in 1961 and a section over Sunset Hill on the western approach to downtown was completed before the lawsuit halted construction.
Seattle construction and recent years
During the construction of the freeway between Seattle and Bellevue, lawsuits were filed on May 28, 1970 and stopped construction of Interstate 90 until the early 1990s. Today, Interstate 90 crosses Lake Washington between Seattle and Bellevue on a pair of floating bridges that are two of the world's longest floating bridges. The westbound lanes travel on the Homer M. Hadley Memorial Bridge, the fifth longest floating bridge, and the eastbound lanes travel on the Lacey V. Murrow Memorial Bridge, the second longest floating bridge. The Lacey V. Murrow Memorial Bridge, originally called the Lake Washington Floating Bridge, opened on July 2, 1940. The bridge sank during construction on November 25, 1990. It was later rebuilt and the new bridge opened later in 1993. The second bridge, the Homer M. Hadley Memorial Bridge, opened on June 4, 1989.
Before 2003, Interstate 90 used to end at a signalled intersection with 4th Avenue S. However, increasing traffic from Downtown Seattle, Colman Dock, Safeco Field, and Qwest Field forced city, county, and state officials to look for improvements to the area. The first stage of the improvements, the SR 519 South Seattle Intermodal Access Project, included the construction of a new on-ramp to Interstate 90 via a new interchange with 4th Avenue S. and Edgar Martínez Drive S. (formerly S. Atlantic Street). Other projects are currently ongoing and have been completed in the recent years on I-90.
Seattle–Bellevue express lanes
From 1992 to 2017, Interstate 90 had a 7.45-mile (11.99 km) network of express lanes from Downtown Seattle to Mercer Island and I-405 in Bellevue, including a set of reversible lanes on the Hadley floating bridge controlled by gates. Prior to their closure, the express lanes carried a annual average of 15,000 vehicles per day. The I-90 reversible express lanes were permanently closed on June 4, 2017, and were replaced by high-occupancy vehicle lanes on the outer lanes of the floating bridge. The right of way will be used for the East Link Extension, a light rail line between Seattle and Redmond that is scheduled to open in 2023.
The west end of the network was at the intersection of 5th Avenue, Airport Way, and Dearborn Street in the International District, adjacent to Uwajimaya, the Union Station complex, and CenturyLink Field. The bi-directional, two-lane highway was joined by ramps from the Downtown Seattle Transit Tunnel, which carries Eastside bus routes through downtown, and continued along the north side of I-90 across its interchange with I-5. The express lanes crossed under the freeway's westbound lanes on the north side of Beacon Hill, continuing east in the median. The express lanes crossed Rainier Avenue on three overpasses, with the outer two serving as the bus-only approach and platform for the Rainier Freeway Station.
Through the Mount Baker Tunnel and on the Homer M. Hadley Memorial Bridge, the express lanes changed into a uni-directional reversible layout with three lanes, while a cross-weave interchange allowed buses to re-enter the mainline lanes and high-occupancy vehicles and single-occupant Mercer Island traffic into the express lanes. On Mercer Island, the express lanes had exits to 77th Avenue Southeast, 80th Avenue Southeast, and Island Crest Way, as well as a westbound entrance from the mainline HOV lanes. The 80th Avenue Southeast ramp was converted to a HOV-only westbound offramp for the mainline lanes in 2012. The eastbound-only express lanes then crossed the East Channel Bridge and merged back into the mainline HOV lanes, with ramps that served Bellevue Way and I-405.
During the last years of operation, the reversible portion of the express lanes carried westbound traffic from 6 a.m. to 12:30 p.m. and eastbound traffic from 2 p.m. to 5 a.m. on weekdays. The express lanes remained opened to eastbound from Friday afternoon to 5 a.m. on Monday, except for special weekend events. The express lanes changed direction at midnight prior to 2012, when the I-5 express lanes were automated, allowing for a single crew to be used for both systems.
