List of Interstate Highways
Dwight D. Eisenhower National System of Interstate and Defense Highways | |
---|---|
System information | |
Formed | June 29, 1956[1] |
Highway names | |
Interstates | Interstate X (I-X) |
System links | |
There are 71 primary Interstate Highways in the Interstate Highway System, a network of freeways in the United States. These primary highways are assigned one- or two-digit route numbers, whereas their associated auxiliary Interstate Highways receive three-digit route numbers. Typically, odd-numbered Interstates run south–north, with lower numbers in the west and higher numbers in the east; even-numbered Interstates run west–east, with lower numbers in the south and higher numbers in the north. Route numbers divisible by 5 usually represent major coast-to-coast or border-to-border routes (ex. I-10 connects Santa Monica, California to Jacksonville, Florida, extending between the Pacific and Atlantic oceans). Auxiliary highways have an added digit prefixing the number of the parent highway.
Five route numbers are duplicated in the system; the corresponding highways are in different regions, reducing potential confusion. In addition to primary highways in the contiguous United States, there are signed Interstates in Hawaii and unsigned Interstates in Alaska and Puerto Rico.
Contiguous United States
[edit]There are 71 primary interstate highways in the 48 contiguous United States as well as five former and one future primary interstate highways. This number does not include auxiliary Interstate Highways.
Number | Length (mi)[2] | Length (km) | Southern or western terminus | Northern or eastern terminus | Formed | Removed | Notes | |
---|---|---|---|---|---|---|---|---|
I-2 | 46.80 | 75.32 | BL US 83 in Peñitas, Texas | I-69E/US 77/US 83 in Harlingen, Texas | 2013 | current | Unfinished in Texas; Texas only | |
I-4 | 132.30 | 212.92 | I-275 in Tampa, Florida | I-95/SR 400 in Daytona Beach, Florida | 1959 | current | Florida only | |
I-5 | 1381.29 | 2,222.97 | Fed. 1/Fed. 1D at Mexican border in San Ysidro, California | Hwy 99 at Canadian border in Blaine, Washington | 1956 | current | Serves three states: California, Oregon, Washington Associated routes: I-105, I-205, I-305, I-405, I-505, I-605, I-705, I-805; Planned: I-905 in California | |
I-8 | 348.25 | 560.45 | Sunset Cliffs Boulevard/Nimitz Boulevard in San Diego, California | I-10 in Casa Grande, Arizona | 1964 | current | Serves two states: California, Arizona | |
I-10 | 2460.34 | 3,959.53 | SR 1 in Santa Monica, California | I-95/US 17/SR 15/SR 228 in Jacksonville, Florida | 1957 | current | Serves eight states: California, Arizona, New Mexico, Texas, Louisiana, Mississippi, Alabama, Florida Associated routes: I-110, I-210, I-310, I-410, I-510, I-610, I-710, I-910 | |
I-11 | 53.90 | 86.74 | US 93 at Arizona state line near Boulder City, Nevada | US 95/SR 157 in Las Vegas, Nevada | 2017 | current | Unfinished in Nevada; Nevada only; planned in one more: Arizona | |
I-12 | 85.59 | 137.74 | I-10 in Baton Rouge, Louisiana | I-10/I-59 in Slidell, Louisiana | 1967 | current | Louisiana only | |
