Route description
[edit]
Lengths
 
mi
km
WA
296.92
477.85
ID
73.55
118.37
MT
552.46
889.10
WY
208.80
336.03
SD
412.76
664.27
MN
275.70
443.70
WI
187.13
301.16
IL
123.89
199.38
IN
156.28
251.51
OH
244.75
393.89
PA
46.30
74.51
NY
385.48
620.37
MA
135.72
218.42
Total
3,099.74
4,988.55
I-90 is the longest Interstate Highway in the United States, spanning 3,099.74 miles (4,988.55 km) across the northern portion of the coterminous part of the country. The transcontinental freeway passes through 13 states in the Pacific Northwest, Mountain West, Great Plains, Midwest, and the Northeast regions of the United States. From the Wisconsin–Illinois state line to Massachusetts, approximately 760 miles (1,220 km) of I-90 uses turnpikes and other tolled highways with the exception of segments in Chicago, northeastern Ohio, Pennsylvania, and Albany, New York. The toll road sections comprise 25 percent of the freeway's total length.
According to 2011 data from the Federal Highway Administration, the busiest section of I-90 is in the Chicago area, where a daily average of 306,574 vehicles use the freeway. The lowest daily traffic counts on I-90 were recorded in Wyoming, where an average of 9,820 vehicles used rural sections of the freeway.
Washington[edit]
Main article: Interstate 90 in Washington
Aerial view of I-90 near North Bend, Washington
The western terminus of I-90 is at an intersection with Washington State Route 519 and 4th Avenue South in the SoDo neighborhood of Seattle. The junction is south of Downtown Seattle, adjacent to the Port of Seattle and two major sports stadiums, Lumen Field and T-Mobile Park. The freeway travels east through an interchange with I-5 and around Beacon Hill before it enters the Mount Baker Ridge Tunnel alongside the 2 Line of the Link light rail system. I-90 emerges from the tunnel on a pair of floating bridges, among the longest of their kind: the eastbound-only Lacey V. Murrow Memorial Bridge and the Homer M. Hadley Memorial Bridge, which carries westbound traffic and the light rail tracks.
The floating bridges cross Lake Washington to Mercer Island, where I-90 travels through a series of tunnels under 14 acres (5.7 ha) of parkland, including Aubrey Davis Park. The freeway continues from the island and enters Bellevue, the largest city of the Eastside region, and intersects I-405 near Factoria. I-90 then travels along Lake Sammamish and through Issaquah as it leaves the Seattle metropolitan area and ascends into the Cascade Range on the Mountains to Sound Greenway, a designated National Heritage Area and National Scenic Byway. The freeway crosses Snoqualmie Pass, elevation 3,022 feet (921 m), at the crest of the mountain range near a ski resort.
From Snoqualmie Pass, I-90 follows the Yakima River into the Kittitas Valley and intersects I-82 in Ellensburg after a brief concurrency with U.S. Route 97 (US 97). The highway crosses the Columbia River on the Vantage Bridge and turns northeast to climb the cliffs of the Columbia Plateau near George. After traveling east across Moses Lake and the surrounding agricultural region, I-90 begins a long concurrency with US 395 at Ritzville as the highways turn northeast towards Spokane. I-90/US 395 is joined by US 2 through western Spokane, where it intersects US 195. The freeway crosses downtown Spokane on an elevated viaduct and splits from US 2 and US 395 to continue east across Spokane Valley towards the Idaho state line.
Idaho[edit]
Main article: Interstate 90 in Idaho
The viaduct bypassing Wallace, Idaho, opened in 1991 as one of the last sections of I-90.
I-90 traverses the Idaho Panhandle region at the north end of the state, where it connects Coeur d'Alene to communities in the Silver Valley. From the Washington state line, the freeway follows the Spokane River through Post Falls and Huetter to the city of Coeur d'Alene, where it intersects US 95, the state's main north–south highway. I-90 then turns southeast to bypass Coeur d'Alene and travel along a series of ridges that face Lake Coeur d'Alene, crossing an arm of the lake on the Veterans Memorial Centennial Bridge.
The freeway continues east across Fourth of July Summit and descends into the Silver Valley, where it follows the Coeur d'Alene River through several small towns along the historic Mullan Road. I-90 serves the cities of Kellogg and Wallace before it ascends into the Bitterroot Range and crosses Lookout Pass, which also marks the Montana state line.