|King||Seattle||0.00||0.00||1A||Edgar Martínez Drive South, South Atlantic Street||Westbound exit and eastbound entrance|
|0.00||0.00||1B||SR 519 north / 4th Avenue South – Seattle City Center, Amtrak, Ferries, Safeco Field, CenturyLink Field||Westbound exit and eastbound entrance|
|0.32||0.51||2||I-5 – Vancouver, Tacoma, Portland, James Street, Madison Street||Signed as exits 2A (south) and 2B (north) eastbound and 2B (south) and 2C (north) westbound|
|1.39||2.24||3||Rainier Avenue||Signed as exits 3A (south) and 3B (north) westbound; no westbound entrance|
|Lake Washington||2.13||3.43||Lacey V. Murrow Memorial Bridge and Homer M. Hadley Memorial Bridge|
|Mercer Island||4.09||6.58||7||West Mercer Way||Eastbound exit and westbound entrance|
|4.91||7.90||7A||77th Avenue Southeast||Eastbound exit and westbound entrance|
|5.07||8.16||—||80th Avenue Southeast||HOV only; westbound exit and eastbound entrance|
|5.17||8.32||7B||Island Crest Way||Signed as exit 7 westbound; HOV only|
|6.41||10.32||8||East Mercer Way|
|Lake Washington||6.78||10.91||East Channel Bridge|
|7.98||12.84||10A||I-405 – Everett, Renton||Signed as exit 10 westbound|
|8.23||13.24||10B||Factoria Boulevard – Factoria||Eastbound exit and westbound entrance|
|9.09||14.63||—||142nd Place Southeast||HOV only|
|9.60||15.45||11B||148th Avenue Southeast – Bellevue College||Westbound exit is via 156th Avenue|
|9.60||15.45||11A||150th Avenue Southeast, 156th Avenue Southeast||Signed as exit 11 westbound|
|11||161st Avenue Southeast||Eastbound exit is via 150th Avenue|
|11.73||18.88||13||West Lake Sammamish Parkway, Lakemont Boulevard Southeast, Southeast Newport Way|
|Issaquah||13.89||22.35||15||SR 900 west (17th Avenue Northwest) – Renton|
|15.20||24.46||17||Front Street, East Lake Sammamish Parkway Southeast|
|16.13||25.96||18||East Sunset Way, Highlands Drive|
|||18.32||29.48||20||High Point Way|
|||20.59||33.14||22||Preston, Fall City|
|||23.72||38.17||25||SR 18 west / Snoqualmie Parkway – Auburn, Tacoma|
|||25.40||40.88||27||Snoqualmie, North Bend||Eastbound exit and westbound entrance|
|North Bend||28.63||46.08||31||SR 202 west – North Bend, Snoqualmie|
|||30.95||49.81||32||436th Avenue Southeast|
|||33.06||53.20||34||468th Avenue Southeast|
|||36.14||58.16||38||Washington State Fire Training Academy, Olallie State Park||Eastbound exit and westbound entrance|
|||37.96||61.09||38||Washington State Fire Training Academy, Olallie State Park||Westbound exit and eastbound entrance|
|||43.91||70.67||45||USFS Road 9030|
|||46.09||74.17||47||Denny Creek, Asahel Curtis|
|Snoqualmie Pass||50.58||81.40||52||SR 906 – West Summit, Alpental||Eastbound exit and westbound entrance|
|Kittitas||51.29||82.54||53||East Summit, Snoqualmie Pass Recreational Area|
|53.03||85.34||54||SR 906 – Hyak, Gold Creek||Access to SR 906|
|||61.30||98.65||62||Stampede Pass, Lake Kachess|
|||62.31||100.28||63||Cabin Creek Road|
|||68.63||110.45||70||Sparks Road – Easton|
|||72.34||116.42||74||West Nelson Siding Road|
|||76.35||122.87||78||Golf Course Road|
|84||Cle Elum, South Cle Elum|
|||84.15||135.43||85||SR 903 north / SR 970 – Cle Elum, Wenatchee|
|||91.91||147.91||93||Elk Heights Road|
|||99.36||159.90||101||Thorp Highway – Thorp|
|||104.35||167.94||106||US 97 north – Ellensburg, Wenatchee||Western end of US 97 overlap|
|Ellensburg||107.65||173.25||109||I‑90 Bus. (Canyon Road) – Ellensburg|
|||109.15||175.66||110||I-82 east / US 97 south – Yakima||Eastern end of US 97 overlap|
|||134.72||216.81||136||Huntzinger Road – Vantage|
|Columbia River||135.72||218.42||Vantage Bridge|
|Grant||||136.08||219.00||137||SR 26 east to SR 243 – Othello, Pullman, Richland|
|||139.65||224.74||139||Scenic View (Wild Horse Monument)|
|||148.07||238.30||149||SR 281 north – Quincy, Wenatchee, George|
|||150.02||241.43||151||SR 283 north / SR 281 north (via SR 281 Spur) – Ephrata, Soap Lake, Quincy, Wenatchee|
|Moses Lake||172.89||278.24||174||Hansen Road – Mae Valley|
|173.69||279.53||175||Westshore Drive – Mae Valley||Westbound exit only|
|174.28||280.48||176||I‑90 Bus. east / SR 171 north – Moses Lake|
|177.74||286.04||179||SR 17 / I‑90 Bus. west – Moses Lake, Ephrata, Othello|
|||181.12||291.48||182||O Road Northeast/Southeast – Wheeler|
|||183.18||294.80||184||Q Road Northeast/Southeast|
|||187.18||301.24||188||U Road Northeast/Southeast – Warden|
