List of Interstate Highways facts for kids

Interstate Highways in the 48 states that border each other. Purple routes are currently built and open freeways, blue are currently open spur routes, and green is proposed routes, future roads, or those being built.

The sign used to mark an interstate.

Primary Interstate Highways are the major interstate highways of the United States and have a one or two-digit route number. Even (0, 2, 4, 6, or 8) route numbers are given to east/west routes, with the smaller numbered routes in the south (I-10) and bigger numbered routes in the north (I-90). Similarly, odd (1, 3, 5, 7, or 9) route numbers are given to north/south routes, with the smaller numbered routes in the west (I-5) and the bigger numbered routes in the east (I-95).

There are five sets of numbers that are used more than once throughout the system; the highways whose numbers are used more than once are separated by big distances to avoid confusion. Below, these are made separate from each other by West and East.

Three-digit Interstates are spur or loop Interstates that usually are in big cities and areas outside of cities. The last two digits of a three-digit Interstate are always the number of the route it is related to. If the first digit is odd (1, 3, 5, 7, or 9), the Interstate is usually a spur route while if the first digit is even (2, 4, 6, 8, or 0), the Interstate is usually a loop route.

Primary Interstates

A total of 67 primary Interstates are in the table below, with 43 of them having three-digit routes. The lengths in the table are as of December 31, 2013.

Routes ending in 0 or 5 are marked in green.

