The intrastate Interstate Highways in the contiguous United States, highlighted in red, not including Interstates 73 and 99.

There are several intrastate Interstate Highways; that is, Interstate Highways that are located entirely within one state. The concept seems contradictory at first; the word "interstate" refers to the way the entire group of highways is funded (as a national system of interconnected highways), not to the route each given highway travels.

[edit] Within the contiguous 48 states

This list includes only primary Interstate highways (those with route numbers less than 100). Most (but not all) three digit Interstates are intrastate.

Interstate Highway	Route	Length[1]	Notes
Interstate 4	Tampa, FL (I-275) to Daytona Beach, FL (I-95)	132.3 mi
Interstate 12	Baton Rouge, LA (I-10) to Slidell, LA (I-10/I-59)	85.6 mi
Interstate 16	Macon, GA (I-75) to Savannah, GA	166.8 mi
Interstate 17	Phoenix, AZ (I-10) to Flagstaff, AZ (I-40)	145.8 mi
Interstate 19	Nogales, AZ (Mexican border) to Tucson, AZ (I-10)	63.4 mi	Interstate 19 reaches the Mexican border, but does not cross any state lines.
Interstate 27	Lubbock, TX (US-87) to Amarillo, TX (I-40)	124.1 mi
Interstate 37	Corpus Christi, TX (US-181) to San Antonio, TX (I-35)	143.0 mi
Interstate 43	Beloit, WI (I-39 & I-90) to Green Bay, WI (US-41)	191.6 mi
Interstate 45	Galveston, TX (TX-124) to Dallas, TX (I-30)	284.9 mi	The only Interstate ending in 5 or 0 to be an Intrastate Highway.
Interstate 49	Lafayette, LA (I-10) to Shreveport, LA (I-20)	208.3 mi	Interstate 49 may eventually reach Kansas City, Missouri.[original research?]
Interstate 73	Emery, NC (US-220) to Greensboro, NC (I-40 & I-85)[2]	56.7 mi[2]	Interstate 73 may eventually reach Michigan and South Carolina.[original research?]
Interstate 86 (west)	Heyburn, ID (I-84) to Pocatello, ID (I-15)	62.9 mi
Interstate 87	New York, NY (I-278) to Champlain, NY (Canadian border)	333.5 mi	Interstate 87 reaches the Canadian border, but does not cross any state lines.
Interstate 88 (west)	Silvis, IL (I-80) to Hillside, IL (I-290)	140.6 mi
Interstate 88 (east)	Binghamton, NY (I-81) to Schenectady, NY (I-90)	117.8 mi
Interstate 96	Muskegon, MI (US-31) to Detroit, MI (I-75)	192.1 mi
Interstate 97	Annapolis, MD (US-50) to Baltimore, MD (I-695)	17.6 mi
Interstate 99	Bedford, PA (I-70/I-76) to Bellefonte, PA (I-80)	85.0 mi	Interstate 99 may eventually extend through New York via US 15 and Maryland to Interstate 68. Surface roads connect it with I-70/I-76 at its current signed south end.[citation needed]

Additionally, there are two Interstate highways that are almost entirely intrastate:

• Interstate 66 is located almost entirely in Virginia, but it has a very short section in the District of Columbia. I-66 is 75 miles in length, one-half mile of it is in D.C.
• Interstate 76 (western section) is located almost entirely in Colorado, but it has a very short section in Nebraska that connects Interstate 80. I-76 is 186 miles in length, less than 3 miles are in Nebraska

[edit] Outside of the contiguous 48 states

As Alaska and Hawaii do not share land borders with any other U.S. state, their Interstate highways are all located fully within their respective state's boundaries. Puerto Rico is not a state; however, it also has highways funded by the Federal Government as Interstate highways.

[edit] Signed Interstates

H-1, H-2, and H-3 stand for Hawaii-1, Hawaii-2, and Hawaii-3, respectively. These freeways are part of the Interstate Highway System and are thus called Interstate highways. These are all located on the heavily-populated island of Oahu, and there are not any on the other islands.

Interstate Highway	Route	Length[1]
Interstate H-1	Kapolei, HI (HI-93) to Honolulu, HI (HI-72)	27.2 mi
Interstate H-2	Pearl City, HI (H-1) to Wahiawā, HI (HI-99)	8.3 mi
Interstate H-3	Hālawa, HI (H-1) to Marine Corps Base Hawaii	15.3 mi

[edit] Unsigned Interstates

Interstate highways in Alaska and Puerto Rico are not signed as Interstate highways, and are designated as such primarily for purposes of Federal funding. Interstates A-1 through A-4 are located in Alaska, and Interstates PRI-1 through PRI-3 are located in Puerto Rico. These highways are not required to meet interstate standards, and as a result, most portions of these interstate highways are not grade-separate freeways. Freeways in Puerto Rico are primarily toll roads that are not funded through the Eisenhower Interstate System. Very few freeways exist in Alaska; they are located primarlily near Anchorage, Fairbanks, and Wasilla.

Interstate Highway	Route	Length[1]
Interstate A-1	Anchorage, AK (A-3) to Canadian border	408.2 mi
Interstate A-2	Tok, AK (A-1) to Fairbanks, AK (A-4)	202.2 mi
Interstate A-3	Anchorage, AK (A-1) to Soldotna, AK	148.1 mi
Interstate A-4	Palmer, AK (A-1) to Fairbanks, AK (A-2)	323.7 mi
Interstate PRI-1	Ponce, PR (PRI-2) to San Juan, PR (PRI-2)	71.1 mi
Interstate PRI-2	Ponce, PR (PRI-1) to San Juan, PR (PRI-3)	138.1 mi
Interstate PRI-3	San Juan, PR (PRI-2) to Ceiba, PR	40.6 mi

[edit] References

edit Main Interstate Highways (major interstates highlighted)
4	5	8	10	12	15	16	17	19	20	22	24	25	26	27	29	30
35	37	39	40	43	44	45	49	55	57	59	64	65	66	68	69
70	71	72	73	74	75	76 (W)		76 (E)		77	78	79	80	81	82
83	84 (W)		84 (E)		85	86 (W)		86 (E)		87	88 (W)		88 (E)		89	90
91	93	94	95	96	97	99	(238)		H-1		H-2		H-3
Unsigned			A-1		A-2		A-3		A-4		PRI-1		PRI-2		PRI-3
Lists		Primary			Main - Intrastate - Suffixed - Future - Gaps
		Auxiliary			Main - Future - Unsigned
		Other			Standards - Business - Bypassed