|Adams||||195.20||314.14||196||Deal Road – Schrag|
|||205.13||330.12||206||SR 21 – Lind, Odessa|
|220||US 395 south / I‑90 Bus. east – Ritzville, Pasco (Tri-Cities)||Western end of US 395 overlap|
|||219.67||353.52||221||SR 261 south – Ritzville, Washtucna|
|||228.95||368.46||231||Tokio, Weigh Station|
|Lincoln||Sprague||242.98||391.04||245||SR 23 – Sprague, Harrington|
|Spokane||||255.41||411.04||257||SR 904 east – Tyler, Cheney|
|||262.02||421.68||264||SR 902 east (Salnave Road) – Cheney, Medical Lake|
|||268.27||431.74||270||SR 904 west – Four Lakes, Cheney|
|||270.53||435.38||272||SR 902 west (Medical Lake Highway) – Medical Lake|
|||274.04||441.02||276||Geiger Boulevard / Grove Road||Former I-90 Bus.|
|Spokane||275.45||443.29||277B||US 2 west – Spokane Airport, Fairchild AFB, Davenport||Western end of US 2 overlap; signed as exit 277 westbound|
|275.92||444.05||277A||Garden Springs – Spokane Falls Community College||Signed as exit 277 westbound; no entrance ramps|
|277.06||445.88||279||US 195 south – Colfax, Pullman|
|277.88||447.20||280A||Maple Street, Walnut Street||Signed as exit 280 eastbound|
|278.64||448.43||280B||Lincoln Street||Eastbound exit is via exit 280|
|279.05||449.09||281||US 2 east / US 395 north (Division Street) – Newport, Colville||Eastern end of US 2/US 395 overlap|
|279.83||450.34||282A||SR 290 east (Trent Avenue) / Hamilton Street||Signed as exit 282 eastbound|
|280.08||450.75||282B||Second Avenue||Westbound exit only|
|281.44||452.93||283B||Thor Street, Freya Street|
|282.05||453.92||—||Havana Street||Eastbound entrance only|
|Spokane Valley||283.32||455.96||285||I‑90 Bus. east (Appleway Boulevard) / Sprague Avenue||No eastbound entrance|
|285.54||459.53||287||Argonne Road – Millwood|
|287.56||462.78||289||SR 27 (Pines Road)|
|288.74||464.68||291A||Evergreen Road – Spokane Valley Mall|
|291.66||469.38||293||I‑90 Bus. west (Barker Road)|
|Liberty Lake||292.63||470.94||294||Country Vista Drive, Appleway Avenue||Westbound exit and eastbound entrance; former BL-90|
|293.89||472.97||296||Liberty Lake, Otis Orchards|
|Spokane Bridge||297.20||478.30||299||Spokane Bridge Road – State Line|
|297.52||478.81||—||I-90 east – Coeur d'Alene||Continuation into Idaho|
|1.000 mi = 1.609 km; 1.000 km = 0.621 mi|
Express lane exits
|Seattle||0.00||0.00||—||Airport Way South, South Dearborn Street||HOV entrance and exit only|
|0.23||0.37||—||Downtown Seattle Transit Tunnel||Bus only|
|1.22||1.96||—||Rainier Freeway Station||Bus only|
|1.67||2.69||—||I-90 west to I-5||Westbound off-ramp only (All Mercer Island SOVs exit here)|
|1.88||3.03||—||I-90 east||Eastbound on-ramp only (All Mercer Island SOVs enter here)|
|Mercer Island||4.59||7.39||7A||77th Avenue SE|
|4.81||7.74||7B||Island Crest Way||All Mercer Island SOVs enter or exit here|
|5.46||8.79||7C||80th Avenue SE||HOV entrance and exit only; converted to an HOV-only outer entrance in 2012|
|6.02||9.69||—||I-90 west||Westbound HOV entrance only|
|6.61||10.64||—||I-90 east||Eastbound HOV exit only|
|Bellevue||6.91||11.12||—||I-405||Eastbound HOV entrance only|
|9||Bellevue Way||HOV entrance and exit only|
|1.000 mi = 1.609 km; 1.000 km = 0.621 mi|
- Multimodal Planning Division (January 27, 2017). "State Highway Log Planning Report 2016, SR 2 to SR 971" (PDF). Washington State Department of Transportation. pp. 624–700. Retrieved June 15, 2018.
- "Table 1: Main Routes of the Dwight D. Eisenhower National System Of Interstate and Defense Highways as of December 31, 2017". Federal Highway Administration. December 31, 2017. Retrieved January 25, 2018.
- Washington State Highways 2014–2015 (PDF) (Map). 1:842,000. Washington State Department of Transportation. 2014. Retrieved June 15, 2018, with inset maps.
- "I-90 Bellevue to North Bend Corridor Planning Study" (PDF). Washington State Department of Transportation. October 2012. p. 1. Retrieved June 16, 2018.
- National Highway System: Washington (PDF) (Map). Federal Highway Administration. October 1, 2012. Retrieved June 15, 2018.
- "Transportation Commission List of Highways of Statewide Significance" (PDF). Washington State Transportation Commission. July 26, 2009. Retrieved June 15, 2018.
- Lloyd, Jennifer (June 10, 2004). "Forever green: Mountains to Sound cooperation will keep it so". The Seattle Times. p. G17. Retrieved June 16, 2018.
