List of auxiliary Interstate Highways

The auxiliary Interstate Highways (also called three-digit Interstate Highways) are a supplemental subset of the freeways of the Interstate Highway System of the United States of America. Similar to the mainline Interstate Highways, these highways also meet all Interstate Highway Standards, they receive the same percentage of Federal funding (90%), and they comply with other Federal standards. The main purpose of the auxiliary Interstate Highways is to serve large American cities and their suburbs. However, some of them provide supplements to the main-route Interstate Highways elsewhere in the United States - in non-urbanized areas. An example of one of these is Interstate 180 (I-180) in Pennsylvania. They also sometimes spare the availability of two-digit Interstate Highway numbers. For example, some of these like I-196 in Michigan and I-540 in Arkansas are more like substitutes for two-digit Interstate numbers.

In some cases, auxiliary Interstate Highways were added onto the original 41,000-mile (66,000 km) long Interstate System to provide an Interstate connection to rapidly-growing cities that had not received even one Interstate Highway in the original plan. Examples of these include I-565 to Huntsville, Alabama, I-185 to Columbus, Georgia, and I-555 to Jonesboro, Arkansas.

In contrast to the primary Interstate Highways, the three-digit highways often run only within or around a single metropolitan area of the United States, whether or not that metropolitan area lies within one state of the United States. In addition, the three-digit are generally shorter, and many do not cross state borders, despite the term "Interstate". Due to the large number of these routes, auxiliary route numbers may be repeated in different states along the mainline. However, no two three-digit Interstates in the same state can share the same number, unless two segments form a gap of a long route that is meant to be complete.

Terminology and guidelines

The basic tenets of the auxiliary Interstates are divided into three branches: spur, loop, and bypass routes. Each one signifies a different characteristic of the auxiliary route.

The first digit of the three digits determines whether a route is a bypass, spur, or beltway. The last two digits are derived from the main Interstate Highway. For instance, I-515 contains an odd number in the first digit– "5", and indicates that this freeway is a spur. The last two digits signify the highway's origin. In this case, the "15" in I-515 shows that it is a supplement to I-15.

Spur route

An Interstate Highway spur route is usually one of the following:

It may serve another section of a city or metropolitan area not served by the main freeway (most often the central business district), terminating at a regular city street/avenue or at a substandard freeway.

It may represent the first portion of a contemplated extended freeway, one that downgrades to below Interstate standards with plans to upgrade it later on (such as I-540 in Arkansas).

It may connect two unrelated Interstate highways - such as I-390 in New York State does.

A spur route's number has an odd number for its first digit.^[1]

Examples of Interstate Highway spur routes are listed below.

I-110 in California links I-10 with the Port of Los Angeles. However, this freeway had been built before Interstate Highways as the Harbor Freeway. It was adopted into the Interstate Highway System later on.

I-380 in Iowa connects the cities of Waterloo and Cedar Rapids with I-80, and it also crosses open countryside.

I-180 in North-Central Pennsylvania connects Williamsport and Lycoming County with I-80 in Milton, which does not actually enter Lycoming County. I-180 also serves as a connection to those traveling to New York and I-86 via U.S. Route 15 and the Future I-99 Corridor^[2] at its western terminus.

Sometimes, a three-digit Interstate Highway branches off from another three-digit Interstate Highway. This is called a "tertiary spur route" of a two-digit Interstate Highway. Tertiary spurs do not connect directly with their parent highways, but they are associated with them via the three-digit highways they do intersect with.

Examples of tertiary spur routes are listed below.

I-795 in Baltimore County, Maryland branches off from I-695, and thus it is a tertiary spur of I-95.

I-380 in Central California is located at the San Francisco Bay Area. This highway begins at I-280, and it never connects with its parent, I-80.

Bypass

A bypass route may traverse around a city, or may run through it with the mainline bypassing. In a typical 3-digit Interstate Highway, bypasses usually have both its two termini junctioned with another Interstate highway. Bypass routes are preceded by an even number in the first digit.^[1]

Examples of bypass routes are listed below.

I-215 in Utah travels part of the perimeter of Salt Lake City.

I-220 in Louisiana serves as a bypass of downtown Shreveport.

Beltway

A beltway (also known as a loop route) completely surrounds a metropolitan city, and it is often connected with multiple junctions to other routes. Unlike other auxiliary Interstate Highways, beltways do not have termini. Beltways are also preceded by an even number in the first digit.

Examples of beltways are listed below.

I-465 in Indiana travels around the city of Indianapolis.

I-285 in Georgia encircles the city of Atlanta and is referred to as the "Perimeter".

I-275 in Ohio, Kentucky and Indiana travels around the city of Cincinnati.

I-494 and I-694 in Minnesota form a bypass loop around the urban cores of Minneapolis and St. Paul.