I-14 | 25.10 | 40.39 | US 190/US 190 Bus in Copperas Cove, Texas | I-35/US 190 in Belton, Texas | 2017 | current | Unfinished in Texas; Texas only; planned in four more: Louisiana, Mississippi, Alabama, Georgia Planned associated routes: I-14N, I-14S, and I-214 in Texas | |
I-15 | 1433.52 | 2,307.03 | I-8/SR 15 in San Diego, California | Highway 4 at Canadian border in Sweetgrass, Montana | 1957 | current | Unfinished in California; serves six states: California, Nevada, Arizona, Utah, Idaho, Montana Associated routes: I-115, I-215, I-315 | |
I-16 | 166.81 | 268.45 | I-75/SR 540 in Macon, Georgia | Montgomery Street in Savannah, Georgia | 1966 | current | Georgia only Associated route: I-516 | |
I-17 | 145.76 | 234.58 | I-10/US 60 in Phoenix, Arizona | I-40/SR 89A in Flagstaff, Arizona | 1961 | current | Arizona only | |
I-19 | 63.35 | 101.95 | I-19 Bus. in Nogales, Arizona | I-10 in Tucson, Arizona | 1972 | current | Arizona only Uses kilometers instead of miles | |
I-20 | 1539.38 | 2,477.39 | I-10 in Reeves County, Texas | I-95/I-20 Bus. in Florence, South Carolina | 1957 | current | Serves six states: Texas, Louisiana, Mississippi, Alabama, Georgia, South Carolina Associated routes: I-220, I-520, I-820 | |
I-22 | 202.22 | 325.44 | I-269/US 78/MS 304 near Byhalia, Mississippi | I-65 in Birmingham, Alabama | 2012 | current | Unfinished in Alabama; serves two states: Mississippi, Alabama Planned associated routes: I-222 and I-422 in Alabama | |
I-24 | 316.36 | 509.13 | I-57 in Pulley's Mill, Illinois | I-75 in Chattanooga, Tennessee | 1962 | current | Serves four states: Illinois, Kentucky, Tennessee, Georgia Associated route: I-124 | |
I-25 | 1061.67 | 1,708.59 | I-10/US 85/US 180 in Las Cruces, New Mexico | I-90/US 87 in Buffalo, Wyoming | 1957 | current | Serves three states: New Mexico, Colorado, Wyoming Associated route: I-225 | |
I-26 | 304.64 | 490.27 | US 11W/US 23/SR 137 in Kingsport, Tennessee | US 17 in Charleston, South Carolina | 1960 | current | Unfinished in North Carolina; serves three states: Tennessee, North Carolina, South Carolina Associated routes: I-126, I-526 | |
I-27 | 124.13 | 199.77 | US 87/Loop 289 in Lubbock, Texas | I-40/US 87/US 287/US 60 in Amarillo, Texas | 1969 | current | Unfinished in Texas; Texas only; planned in one more: New Mexico | |
I-29 | 755.51 | 1,215.88 | I-35/I-70/US 24/US 40/US 71 in Kansas City, Missouri | US 81 and PTH 75 at Canadian border in Pembina, North Dakota | 1958 | current | Serves four states: Missouri, Iowa, South Dakota, North Dakota Associated routes: I-129, I-229 | |
I-30 | 366.76 | 590.24 | I-20 in Fort Worth, Texas | I-40/US 65/US 67/US 167 in North Little Rock, Arkansas | 1957 | current | Serves two states: Texas, Arkansas Associated routes: I-430, I-530, I-630 | |
I-31 | — | — | I-94 in Fargo, North Dakota | US 81 and PTH 75 at Canadian border in Pembina, North Dakota | 1957 | 1958 | Served North Dakota only Replaced by a northward extension of I-29 | |
I-35 | 1568.38 | 2,524.06 | US 83/Victoria Street in Laredo, Texas | MN 61/LSCT/26th Avenue in Duluth, Minnesota | 1956 | current | Serves six states: Texas, Oklahoma, Kansas, Missouri, Iowa, Minnesota Associated routes: I-35E, I-35W, I-135, I-235, I-335, I-435, I-535, I-635 | |
