Interstate 81 (English Wikipedia)

Rice, Otis K.; Brown, Stephen W. (1993). West Virginia: A History. Lexington: University Press of Kentucky. p. 10. ISBN 978-0-8131-1854-3. Retrieved February 2, 2018.
Bonnell, Robert O.; Bennett, Edgar T.; McMullen, John J. (December 15, 1958). Report of the State Roads Commission of Maryland (1957–1958 ed.). Baltimore: Maryland State Roads Commission. p. 82. Retrieved November 15, 2010.

archive.today

"Fort Drum connector road officially open". Syracuse, NY: YNN Central New York. December 6, 2012. Archived from the original on February 10, 2013. Retrieved February 2, 2018.

books.google.com

Fiske, E.B.; Logue, R. (2006). The Fiske Guide to Colleges. New York: Times Books. p. 358. ISBN 9781402203749. Retrieved February 26, 2018 – via Google Books. The university straddles Interstate 81, an outlet to several major East Coast cities.
Harbaugh, Charles IV; Pennington, Jeff (2015). Middletown. Images of America. Charleston, SC: Arcadia Publishing. p. 10. ISBN 978-1-4671-2242-9. Retrieved February 26, 2018 – via Google Books.

collegiatetimes.com

Rossi, Isabella (February 12, 2019). "Sex trafficking closer to home than most Virginians would think". Collegiate Times. Retrieved June 22, 2020.

davidrumsey.com

White, M. Wood (1873). "Counties of Morgan, Berkeley, Jefferson" (Map). White's Topographical, County & District Atlas of West Virginia. 1:310,000. M.W. White. p. 22. OCLC 62726043. Retrieved February 2, 2018 – via David Rumsey Map Collection.

dot.gov

fhwa.dot.gov

"Table 1: Main Routes of the Dwight D. Eisenhower National System Of Interstate and Defense Highways". FHWA Route Log and Finder List. Federal Highway Administration. December 31, 2021. Retrieved July 14, 2022.
Natzke, Stefan; Neathery, Mike & Adderly, Kevin (June 20, 2012). "What is the National Highway System?". National Highway System. Washington, DC: Federal Highway Administration. Retrieved July 1, 2012.

highways.dot.gov

"Previous Interstate Facts of the Day". Eisenhower Interstate Highway System Home Page. See June 8, 2010. Archived from the original on April 26, 2006. Retrieved February 3, 2018.

fultonhistory.com

"Penn-Can Road Vital to Broome, Majority at Hearing Says" (PDF). The Binghamton Press. January 9, 1957. p. 3. Archived from the original (PDF) on January 30, 2022. Retrieved February 3, 2018 – via Fulton County Historical Society.

greaternyroads.info

State of New York Department of Transportation (January 1, 1970). Official Description of Touring Routes in New York State (PDF) (Map). Albany: New York State Department of Transportation. Retrieved February 3, 2018.^{[full citation needed]}

i-81coalition.org

"Corridor Coalition". I-81coalition.org. Retrieved January 29, 2018.

maps.google.com

"Overview Map of I-81 in New York" (Map). Google Maps. April 16, 2012. Retrieved February 3, 2018.

maryland.gov

msa.maryland.gov

Maryland State Roads Commission (1958). Maryland: Official Highway Map (PDF) (Map). Baltimore: Maryland State Roads Commission.^{[full citation needed]}
Maryland State Roads Commission (1959). Maryland: Official Highway Map (PDF) (Map). Baltimore: Maryland State Roads Commission.^{[full citation needed]}

roads.maryland.gov

Highway Information Services Division (December 31, 2013). Highway Location Reference. Maryland State Highway Administration. Retrieved February 3, 2018.
- Washington County (PDF). pp. 13–19.

measuringworth.com

Johnston, Louis; Williamson, Samuel H. (2023). "What Was the U.S. GDP Then?". MeasuringWorth. Retrieved November 30, 2023. United States Gross Domestic Product deflator figures follow the MeasuringWorth series.

millershousemuseum.org

"Roads". Miller's House Museum. Retrieved July 16, 2018.

mountainx.com

Allen, Calvin (July 16, 2003). "The Political History of I-26". Mountain Xpress. Asheville, NC. Retrieved February 2, 2018.

nvdaily.com

Zuckerman, Jake (January 26, 2017). "FBI forms human trafficking task force along I-81". North Virginia Daily. Retrieved June 22, 2020.

ny.gov

dot.ny.gov

Highway Data Services Bureau. "2014 Traffic Volume Report for New York State" (PDF). Albany: New York State Department of Transportation. Retrieved February 2, 2018.

virginiadot.org

"I-81 History". Virginia Department of Transportation. Archived from the original on November 13, 2007. Retrieved January 29, 2018.
Virginia Department of Transportation. "Virginia Interstate Exits". Virginia Department of Transportation. Retrieved February 3, 2018.
Virginia Department of Transportation (2013). "2012 Virginia Department of Transportation Daily Traffic Volume Estimates Including Vehicle Classification Estimates" (PDF). Virginia Department of Transportation.

web.archive.org

"Previous Interstate Facts of the Day". Eisenhower Interstate Highway System Home Page. See June 8, 2010. Archived from the original on April 26, 2006. Retrieved February 3, 2018.
"Penn-Can Road Vital to Broome, Majority at Hearing Says" (PDF). The Binghamton Press. January 9, 1957. p. 3. Archived from the original (PDF) on January 30, 2022. Retrieved February 3, 2018 – via Fulton County Historical Society.
"I-81 History". Virginia Department of Transportation. Archived from the original on November 13, 2007. Retrieved January 29, 2018.

whptv.com

"I-81 Safety Conference". Harrisburg, PA: WHP-TV. Retrieved October 4, 2014.^{[permanent dead link‍]}

wikimedia.org

commons.wikimedia.org

American Association of State Highway Officials (August 14, 1957). Official Route Numbering for the National System of Interstate and Defense Highways (Map). Scale not given. Washington, DC: American Association of State Highway Officials – via Wikimedia Commons.
American Association of State Highway Officials (June 27, 1958). Official Route Numbering for the National System of Interstate and Defense Highways as Adopted by the American Association of State Highway Officials (Map). Scale not given. Washington, DC: American Association of State Highway Officials. Retrieved February 7, 2018 – via Wikimedia Commons.

witf.org

I-81 Corridor group^{[dead link‍]}

worldcat.org

search.worldcat.org

Perrier, Dianne (2010). Interstate 81: The Great Warriors Trace. Gainesville: University Press of Florida. ISBN 978-0-8130-3481-2. OCLC 502304332.^{[page needed]}
White, M. Wood (1873). "Counties of Morgan, Berkeley, Jefferson" (Map). White's Topographical, County & District Atlas of West Virginia. 1:310,000. M.W. White. p. 22. OCLC 62726043. Retrieved February 2, 2018 – via David Rumsey Map Collection.

ynn.com

watertown.ynn.com

"Fort Drum connector road officially open". Syracuse, NY: YNN Central New York. December 6, 2012. Archived from the original on February 10, 2013. Retrieved February 2, 2018.