Interstate 90


The Chicago Skyway, a toll facility owned by the City of Chicago, carries Interstate 90 over industrial areas and the South Side of Chicago before connecting with the Dan Ryan Expressway (Interstate 94) south of downtown Chicago. See below for more about the skyway. Photo taken 09/02/05.


The longest Interstate Highway, Interstate 90 serves major northern cities such as Seattle, Chicago, Cleveland, Buffalo, Albany, and Boston. Smaller cities such as Spokane, Butte, Billings, Sheridan, Moorcroft, Rapid City, Sioux Falls, Austin, Wisconsin Dells, Madison, Rockford, South Bend, Toledo, Erie, Syracuse, and Springfield also dot Interstate 90 on its travels.

The eastern third of Interstate 90's routing predates the Interstate system and follows tolled turnpikes. Some of the tolled sections of Interstate 90 include the Northwest Tollway (between Beloit and O'Hare International Airport), the Chicago Skyway (between Interstate 94 and the Indiana State Line), the Indiana East/West Tollway, the Ohio Turnpike, the New York Thruway, and the Massachusetts Turnpike (Mass Pike). Some sections of these toll roads predated the 1956 Interstate Highway Act (and therefore Interstate 90).

High Priority Corridor

Interstate 90 in the Seattle metropolitan area is part of High Priority Corridor 35: FAST Corridor.


For a history of the completion of Interstate 90 in Wyoming, visit Interstate 90 @ AARoads.

Planned Improvements

In Cleveland, plans to improve access to that city's lakefront involve the construction of the infamous "Dead Man's Curve." Construction to reconfigure the curve (interchange of Interstate 90 and Ohio 2), reconfigure exits into downtown, and add lanes is expected to last from 2006 until 2016. For more on this project, visit The Cleveland Plain Dealer webpage or the Innerbelt Project (Official Site). In addition, plans call for the removal of portions of the Ohio 2/Shoreway freeway from the lakeshore. The city of Cleveland is seeking $68 million to remove portions of the Shoreway and construct a pedestrian-scale boulevard.

In the Boston metropolitan area, some local politicians are considering creating a one-way toll along the Massachusetts Turnpike in metropolitan Boston. Specifically, the toll plaza near Weston and the Interstate 95/Massachusetts 128 interchange may become a toll only for inbound (eastbound) traffic, but those cars would pay double the current toll since there would be no toll barrier along westbound. The concept was proposed by Massachusetts Turnpike Authority Board member Christy Mihos in early 2004, but it faces some difficulty, especially due to concerns about toll evasion, which would result in more vehicles bypassing the tolls by using local streets and other alternate routes.3

Washington Wildlife Bridge

As part of a project to expand capacity along Interstate 90 in the Cascade Mountains is a partnership between the Washington State Department of Transportation and several conservation groups to invest in wildlife corridors and protected habitats for species native to the area. These wildlife structures will allow for continuous range for a variety of animals that might migrate over the freeway. For more information on this project, visit Interstate 90 Wildlife Bridges.10

Wallace, Idaho

One of the last sections of Interstate 90 to open to through traffic was the section bypassing the town of Wallace, Idaho. In fact, the town of Wallace represented the final traffic signal to be bypassed by the transcontinental freeway. To avoid having the freeway pass directly through the town as originally planned, residents added Wallace to the National Register of Historic Places in 1976. As a result, the freeway was rerouted away from town via a viaduct that would carry the freeway around the town through some previously undisturbed terrain. Old U.S. 10 became Business Loop I-90, and the business loop was the de facto route for the Interstate through the mid to late 1980s while the bypass was under construction. The Interstate 90 bypass was opened to traffic in 1991, and the traffic signal was retired shortly thereafter.4

The final traffic light on Interstate 90 is still functioning in downtown Wallace along Old U.S. 10 (now Business Loop I-90). Photo taken by AARoads and Chris Kalina (09/01/06) - Thanks to Dan Radigan for the original photo.

What happened to South Dakota's Exit 66?