I-37 | 143.00 | 230.14 | US 181 in Corpus Christi, Texas | I-35/US 281 in San Antonio, Texas | 1959 | current | Texas only | |
I-39 | 306.14 | 492.68 | I-55 in Normal, Illinois | WIS 29/US 51 in Wausau, Wisconsin | 1984 | current | Serves two states: Illinois, Wisconsin | |
I-40 | 2556.61 | 4,114.46 | I-15 in Barstow, California | US 117/NC 132 in Wilmington, North Carolina | 1964 | current | Serves eight states: California, Arizona, New Mexico, Texas, Oklahoma, Arkansas, Tennessee, North Carolina Associated routes: I-140, I-240, I-440, I-540, I-640, I-840 | |
I-41 | 175.00 | 281.64 | I-94/US 41 in Russell, Illinois | I-43/US 41/US 141 in Howard, Wisconsin | 2015 | current | Serves two states: Illinois, Wisconsin | |
I-42 | 190 | 310 | I-35 in Noble County, Oklahoma | I-49 in Springdale, Arkansas | proposed | — | Future Interstate; will serve two states: Oklahoma, Arkansas | |
I-42 | 31.5 | 50.7 | I-40/US 70 in Garner, North Carolina | US 70 in Goldsboro, North Carolina | 2024 | current | Unfinished in North Carolina; North Carolina only | |
I-43 | 191.55 | 308.27 | I-39/I-90 in Beloit, Wisconsin | I-41/US 41/US 141 in Howard, Wisconsin | 1981 | current | Wisconsin only | |
I-44 | 636.69 | 1,024.65 | US 82/US 277/US 281/US 287 in Wichita Falls, Texas | I-70 in St. Louis, Missouri | 1958 | current | Serves three states: Texas, Oklahoma, Missouri Associated routes: I-244, I-344, I-444 | |
I-45 | 284.91 | 458.52 | SH 87 in Galveston, Texas | I-30/US 67/US 75 in Dallas, Texas | 1971 | current | Texas only Associated route: I-345 | |
I-49 | 528.02 | 849.77 | I-10/US 167/LA 182 in Lafayette, Louisiana | I-435/I-470/US 50/US 71 in Kansas City, Missouri | 1984 | current | Unfinished in Arkansas and Louisiana; serves three states: Louisiana, Arkansas, Missouri; planned in one more: Texas | |
I-55 | 964.25 | 1,551.81 | I-10 in LaPlace, Louisiana | US 41 in Chicago, Illinois | 1960 | current | Serves six states: Louisiana, Mississippi, Tennessee, Arkansas, Missouri, Illinois Associated routes: I-155, I-255, I-355, I-555 | |
I-57 | 508.92 | 819.03 | I-40 in Little Rock, Arkansas | I-94 in Chicago, Illinois | 1965 | current | Unfinished in Missouri and Arkansas; serves three states: Arkansas, Missouri, Illinois. | |
I-59 | 445.23 | 716.53 | I-10/I-12 in Slidell, Louisiana | I-24 in Wildwood, Georgia | 1960 | current | Serves four states: Louisiana, Mississippi, Alabama, Georgia Associated routes: I-359, I-459, I-759 | |
I-64 | 963.52 | 1,550.64 | I-70/US 61 in Wentzville, Missouri | I-264/I-664 in Chesapeake, Virginia | 1961 | current | Serves six states: Missouri, Illinois, Indiana, Kentucky, West Virginia, Virginia Associated routes: I-264, I-464, I-564, I-664 | |
I-65 | 887.30 | 1,427.97 | I-10 in Mobile, Alabama | US 12/US 20 in Gary, Indiana | 1958 | current | Serves four states: Alabama, Tennessee, Kentucky, Indiana Associated routes: I-165, I-265, I-465, I-565, I-865; Planned: I-365 in Kentucky | |
I-66 | — | — | Wichita, Kansas | Near Pikeville, Kentucky | 1991 | [3] | 2015Served four states: Kansas, Missouri, Illinois, Kentucky Associated routes: I-66 Spur in Kentucky The project was unpopular and ultimately cancelled without the interstate being completed; I-66 Spur eventually became I-165 | |