- Jackson, Kritsin (July 22, 1998). "Northwest Notebook: Two Washington highways honored for their scenery". The Seattle Times. p. F8.
- "2016 Annual Traffic Report" (PDF). Washington State Department of Transportation. pp. 116–120. Retrieved June 15, 2018.
- Ferguson, Adele (June 26, 1992). "Heading east: speed, bumps, runaway trucks". Kitsap Sun. Retrieved June 30, 2018.
- "Washington will not raise I-90 speed limit to 75". Spokesman-Review. Associated Press. May 11, 2016. Retrieved June 30, 2018.
- Lindblom, Mike (August 6, 2008). "Port clears way for I-90 link to waterfront". The Seattle Times. Retrieved June 16, 2018.
- Lindblom, Mike (July 11, 2009). "Sports fans to find relief at Stadium light-rail stop". The Seattle Times. Retrieved June 16, 2018.
- Johnston, Steve (February 17, 1992). "Reversible car-pool lane debuts on I-90". The Seattle Times. p. B1. Retrieved June 16, 2018.
- "SR 519 Intermodal Access Project Phase 2 Transportation Discipline Report" (PDF). Washington State Department of Transportation. February 2008. pp. 2–5, 4–38, 5–50. Archived from the original (PDF) on February 22, 2017. Retrieved June 16, 2018.
- Google (June 15, 2018). "Interstate 90, Washington" (Map). Google Maps. Google. Retrieved June 15, 2018.
- Johnson, Annie (May 15, 2017). "Ch-ch-ch-changes: Facing change on I-90 with new HOV lanes opening next month". WSDOT Blog. Washington State Department of Transportation. Retrieved June 16, 2018.
- "Final List of Nationally and Exceptionally Significant Features of the Federal Interstate Highway System" (PDF). Federal Highway Administration. November 1, 2006. Retrieved June 16, 2018.
- Clarridge, Christine (May 16, 2008). "Mugging of cyclist in tunnel spurs warning". The Seattle Times. p. B1. Retrieved June 16, 2018.
- Campanario, Gabriel (June 21, 2013). "Mount Baker viewpoint lets you find your place in the universe". The Seattle Times. Retrieved June 16, 2018.
- Lindblom, Mike (May 14, 2017). "World's first light rail on a floating bridge: For I-90, Sound Transit had to invent 'a brilliant solution'". The Seattle Times. p. A1. Retrieved June 15, 2018.
- Gutierrez, Scott (February 29, 2012). "Washington: Floating bridge capitol of the world". Seattle Post-Intelligencer. Retrieved June 15, 2018.
- "East Link Extension, I-90 Segment Fact Sheet: Seattle" (PDF). Sound Transit. October 2016. p. 10. Retrieved June 16, 2018.
- "SR 90 – Exit 10: Junction SR 405/Richards Road" (PDF). Washington State Department of Transportation. March 13, 1997. Retrieved June 16, 2018.
- "WSDOT Bridge List" (PDF). Washington State Department of Transportation. November 2017. p. 188. Retrieved June 16, 2018.
- Stiles, Marc (July 11, 2014). "T-Mobile merger would be really bad news for Bellevue office market". Puget Sound Business Journal. Retrieved June 16, 2018.
- Brown, Charles E. (April 23, 2007). "Q&A: Bottleneck near Eastgate; Ramp restrictions". The Seattle Times. p. B1. Retrieved June 16, 2018.
- Brown, Charles (November 18, 1980). "Bellevue Airfield conversion begins". The Seattle Times. p. C24.
- Snoqualmie Pass, WA (PDF) (Map). 1:24,000. United States Forest Service. 1994. Retrieved June 16, 2018.
- "Hone up on pass knowledge as you wait for crews to dig out your favorite route". Yakima Herald-Republic. April 16, 2018. Archived from the original on June 16, 2018. Retrieved June 16, 2018.
- "How the Denny Creek Viaduct preps for winter". PEMCO. November 26, 2014. Retrieved June 16, 2018.
- Doughton, Sandi (June 8, 2015). "Making way for wildlife". The Seattle Times. p. A1. Retrieved June 15, 2018.
- Ripley, Richard (November 20, 2008). "Four-day Snoqualmie Pass closure cost $27.9 million". Spokane Journal of Business. Retrieved June 16, 2018.
- Lindblom, Mike (July 7, 2011). "I-90 work to smooth flow of traffic, wildlife". The Seattle Times. p. A1. Retrieved June 16, 2018.
- Regimbal, Alec (July 20, 2017). "I-90 archway is half of planned wildlife overpass". Yakima Herald-Republic. Retrieved June 16, 2018.
- Bush, Evan (September 22, 2016). "'Elk like open; they don't like stuff above their head': I-90 wildlife overpass is under way". The Seattle Times. p. B4. Retrieved June 16, 2018.