To the east of Rapid City, South Dakota at Box Elder, the Exit 66 partial cloverleaf interchange has closed. On October 1, 2003, the North Ellsworth Road interchange is no longer open. This closure coincides with the Summer 2003 opening of a new Exit 67 interchange at Liberty Boulevard. Local officials who fear the potential closing of nearby Ellsworth Air Force Base successfully lobbied the state and federal government to construct a new interchange and access road to the facility's main gate. The move was made to address concerns about commercial development in the so-called accident-potential zone to the south of the Ellsworth runway. It is hoped that the interchange closure will help bolster the chances of Ellsworth A.F.B. avoiding the next round of base closings slated for 2005.2

Jane Addams (Northwest) Tollway

Plans call for Interstate 39-90 (Jane Addams Memorial [Northwest] Tollway) between Rockford and the Illinois-Wisconsin State Line to be widened to six lanes. Bridge widening in southern Wisconsin between the state line and Madison started in 2003, with hopes of expanding the freeway to six lanes eventually. For more information, see the official Illinois Tollway Project Page: Newburg Road to Rockton Road - Reconstruct and Widen.

The Cherry Valley Interchange project, which reconstructs the connection between Interstate 90 (Jane Addams Memorial [Northwest] Tollway) and Interstate 39 in Rockford, is currently underway. The project is scheduled for completion by the end of 2009. This project was made possible as a result of the Illinois governor's tollway improvement plan announced in 2005. Plans call for an upgrade to the interchange including high-speed ramps to connect Interstate 39 and Interstate 90 in all directions, starting with "through" connections for both directions of Interstate 39. An additional project widens Interstate 39 and U.S. 20 south of Rockford through the Illinois Department of Transportation. Through these projects, high-speed freeway connections will replace the existing trumpet interchange at the junction of Interstate 39 and Interstate 90.20

Chicago Skyway

The Chicago Skyway is a steel cantilever bridge that connects the Dan Ryan Expressway (Interstate 94) with the Indiana Toll Road (Interstate 90) in the city of Chicago. Dominating the southeastern skyline of Chicago, the 7.8-mile Skyway was constructed in the 1950s and opened in April 1958 to cross over steel mills, railroads, homes, and the Calumet River. The bridge did not carry as much traffic as anticipated, but the growth of casinos in Northwestern Indiana has increased traffic counts. In addition, the Skyway underwent a reconstruction project between 1999 and 2004.5

Prior to the completion of this project, the road was falling apart. In fact, in 1999, city of Chicago administrators determined that the Chicago Skyway was never officially incorporated into the Interstate Highway System.6 This might be due to the fact that the Skyway was not up to current Interstate standards. As a result of this determination, all Interstate 90 reassurance shields have an additional "TO" banner affixed above the Interstate 90 reassurance shields. With the recent completion of the new Skyway deck, ramps, and three continuous, through lanes of travel, it is possible that the Skyway is closer to meeting Interstate standards. Of course, the Chicago Skyway is one of many Interstate Highways that are not up to the latest Interstate standards (see most of Interstate 278 in New York, for instance). As a result of this finding, one could claim that Interstate 90 has a gap, but to the average driver, it is not noticeable.

With the completion of the reconstruction of the Skyway in November 2004, the Chicago City Council voted to lease the Chicago Skyway to a private company, the Cintra-Macquarie Consortium, for 99 years. The agreement would start in January 2005, and it calls for the Spanish-Australian Cintra-Macquarie Consortium to pay $1.82 billion to the City of Chicago. In exchange, the Consortium can collect the toll proceeds and provide for administration, toll collection, maintenance, and operations of the Skyway. The City of Chicago, meanwhile, will continue to provide police to patrol the freeway. This arrangement is the first of its kind in the country.

Indiana Toll Road

From Chicago east to Boston, over 75% of Interstate 90 follows toll roads, including the Chicago Skyway, Indiana Toll Road, Ohio Turnpike, New York Thruway, and Massachusetts Turnpike. The only state in which Interstate 90 evades a toll is Pennsylvania, a state known for having an extensive turnpike system.