Interstate	Route, States Served & Associated routes (* not signposted as interstates) (sort by number of states served)	Length (mi.)
I-02 I-2	01 Palmview, Texas (US-83) to Harlingen, Texas (I-69E / US-77) Texas Intrastate Interstate Associated routes: none	46.80
I-04 I-4	01 Tampa, Florida (I-275) to Daytona Beach, Florida (I-95) Florida Intrastate Interstate Associated routes: none	132.30
I-05 I-5	03 San Ysidro, California (Mexico and MX-1) to Blaine, Washington (Canada and BC 99) 3 States Served: CA, OR, WA Associated routes: I-105, I-205, I-305*, I-405, I-505, I-605, I-705, I-805	1,381.29
I-08 I-8	02 San Diego, California (Sunset Cliffs Blvd.) to Casa Grande, Arizona (I-10) 2 States Served: CA, AZ Associated routes: none	348.25
I-10	08 Santa Monica, California (CA-1) to Jacksonville, Florida (I-95) 8 States Served: CA, AZ, NM, TX, LA, MS, AL, FL Associated routes: I-110, I-210, I-310, I-410, I-510, I-610, I-710, I-910*	2,460.34
I-12	01 Baton Rouge, Louisiana (I-10) to Slidell, Louisiana (I-10 / I-59) Louisiana Intrastate Interstate Associated routes: none	85.59
I-15	06 San Diego, California (I-8/CA-15) to Sweetgrass, Montana (Canada and Hwy 4) 6 States Served: CA, NV, AZ, UT, ID, MT Associated routes: I-115, I-215, I-315*, I-515	1,433.52
I-16	01 Macon, Georgia (I-75) to Savannah, Georgia (Montgomery St.) Georgia Intrastate Interstate Associated route: I-516	166.81
I-17	01 Phoenix, Arizona (I-10) to Flagstaff, Arizona (AZ-89A) Arizona Intrastate Interstate Associated routes: none	145.76
I-19	01 Nogales, Arizona (Mexico and MX-15) to Tucson, Arizona (I-10) Arizona Intrastate Interstate Associated routes: none	63.35
I-20	06 Kent, Texas (I-10) to Florence, South Carolina (I-95) 6 States Served: TX, LA, MS, AL, GA, SC Associated routes: I-220, I-520, I-820	1,539.38
I-22	02 Memphis, Tennessee (I-55 & I-40) to Birmingham, Alabama (I-65/US 31) 2 States Served: Mississippi, Alabama. Planned: Tennessee Associated route: I-422 (planned)	213.0
I-24	04 Pulley's Mill, Illinois (I-57) to Chattanooga, Tennessee (I-75) 4 States Served: Georgia Associated route: I-124	316.36
I-25	03 Las Cruces, New Mexico (I-10) to Buffalo, Wyoming (I-90) 3 States Served: Wyoming Associated route: I-225	1,062.77
I-26	03 Kingsport, Tennessee (US-11W) to Charleston, South Carolina (US-17) 3 States Served: South Carolina Associated routes: I-126, I-526	346
I-27	01 Lubbock, Texas (US-87 and Loop 289) to Amarillo, Texas (I-40) Texas Intrastate Interstate Associated routes: none	124.13
I-29	04 Kansas City, Missouri (I-35 & I-70) to Pembina, North Dakota (Canada and US 81 and PTH 29) 4 States Served: North Dakota Associated routes: I-129, I-229	755.51
I-30	02 Fort Worth, Texas (I-20) to North Little Rock, Arkansas (I-40) 2 States Served: Arkansas Associated routes: I-430, I-530, I-630	366.76
I-35	06 Laredo, Texas (Mexico) to Duluth, Minnesota (MN-61) 6 States Served: TX, OK, KS, MO, IA, MN Associated routes: I-35E, I-35W, I-135, I-235, I-335, I-435, I-535, I-635	1,568.38
I-37	01 Corpus Christi, Texas (US-181) to San Antonio, Texas (I-35) Texas Intrastate Interstate Associated routes: none	143.00
I-39	02 Normal, Illinois (I-55) to Wausau, Wisconsin (WIS 29 & US-51) 2 States Served: Wisconsin Associated routes: none	306.14
I-40	08 Barstow, California (I-15) to Wilmington, North Carolina (NC-132) 8 States Served: CA, AZ, NM, TX, OK, AR, TN, NC Associated routes: I-140, I-240, I-440, I-540, I-840	2,554.10
I-43	01 Beloit, Wisconsin (I-39 and I-90) to Howard, Wisconsin (US-41 and US-141) Wisconsin Intrastate Interstate Associated routes: none	191.55
I-44	03 Wichita Falls, Texas (US-277, US-281, and US-287) to St. Louis, Missouri (I-55) 3 States Served: Missouri Associated routes: I-244, I-444*	633.79
I-45	01 Galveston, Texas (TX-87) to Dallas, Texas (I-30) Texas Intrastate Interstate Associated route: I-345*	284.91
I-49	01 Lafayette, Louisiana (I-10) to Shreveport, Louisiana (I-20) Louisiana Intrastate Interstate Associated routes: none	208.25
I-55	06 Laplace, Louisiana (I-10) to Chicago, Illinois (US-41, Lake Shore Drive) 6 States Served: LA, MS, TN, AR, MO, IL Associated routes: I-155, I-255, I-355	964.25
I-57	02 Miner, Missouri (I-55) to Chicago, Illinois (I-94) 2 States Served: Illinois Associated routes: none	386.12
I-59	04 Slidell, Louisiana (I-10 & I-12) to Lookout Mountain, Georgia (I-24) 4 States Served: Georgia Associated routes: I-359, I-459, I-759	445.23
I-64	06 Wentzville, Missouri (I-70) to Chesapeake, Virginia (I-264 & I-664) 6 States Served: MO, IL, IN, KY, WV, VA Associated routes: I-164, I-264 (KY), I-264 (VA), I-464, I-564, I-664	953.74
I-65	04 Mobile, Alabama (I-10) to Gary, Indiana (I-90) 4 States Served: Indiana Associated routes: I-165, I-265, I-465, I-565, I-865	887.30
I-66	02 Middletown, Virginia (I-81) to Washington, D.C. (US-29) 2 States Served: District of Columbia Associated routes: none	76.28
I-68	02 Morgantown, West Virginia (I-79) to Hancock, Maryland (I-70) 2 States Served: Maryland Associated routes: none	113.15
I-69	04 Victoria, Texas (I-69E / US 77 future & I-69W / US 59 future) to Port Huron, Michigan (Canada and Hwy 402) 6 States Served: TX, MS, TN, KY, IN, MI. 2 Planned: LA, AR Associated route: I-469 I-269 future, I-369 planned	705.40