Exceptions

Connection discrepancies

New York City has numerous auxiliary routes designated as being from I-78, but none of the auxiliary routes of I-78 actually intersects with it. This is because I-78 was long ago intended to continue farther east from its present terminus at the beginning of the Holland Tunnel in New Jersey. It was to cross southern Manhattan, then go through the Borough of Queens, and from there across Long Island, New York. This entire planned part of I-78 was canceled during the 1970s—after I-278, I-478, I-678, and I-878 were already completely or partially in existence.

In the New York City area, the Long Island Expressway, signed as I-495, does not connect with Interstate 95 directly, but it does intersect with I-295, which in turn, does intersect with I-95. The connector from the New Jersey Turnpike (which is signed as I-95 in northern New Jersey) to the Lincoln Tunnel was to have been part of I-495 despite not being up to the standards of the Interstate Highway System. An expressway across Midtown Manhattan was to have connected the Lincoln Tunnel with the Queens-Midtown Tunnel, but was canceled due to concerns regarding building such a highway in the densely built Midtown area. The LIE was eventually built from the end of the Queens-Midtown Tunnel to a terminus near Riverhead on Long Island. An extension from there, to cross the end of Long Island Sound to I-95 in Connecticut, was never built. The New Jersey approach became New Jersey State Route 495.

In the Los Angeles area, I-210 does not connect with Interstate 10 directly, nor with any other auxiliary Interstate of I-10, although they are connected through numerous other Interstates. When the California State Route 210 is re-signed I-210, it will finally connect with I-10.

An auxiliary route numbered I-238 connects San Leandro with Castro Valley, California, yet there is no I-38 anywhere. The highway was so numbered for simple convenience since it had been previously numbered as California State Route 238. After this highway was upgraded to Interstate Highway standards, it was adopted into the Interstate Highway System. A number "I-X80" would have fit it as an auxiliary route of I-80, but at the time of I-238's designation, all of the auxiliary routes numbers of I-80 had already been used in California (Interstates 280 through 980). "I-180" was unavailable because the California Department of Transportation does not allow duplicate route numbers and there was already California State Route 180 in existence at the time. I-480 is available today but was being used for the Embarcadero Freeway, which has since been demolished.

Pittsburgh, PA has two recently created exceptions. I-376 and I-279 had conformed to numbering conventions until 2009 when I-376 was extended from its previous terminus in Downtown Pittsburgh to its present terminus north of I-80. I-376 acted as a spur from its parent (I-76) in Monroeville (Allegheny County), but now links back up with I-76 in Lawrence County. Likewise, I-279 was a loop that met up with its parent (I-79) at two locations in Allegheny County, but now terminates in Downtown Pittsburgh (having been truncated at its intersection with I-376), and functions as a spur route from I-79.

Augusta, GA area also has a recent exception. I-520 had conformed to numbering conventions until late 2009 as well, when I-520 was extended in South Carolina back to I-20 and is now a loop.

Sometimes, when a spur route from a mainline Interstate highway does not meet Interstate Highway standards, a state route shield sometimes uses the parent Interstate route number as a suffix to imply that this number was derived from the Interstate Highway's.

Short mainline routes

Some mainline routes (1/2 digit Interstates) are sometimes less than half the length of the longest auxiliary Interstates, thus they fall closer to the geographical criteria for mainline routes than they do for auxiliary routes. This is often the case for intrastate mainline Interstate highways.

Interstate 27 goes from Lubbock, TX to Amarillo, TX for 100 miles.
Interstate 86 (west) in Idaho is a spur off Interstate 84.

Auxiliary Interstates

Below is a list of auxiliary Interstate Highway designations in the United States. They are sorted in the following order:

numerically by the primary Interstate Highway (one or two digits)
alphabetically by the state of the auxiliary Interstate
numerically by the auxiliary Interstate itself

Contents:	H-1 I-5 I-10 I-15 I-16 I-20 I-24 I-25 I-26 I-29 I-30 I-35 I-40 I-44 I-45 I-55 I-59 I-64 I-65 I-66 I-69 I-70 I-71 I-72 I-74 I-75 I-76(E) I-77 I-78 I-79 I-80 I-81 I-82 I-83 I-84(E) I-84(W) I-85 I-86 I-87 I-89 I-90 I-91 I-93 I-94 I-95 I-96