Through Indiana, Interstate 90 follows the Indiana Toll Road in its entirety. Authorized for construction in 1951, the Toll Road was constructed and fully open to traffic by 1956, the same year in which the Interstate Highway System was authorized by the federal government. The Toll Road was later added to the Interstate Highway System after it was completed. In 2006, the state of Indiana approved leasing and privatizing the Indiana Toll Road.11 A bid for this lease came in at $3.85 million by the same Spanish-Australian consortium that leased the Chicago Skyway from the city of Chicago. The lease would last for 75 years. Governor Mitch Daniels negotiated the lease, and the state House of Representatives approved the lease on February 1, 2006. The Senate approved the lease as part of the governor's "Major Moves" program. By the middle of March 206, Major Moves was law. The lease of the Indiana Toll Road is scheduled to take effect on July 1, 2006. Funds generated by this lease are planned for various transportation projects around the state. 121314

For more information, visit Indiana Department of Transportation Motorist Information: Indiana East-West Toll Road.

Ohio Turnpike

Interstate 90 follows the Ohio Turnpike from the Indiana Toll Road east to near the Cleveland metropolitan area. The act that created the Ohio Turnpike Commission was passed in 1949, and construction began on the Turnpike in October 1952. The 241-mile freeway was built in 38 months, with the route fully opened on October 1, 1955. For more information, visit the official Ohio Turnpike History page.

Several sections of Interstate 90 in the eastern United States uses toll roads. Together with Interstate 80, Interstate 90 follows the Ohio Turnpike westbound as it crosses Exit 13, Junction Ohio 15. Photo taken 09/02/05.

Cleveland's Dead Man's Curve

To the east of the turnpike segment, Interstate 90 serves downtown Cleveland and the south shore of Lake Erie. Interstate 90 east drops to 35 miles per hour as it abruptly turns from north to northeast and merges with Ohio 2 (Cleveland Memorial Shoreway). This curve, locally known as Dead Man's Curve, is among the most substandard segments of Interstate 90, was built in 1959 with a 50 miles per hour speed limit, had the reduced speed limit enforced in 1965, and had banked curves added in 1969.19 However, accidents continue at this site because no one expects an Interstate highway to have a 35-mile-per-hour curve on it. Photo taken by Steve Hanudel (06/18/06).

New York Thruway

The mainline of the New York Thruway was opened to traffic in stages between 1954 and 1957. Interstate 90 was designated on the Thruway at a later time, after the original opening date of the superhighway. The section of the Thruway that carries Interstate 90 was opened in order from west to east:7

  • Pennsylvania State Line to Silver Creek (41 miles) - August 21, 1957
  • Silver Creek to Buffalo (29 miles) - December 14, 1957
  • Buffalo to Rochester (63 miles) - August 25, 1954
  • Rochester to Lowell (115 miles) - June 24, 1954 (first segment of Thruway ever opened)
  • Lowell to Westmoreland (5 miles) - September 20, 1954
  • Westmoreland to Albany (95 miles) - October 26, 1954
  • Berkshire Section (18 miles) - October 8, 1958

The remaining section of Interstate 90 in New York, between Albany and the Berkshire Section of the Thruway, is maintained by the New York State Department of Transportation. For more on the history of the Thruway, visit the official New York Thruway Factbook.

Massachusetts Turnpike and the "Big Dig"

The 138-mile Massachusetts Turnpike System consists of two sections:

  • Original Mainline - from the New York state line and Exits 14-15 (Junction Interstate 95 and Massachusetts 128) on town limits between Weston and Newton
  • Metropolitan Highway System (MHS) carries the turnpike from that interchange east to Massachusetts 1A near Logan International Airport; this section also includes the myriad tunnels and bridges that were built as part of the Big Dig project in and around downtown Boston and the airport