- "I-90 open in both directions over Snoqualmie Pass". The Seattle Times. December 24, 2015. Retrieved June 16, 2018.
- "Snoqualmie Historical Closure and Snowfall Records". Washington State Department of Transportation. Retrieved June 16, 2018.
- "Avalanche Zones & Chain up/off areas on Stevens Pass and Snoqualmie Pass" (PDF). Washington State Department of Transportation. December 2016. Retrieved June 16, 2018.
- "Organized Chain-Up on Snoqualmie Pass". Washington State Department of Transportation. Retrieved June 16, 2018.
- Faulk, Mike (February 17, 2016). "Horrible weather plagues drivers across Snoqualmie Pass: 72 closures in nine weeks". Yakima Herald-Republic. Retrieved June 16, 2018.
- "SR 20 - North Cascades Highway - Frequently Asked Questions". Washington State Department of Transportation. Retrieved June 16, 2018.
- Sullivan, Amanda; Danberg, Amy (July 2009). "Reconstructing Snoqualmie Pass". Public Roads. Federal Highway Administration. 73 (1). Retrieved June 16, 2018.
- Johnston, Mike (May 7, 2008). "County approves Vantage wind farm". The Daily Record. Ellensburg, Washington. Retrieved June 16, 2018.
- Grunbaum, Rami (September 9, 2012). "Wind farm lets you bike, hike or hunt among towering turbines". The Seattle Times. p. J3. Retrieved June 16, 2018.
- Nelson, Dan A. (November 25, 2004). "High-desert hikes: Burn off holiday calories in decidedly different Eastern Washington". The Seattle Times. p. G6.
- Lacitis, Erik (August 4, 2008). "All the pretty horses of Vantage are only half done". The Seattle Times. p. A1. Retrieved June 16, 2018.
- Layton, Jeff (June 10, 2018). "For summer fun in Potholes State Park, just add water (and sand dunes)". The Seattle Times. p. H2. Retrieved June 16, 2018.
- "WSDOT Corridor Sketch Summary, I-90: Sprague Ave. I/C to Idaho State Line (Interstate 90 East)" (PDF). Washington State Department of Transportation. March 19, 2018. Retrieved June 16, 2018.
- Ott, Jennifer (May 9, 2013). "Sunset Highway". HistoryLink. Retrieved June 16, 2018.
- "King County Historic and Scenic Corridors Project Final Report". King County. December 2009. Retrieved June 16, 2018.
- Lange, Greg (November 4, 1998). "Seattle Weekly Intelligencer announces on October 7, 1867, that the first wagon road has been completed over Snoqualmie Pass". HistoryLink. Retrieved June 16, 2018.
- "King County Historic and Scenic Corridors Project Final Report: Inventory of Heritage Corridors". King County. December 2009. pp. 85–88. Retrieved June 16, 2018.
- "History of Roads & Highways in the State of Washington" (PDF). Washington State Department of Transportation. 1965. p. 9. Retrieved June 16, 2018.
- "Toll Road No More". Seattle Post-Intelligencer. October 28, 1893. p. 8. Retrieved June 16, 2018 – via Newspapers.com.
- "Chapter LVII: Snoqualmie Pass Wagon Road" (PDF). Session Laws of the State of Washington, 1899. Washington State Legislature. March 13, 1899. pp. 99–100. Retrieved June 16, 2018.
- "Forty Years with the Washington Department of Highways" (PDF). Washington State Department of Transportation. 1945. Retrieved June 16, 2018.
- "Wenatchee To Be Benefitted; Trans-State Highway to Go Through this valley—Legislature to Get Busy". The Wenatchee Daily World. November 22, 1907. p. 1. Retrieved June 16, 2018 – via Newspapers.com.
- "Good Roads Department: Washington State Highways". The Ranch. Seattle. November 15, 1907. p. 26. Retrieved June 16, 2018 – via Newspapers.com.
- "Good Roads Department: Plan Main Roads for State". The Ranch. Seattle. June 1, 1908. p. 18. Retrieved June 16, 2018 – via Newspapers.com.
- "Chapter 92: Establishing Certain State Roads" (PDF). Session Laws of the State of Washington, 1909. Washington State Legislature. March 13, 1909. pp. 190–191. Retrieved June 16, 2018.
- "Spokane to Seattle by Auto is Rough Tour". Oakland Tribune. October 29, 1911. p. 36. Retrieved June 16, 2018 – via Newspapers.com.
- "Good Roads Association Outlines Great Highways". Kennewick Courier. May 31, 1912. p. 3. Retrieved June 16, 2018 – via Newspapers.com.
- "Public Highway Bill Passes". Aberdeen Herald. March 14, 1913. p. 1. Retrieved June 16, 2018 – via Newspapers.com.
- "Snoqualmie Pass Road Under Way". The Seattle Times. March 8, 1914. p. 2.
- Map of Washington State Highways Authorized by Legislative Acts of 1913, with 1915 changes (Map). 1 inch = 18 miles. Washington State Highway Commission. Retrieved June 16, 2018 – via Washington State University Libraries Digital Collection.