I-70	10 Cove Fort, Utah (I-15) to Baltimore, Maryland (I-695) 10 States Served: UT, CO, KS, MO, IL, IN, OH, WV, PA, MD Associated routes: I-170, I-270, I-370, I-470, I-670	2,153.13
I-71	02 Louisville, Kentucky (I-64) to Cleveland, Ohio (I-90) 2 States Served: Ohio Associated routes: I-271, I-471	345.57
I-72	02 Hannibal, Missouri (US-61) to Champaign, Illinois (I-57) 2 States Served: Illinois Associated route: I-172	179.29
I-73	01 Candor, North Carolina (US-220) to Greensboro, North Carolina (I-40 & I-85) North Carolina Intrastate Interstate Associated routes: none	12.27
I-74	07 West Bettendorf, Iowa (I-80) to Cincinnati, Ohio (I-75) 7 States Served: IA, IL, IN, OH, WV, VA, NC Associated route: I-474	416.71
I-74	02 East Cana, Virginia (I-77) to Mount Airy, North Carolina (US-52) 2 States Served: VA, NC. Planned: WV Associated routes: none	12.10
I-75	06 Hialeah, Florida (FL-826) to Sault Ste. Marie, Michigan (Canada) 6 States Served: FL, GA, TN, KY, OH, MI Associated routes: I-175, I-275, I-375, I-475, I-575, I-675	1,786.47
I-76	02 West Denver, Colorado (I-70) to Big Springs, Nebraska (I-80) 2 States Served: Nebraska Associated routes: none	187.34
I-76	03 East Westfield Center, Ohio (I-71) to Camden, New Jersey (I-295) 3 States Served: New Jersey Associated routes: I-176, I-276, I-376, I-476, I-676	434.36
I-77	05 Columbia, South Carolina (I-26) to Cleveland, Ohio (I-90) 5 States Served: Ohio Associated routes: I-277	610.10
I-78	03 Union Twp., Pennsylvania (I-81) to New York, New York 3 States Served: New York Associated routes: I-278, I-478*, I-678, I-878*	143.56
I-79	02 Charleston, West Virginia (I-77) to Erie, Pennsylvania (PA-5) 2 States Served: Pennsylvania Associated routes: I-279, I-579	343.24
I-80	11 San Francisco, California (U.S. Route 101) to Fort Lee, New Jersey (I-95) 11 States Served: CA, NV, UT, WY, NE, IA, IL, IN, OH, PA, NJ Associated routes: I-180, I-280, I-380, I-480, I-580, I-680, I-780, I-880, I-980	2,899.54
I-81	06 Dandridge, Tennessee (I-40) to Fisher's Landing, New York (Canada) 6 States Served: TN, VA, WV, MD, PA, NY Associated routes: I-181, I-381, I-481, I-581	854.89
I-82	02 Ellensburg, Washington (I-90) to Hermiston, Oregon (I-84) 2 States Served: Oregon Associated route: I-182	143.58
I-83	02 Baltimore, Maryland to Harrisburg, Pennsylvania (I-81) 2 States Served: Pennsylvania Associated route: I-283	85.3
I-84	03 West Portland, Oregon (I-5) to Echo, Utah (I-80) 3 States Served: Utah Associated route: I-184	769.62
I-84	04 East Scranton, Pennsylvania (I-81) to Sturbridge, Massachusetts (I-90) 4 States Served: Massachusetts Associated routes: I-384, I-684	232.4
I-85	05 Montgomery, Alabama (I-65) to Petersburg, Virginia (I-95) 5 States Served: Virginia Associated routes: I-185, I-285, I-385, I-485, I-585, I-785, I-985	668.75
I-86	01 West Heyburn, Idaho (I-84) to Pocatello, Idaho (I-15) Idaho Intrastate Interstate Associated routes: none	62.85
I-86	02 East Erie, Pennsylvania (I-90) to Elmira, New York (NY-17) 2 States Served: New York Associated routes: none	183.56
I-87	01 New York, New York (I-278) to Champlain, New York (Canada) New York Intrastate Interstate Associated routes: I-287, I-587, I-787	333.49
I-88	01 West Barstow, Illinois (I-80) to Chicago, Illinois (I-290) Illinois Intrastate Interstate Associated routes: none	140.6
I-88	01 East Binghamton, New York (I-81) to Schenectady, New York (I-90) New York Intrastate Interstate Associated routes: none	117.75
I-89	02 Bow, New Hampshire (I-93) to Highgate Springs, Vermont (Canada) 2 States Served: Vermont Associated route: I-189	191.12
I-90	13 Seattle, Washington (WA-519) to Boston, Massachusetts (MA-1A) 13 States Served: WA, ID, MT, WY, SD, MN, WI, IL, IN, OH, PA, NY, MA Associated routes: I-190, I-290, I-390, I-490, I-590, I-690, I-790, I-890, I-990	3,020.54
I-91	03 New Haven, Connecticut/North Haven, Connecticut (I-95) to Derby Line, Vermont (Canada) 3 States Served: Vermont Associated routes: I-291, I-391, I-691	290.37
I-93	03 Canton, Massachusetts (I-95) to St. Johnsbury, Vermont (I-91) 3 States Served: Vermont Associated routes: I-293, I-393	189.95
I-94	07 Billings, Montana (I-90) to Port Huron, Michigan (Canada) 7 States Served: MT, ND, MN, WI, IL, IN, MI Associated routes: I-194, I-294, I-394, I-494, I-694, I-794, I-894	1,585.20
I-95	16 Miami, Florida (US-1) to Houlton, Maine (Canada) 15 States Served: FL, GA, SC, NC, VA, MD, DE, PA, NJ, NY, CT, RI, MA, NH, ME Associated routes: I-195, I-295, I-395, I-495, I-595, I-695, I-795, I-895	1,925.74
I-96	01 Muskegon, Michigan (US-31) to Detroit, Michigan (I-75) Michigan Intrastate Interstate Associated routes: I-196, I-296*, I-496, I-696	192.06
I-97	01 Annapolis, Maryland (US-50) to Baltimore, Maryland (I-695) Maryland Intrastate Interstate Associated routes: none	17.62
I-99	01 Bedford, Pennsylvania (I-76) to Painted Post, New York (I-86) Unfinished Pennsylvania section: Bellefonte, Pennsylvania (I-80) to New York border near Lawrenceville, Pennsylvania (US 15) 2 states served: New York Associated routes: none	98.86