Legend
Existing route	Unsigned route	Future route

Interstate	Length^[3]	Southern/Western terminus	Northern/Eastern terminus
Interstate H-1
Hawaii
H-201	4.10 mi (6.60 km)	H-1 in Halawa	H-1 in Honolulu
Interstate	Length^[3]	Southern/Western terminus	Northern/Eastern terminus
Interstate 5
California
I-105	17.32 mi (27.87 km)	SR 1 in El Segundo	I-605 in Norwalk
I-205	12.97 mi (20.87 km)	I-580 near Tracy	I-5 near Tracy
I-305	8.44 mi (13.58 km)	I-80 in West Sacramento	I-80 Bus. / US 50 / SR 99 in Sacramento
I-405	72.15 mi (116.11 km)	I-5 in Irvine	I-5 in Mission Hills
I-505	32.98 mi (53.08 km)	I-80 in Vacaville	I-5 in Dunnigan
I-605	27.40 mi (44.10 km)	I-405 in Seal Beach	I-210in Irwindale
I-805	28.02 mi (45.09 km)	I-5 in San Ysidro	I-5 in San Diego near the University of California, San Diego
I-905	Proposed auxiliary route to connect to the Mexican border in the San Diego area
Oregon
I-105	3.49 mi (5.62 km)	OR 99 in Eugene	I-5 in Springfield
I-405	3.53 mi (5.68 km)	I-5 in Portland	I-5 in Portland
Oregon-Washington
I-205	36.64 mi (58.97 km)	I-5 in Tualatin, OR	I-5 in Salmon Creek, WA
Washington
I-405	30.30 mi (48.76 km)	I-5 / SR 518 in Tukwila	I-5 / SR 525 in Lynnwood
I-605	Proposed to bypass Seattle
I-705	1.50 mi (2.41 km)	I-5 / SR 7 in Tacoma	Schuster Parkway in Tacoma
Interstate	Length^[3]	Southern/Western terminus	Northern/Eastern terminus
Interstate 10
California
I-110	20.43 mi (32.88 km)	SR 47 in San Pedro, Los Angeles	I-10 / SR 110 in Los Angeles
I-210	48.52 mi (78.09 km)	I-5 in Sylmar	SR 210 / SR 57 in Glendora
I-710	19.66 mi (31.64 km)	Terminal Island in Long Beach	Valley Boulevard in Alhambra
Florida
I-110	6.94 mi (11.17 km)	US 98 Bus. near Pensacola	I-10 near Pensacola
Louisiana
I-110	8.89 mi (14.31 km)	I-10 in Baton Rouge	US 61 in Baton Rouge
I-210	12.40 mi (19.96 km)	I-10 near Sulphur	I-10 in Lake Charles
I-310	11.25 mi (18.11 km)	US 90 in Boutte	I-10 near Kenner
I-510	5.10 mi (8.21 km)	LA 47 in New Orleans	I-10 in New Orleans
I-610	4.52 mi (7.27 km)	I-10 at the Orleans-Jefferson Parish	I-10 in New Orleans
I-910	9.70 mi (15.61 km)	US 90 Bus. in Marrero	I-10 in New Orleans
Mississippi
I-110	4.10 mi (6.60 km)	US 90 in Biloxi	I-10 in D'Iberville
Texas
I-110	0.92 mi (1.48 km)	United States-Mexico border in El Paso	I-10 in El Paso
I-410	49.49 mi (79.65 km)	Beltway around San Antonio
I-610	37.97 mi (61.11 km)	Beltway around Houston
Interstate	Length^[3]	Southern/Western terminus	Northern/Eastern terminus
Interstate 15
California
I-215	54.50 mi (87.71 km)	I-15 in Murrieta	I-15 in Devore
Montana
I-115	1.19 mi (1.92 km)	I-15 / I-90 in Butte	Iron Street in Butte
I-315	0.83 mi (1.34 km)	I-15 in Great Falls	I-15 Bus. / US 89 Great Falls
Nevada
I-215	13 mi (20.921 km)	I-15 / CC 215 near Paradise	I-515 / US 93 / US 95 / SR 564 in Henderson
I-515	20.54 mi (33.06 km)	US 93 / US 95 in Henderson	I-15 / US 93 / US 95 in Las Vegas
Utah
I-215	29.02 mi (46.70 km)	I-80 in Salt Lake City	I-15 in North Salt Lake
Interstate	Length^[3]	Southern/Western terminus	Northern/Eastern terminus
Interstate 16
Georgia
I-516	6.49 mi (10.44 km)	SR 21 / SR 204 in Savannah	SR 21 in Garden City
Interstate	Length^[3]	Southern/Western terminus	Northern/Eastern terminus
Interstate 20
Georgia-South Carolina
I-520	17.48 mi (28.13 km)	I-20 in Augusta, GA	I-20 in North Augusta, SC