I-66 | 76.28 | 122.76 | I-81 in Front Royal, Virginia | US 29 in Washington, D.C. | 1961 | current | Serves DC and one state: Virginia | |
I-68 | 113.15 | 182.10 | I-79 in Morgantown, West Virginia | I-70 in Hancock, Maryland | 1991 | current | Serves two states: West Virginia, Maryland | |
I-69 | 879.82 | 1,415.93 | US 59 in Rosenberg, Texas | Highway 402 at Canadian border in Port Huron, Michigan | 1957 | current | Unfinished in Texas, Mississippi, Kentucky, and Indiana; serves six states: Texas, Mississippi, Kentucky, Indiana, Michigan. Planned/started in 3 more: Louisiana, Arkansas, Tennessee Associated routes: I-69C, I-69E, I-69W, I-169, I-269, I-369, I-469; Planned: I-569 in Kentucky | |
I-70 | 2172.16 | 3,495.75 | I-15 in Cove Fort, Utah | I-695 in Woodlawn, Maryland | 1956 | current | Serves 10 states: Utah, Colorado, Kansas, Missouri, Illinois, Indiana, Ohio, West Virginia, Pennsylvania, Maryland Associated routes: I-170, I-270, I-370, I-470, I-670 | |
I-71 | 345.57 | 556.14 | I-64 in Louisville, Kentucky | I-90 in Cleveland, Ohio | 1959 | current | Serves two states: Kentucky, Ohio Associated routes: I-271, I-471 | |
I-72 | 179.29 | 288.54 | US 61 in Hannibal, Missouri | Church Street and University Avenue in Champaign, Illinois | 1970 | current | Serves two states: Missouri, Illinois Associated route: I-172 | |
I-73 | 99.43 | 160.02 | US 220 near Stokesdale, North Carolina | I‑74 and US 220 in Randleman, North Carolina | 1997 | current | Unfinished in North Carolina; North Carolina only; planned in five more: South Carolina, Virginia, West Virginia, Ohio, Michigan | |
I-74 | 491.74 | 791.38 | I-80 in Bettendorf, Iowa | US 74/NC 41 near Lumberton, North Carolina | 1974 | current | Unfinished in Ohio and North Carolina; serves five states: Iowa, Illinois, Indiana, Ohio, North Carolina; planned in three more: West Virginia, Virginia, South Carolina Associated routes: I-474; Planned: I-274 in North Carolina | |
I-75 | 1786.47 | 2,875.04 | SR 826/SR 916/SR 924 in Miami Lakes, Florida | Canadian border at Sault Ste. Marie, Michigan | 1958 | current | Serves six states: Florida, Georgia, Tennessee, Kentucky, Ohio, Michigan Associated routes: I-175, I-275, I-375, I-475, I-575, I-675 | |
I-76 | 186.48 | 300.11 | I-70 at Denver, Colorado | I-80 at Big Springs, Nebraska | 1975 | current | Serves two states: Colorado, Nebraska | |
I-76 | 435.66 | 701.13 | I-71 in Westfield Center, Ohio | I-295 at Bellmawr, New Jersey | 1964 | current | Serves three states: Ohio, Pennsylvania, New Jersey Associated routes: I-176, I-276, I-376, I-476, I-676 | |
I-77 | 610.10 | 981.86 | I-26 in Columbia, South Carolina | I-90 in Cleveland, Ohio | 1958 | current | Serves five states: South Carolina, North Carolina, Virginia, West Virginia, Ohio Associated route: I-277 | |
I-78 | 146.28 | 235.41 | I-81 at Jonestown, Pennsylvania | Canal Street in New York City | 1957 | current | Serves three states: Pennsylvania, New Jersey, New York Associated routes: I-278, I-478, I-678, I-878 | |
I-79 | 343.46 | 552.75 | I-77 in Charleston, West Virginia | PA 5 in Erie, Pennsylvania | 1967 | current | Serves two states: West Virginia, Pennsylvania Associated routes: I-279, I-579 | |