- State of Washington Showing State Highways Authorized by Legislative Acts of 1915 (Map). Cartography by Rand McNally. Washington State Bureau of Statistics and Immigration. 1915. Retrieved June 16, 2018 – via Washington State Archives.
- "Rain Postpones Opening of Road". The Seattle Times. September 29, 1914. p. 4.
- "Sunset Highway Finished". The Seattle Times. October 4, 1914. p. 1.
- "Big Celebration at Snoqualmie Pass Arranged". The Seattle Times. June 24, 1915. p. 4.
- McDonald, Lucile (July 18, 1965). "Snoqualmie Pass Road Is 50 Years Old". The Seattle Times. p. 2.
- Wagner, Frederick (July 2, 1915). "New Road Across Mountains is Dedicated". The Seattle Times. p. 10.
- "Chapter 110: Amending Highway Classification Act" (PDF). Session Laws of the State of Washington, 1919. Washington State Legislature. March 14, 1919. pp. 267–272. Retrieved June 16, 2018.
- Dyer, R. M. (March 9, 1919). "State Roads Will Take High Rank". The Seattle Times. p. 8.
- "Changes Proposed in Washington Highways". The Seattle Times. February 2, 1919. p. 9.
- "Blewett Pass to Open Sunday". The Leavenworth Echo. May 5, 1922. p. 1. Retrieved June 16, 2018 – via Newspapers.com.
- "Blewett Is Short Cut". The Seattle Times. November 20, 1921. p. 7.
- "State Reports on Highways". Lynden Tribune. September 8, 1921. p. 9. Retrieved June 16, 2018 – via Newspapers.com.
- "Chapter 185: Primary and Secondary State Highways" (PDF). Session Laws of the State of Washington, 1923. Washington State Legislature. March 19, 1923. pp. 627–632. Retrieved June 16, 2018.
- "State Legislature Closes Sessions Thursday Night". Chehalis Bee-Nugget. March 9, 1923. p. 1. Retrieved June 16, 2018 – via Newspapers.com.
- "Trail Is Shortened". The Seattle Times. May 6, 1925. p. 3.
- Rand McNally Official 1925 Auto Trails Map of Washington and Oregon (Map). 1:1,077,120. Rand McNally. 1925. Retrieved June 16, 2018 – via David Rumsey Historical Map Collection.
- American Association of State Highway Officials (November 11, 1926). United States System of Highways Adopted for Uniform Marking by the American Association of State Highway Officials (Map). 1:7,000,000. Washington, D.C.: Bureau of Public Roads. OCLC 32889555. Retrieved June 16, 2018 – via University of North Texas Libraries.
- "Highways Center in City Roads Total 45,000 Miles". The Seattle Times. August 7, 1927. p. 6.
- "Blewett Pass Road May Be Kept Clear of Winter's Storm". The Seattle Times. October 5, 1930. p. 12.
- "Snoqualmie Paving Nears Completion". The Seattle Times. September 8, 1933. p. 10.
- Lundin, John W.; Lundin, Stephen J. (March 29, 2013). "Seattle's Municipal Ski Park at Snoqualmie Summit (1934-1940)". HistoryLink. Retrieved June 16, 2018.
- Highways of the State of Washington (Map). Cartography by Rand McNally. Washington State Department of Highways. 1939. OCLC 5673231. Retrieved June 16, 2018 – via Washington State Archives.
- "Chapter 190: Establishment of Primary State Highways" (PDF). Session Laws of the State of Washington, Twenty-Fifth Session. Washington State Legislature. March 17, 1937. p. 933–943. Retrieved June 16, 2018.
- Highways of the State of Washington (Map). Cartography by Rand McNally. Washington State Department of Highways. 1944. OCLC 5673231. Retrieved June 17, 2018 – via David Rumsey Historical Map Collection.
- Weingroff, Richard (January 30, 2008). "U.S. 2: Houlton, Maine, to Everett, Washington". Federal Highway Administration. Retrieved June 17, 2018.
- State of Washington Highway Map (Map). Cartography by Rand McNally. Washington State Department of Highways. 1950. OCLC 5673231. Retrieved June 17, 2018 – via Washington State Archives.
- Shell Oil Company; H.M. Gousha Company (1956). Shell Street Map of Seattle (Map). Shell Oil Company. Retrieved June 17, 2018 – via David Rumsey Historical Map Collection.
- "Lake Pontoon Bridge is Biggest Thing Afloat". The Seattle Times. June 30, 1940. p. 3.
- Boswell, Sharon; McConaghy, Lorraine (June 16, 1996). "A bridge to the future". The Seattle Times. Retrieved June 17, 2018.
- "Washington State Highways Traverse Scenic Wonderland". The Seattle Times. July 27, 1941. p. 48.
- "$582,460 For Issaquah Road". The Seattle Times. March 18, 1941. p. 7.