Louisiana
I-220	17.62 mi (28.36 km)	I-20 in Shreveport	I-20 in Bossier City
Mississippi
I-220	12.01 mi (19.33 km)	I-20 in Jackson	I-55 in Ridgeland
Texas
I-820	35.17 mi (56.60 km)	Beltway around Fort Worth
Interstate	Length^[3]	Southern/Western terminus	Northern/Eastern terminus
Interstate 24
Tennessee
I-124	1.97 mi (3.17 km)	I-24 in Chattanooga	US-27 in Chattanooga
Interstate	Length^[3]	Southern/Western terminus	Northern/Eastern terminus
Interstate 25
Colorado
I-225	12.00 mi (19.31 km)	I-25 in Denver	I-70 in Aurora
Interstate	Length^[3]	Southern/Western terminus	Northern/Eastern terminus
Interstate 26
South Carolina
I-126	3.68 mi (5.92 km)	I-26 in Columbia	US 21 / US 76 / US 176 / US 321 in Columbia
I-526	19.26 mi (31.00 km)	I-526 Bus. / US 17 in Mount Pleasant	US 17 in Charleston
Interstate	Length^[3]	Southern/Western terminus	Northern/Eastern terminus
Interstate 29
Iowa-Nebraska
I-129	3.48 mi (5.60 km)	US-20 / US-75 / US-77 in South Sioux City, NE	I-29 / US 20 / US 75 in Sioux City, IA
Missouri
I-229	14.97 mi (24.09 km)	I-29 in St. Joseph	I-29 / US 59 / US 71 in St. Joseph
South Dakota
I-229	11.33 mi (18.23 km)	I-29 in Sioux Falls	I-90 near Sioux Falls
Interstate	Length^[3]	Southern/Western terminus	Northern/Eastern terminus
Interstate 30
Arkansas
I-130	Proposed route in Texarkana
I-430	12.93 mi (20.81 km)	I-30 / U.S. 67 in Little Rock	I-40 / U.S. 65 in Little Rock
I-530	46.65 mi (75.08 km)	U.S. 65 in Pine Bluff	I-30 / I-440 in Little Rock
I-630	7.40 mi (11.91 km)	I-430 near Little Rock	I-30 in Little Rock
Interstate	Length^[3]	Southern/Western terminus	Northern/Eastern terminus
Interstate 35
Iowa
I-235	13.78 mi (22.18 km)	I-35 / I-80 in West Des Moines	I-35 / I-80 near Des Moines
Kansas
I-135	95.74 mi (154.08 km)	KTA / I-35 in Wichita	I-70 / US-81 in Salina
I-235	16.52 mi (26.59 km)	K-96 in Wichita	I-135 in Wichita
I-335	50.13 mi (80.68 km)	I-35 / US-50 in Emporia	I-470 in Topeka
Kansas-Missouri
I-435	80.81 mi (130.05 km)	Beltway around Kansas City, KS and Kansas City, MO
I-635	12.67 mi (20.39 km)	I-35 in Overland Park, KS	I-29 / US 71 in Kansas City, MO
Minnesota-Wisconsin
I-535	2.78 mi (4.47 km)	I-35 / US 53 in Duluth, MN	US 53 / WIS 35 in Superior, WI
Oklahoma
I-235	5.36 mi (8.63 km)	I-35 / I-40 in Oklahoma City	I-44 in Oklahoma City
Texas
I-635	37.00 mi (59.55 km)	SH 121 in Grapevine	I-20 in Balch Springs
Interstate	Length^[3]	Southern/Western terminus	Northern/Eastern terminus
Interstate 40
Arkansas
I-440	9.96 mi (16.03 km)	I-30 / I-530 near Little Rock	I-40 / Hwy. 440 near Little Rock
I-540	80.72 mi (129.91 km)	U.S. 271 / Hwy. 253 near Fort Smith	U.S. 62 / U.S. 71 in Bentonville
North Carolina
I-140	27 mi (44 km)	US 421 near Navassa	US 17 near Ogden
I-240	9.14 mi (14.71 km)	I-40 / I-26 near Asheville	I-40 in eastern Asheville
I-440	16.40 mi (26.39 km)	I-40 / US 1 / US 64 near Cary	I-40 near Raleigh
I-540	26 mi (42 km)	I-40 near Durham	US 64 / US 264 near Knightdale
I-840	Future part of the Greensboro Urban Loop
Oklahoma
I-240	16.22 mi (26.10 km)	I-44 / US-62 in Oklahoma City	I-40 / US-270 in Oklahoma City
Tennessee
I-140	11.1 miles (17.86 km)	I-40 / I-75 near Farragut	US-129 near Alcoa
I-240	19.27 mi (31.01 km)	I-40 in Memphis	I-40 in Memphis
I-440	8 mi (13 km)	I-40 in Nashville	I-24 in Nashville
