Editing Interstate Highway System (section)

====Expansions and removals====
{{see also|Future Interstate Highways|Freeway removal}}
The Interstate Highway System has been expanded numerous times. The expansions have both created new designations and extended existing designations. For example, [[Interstate 49|I-49]], added to the system in the 1980s as a freeway in [[Louisiana]], was designated as an expansion corridor, and FHWA approved the expanded route north from [[Lafayette, Louisiana]], to [[Kansas City, Missouri]]. The freeway exists today as separate completed segments, with segments under construction or in the planning phase between them.<ref>{{cite web |url = http://www.modot.org/southwest_archive/I-49MapsandInformation.htm |author = Missouri Department of Transportation |date = n.d. |publisher = Missouri Department of Transportation |work = Interstate I-49 Expansion Corridor in Southwest District of Missouri |title = Converting US Route 71 to I-49 |url-status = dead |archive-url = https://web.archive.org/web/20130117094333/http://www.modot.org/southwest_archive/I-49MapsandInformation.htm |archive-date = January 17, 2013 |author-link = Missouri Department of Transportation }}</ref>

In 1966, the FHWA designated the entire Interstate Highway System as part of the larger [[Pan-American Highway]] System,<ref>{{cite book |author = New Mexico State Highway and Transportation Department |url = http://www.nmshtd.state.nm.us/upload/contents/445/Memorial.pdf |title = State of New Mexico Memorial Designations and Dedications of Highways, Structures and Buildings |year = 2007 |location = Santa Fe |publisher = New Mexico State Highway and Transportation Department |page = 14 |url-status = dead |archive-url = https://web.archive.org/web/20110716081405/http://www.nmshtd.state.nm.us/upload/contents/445/Memorial.pdf |archive-date = July 16, 2011 |author-link = New Mexico State Highway and Transportation Department }}</ref> and at least two proposed Interstate expansions were initiated to help trade with Canada and Mexico spurred by the [[North American Free Trade Agreement]] (NAFTA). Long-term plans for [[Interstate 69|I-69]], which currently exists in several separate completed segments (the largest of which are in [[Indiana]] and [[Texas]]), is to have the highway route extend from [[Tamaulipas]], Mexico to [[Ontario]], Canada. The planned [[Interstate 11|I-11]] will then bridge the Interstate gap between [[Phoenix, Arizona]] and [[Las Vegas, Nevada]], and thus form part of the [[CANAMEX Corridor]] (along with [[Interstate 19|I-19]], and portions of [[Interstate 10|I-10]] and [[Interstate 15|I-15]]) between [[Sonora]], Mexico and [[Alberta]], Canada.