Montana[edit]
Main article: Interstate 90 in Montana
I-90 at Lookout Pass on the Idaho–Montana border
Montana has the longest section of I-90, at almost 552 miles (888 km), despite the highway only serving a portion of the state's east–west width. It descends from Lookout Pass along the St. Regis and Clark Fork rivers between the foothills of the Bitteroot Range and Coeur d'Alene Mountains. The freeway travels east through the Alberton Gorge and crosses the Clark Fork River several times before it reaches the head of the Missoula Valley. After a short concurrency with US 93, I-90 runs along the north side of Missoula and joins US 12 to continue southeast along the foothills of the Garnet Range and Sapphire Mountains.
After it splits from US 12 in Garrison, the freeway turns south to traverse the Deer Lodge Valley. It then turns east to serve Butte, where it overlaps with I-15 for eight miles (13 km) and intersects I-115. I-90 then continues southeast and crosses the Rocky Mountains and Continental Divide at Homestake Pass, which is the highest point on the entire Interstate at 6,329 feet (1,929 m). The freeway travels east across the Jefferson Valley and passes the headwaters of the Missouri River near Three Forks. It then enters the Gallatin Valley.
I-90 travels around Bozeman, where it is joined by US 191, and crosses Bozeman Pass between the Bridger and Gallatin mountains. At the east end of the mountains, the freeway begins to follow the Yellowstone River and is briefly concurrent with US 89, which serves Yellowstone National Park, and splits from US 191 at Big Timber. I-90 continues along the Yellowstone River through Billings, overlapping with US 87 and US 212, until it reaches Lockwood, the western terminus of I-94. The freeways split and I-90 continues east across the Bighorn Basin before it turns south near Hardin to follow the Little Bighorn River into the Crow Indian Reservation. The highway passes the site of the Battle of the Little Bighorn near Crow Agency and continues south along the river and the Wolf Mountains into Wyoming.
From 1995 to 1999, there was no numbered daytime speed limit on rural highways in Montana, including I-90. The speed limit was simply defined as "reasonable and proper" as determined on a case-by-case basis by the Montana Highway Patrol until the Montana Supreme Court ruled it was unconstitutional. The maximum daytime speed limit in Montana was initially set at 75 mph (120 km/h) in 1999 and was later raised to 80 mph (130 km/h) in 2015.
Wyoming[edit]
Main article: Interstate 90 in Wyoming
View of southern Sheridan, Wyoming, from I-90
I-90 serves a portion of northeastern Wyoming that is primarily rural. The freeway, briefly concurrent to US 14, travels southeast along a series of creeks to Sheridan in the northeastern foothills of the Bighorn Mountains. I-90 and US 87 split in Sheridan and travel parallel to each other to Fort Phil Kearny, where they rejoin and continue south past Lake Desmet to Buffalo. The highways split again near Buffalo at a junction with I-25, which overlaps with US 87 to Casper.
From Buffalo, the highway turns east to cross the Powder River Basin, a region with several large coal mines. I-90 then reaches Gillette, where it begins a concurrency with US 14 and US 16 to a three-way split in Moorcroft. The freeway continues into the Bear Lodge Mountains (part of the Black Hills) and is rejoined in Sundance by US 14, which looped north to serve the Devils Tower. I-90/US 14 then continues northeast to Beulah, where it enters South Dakota.
South Dakota[edit]
Main article: Interstate 90 in South Dakota
The Lewis and Clark Memorial Bridge, which carries I-90 over the Missouri River near Chamberlain, South Dakota
I-90/US 14 enters South Dakota near Spearfish and travels east through prairie land, where it is briefly concurrent with US 85. Beyond Sturgis, the freeway turns south and follows the edge of the Black Hills to Rapid City, the gateway to Mount Rushmore. It then skirts the northern edge of Rapid City, which is served by spur route I-190, and passes Ellsworth Air Force Base while it continues east across the plains. I-90 splits from US 14 near Wall, home to the Wall Drug roadside attraction and located northeast of Badlands National Park.