I-640	7.03 mi (11 km)	I-40 in Knoxville	I-40 in Knoxville
Interstate	Length^[3]	Southern/Western terminus	Northern/Eastern terminus
Interstate 44
Oklahoma
I-244	15.75 mi (25.35 km)	I-44 in Tulsa	I-44 in Tulsa
I-444	2.51 mi (4.04 km)	I-244 in Tulsa	I-244 in Tulsa
Interstate	Length^[3]	Southern/Western terminus	Northern/Eastern terminus
Interstate 45
Texas
I-345	1.4 mi (2.25 km)	I-45 / I-35 in Dallas	US 75 in Dallas
Interstate	Length^[3]	Southern/Western terminus	Northern/Eastern terminus
Interstate 55
Arkansas
I-555	44 mi (70.81 km)	I-55 in Turrell	AR 91 in Jonesboro
Illinois
I-155	32.13 mi (51.71 km)	I-74 in Morton	I-55 in Lincoln
I-355	32.51 mi (52.67 km)	I-80 in New Lenox	I-290 in Itasca
Illinois-Missouri
I-255	30.82 mi (49.90 km)	I-55 / I-270 in Mehlville, MO	IL 255 in Pontoon Beach, IL
Missouri-Tennessee
I-155	26.77 mi (43.08 km)	I-55 near Hayti, MO	US 51 at Dyersburg, TN
Interstate	Length^[3]	Southern/Western terminus	Northern/Eastern terminus
Interstate 59
Alabama
I-359	2.3 mi (3.70 km)	I-20 / I-59 in southern Tuscaloosa	15th Street in downtown Tuscaloosa
I-459	32 mi (51.50 km)	I-20 / I-59 in Bessemer	I-59 in Trussville
I-759	4.5 mi (7.24 km)	I-59 in Attalla	US-411 / SR-759 in Gadsden
Interstate	Length^[3]	Southern/Western terminus	Northern/Eastern terminus
Interstate 64
Indiana
I-164	21.24 mi (34.18 km)	I-64 / I-69 in Evansville	US 41 in Evansville
Kentucky
I-264	22.93 mi (36.90 km)	I-64 in Louisville	I-71 in Louisville
Virginia
I-264	25 mi (40.23 km)	I-64 / I-664 in Chesapeake	Parks Ave in Virginia Beach
I-464	5.66 mi (9.11 km)	I-64 in Chesapeake	I-264 in Norfolk
I-564	2.77 mi (4.46 km)	SR 337	I-64 in Norfolk
I-664	20.79 mi (33.46 km)	I-64 / I-264 in Chesapeake	I-64 in Hampton
Interstate	Length^[3]	Southern/Western terminus	Northern/Eastern terminus
Interstate 65
Alabama
I-165	4.9 mi (7.89 km)	US-43 in Mobile	I-65 in Mobile
I-565	34 mi (54.72 km)	I-65 / US-72 / SR-20 in Decatur	US-72 in Huntsville
Indiana
I-265	32 mi (51.50 km)	I-64 in New Albany	SR 62 / SR 265
I-465	53 mi (85.30 km)	Beltway around Indianapolis
I-865	5 mi (8.05 km)	I-65 near Indianapolis	I-465 near Indianapolis
Kentucky
I-265	24.48 mi (39.40 km)	I-65 in Louisville	I-71 in Louisville
Interstate	Length^[3]	Southern/Western terminus	Northern/Eastern terminus
Interstate 69
Indiana
I-469	30.83 mi (49.62 km)	I-69 in Fort Wayne	I-69 in Fort Wayne
Mississippi-Tennessee
I-269	Memphis, TN outer beltline, currently under construction.
Interstate	Length^[3]	Southern/Western terminus	Northern/Eastern terminus
Northern Kentucky
I-369	Henderson, KY I-69(future) Pennyrile Parkway to Owensboro, KY US 60 23.441 mile spur to Owensboro
Interstate 70
Colorado
I-270	5.31 mi (8.55 km)	I-25 / US 36 at Welby	I-70 / US 36 at Denver
Illinois-Missouri
I-270	50.59 mi (81.42 km)	I-55 / I-255 in Mehlville	I-55 / I-70 near Troy
Kansas
I-470	13.72 mi (22.08 km)	I-70 in Topeka	I-70 in Topeka
Kansas-Missouri
I-670	2.81 mi (4.52 km)	I-70 in Kansas City, KS	I-70 in Kansas City, MO
Maryland
I-270	34.70 mi (55.84 km)	I-70 near Frederick	I-495 north of Bethesda
I-370	3.13 mi (5.04 km)	I-270 in Gaithersburg	MD 200 in Derwood
Missouri
I-170	11.17 mi (17.98 km)	I-64 / US 40 in Richmond Heights	I-270 in Hazelwood
I-470	16.72 mi (26.91 km)	I-435 in Kansas City	I-70 in Independence, Missouri
Ohio