The original mainline began construction in 1955 and opened in 1957, which was only one year after the Interstate Highway System was authorized in 1956. The completed original mainline carried the Massachusetts Turnpike from the New York Thruway east to what is now Interstate 95/Massachusetts 128. In 1960, attention turned toward construction of the final 15 miles of the turnpike into the city center. It would prove to be a difficult stretch to construct, as it passed through areas already built out. Groundbreaking for the extension was in September 1962, and the route was extended east to today's Interstate 93 by February 1965.7 An ancillary route, the Interstate 695 Inner Belt, was planned to connect the Turnpike to Interstate 93 (then planned as part of Interstate 95). However, that road was not constructed as a result of protest, including protests from students at the Massachusetts Institute of Technology (MIT).8

As part of the "Big Dig" project in Boston, the Turnpike experienced another extension. Interstate 90 was extended from the original eastern terminus at Interstate 93 through the Fort Point (Tip O'Neill) Tunnel and Ted Williams Tunnel to Boston's Logan International Airport in 2003. The new terminus Interstate 90 is now located at Massachusetts 1A northwest of the airport as a result of this extension. More information is available on the official website. See also the Interstate 93 Gateway page.


In Illinois, the sections of Interstate 90 were built in the 1950s and 1960s. The Northwest Tollway, which brings Interstate 90 southeast from Wisconsin to Rockford, Elgin, to Chicago near O'Hare International Airport was constructed starting in 1956 and was completed by 1958.15 The construction of the 76-mile Northwest Tollway (and the other original tollways) was funded by a bond issuance in the amount of $415 million by the state tollway commission (which was created in 1953).18 The Northwest Tollway merges into the Kennedy Expressway near O'Hare International Airport.

The Kennedy Expressway, which connects O'Hare International Airport with the Chicago Loop (Interstate 290/Eisenhower Expressway), opened to traffic on November 5, 1960. This 16-mile expressway was constructed at a cost of $237 million. The section from the airport to the Northwest Tollway merge is designated as Interstate 190 (formerly Illinois 594, pre-1978); the section from the Northwest Tollway merge to the Edens Expressway merge is designated as Interstate 90 (formerly Illinois 194, pre-1978); and the section from the Edens Expressway southeast to the Interstate 290 junction (Circle Interchange) is designated as Interstate 90-94 (originally just Interstate 94, prior to 1978 when Interstate 90 was routed on the Eisenhower Expressway). It was originally named the Northwest Expressway, but it was renamed the John F. Kennedy Expressway on November 29, 1963, one week to the minute after the famous U.S. President was assassinated in Dallas, Texas. On February 1, 1970, new rapid transit rail service went into operation in the Kennedy Expressway median, shortly after commuter rail service began on the Dan Ryan Expressway segment of Interstate 90-94.15, 16

The Dan Ryan Expressway, which continues the limited access route from Interstate 290/Eisenhower Expressway south to Interstate 57, opened on December 15, 1962. It was designated initially as Interstate 90-94 from downtown to the Skyway and as Interstate 90 from the Chicago Skyway to the Interstate 57 split. However, Interstate 90 and Interstate 94 were swapped shortly thereafter, with Interstate 94 following the entire length of the Dan Ryan and Interstate 90 exiting via the Chicago Skyway. This freeway, planned as the "South Expressway," was named in memory of Dan Ryan, who was the president of the Cook County Board of Commissioners and had died in 1961, just before the expressway opened. Dan Ryan was a known expressway proponent in Chicagoland and was responsible for the construction of several urban freeways. The Dan Ryan Rapid Transit line follows the median of the Dan Ryan Expressway; the rail line opened to commuters on September 28, 1969. Similar rail lines have since been placed in median and other right of way locations along other urban freeways throughout the country, but Chicago is considered to be a pioneer in the implementation of this concept.15, 17

The Chicago Skyway, as mentioned in the "Chicago Skyway" section above, opened in June 1958.15 It was not constructed using proceeds from the Illinois State Tollway Commission original bond issuance; it was instead funded by the city of Chicago separately.18

From the 1960s until 1978, Interstate 90 followed the Eisenhower (Congress) Expressway and Eisenhower Extension rather than the Kennedy Expressway and Northwest Tollway. For more on this historic route, visit Interstate 290 Illinois.