I-80 | 2899.59 | 4,666.44 | US 101 in San Francisco, California | I-95 in Teaneck, New Jersey | 1956 | current | Serves 11 states: California, Nevada, Utah, Wyoming, Nebraska, Iowa, Illinois, Indiana, Ohio, Pennsylvania, New Jersey Associated routes: I-180, I-238, I-280, I-380, I-480, I-580, I-680, I-780, I-880, I-980 | |
I-81 | 855.02 | 1,376.02 | I-40 in Dandridge, Tennessee | Hwy 137 at Canadian border on Wellesley Island, New York | 1961 | current | Serves six states: Tennessee, Virginia, West Virginia, Maryland, Pennsylvania, New York Associated routes: I-381, I-481, I-581, I-781 | |
I-82 | 143.58 | 231.07 | I-90 in Ellensburg, Washington | I-84 in Hermiston, Oregon | 1957 | current | Serves two states: Washington, Oregon Associated route: I-182 | |
I-82 | — | — | I-81/I-84/US 6 in Scranton, Pennsylvania | I-95 in Teaneck, New Jersey | 1957 | 1958 | Served two states: Pennsylvania, New Jersey Was the initial designation to what is now I-380 and I-80 | |
I-82 | — | — | I-84 in East Hartford, Connecticut | Providence, Rhode Island | 1956 | 1968 | Served one state: Connecticut, was planned for one state: Rhode Island Redesignated as I-84 in 1968 | |
I-83 | 85.03 | 136.84 | President Street and Fayette Street in Baltimore, Maryland | I-81 in Harrisburg, Pennsylvania | 1959 | current | Serves two states: Maryland, Pennsylvania Associated route: I-283 | |
I-84 | 769.62 | 1,238.58 | I-5 in Portland, Oregon | I-80 in Echo, Utah | 1980 | current | Serves three states: Oregon, Idaho, Utah Associated route: I-184 | |
I-84 | 232.71 | 374.51 | I-81 in Scranton, Pennsylvania | I-90 in Sturbridge, Massachusetts | 1963 | current | Serves four states: Pennsylvania, New York, Connecticut, Massachusetts Associated routes: I-384, I-684 | |
I-85 | 666.05 | 1,071.90 | I-65 in Montgomery, Alabama | I-95 in Petersburg, Virginia | 1958 | current | Unfinished in Alabama; serves five states: Alabama, Georgia, South Carolina, North Carolina, Virginia Associated routes: I-185, I-285, I-385, I-485, I-585, I-785, I-885, I-985; Future/Planned: I-685 in both Alabama and North Carolina | |
I-86 | 62.85 | 101.15 | I-84 near Declo, Idaho | I-15 in Chubbuck, Idaho | 1980 | current | Idaho only | |
I-86 | 223.39 | 359.51 | I-90 near North East, Pennsylvania | NY 17/NY 79 in Windsor, New York | 1999 | current | Unfinished in New York; serves two states: Pennsylvania, New York | |
I-86 | 38.97 | 62.72 | I-84 in East Hartford, Connecticut | I-90 in Sturbridge, Massachusetts | 1968 | 1984 | Served two states: Connecticut, Massachusetts Redesignated as I-84 in 1984 when the I-84 Hartford-Providence corridor was cancelled | |
I-87 | 12.90 | 20.76 | I-40/I-440/US 64/US 264 in Raleigh, North Carolina | US 64/US 264 in Wendell, North Carolina | 2017 | current | Unfinished in North Carolina; North Carolina only; planned in one more: Virginia Associated route: I-587 Shortest Interstate highway in contiguous United States | |
I-87 | 333.49 | 536.70 | I-278 in New York City | A-15 at Canadian border in Champlain, New York | 1957 | current | New York only Associated routes: I-287, I-587, I-787 | |