- "Snoqualmie Snowsheds to Be Ready in 6 Weeks, but Cars Without Chains Still to Be Nuisance". The Seattle Times. November 11, 1950. p. 16.
- "Highway 99 Project Still Has '55 Target". The Seattle Times. United Press International. September 24, 1954. p. 34.
- Barr, Robert A. (July 6, 1958). "'Road Factory' Lays Concrete For Highway". The Seattle Times. p. 16.
- Weingroff, Richard F. "Designating the Urban Interstates". Federal Highway Administration. Retrieved June 21, 2018.
- Weingroff, Richard F. (1996). "Federal-Aid Highway Act of 1956, Creating the Interstate System". Public Roads. Federal Highway Administration. 60 (1). ISSN 0033-3735. Retrieved June 15, 2018.
- Bureau of Public Roads (April 27, 1939). Toll Roads and Free Roads. Government Printing Office. p. 17. OCLC 2843728. Retrieved June 20, 2018 – via HathiTrust.
- Weingroff, Richard F. (1996). "A Vast System of Interconnected Highways: Before the Interstates" (PDF). Federal Highway Administration. pp. 207, 213, 265, 317. Retrieved June 20, 2018.
- Miller, James N. (July 23, 1939). "14,000 Mile Super Highway To Speed Transportation". The Seattle Times. p. 3.
- National Interregional Highway Committee (January 12, 1944). "The general location of routes of the recommended interregional highway system" (Map). Interregional Highways. Government Printing Office. p. 7. OCLC 913715306. Retrieved June 21, 2018 – via HathiTrust.
- Frein Johnson, Alice (June 28, 1956). "Federal Aid Possible for Tunnel Through Cascades". The Seattle Times. p. 19.
- Hittle, Leroy (October 9, 1957). "State's Two Major Highways To Be Renumbered In Defense System". Port Angeles Evening News. Associated Press. p. 1. Retrieved June 21, 2018 – via Newspapers.com.
- American Association of State Highway Officials (August 14, 1957). Official Route Numbering for the National System of Interstate and Defense Highways (Map). Public Roads Administration. Retrieved June 21, 2018 – via Wikimedia Commons.
- Cannata, Amy (September 10, 2006). "Freeway at 50". Spokesman-Review. Retrieved May 11, 2018.
- Dieffenbach, Al (November 16, 1961). "Freeway is Five: Traffic Benefits Are Listed". Spokane Daily Chronicle. p. 1. Retrieved June 22, 2018 – via Google News Archive.
- "State Reveals Highway-Fund Allotments". The Seattle Times. Associated Press. January 21, 1957. p. 3.
- Dieffenbach, Al (November 16, 1957). "Deathless Record Intact on First Anniversary". Spokane Daily Chronicle. p. 1. Retrieved June 22, 2018 – via Google News Archive.
- Rivers, Robin (September 18, 1999). "Road to growth: Construction of Interstate 90 through the valley laid the groundwork for suburban development". Spokesman-Review. p. V1.
- "Freeway Section Is Open". The Spokesman-Review. October 24, 1964. p. 6. Retrieved July 27, 2018 – via Google News Archive.
- "Opening of Bypass Set For Monday Afternoon". Columbia Basin Herald. June 20, 1958. p. 1.
- "Difficult Work on 13A Poses Problems". Washington Highway News. 8 (11). Washington State Department of Highways. April 1960. pp. 18–19. OCLC 29654162. Retrieved September 5, 2018 – via WSDOT Library Digital Collections.
- "State Dedicates Vantage Bridge". The Seattle Times. Associated Press. November 9, 1962. p. 5.
- "Road is Open". The Spokesman-Review. November 24, 1959. p. 6. Retrieved July 27, 2018 – via Google News Archive.
- Reddin, John J. (October 26, 1959). "New Sunset Highway Four-Lane Link Opened". The Seattle Times. p. 10.
- "Freeway Link To Cle Elum Is Dedicated". The Seattle Times. Associated Press. September 30, 1964. p. 23.
- U.S. Route Numbering Subcommittee (June 24, 1969). "U.S. Route Numbering Subcommittee Agenda Showing Action Taken by the Executive Committee" (PDF) (Report). Washington, DC: American Association of State Highway Officials. p. 8. Retrieved June 22, 2018 – via Wikimedia Commons.
- Special Committee on U.S. Route Numbering (June 17, 1975). "Route Numbering Committee Agenda Showing Action Taken by the Executive Committee" (PDF) (Report). Washington, DC: American Association of State Highway and Transportation Officials. p. 1. Retrieved June 22, 2018 – via Wikimedia Commons.
- City of Spokane Engineering Department (June 1948). Origin and Destination Traffic Survey of Spokane, Washington (Report). Washington State Department of Highways. pp. 66–68. OCLC 31032630. Retrieved September 24, 2018 – via WSDOT Library Digital Collections.
- "Then and Now: Liberty Park gave way to I-90". The Spokesman-Review. March 9, 2015. Retrieved September 24, 2018.