Parallel/Historical U.S. Routes

From Seattle east to Billings, Interstate 90 replaced U.S. 10. From Billings southeast to Buffalo, Wyoming, Interstate 90 parallels U.S. 87, then follows U.S. 14 from Buffalo east to Wall, South Dakota. At Wall, Interstate 90 replaced U.S. 16 east all the way to Tomah, Wisconsin. From Tomah southeast to Chicago, Interstate 90 more or less follows U.S. 14 again, but it picks up U.S. 20 at Rockford. Interstate 90 and U.S. 20 remain parallel to each other from Chicago east to Boston, with some proximity to U.S. 6 in Ohio.

This view of Interstate 90 westbound is afforded from the Mullan Trail Road overpass near Lake Coeur d'Alene in the panhandle of Idaho. Photo taken 09/01/06.

Highway Guides

Interstate 90 Profile of Eastern/Western Terminus

Click below to see profiles of the eastern and western termini:


  1. Mileage update provided by Gary S. Peterson.
  2. "Exit 66 now road to nowhere." The Rapid City Journal, October 2, 2003.
  3. "Drivers favor one-way toll plan: Heavy traffic on the Massachusetts Turnpike" by Peter Reuell, Metro West News, Wednesday, January 28, 2004.
  4. The Evolution of Interstate 90 between Seattle and Missoula, by Erick Johnson, Eastern Washington University
  5. How a road changed everything: The skyway was a construction feat 50 years ago: `It was something to watch that road being built. Why, you would think the whole world was coming to an end.' by Bill Glauber, Chicago Tribune, November 24, 2004
  6. Chicago Skyway no longer an Interstate, post on Misc.Transport.Road, August 20, 1999, by Rich Carlson
  7. New York Thruway Factbook
  8. About the Massachusetts Turnpike, the Main Street of Massachusetts
  9. Divided Highways: Building the Interstate Highways, Transforming American Life in 1997 by Tom Lewis, Viking Penguin/Penguin Books, page 199.
  10. Personal Email from Jen Watkins, "Interstate 90 Info," 3/10/05, and I-90 Wildlife Bridges Coalition
  11. Indiana Toll Road: Toll Road For Sale?
  12. "Toll Road plan clears senate: Chambers' leaders say differences remain". Indianapolis Star, by Theodore Kim, March 3, 2006.
  13. Toll Road bill signed, Daniels moves quickly. Indianapolis Star, by Theodore Kim, March 16, 2006.
  14. "A tale of 2 projects -- and political implications". Indianapolis Star, by John Ketzenberger, March 21, 2006.
  15. Encyclopedia of Chicago: Expressways by Dennis McClendon of the Chicago Historical Society
  16. Chicago Timeline: 1960 Northwest Expressway Completed; November 29, 1963 Renamed The John F. Kennedy Expressway, Chicago Public Library, updated August 1997
  17. Chicago Timeline: 1962 Dan Ryan Expressway Opened, Chicago Public Library, updated March 2006
  18. Encyclopedia of Chicago: Tollways by David M. Young of the Chicago Historical Society
  19. Dead Man's Curve could be worse - in fact, it was in the Cleveland Plain Dealer, April 22, 2001, by James F. Sweeney.
  20. Todd Applegate, personal email ("Updates on I-39/90/US 20 in Rockford, IL"), December 28, 2007.

Page Updated July 29, 2008.