The freeway travels southeast into the Buffalo Gap National Grassland and also passes a pair of decommissioned missile silos that form the Minuteman Missile National Historic Site. I-90 continues east along the top of a plateau that faces the White River and passes near Kadoka and Murdo. US 83 briefly joins the highway from Murdo to Vivian, where it splits off to serve the state capital of Pierre. It then crosses the Missouri River on the Lewis and Clark Memorial Bridge near Chamberlain and passes a rest area which overlooks the river and includes the 50-foot (15 m) Dignity statue. From Chamberlain, I-90 continues east across the plains and past several small towns near the city of Mitchell. It then reaches the Sioux Falls area, where it bypasses the city to the north and intersects I-29 and I-229. I-90 leaves Sioux Falls and crosses into Minnesota near Brandon.
Minnesota[edit]
Main article: Interstate 90 in Minnesota
Historic marker to commemorate the completion of I-90 in 1978 near Blue Earth, Minnesota
I-90 crosses the southern portion of Minnesota and carries unsigned Legislative Route 391 across the state. From the South Dakota border near Beaver Creek to Albert Lea, the freeway travels east across farmland and towns in the plains and rolling hills of the Buffalo Ridge. It also intersects several north–south highways, including US 75 in Luverne, US 59 in Worthington, US 71 in Jackson, and US 169 in Blue Earth. I-90 travels around the northern outskirts of Albert Lea and intersects I-35 northeast of the city. It then reaches Austin and a brief concurrency with US 218.
From Austin, the freeway turns northeast to head towards Rochester, which it bypasses to the south and intersects US 63 and US 52. I-90 continues east into the hilly Driftless Area and descends from the bluffs that overlook Lake Onalaska on the Mississippi River. It turns southeast at Dakota and is joined by US 14 until the highways split near La Crescent. I-90 turns east before it reaches La Crescent, where it crosses the Mississippi River on the Dresbach Bridge into Wisconsin.
Wisconsin[edit]
Main article: Interstate 90 in Wisconsin
I-90 Mississippi River bridge near La Crosse
I-90 enters Wisconsin near La Crosse and bisects French Island before it reaches Onalaska. This section is briefly concurrent to US 53 between La Crosse and Onalaska. The freeway travels east, generally along the La Crosse River, through several towns and Fort McCoy before it reaches a junction with I-94 in Tomah. The two Interstates join at Tomah and travel southeast along the edge of the hills of the Western Upland, following the Lemonweir and Wisconsin rivers. It passes Wisconsin Dells, situated on the gorge of the same name and home to several water parks and theme parks.
The freeway travels east from Wisconsin Dells to the Portage area, where I-39 begins its concurrency with I-90/I-94. The highway then crosses the Wisconsin River and travels south towards Madison, where it forms an eastern bypass of the city. East of Madison, I-94 separates from I-39/I-90, which continues southeast through Edgerton and Janesville. The highway turns south and enters Beloit, where it intersects I-43 and crosses into Illinois.
Illinois[edit]
Main article: Interstate 90 in Illinois
The Kennedy Expressway, looking southeast towards the Chicago skyline
I-90 uses several sections of the Illinois Tollway system as it traverses the northeastern corner of the state, primarily in the Chicago metropolitan area. It enters the state from Beloit, Wisconsin, and remains concurrent to I-39 and US 51 on the Jane Addams Memorial Tollway through the eastern outskirts of Rockford, where the highways split off. I-90 continues on the tollway as it follows US 20 southeast through Belvidere and Elgin in the Fox Valley.
The tollway cuts through the northwestern suburbs of Chicago, where it intersects I-290 in Schaumburg and passes the north side of O'Hare International Airport. On the east side of the airport in Rosemont, I-90 intersects I-294 and I-190, the latter of which serves the airport's passenger terminals and marks the end of the tollway. The freeway, now named the Kennedy Expressway, travels through northwestern Chicago, where the Blue Line of the "L" rapid transit system runs in the median and serves several stops. I-90 turns southeast and is rejoined by I-94 in Irving Park, where it gains a set of reversible express lanes that travel for 6.2 miles (10.0 km) toward the Near West Side.
The Kennedy Expressway travels south through the Near West Side, opposite the Chicago River from the Chicago Loop (the city's central business district), and intersects I-290 again at the Jane Byrne Interchange. The freeway continues onto the Dan Ryan Expressway and crosses the Chicago River near Chinatown and an interchange with I-55. The Dan Ryan is the widest section of I-90, at 12 through lanes, and is split between local and express lanes. I-90/I-94 is joined by the "L" Red Line in the median of the expressway through the city's South Side, where it passes Rate Field, the Illinois Institute of Technology campus, and Washington Park. I-90 splits from the Dan Ryan Expressway in Englewood and turns southeast onto the tolled Chicago Skyway. The tolled Skyway travels towards the Indiana state line, which the freeway crosses near the Calumet River in the East Side.