Interstates outside of the mainland

Interstate Highways are not only in the 48 states of the United States that border, but there are also Interstates in Hawaii, Alaska, and Puerto Rico.

Hawaiian Interstates

The Interstate Highways in the island of Oʻahu, Hawaii are signed with the normal Interstate shield, with the letter "H-" added before the number. They are fully controlled-access routes built to the same standards as the Interstate routes in the main part of the United States.

Interstate	Route	Length (miles)
H-1	Kapolei, Hawaii (HI-93) to Honolulu, Hawaii (HI-72) Associated route: H-201	27.16
H-2	Pearl City, Hawaii (H-1) to Wahiawa, Hawaii (HI-99)	8.33
H-3	Halawa, Hawaii (H-1 & H-201) to Marine Corps Base Hawaii	15.32

Alaska and Puerto Rico

The Federal Highway Administration gives money to 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 do not have to meet the same standards as the Interstate routes in the main part of the United States.

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.

Alaska

Map of the Interstates in Alaska

Alaska's Interstates do not have signs to mark them, although they all have state highway numbers that are not the same as the Interstate numbers.

• Interstate A-1
• Interstate A-2
• Interstate A-3
• Interstate A-4

Puerto Rico

Map of the Interstates in Puerto Rico

Like Alaska, Puerto Rico signs its Interstates as territorial routes, and the numbers are not the same as their official Interstate designations. Many of the territory's routes are freeway-standard toll roads.

• Interstate PR-1
• Interstate PR-2
• Interstate PR-3

Related pages

• List of auxiliary Interstate Highways
• List of business routes of the Interstate Highway System