State Washington
Mileage 296.92
Cities Seattle, Bellevue, Ellensburg, Moses Lake, Spokane
Junctions Interstate 5, Interstate 405, Interstate 82
State Idaho
Mileage 73.55
Cities Coeur d'Alene, Kellogg, Wallace
Junctions None
State Montana
Mileage 551.68*
Cities Missoula, Deer Lodge, Butte, Bozeman, Livingston, Laurel, Billings, Hardin
Junctions Interstate 15, Interstate 115, Interstate 15, Interstate 94
State Wyoming
Mileage 208.80
Cities Sheridan, Buffalo, Gillette
Junctions Interstate 25
State South Dakota
Mileage 412.76
Cities Spearfish, Sturgis, Rapid City, Chamberlain, Mitchell, Sioux Falls
Junctions Interstate 190, Interstate 29, Interstate 229
State Minnesota
Mileage 275.70
Cities Worthington, Fairmont, Albert Lea, Austin, Rochester
Junctions Interstate 35
State Wisconsin
Mileage 108.61 (187+)
Cities La Crosse, Onalaska, Tomah, Madison, Beloit
Junctions Interstate 94, Interstate 39, Interstate 94, Interstate 43
State Illinois
Mileage 123.89#
Cities Rockford, Elgin, Chicago
Junctions Interstate 39, Interstate 290, Interstate 294, Interstate 190, Interstate 94, Interstate 290, Interstate 55, Interstate 94
State Indiana
Mileage 156.28**
Cities Hammond, Gary, South Bend, Elkhart
Junctions Interstate 65, Interstate 80/94, Interstate 69
State Ohio
Mileage 244.75++
Cities Toledo, Elyria, Cleveland, Ashtabula, Conneaut
Junctions Interstate 475, Interstate 75, Interstate 280, Interstate 80, Interstate 71/Interstate 490, Interstate 77, Interstate 271
State Pennsylvania
Mileage 46.40
Cities Erie
Junctions Interstate 79
State New York
Mileage 385.48
Cities Dunkirk, Buffalo, Batavia, Rochester, Syracuse, Oneida, Utica, Amsterdam, Schenectady, Albany
Junctions Interstate 190, Interstate 290, Interstate 490, Interstate 390, Interstate 490, Interstate 690, Interstate 81, Interstate 481, Interstate 790, Interstate 890, Interstate 88, Interstate 890, Interstate 87, Interstate 787, New York Thruway/ Berkshire Connection
State Massachusetts
Mileage 135.72 (137.6##)
Cities Springfield, Holyoke, Worcester, Framingham, Boston
Junctions Interstate 91, Interstate 391, Interstate 291, Interstate 84, Interstate 290/Interstate 395, Interstate 495, Interstate 95, Interstate 93
TOTAL 3,020.54
NOTE on the total: (This would be approximately 3,100 miles if shared alignment with I-94 in Wisconsin is included.)
Source: December 31, 2014 Interstate Route Log and Finders List
* - 7.65 miles on I-15
+ - approximately 187 miles total, of which 108.61 miles are independent of I-39 and the rest are combined with I-39
# - 15.39 miles on I-94
** - 135.60 miles on I-80
++ - 142.80 miles on I-80
## - Prior to the opening of the Ted Williams Tunnel, Interstate 90 was 135.72 miles long.1
Interstate 90 Annual Average Daily Traffic

State Location AADT Composite Year
Washington Seattle 150,600* 2002
Washington East of Moses Lake 9,200 2002
Washington Spokane 107,000 2002
Idaho Coeur d'Alene 47,000 2002
Idaho Mullan 6,300 2002
Wyoming Parkman 4,380 2002
Wyoming Sheridan 8,750 2002
Wyoming Gillette 9,820 2002
Indiana Gary 44,160 2002
Indiana South Bend 25,600 2002
Pennsylvania Erie 47,000 2002
Pennsylvania State Line 19,000 2002
New York Buffalo 143,300 2002
New York Syracuse 39,200 2002
New York Utica 25,800 2002
New York Albany 120,700 2002
New York Niverville 16,800 2002
Massachusetts West Stockbridge 20,592 2000
Massachusetts Chicopee 53,302 2000
Massachusetts Weston 119,006 2000
Massachusetts Boston 104,507 2000
Source: 2002 Annual Traffic Report (WSDOT)
2002 Rural Traffic Flow Map (ITD)
2002 Wyoming Vehicle Mile Book (WYDOT)
INDOT 2000 Annual Average Daily Traffic Volumes Map
Pennsylvania Traffic Volumes 2002 (Penndot)
NYSDOT 2002 Traffic Volume Report
Mass Highway Traffic Volume Counts (2002)
* - estimate 148,000 mainline and 2,600 reversible lanes
Complete Interstate 90 AADT data.
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