I-270	54.97 mi (88.47 km)	Beltway around Columbus
I-670	9.37 mi (15.08 km)	I-70 in Columbus	I-270 on the east side of Columbus, near Port Columbus International Airport, Easton Town Center, and Gahanna.
Ohio-West Virginia
I-470	6.69 mi (10.77 km)	I-70 near Blaine, OH	I-70 in Elm Grove, WV
Interstate	Length^[3]	Southern/Western terminus	Northern/Eastern terminus
Interstate 71
Kentucky-Ohio
I-471	5.75 mi (9.25 km)	I-275 near Newport	I-71 in Cincinnati
Ohio
I-271	40 mi (64.37 km)	I-71 in Medina	I-90in Willoughby
Interstate	Length^[3]	Southern/Western terminus	Northern/Eastern terminus
Interstate 72
Illinois
I-172	19.69 mi (31.69 km)	I-72 in Quincy	US 24 in Quincy
Interstate	Length^[3]	Southern/Western terminus	Northern/Eastern terminus
Interstate 74
Illinois
I-474	14.88 mi (23.95 km)	I-74 in Peoria	I-74 in Morton
North Carolina
I-274	Proposed route in Winston-Salem
Interstate	Length^[3]	Southern/Western terminus	Northern/Eastern terminus
Interstate 75
Florida
I-175	1.44 mi (2.32 km)	I-275 in St. Petersburg	SR 687 in St. Petersburg
I-275	63.39 mi (102.02 km)	I-75 near Memphis	I-75 in Wesley Chapel
I-375	1.34 mi (2.16 km)	I-275 in St. Petersburg	US 92 in St. Petersburg
Georgia
I-475	15.8 mi (25.43 km)	I-75 in Macon	I-75 in Macon
I-575	30.9 mi (49.73 km)	I-75 in Kennesaw	SR 5 west of Nelson
I-675	11.04 mi (17.77 km)	I-75 in Stockbridge	I-285 southeast of Atlanta
Indiana-Kentucky-Ohio
I-275	83.71 mi (134.72 km)	Beltway around Cincinnati
Michigan
I-275	35.01 mi (56.34 km)	I-75 near Monroe	I-96 / I-696 / M-5 in Farmington Hills
I-375	1.06 mi (1.71 km)	Greenspur 375 to Civic Center	I-75 in Detroit
I-475	16.99 mi (27.34 km)	I-75 in Grand Blanc Charter Township	I-75 / US 23 in Mount Morris Charter Township
I-675	7.73 mi (12.44 km)	I-75 / US 23 in Buena Vista Charter Township	I-75 / US 23 in Kochville Township
Ohio
I-475	20.37 mi (33 km)	I-75 in Perrysburg	I-75 in Toledo
I-675	26.53 mi (43 km)	I-75 near Miamisburg	I-70 near Medway
Tennessee
I-275	2.98 mi (5 km)	I-40 in Knoxville	I-75 / I-640 in Knoxville
Interstate	Length^[3]	Southern/Western terminus	Northern/Eastern terminus
Interstate 76 (east)
Pennsylvania
I-176	11.33 mi (18.23 km)	I-76 / Penna. Tpk. in Morgantown	US 422 near Reading
I-276	32.65 mi (52.55 km)	I-76 in King of Prussia	NJ Turnpike Ext. in Bristol Township (current) I-95 / I-195 in Bensalem (future)
I-376	80.6 mi (129.71 km)	I-80 near Hermitage	I-76 / US 22 in Monroeville
I-476	132.10 mi (212.59 km)	I-95 near Chester	I-81 near Clarks Summit
I-576	Proposed Southern Beltway route from Pittsburgh International Airport to I-376
I-676	6.90 mi (11.1 km)	I-76 / US 30 in Philadelphia	I-76 in Camden
Interstate	Length^[3]	Southern/Western terminus	Northern/Eastern terminus
Interstate 77
Ohio
I-277	4.14 mi (6.66 km)	I-76 in Akron	I-77 in Akron
North Carolina
I-277	4.41 mi (7.10 km)	Beltway around uptown Charlotte, NC
Interstate	Length^[3]	Southern/Western terminus	Northern/Eastern terminus
Interstate 78
New York
I-278	35.6 mi (57.3 km)	US 1 / US 9 in Linden, NJ	Bruckner Interchange in Bronx, New York
I-478	2.14 mi (3.44 km)	I-278 in Brooklyn, New York	NY 9A in Manhattan, New York
I-678	14 mi (23 km)	John F. Kennedy International Airport in Queens, New York	Bruckner Interchange in Bronx, New York