Indiana[edit]
Main article: Indiana Toll Road
A section of the Indiana Toll Road (carrying I-90) in Gary, Indiana
The entirety of I-90 within Indiana is concurrent with the Indiana Toll Road, which crosses the state's northern fringe and is mostly shared with I-80. From the Illinois state line, the tollway travels south through Hammond and turns east to follow the Grand Calumet River through northern Gary, where it intersects US 41 and US 12. I-90 then crosses I-65 in eastern Gary and I-94 in Lake Station, where it begins a concurrency with I-80.
I-94 travels northeast near the Lake Michigan shoreline from Lake Station to Michigan City, while the Indiana Toll Road (I-80/I-90) follows it to the south. The tollway then moves closer to the Michigan–Indiana state line and turns east, passing through the northern outskirts of South Bend and Elkhart. In South Bend, it intersects US 31 and passes near the University of Notre Dame. I-80/I-90 travels parallel to the state line until it reaches an interchange with I-69 near Fremont, where it turns southeast. The tollway then turns east and crosses the Ohio state line near Angola.
Ohio[edit]
Main article: Interstate 90 in Ohio
See also: Ohio Turnpike
Aerial view of Ohio Turnpike exit 142, showing the connector between I-90 and I-80 on the turnpike
At the state line near Montpelier, I-80/I-90 transitions from the Indiana Toll Road to the Ohio Turnpike, which crosses northern Ohio. The highway continues east around several rural towns as it approaches the Toledo area. The turnpike crosses under I-475 in Maumee without an interchange; access to I-475 is instead provided through a nearby junction with US 20. I-80/I-90 then continues southeast across the Maumee River to Rossford on the southern outskirts of Toledo, where it intersects I-75.
The turnpike travels southeast through a rural area near the southwest shore of Lake Erie, where it passes the cities of Fremont and Sandusky. Near Norwalk, the highway turns northeast to follow State Route 2 (SR 2) and heads to Elyria, where I-90 splits from I-80 (which remains on the turnpike). The freeway then merges with SR 2 and continues northeast through the lakeshore suburbs west of Cleveland, including Rocky River and Lakewood. I-90 and SR 2 separate after crossing the Rocky River and travel parallel to each other as they enter Cleveland. I-90 continues through the southwestern residential neighborhoods of Cleveland and reaches a junction with I-71 and I-490 in Tremont, where it turns north.
From Tremont, I-90 turns north onto the Innerbelt Freeway and crosses the Cuyahoga River into Downtown Cleveland on the George V. Voinovich Bridges. The Innerbelt skirts the south side of Downtown Cleveland, where it intersects I-77 near Progressive Field and turns north to bisect the Goodrich–Kirtland Park neighborhood. Near Cleveland Burke Lakefront Airport, the freeway makes a sharp, 90-degree turn (nicknamed "Dead Man's Curve" for its frequent crashes) and rejoins SR 2 on the Cleveland Memorial Shoreway until they split again in Euclid. I-90 briefly turns southeast but resumes its northeastern route after a junction with I-271 in Willoughby Hills. The freeway travels parallel to the Lake Erie shoreline through farmland and exurban towns and crosses into Pennsylvania near Conneaut.
Pennsylvania[edit]
Main article: Interstate 90 in Pennsylvania
Within Pennsylvania, I-90 is non-tolled and generally travels northeast around several communities on the Lake Erie shoreline and remains entirely in Erie County. It enters the state in Springfield Township and passes through rural areas along the lake shore, parallel to US 20 and the Lake Road. The freeway then travels through the southern outskirts of Erie, where it intersects I-79 and US 19. I-90 returns to the rural areas of northeastern Erie County and intersects I-86 before it reaches the New York state line near the borough of North East. At 46 miles (74 km), the Pennsylvania section is I-90's shortest within a single state.
