Interstate Highways in Alaska
|Dwight D. Eisenhower National System of Interstate and Defense Highways|
Shields for Interstates in Alaska
Map of the Interstates of Alaska
|Length:||1,082.22 mi (1,741.66 km)|
|Interstates:||Interstate A-n (A-n)|
|State:||Alaska Route n (AK-n)|
The Interstate Highways in Alaska are all owned and maintained by the U.S. state of Alaska. The Alaska Department of Transportation & Public Facilities (DOT&PF) is responsible for the maintenance and operations of the Interstate Highways. The Interstate Highway System in Alaska comprises four highways that cover 1,082.22 miles (1,741.66 km). The longest of these is A-1, at 408.23 miles (656.98 km) long, while the shortest route is A-3, at 148.12 miles (238.38 km) long.
Interstates in Alaska follow the numbering system Interstate A-n, where n represents the number of the Interstate. This follows the similar numbering systems for Hawaii and Puerto Rico. Currently, all Interstates in Alaska are unsigned  and are not generally referred to by their highway numbers. In fact most Alaskans are unaware of those numbers. The Interstate Highway System was expanded to Alaska in 1976, by the Federal-Aid Highway Act of 1976, which defined the system for Interstates in Alaska and Puerto Rico under Title 23, Chapter 1, Section 103 (c)(1)(B)(ii) of the U.S. Code.
Most of the lengths of the Interstates in Alaska are not constructed to Interstate Highway standards, but are small, rural, two-lane, undivided highways. Title 23 provides that "Highways on the Interstate System in Alaska and Puerto Rico shall be designed in accordance with such geometric and construction standards as are adequate for current and probable future traffic demands and the needs of the locality of the highway." Some portions of these highways are built to Interstate standards, though. The Seward Highway, part of A-3, is built to freeway standards in Anchorage. The Glenn Highway, which is part of A-1, is built to freeway standards from Anchorage to Wasilla. A very small portion of the George Parks Highway, A-4, is constructed to freeway standards in Wasilla. In and around Fairbanks, the Richardson Highway, part of A-2, is constructed to freeway standards. In addition to these highways, the Johansen Expressway, in Fairbanks, and the Minnesota Drive Expressway, in Anchorage, are constructed to expressway standards.
|Number||Length (mi)||Length (km)||Southern or western terminus||Northern or eastern terminus||Formed||Removed||Notes|
|I‑A1||408.23||656.98||Anchorage||Canadian border in Alcan Border||1976||current||Glenn Highway, Richardson Highway, Tok Cut-Off, Alaska Highway|
|I‑A2||202.18||325.38||Tok||Fairbanks||1976||current||Alaska Highway, Richardson Highway|
|I‑A3||148.12||238.38||Anchorage||Soldotna||1976||current||Seward Highway, Sterling Highway|
|I‑A4||323.69||520.93||Gateway, near Palmer||Fairbanks||1976||current||Parks Highway|
The George Parks Highway, which comprises the entirety of Interstate A4.
- Staff (October 31, 2002). "Table 1: Main Routes of the Dwight D. Eisenhower National System Of Interstate and Defense Highways as of October 31, 2002". Route Log and Finder List. Federal Highway Administration. Retrieved September 27, 2008.
- Staff. "Interstate Frequently Asked Questions". Federal Highway Administration. Retrieved May 31, 2012.
- Weingroff, Richard F. (April 7, 2011). "Interstates in Hawaii: Are We Crazy???". Ask the Rambler. Federal Highway Administration. Retrieved March 15, 2011.
- United States Congress. "Title 23, Chapter 1, Section §103". U.S. Government Printing Office. Retrieved May 31, 2012.
- Google Inc. "Overview Map of Interstate A-3". Google Maps (Map). Cartography by Google, Inc. https://maps.google.com/maps?f=d&source=s_d&saddr=AK-1+N&daddr=Ingra+St&geocode=FevymgMd5Qz_9g%3BFUQXpgMdMDYR9w&abauth=4fc6f6fff2elbK6k1q8jIlmQizuw4hd0kLw&vps=5&ei=AwPHT-LjIJLcM42PlfgI&jsv=417c&sll=61.215499,-149.85918&sspn=0.012316,0.027595&vpsrc=0&hl=en&mra=ls&num=10&mid=1338442508. Retrieved May 31, 2012.
- Google Inc. "Overview Map of Interstate A-1". Google Maps (Map). Cartography by Google, Inc. https://maps.google.com/maps?f=d&source=s_d&saddr=Ingra+St&daddr=Tok+Cutoff&geocode=FUQXpgMdMDYR9w%3BFRBnxgMdYCl69w&abauth=4fc70310hxhHgyanr2dWt8YFXnPtQL9RvnU&vps=5&ei=XgTHT42MD4byM8H6pdEI&jsv=417c&sll=63.31885,-143.036499&sspn=0.367521,0.883026&vpsrc=0&hl=en&mra=ls&num=10&mid=1338442857. Retrieved May 31, 2012.
- Google Inc. "Overview Map of Interstate A-4". Google Maps (Map). Cartography by Google, Inc. https://maps.google.com/maps?f=d&source=s_d&saddr=AK-2+E&daddr=Interstate+a-4+E&geocode=FSUV3QMd6z4y9w%3BFfMRqwMdoJga9w&abauth=4fc7055e0FVP1QE0bsLT8bZtLjNwhY8eC9c&vps=5&ei=6AXHT_7YEZ7GMoP1sfgI&jsv=417c&sll=61.604437,-149.251328&sspn=0.194617,0.441513&vpsrc=6&hl=en&mra=ls&num=10&mid=1338443251. Retrieved May 31, 2012.
- Google Inc. "Overview Map of Interstate A-2". Google Maps (Map). Cartography by Google, Inc. https://maps.google.com/maps?f=d&source=s_d&saddr=AK-2+E&daddr=AK-2+W&geocode=FSUV3QMd6z4y9w%3BFZ5wuwMdjHqY9w&abauth=4fc7046dyoFto1TE_LXSviaNLQFweuvSBI8&vps=5&ei=UAXHT6yaH4_OMIy_mfgO&jsv=417c&sll=64.812872,-147.732296&sspn=0.043541,0.110378&vpsrc=6&hl=en&mra=ls&num=10&mid=1338443098. Retrieved May 31, 2012.
- Witt, Jennifer W. (2010) (PDF). Annual Traffic Volume Report (Report) (2008-2009-2010 ed.). Alaska Department of Transportation & Public Facilities. http://www.dot.state.ak.us/stwdplng/mapping/trafficmaps/trafficdata_reports_cen/2010_ATVR_FINAL_All_Posted.pdf. Retrieved March 15, 2012.
- Birkholz, Ethan (2010) (PDF). Annual Traffic Volume Report (Report) (2008-2009-2010 ed.). Alaska Department of Transportation & Public Facilities. http://www.dot.alaska.gov/stwdplng/mapping/trafficmaps/trafficdata_reports_nor/NRVolumeRpt2008-10.pdf. Retrieved May 31, 2012.
- Federal Highway Administration. "Dwight D. Eisenhower Interstate Routes Statewide". U.S. Department of Transportation. Retrieved May 31, 2012.
- Federal Highway Administration. "Alaska Department of Transportation and Public Facilities Routes by Description: CDS Route Numbers as of 28 October 2008". U.S. Department of Transportation. Retrieved May 31, 2012.