I-878	0.70 mi (9.16 km)	I-678 in Queens, New York City near JFK Airport	JFK Expressway in Queens, New York City near JFK Airport
Interstate	Length^[3]	Southern/Western terminus	Northern/Eastern terminus
Interstate 79
Pennsylvania
I-279	13.20 mi (21.24 km)	I-376 / US 22 / US 30 in Pittsburgh	I-79 in Franklin Park
I-579	1.57 mi (2.53 km)	PA 885 in Pittsburgh	I-279 / PA 28 in Pittsburgh
Interstate	Length^[3]	Southern/Western terminus	Northern/Eastern terminus
Interstate 80
California
I-280	57 mi (91.73 km)	I-680 / US 101 in San Jose	King Street in San Francisco
I-380	1.5 mi (2.41 km)	I-280 in San Bruno	US 101
I-580	71 mi (114.26 km)	US 101 in San Rafael	I-5 near Westley
I-680	71 mi (114 km)	I-280 / US 101 in San Jose	I-80 in Cordelia
I-780	6.52 mi (10.49 km)	I-80 in Vallejo	I-680 in Benicia
I-880	45 mi (72 km)	I-280 / SR 17 in San Jose	I-580 / I-80 in Oakland
I-980	2.02 mi (3.25 km)	I-880 in Downtown Oakland	I-580 / SR 24 in Oakland
Illinois
I-180	13.19 mi (21.22 km)	IL 26 / IL 71 in Hennepin, Illinois	I-80 near Princeton, Illinois
Illinois-Iowa
I-280	26.98 mi (43.42 km)	I-80 near Davenport, IA	I-74 / I-80 near Colona, IL
Iowa
I-380	73.05 mi (117.56 km)	I-80 near Iowa City	US 218 in Waterloo
Iowa-Nebraska
I-480	4.90 mi (7.89 km)	I-80 / US-75 in Omaha, NE	I-29 / US 6 in Council Bluffs, IA
I-680	42.86 mi (68.98 km)	I-80 in Omaha, NE	I-80 near Neola, IA
Nebraska
I-180	3.47 mi (5.58 km)	US-34 in Lincoln	I-80 / US-34 / US-77 in Lincoln
Nevada
I-580	4.99 mi (8.03 km)	Neil Road in Reno	I-80 in Reno
New Jersey
I-280	17.85 mi (28.73 km)	I-80 in Parsippany-Troy Hills	I-95 / NJ Turnpike in Kearny
Ohio
I-280	12.41 mi (19.97 km)	I-75 in Toledo	I-80 / I-90 / Ohio Tpk. in Lake Township
I-480	41.77 mi (67.22 km)	I-80 / Ohio Tpk. near North Ridgeville	I-80 / Ohio Tpk. near Streetsboro
I-680	16.43 mi (26.44 km)	I-76 / Ohio Tpk. in North Lima,	I-80 / SR 11 near Mineral Ridge,
Pennsylvania
I-180	28.85 mi (46.43 km)	US 15 / US 220 in Williamsport	I-80 / PA 147 near Milton
I-380	24.76 mi (39.85 km)	I-80 in Tunkhannock Township	I-81 / I-84 / US 6 in Dunmore
Wyoming
I-180	1.09 mi (1.75 km)	I-80 in Cheyenne	US 30/Bus I-80
Interstate	Length^[3]	Southern/Western terminus	Northern/Eastern terminus
Interstate 81
New York
I-481	15.04 mi (24.2 km)	I-81 in Onondaga	I-81 / NY 481 in North Syracuse
I-781	4.9 mi (7.89 km)	I-81 in Pamelia	Fort Drum main gate in Le Ray
Virginia
I-381	1.70 mi (2.74 km)	SR 381 in Bristol	I-81 in Bristol
I-581	6.35 mi (10.22 km)	US 220 / SR 24 in Roanoke	I-81 near Hollins
Interstate	Length^[3]	Southern/Western terminus	Northern/Eastern terminus
Interstate 82
Washington
I-182	15.19 mi (24.45 km)	I-82 / US 12 near Richland	US 12 / US 395 in Pasco
Interstate	Length^[3]	Southern/Western terminus	Northern/Eastern terminus
Interstate 83
Pennsylvania
I-283	2.91 mi (4.683 km)	I-76 / Penna. Tpk. near Highspire	I-83 / US 322/Capital Beltway near Harrisburg
Interstate	Length^[3]	Southern/Western terminus	Northern/Eastern terminus
Interstate 84 (east)
Connecticut
I-384	8.53 mi (13.73 km)	I-84 / US 6 in East Hartford	US 6 / US 44 in Bolton
New York/Connecticut
I-684	28.4 mi (45.7 km)	I-287 near White Plains	NY 22 near Brewster
Interstate	Length^[3]	Southern/Western terminus	Northern/Eastern terminus
Interstate 84 (west)
Idaho
I-184	3.62 mi (6.00 km)	I-84 in Boise	US-20 / US-26