- "Debate Is Spirited on Freeway Route". The Spokesman-Review. November 22, 1958. p. 1. Retrieved September 24, 2018 – via Google News Archives.
- Tegner, Bob (March 21, 1958). "$33,000,000 East-West Freeway Route Chosen: Fourth and Fifth Picked; Viaduct, Span Included". The Spokesman-Review. p. 1. Retrieved September 24, 2018 – via Google News Archives.
- "Freeway Gets Green Light". Spokane Daily Chronicle. June 7, 1965. p. 1. Retrieved September 24, 2018 – via Google News Archive.
- Washington State Department of Transportation. "History of WSDOT (1978–1990)". Washington State Department of Transportation. Archived from the original on August 30, 2008. Retrieved August 11, 2008.
- Washington State Department of Transportation. "History of WSDOT (1967–1977)". Washington State Department of Transportation. Archived from the original on October 5, 2006. Retrieved August 11, 2008.
- Washington State Department of Transportation. "History of WSDOT (1921–1940)". Washington State Department of Transportation. Archived from the original on October 11, 2008. Retrieved August 11, 2008.
- Washington State Department of Transportation. "History of WSDOT (1991–2004)". Washington State Department of Transportation. Archived from the original on October 5, 2006. Retrieved August 11, 2008.
- "Mountains To Sound Greenway (Washington)". Retrieved August 24, 2008.
- Washington State Department of Transportation. "Construction Projects on Interstate 90". Washington State Department of Transportation. Retrieved August 11, 2008.
- Whitely, Peyton (January 17, 1992). "HOV lanes along I-90 will shift to the left". The Seattle Times. p. E2. Retrieved June 25, 2018.
- "I-90 Express Lanes Map". Washington State Department of Transportation. Archived from the original on August 9, 2016. Retrieved June 25, 2018.
- Higgins, Mark (December 6, 2000). "Council eyes I-90 HOV lanes". The Seattle Times. p. B1.
- Metzger, Katie (June 5, 2017). "I-90 center lanes closed as of June 4 for light rail construction". Mercer Island Reporter. Retrieved June 27, 2018.
- Lindblom, Mike (June 1, 2017). "Mercer Island braces for new I-90 bottlenecks as light-rail work begins". The Seattle Times. p. A1. Retrieved June 25, 2018.
- Peterson, Julie (July 9, 1999). "Store's expansion is raising a ruckus—Uwajimaya at odds with some neighbors". The Seattle Times. p. B1.
- Lindblom, Mike (June 3, 2014). "Bus riders stranded on I-90 ramp after agencies screw up". The Seattle Times. p. B1. Retrieved June 25, 2018.
- "SR 5 – Exit 164A/B: Junction SR 90/4th Avenue/Dearborn Street" (PDF). Washington State Department of Transportation. October 31, 2017. Retrieved June 25, 2018.
- "Interstate Guide: I-90 Reversible Express Lanes". Washington State Department of Transportation. Retrieved June 25, 2018.
- Lilly, Dick (February 19, 1991). "South end wants in as Metro maps rapid-transit plans". The Seattle Times. p. A1.
- "SR 90 – Exit 3: Junction Rainier Avenue South" (PDF). Washington State Department of Transportation. January 12, 2006. Archived from the original (PDF) on January 27, 2017. Retrieved June 25, 2018.
- Foster, George (July 3, 2001). "Federal agency objects to narrow lanes". Seattle Post-Intelligencer. p. A1.
- "SR 90 – Exit 7: Junction Island Crest Way" (PDF). Washington State Department of Transportation. January 8, 2015. Archived from the original (PDF) on January 27, 2017. Retrieved June 25, 2018.
- "Changes ahead for I-90 Express Lanes" (Press release). Washington State Department of Transportation. January 18, 2012. Archived from the original on July 10, 2014. Retrieved January 2, 2015.
- "Future I-90 Ramp Access Summary" (PDF). City of Mercer Island. June 16, 2016. Retrieved June 25, 2018.
- "SR 9 – Exit 9: Junction Bellevue Way" (PDF). Washington State Department of Transportation. May 18, 2016. Archived from the original (PDF) on January 27, 2017. Retrieved June 25, 2018.
- "I-5 and I-90 Express Lanes". Washington State Department of Transportation. Archived from the original on August 5, 2016. Retrieved June 25, 2018.
- "New hours for I-90 express lanes reflect efficiency" (Press release). Washington State Department of Transportation. August 31, 2012. Archived from the original on July 10, 2014. Retrieved June 25, 2018.
- Strategic Planning Division (January 25, 2013). "State Highway Log Planning Report 2012, SR 2 to SR 971" (PDF). Washington State Department of Transportation. pp. 687–688. Retrieved June 16, 2018.
- Media related to Category:Interstate 90 in Washington (state) at Wikimedia Commons
- Interstate 90 at Highways of Washington State
- Interstate 90 at AARoads