I-88 | 140.60 | 226.27 | I-80/IL 92 in East Moline, Illinois | I-290/IL 110 in Hillside, Illinois | 1987 | current | Illinois only | |
I-88 | 117.75 | 189.50 | I-81 in Binghamton, New York | I-90 in Schenectady, New York | 1968 | current | New York only | |
I-89 | 191.12 | 307.58 | I-93/SR 3A in Bow, New Hampshire | Route 133/Future A-35 at Canadian border in Highgate, Vermont | 1960 | current | Serves two states: New Hampshire, Vermont Associated route: I-189 | |
I-90 | 3020.44 | 4,860.93 | SR 519/4th Avenue/Edgar Martinez Drive in Seattle, Washington | MA 1A in Boston, Massachusetts | 1956 | current | Serves 13 states: Washington, Idaho, Montana, Wyoming, South Dakota, Minnesota, Wisconsin, Illinois, Indiana, Ohio, Pennsylvania, New York, Massachusetts Associated routes: I-190, I-290, I-390, I-490, I-590, I-690, I-790, I-890, I-990 Longest Interstate highway | |
I-91 | 290.37 | 467.31 | I-95/Route 34 in New Haven, Connecticut | A-55 at Canadian border in Derby Line, Vermont | 1958 | current | Serves three states: Connecticut, Massachusetts, Vermont Associated routes: I-291, I-391, I-691 | |
I-93 | 189.95 | 305.69 | I-95/US 1 in Canton, Massachusetts | I-91 in St. Johnsbury, Vermont | 1957 | current | Serves three states: Massachusetts, New Hampshire, Vermont Associated routes: I-293, I-393 | |
I-94 | 1585.20 | 2,551.13 | I-90 in Lockwood, Montana | Highway 402 at Canadian border in Port Huron, Michigan | 1956 | current | Serves seven states: Montana, North Dakota, Minnesota, Wisconsin, Illinois, Indiana, Michigan Associated routes: I-194, I-294, I-394, I-494, I-694, I-794, I-894 | |
I-95 | 1919.31 | 3,088.83 | US 1 in Miami, Florida | NB 95 at Canadian border in Houlton, Maine | 1957 | current | Serves DC and 15 states: Florida, Georgia, South Carolina, North Carolina, Virginia, Maryland, Delaware, Pennsylvania, New Jersey, New York, Connecticut, Rhode Island, Massachusetts, New Hampshire, Maine Associated routes: I-195, I-295, I-395, I-495, I-595, I-695, I-795, I-895 Longest primary north-south Interstate highway | |
I-96 | 192.06 | 309.09 | US 31 in Norton Shores, Michigan | I-75 in Detroit, Michigan | 1959 | current | Michigan only Associated routes: I-196, I-296, I-496, I-696 | |
I-97 | 17.62 | 28.36 | US 50/US 301 in Annapolis, Maryland | I-695/I-895A in Glen Burnie, Maryland | 1987 | current | Maryland only | |
I-99 | 98.34 | 158.26 | US 220 in Bedford, Pennsylvania | I-86/NY 17 in Painted Post, New York | 1998 | current | Unfinished in Pennsylvania; serves two states: Pennsylvania, New York | |
|
Other regions
[edit]In addition to the 48 contiguous states, Interstate Highways are found in Hawaii, Alaska, and Puerto Rico. The Federal Highway Administration funds four routes in Alaska and three routes in Puerto Rico under the same program as the rest of the Interstate Highway System. However, these routes are not required to meet the same standards as the mainland routes:
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.[4]
Hawaii
[edit]The Interstate Highways on the island of Oʻahu, Hawaii are signed with the standard Interstate Highway shield, with the letter "H-" prefixed before the number. They are fully controlled-access routes built to the same standards as the mainland Interstate Highways.
