Editing Interstate 90 (section)

{{Short description|Interstate Highway across northern United States}}
{{Use American English|date=April 2025}}
{{Featured article}}
{{Use mdy dates|date=October 2017}}
{{Infobox road
|country=USA
|type=I
|route=90
|map={{maplink|frame=yes|plain=yes|frame-align=center|frame-width=310|frame-height=240|type=line|from=Interstate 90.map}}
|map_custom=yes
|map_notes=Map of the contiguous United States with I-90 highlighted in red
|map_alt=A map of the contiguous United States showing the route of Interstate 90 as it travels from west to east through the northern states.
|length_mi=3099.74
|length_ref=<ref name="FHWA-Routes">{{cite web |date=January 26, 2022 |title=Table 1: Main Routes of the Dwight D. Eisenhower National System of Interstate and Defense Highways as of December 31, 2021 |url=https://www.fhwa.dot.gov/planning/national_highway_system/interstate_highway_system/routefinder/table01.cfm |work=Route Log and Finder List |publisher=[[Federal Highway Administration]] |access-date=February 10, 2022 |archive-date=April 22, 2012 |archive-url=https://web.archive.org/web/20120422220808/http://www.fhwa.dot.gov/reports/routefinder/table1.cfm |url-status=live }}</ref><ref name=WisDOT/>
|established=1956
|direction_a=West
|direction_b=East
|terminus_a={{Jct|state=WA|SR|519}} in [[Seattle, Washington|Seattle, WA]]
|junction={{plainlist|1=<!--Only list a maximum of 10 junctions here per [[WP:USRD/STDS]] and discuss on the talk page before changing what is here.-->
*{{Jct|country=USA|I|5}} in Seattle, WA
*{{Jct|country=USA|I|15}} near [[Butte, Montana|Butte, MT]]
*{{Jct|country=USA|I|25}} near [[Buffalo, Wyoming|Buffalo, WY]]
*{{Jct|country=USA|I|35}} in [[Albert Lea, Minnesota|Albert Lea, MN]]
*{{Jct|country=USA|I|55}} in [[Chicago, Illinois|Chicago, IL]]
*{{Jct|country=USA|I|65}} in [[Gary, Indiana|Gary, IN]]
*{{Jct|country=USA|I|80|I|94|US|6}} in [[Lake Station, Indiana|Lake Station, IN]]
*{{Jct|country=USA|I|75}} in [[Rossford, Ohio|Rossford, OH]]
*{{Jct|country=USA|I|80}} in [[Elyria, Ohio|Elyria, OH]] 
*{{Jct|country=USA|I|87|dab1=New York}} in [[Albany, New York|Albany, NY]]
*{{Jct|country=USA|I|95}} in [[Weston, Massachusetts|Weston, MA]]}}
|terminus_b={{Jct|state=MA|Route|1A|extra=Airport}}/[[Logan International Airport]] in [[Boston, Massachusetts|Boston, MA]]
|states= [[Washington (state)|Washington]], [[Idaho]], [[Montana]], [[Wyoming]], [[South Dakota]], [[Minnesota]], [[Wisconsin]], [[Illinois]], [[Indiana]], [[Ohio]], [[Pennsylvania]], [[New York (state)|New York]], [[Massachusetts]]
}}

'''Interstate 90''' ('''I-90''') is an east–west transcontinental [[freeway]] and the longest [[Interstate Highway]] in the [[United States]] at {{convert|3,099.7|mi|km|}}. It begins in [[Seattle, Washington]], and travels through the [[Pacific Northwest]], [[Mountain states|Mountain West]], [[Great Plains]], [[Midwestern United States|Midwest]], and the [[Northeastern United States|Northeast]], ending in [[Boston]], Massachusetts. The highway serves 13 states and has 15 [[List of auxiliary Interstate Highways|auxiliary routes]], primarily in major cities such as [[Chicago]], [[Cleveland]], [[Buffalo, New York|Buffalo]], and [[Rochester, New York|Rochester]].

I-90 begins at [[Washington State Route 519]] in Seattle and crosses the [[Cascade Range]] in Washington and the [[Rocky Mountains]] in [[Montana]]. It then traverses the northern Great Plains and travels southeast through [[Wisconsin]] and the Chicago area by following the southern shore of [[Lake Michigan]]. The freeway continues across [[Indiana]] and follows the shore of [[Lake Erie]] through [[Ohio]] and [[Pennsylvania]] to Buffalo. I-90 travels across New York by roughly following the historic [[Erie Canal]] and traverses [[Massachusetts]], reaching its eastern terminus at [[Massachusetts Route 1A]] near [[Logan International Airport]] in Boston.

The freeway was established by the [[Federal-Aid Highway Act of 1956]], replacing a series of existing [[United States Numbered Highway System|U.S. highways]] that had been preceded by local roads and [[auto trail]]s established in the early 20th century. I-90 was numbered in 1957, reflecting its status as the northernmost transcontinental route of the system, and construction was underway on several sections with funding from the Federal-Aid Highway Act.

The route also incorporates several [[toll road]]s that predate the Interstate Highway System, including the [[Jane Addams Memorial Tollway]], [[Indiana Toll Road]], [[Ohio Turnpike]], [[New York State Thruway]], and the [[Massachusetts Turnpike]]. These toll roads opened in the 1950s and were followed by toll-free sections in Pennsylvania and Wisconsin that were finished in the 1960s. The Midwestern sections of I-90 were fully completed in 1978, and most of the route between Seattle and [[South Dakota]] opened by 1987. The final section, near the western terminus in Seattle, opened in September 1993; an eastern extension in Boston was completed in 2003 as part of the [[Big Dig]] project.