New York[edit]
Main article: Interstate 90 in New York
See also: New York State Thruway
The New York State Thruway near Amsterdam
I-90 enters New York in Chautauqua County and runs concurrently with the mainline of the tolled New York State Thruway. It travels northeast along the Lake Erie shoreline between Lake Road to the north and US 20 to the south through Dunkirk and Fredonia. The highways enter the Buffalo area, where the toll road runs north–south through Cheektowaga and forms an eastern bypass, using auxiliary routes I-190 and I-290 to serve the city. At a junction with I-290 near Buffalo Niagara International Airport, I-90 turns east to follow the historic Water Level Route of the New York Central Railroad, itself parallel to the 19th-century Erie Canal.
The Thruway passes south of Rochester, which it serves via a loop on I-490 and the direct north–south spur I-390. I-90 travels through the Finger Lakes region and moves closer to the Erie Canal as it approaches the Syracuse area. It travels through the city's northern outskirts, where it intersects I-690, I-81, and I-481 from west to east. It then continues to Utica, where the Thruway runs along the north side of the Mohawk River (part of the Erie Canal). The section through Utica, connected to the city's downtown via I-790, was built between the lines of SR 49, which does not merge with the Thruway.
I-90 then closely follows the Mohawk River southeast through several towns and villages between the foothills of the Catskill and Adirondack mountains. The Thruway then reaches Schenectady, which it bypasses to the southwest and intersects I-88 and I-890, the latter of which serves the city's downtown. The highway continues southeast into Albany to a junction with I-87, where I-90 splits from the Thruway, which turns south to serve New York City. I-90 travels east as a toll-free freeway through the northern neighborhoods of Albany and intersects I-787 before it crosses the Hudson River. The freeway travels south around Rensselaer and rejoins the Thruway via the Berkshire Connector, which continues east into the Taconic Mountains toward the Massachusetts state line.
The mileposts and sequential exit numbers on the New York State Thruway mainline originate from New York City, increasing northward on I-87 and westward on I-90; as a result, the mileposts and exit numbers on I-90 through most of New York run backwards compared to the federal preference for mile-based numbers increasing from west to east. The Berkshire Connector uses west-to-east mileposts and exit numbers with a "B" prefix; the toll-free section of I-90 through Albany and Rensselaer uses conventional west-to-east mileposts and exit numbers despite being geographically north–south. I-90 is currently the only Interstate that has a complete set of nine spur routes within one state, all numbers being used. In addition, I-990, a short spur route near Buffalo that is not directly connected to I-90, is the highest number given to an Interstate.
Massachusetts[edit]
Main article: Massachusetts Turnpike
View of the Massachusetts Turnpike in Boston's Fenway–Kenmore neighborhood, seen from the Prudential Tower. Fenway Park is visible at top left.
I-90 in Massachusetts is concurrent with the entirety of the Massachusetts Turnpike (also known as "the Pike" or "MassPike"). The turnpike begins at the New York state line in West Stockbridge and travels southeast through the Berkshires to the Pioneer Valley. The highway travels through the northern suburbs of Springfield, where it intersects I-91 and crosses the Connecticut River into Chicopee. I-90 then crosses over I-391 without an interchange and serves as the northern terminus of I-291 on the eastern outskirts of the city. The turnpike continues east through the hills of Central Massachusetts and serves as the eastern terminus of I-84 in the town of Sturbridge.
From Sturbridge, the turnpike travels northeast towards Worcester and passes through the city's southern outskirts. It serves as the respective northern and western terminus of I-395 and I-290 in Auburn, located southwest of Worcester, and continues to an interchange with I-495 near Westborough at the edge of Greater Boston. I-90 travels through the western suburbs of Boston and travels through Framingham before it intersects I-95/Route 128, the main beltway around Boston, on the border of Weston and Newton. The turnpike continues along the Charles River into Boston, where it descends into a tunnel that passes Boston University, Fenway Park, and under the Prudential Tower complex in the Back Bay neighborhood.
I-90 intersects I-93 on the south side of Downtown Boston and travels under the Fort Point Channel to serve the Seaport District. The turnpike then enters the Ted Williams Tunnel, which travels northeast under Boston Harbor to the passenger terminals at Logan International Airport. After it passes the northwest side of the airport, I-90 terminates at an interchange with Route 1A in East Boston. The section between I-93 and the airport was opened in the early 2000s as part of the Big Dig megaproject, which rebuilt several Boston freeways and extended I-90 by 3.5 miles (5.6 km).