Number | Length (mi)[2] | Length (km) | Southern or western terminus | Northern or eastern terminus | Formed | Removed | Notes | |
---|---|---|---|---|---|---|---|---|
H-1 | 27.16 | 43.71 | Route 93 in Kapolei | Route 72 in Honolulu | 1960 | current | Associated route: H-201 | |
H-2 | 8.33 | 13.41 | H-1 in Pearl City | Route 99 in Wahiawa | 1960 | current | ||
H-3 | 15.32 | 24.66 | H-1/H-201 in Halawa | Marine Corps Base Hawaii | 1997 | current | ||
Alaska
[edit]Alaska's Interstate Highways are unsigned as such, although they all have state highway numbers that do not match the Interstate Highway numbers.[5]
Number | Length (mi)[2] | Length (km) | Southern or western terminus | Northern or eastern terminus | Formed | Removed | Notes | |
---|---|---|---|---|---|---|---|---|
A-1 | 408.23 | 656.98 | Anchorage | Canadian border in Alcan Border | 1976 | current | Glenn Highway, Richardson Highway, Tok Cut-Off, Alaska Highway[6][7][8][9] | |
A-2 | 202.18 | 325.38 | Tok | Fairbanks | 1976 | current | Alaska Highway, Richardson Highway[7][8][9] | |
A-3 | 148.12 | 238.38 | Anchorage | Soldotna | 1976 | current | Seward Highway, Sterling Highway[6][8][9] | |
A-4 | 323.69 | 520.93 | Gateway, near Palmer | Fairbanks | 1976 | current | Parks Highway[6][7][8][9] | |
Puerto Rico
[edit]Puerto Rico signs its Interstate Highways as territorial routes, as the numbers do not match their official Interstate Highway designations. Many of the territory's routes are freeway-standard toll roads.[10]
Number | Length (mi)[2] | Length (km) | Southern or western terminus | Northern or eastern terminus | Formed | Removed | Notes | |
---|---|---|---|---|---|---|---|---|
PR-1 | 71.08 | 114.39 | PR-2 in Ponce | PR-2 in San Juan | 1976 | current | Follows PR-52 | |
PR-2 | 138.13 | 222.30 | PR-1 in Ponce | PR-3 in San Juan | 1976 | current | Follows PR-22 | |
PR-3 | 40.56 | 65.27 | PR-3 in Humacao | PR-2 in San Juan | 1976 | current | Follows PR-66 | |
See also
[edit]
References
[edit]- ^ Weingroff, Richard F. (Summer 1996). "Federal-Aid Highway Act of 1956, Creating the Interstate System". Public Roads. 60 (1). Washington, DC: Federal Highway Administration. Retrieved March 16, 2012.
- ^ a b c d "Table 1: Main Routes of the Dwight D. Eisenhower National System Of Interstate and Defense Highways as of December 31, 2018". FHWA Route Log and Finder List. Federal Highway Administration. May 6, 2019. Retrieved April 21, 2021.
- ^ Nelsen, Carrie (July 9, 2015). "For Immediate Release" (PDF) (Press release). Illinois Department of Transportation. Archived from the original (PDF) on September 6, 2015.
- ^ Staff. "FHWA Route Log and Finder List". Federal Highway Administration. Retrieved May 24, 2007.
- ^ Voss, Oscar. "Alaska Roads: Interstate ends photos". Retrieved May 24, 2007.
- ^ a b c Witt, Jennifer W. (2010). Annual Traffic Volume Report (PDF) (Report) (2008-2009-2010 ed.). Alaska Department of Transportation & Public Facilities. Archived from the original (PDF) on March 30, 2014. Retrieved March 15, 2012.
- ^ a b c Birkholz, Ethan (2010). Annual Traffic Volume Report (PDF) (Report) (2008-2009-2010 ed.). Alaska Department of Transportation & Public Facilities. Archived from the original (PDF) on April 17, 2014. Retrieved May 31, 2012.
- ^ a b c d Staff. "Dwight D. Eisenhower Interstate Routes Statewide" (PDF). Federal Highway Administration. Retrieved May 31, 2012.
- ^ a b c d Staff. "Alaska Department of Transportation and Public Facilities Routes by Description: CDS Route Numbers as of 28 October 2008" (PDF). Federal Highway Administration. Retrieved May 31, 2012.
- ^ Voss, Oscar. "Puerto Rico road photos". Retrieved May 24, 2007.