Interstate	Length^[3]	Southern/Western terminus	Northern/Eastern terminus
Interstate 85
Alabama
I-685	14.44 mi	Proposed auxiliary route to connect Interstate 65 in downtown Montgomery to Interstate 85 in the eastern part of the city
Georgia
I-185	49.30 mi (79.34 km)	US 27 / US 280 / SR 520 in Columbus	I-85 near LaGrange
I-285	63.98 mi (102.97 km)	Beltway around Atlanta
I-985	24.04 mi (38.69 km)	I-85 near Buford	SR 369 near Gainesville
North Carolina
I-285	23 mi (37 km)	I-40 / US 52 / US 311 / NC 8 in Winston-Salem	I-85 / US 52 / US 70 in Lexington
I-485	62 mi (99.78 km)	NC 115 in Huntersville	I-85 in Charlotte
North Carolina-Virginia
I-785	45 mi (72.42 km)	I-40 / I-40 / I-85 in Greensboro, NC	US 29 in Danville, VA
South Carolina
I-185	17.70 mi (28.49 km)	I-385 near Mauldin	US 29
I-385	42.16 mi (67.85 km)	I-26 near Clinton	US 276 in Greenvile
I-585	2.25 mi (3.62 km)	US 221 in Spartanburg	SC 56 / US 176 near Spartanburg
Interstate	Length^[3]	Southern/Western terminus	Northern/Eastern terminus
Interstate 87
New Jersey-New York
I-287 (Partial beltway around New York City)	98.65 mi (158.73 km)	I-95 / NJ Turnpike in Edison, NJ	I-95 in Rye, NY
New York
I-587	1.21 mi (1.95 km)	I-87 / Thruway / NY 28 in Kingston	NY 28 / NY 32 in Kingston
I-787	9.55 mi (15.37 km)	I-87 / Thruway / I-87 in Albany	NY 7 in Green Island
Interstate	Length^[3]	Southern/Western terminus	Northern/Eastern terminus
Interstate 89
Vermont
I-189	1.49 mi (2.4 km)	US 7 in South Burlington	I-89 in South Burlington
Interstate	Length^[3]	Southern/Western terminus	Northern/Eastern terminus
Interstate 90
Illinois
I-190	3.07 mi (5 km)	O'Hare International Airport in Chicago	I-90 in Chicago
I-290	29.84 mi (48.02 km)	I-90 / IL 53 in Rolling Meadows	I-90 / I-94/Congress Parkway in Chicago
Massachusetts
I-190	19.26 mi (31 km)	I-290 in Worcester	Route 2 in Leominster
I-290	20.16 mi (32.44 km)	Mass Pike I-90 / I-395 in Auburn	I-495 in Marlborough
New York
I-190	28.34 mi (45.61 km)	I-90 / Thruway in Cheektowaga	Highway 405 in Lewiston
I-290	9.80 mi (15.77 km)	I-190 in Tonawanda	I-90 / Thruway in Williamsville
I-390	75.86 mi (122.08 km)	I-86 / NY 17 in Avoca	I-490 in Gates
I-490	37.40 mi (60.19 km)	I-90 / Thruway in Bergen	I-90 / Thruway in Victor
I-590	5.07 mi (8.16 km)	I-390 in Brighton	I-490 / NY 590 in Rochester
I-690	14.19 mi (22.84 km)	I-90 / Thruway / NY 690 in Van Buren	I-481 in East Syracuse
I-790	2.41 mi (4 km)	I-90 / Thruway in Deerfield	NY 5A / NY 55 in Utica
I-890	9.45 mi (15.21 km)	I-90 / Thruway in Rotterdam	I-90 / Thruway in Guilderland
I-990	6.35 mi (10.22 km)	I-290 in Amherst	NY 263 near Lockport
Ohio
I-490	2.43 mi (4 km)	I-90 / I-71 in Cleveland	55th Street East in Cleveland
South Dakota
I-190	2 mi (3 km)	I-90 in Rapid City	US 16 in Rapid City
Interstate	Length^[3]	Southern/Western terminus	Northern/Eastern terminus
Interstate 91
Connecticut
I-291	6.40 mi (10.3 km)	I-91 in Windsor	I-84 in Manchester
I-691	8.92 mi (14.36 km)	I-84 at the Southington-Cheshire Town Line	I-91 in Meriden
Massachusetts
I-291	5.44 mi[1] (8.75 km)	I-91 in Springfield	Mass Pike I-90 in Chicopee
I-391	4.86 mi (7.82 km)	I-91 in Chicopee	High Street in Holyoke
Interstate	Length^[3]	Southern/Western terminus	Northern/Eastern terminus
Interstate 93
New Hampshire
I-293	11.43 mi (18.39 km)	I-93 / NH 101 in Manchester	Everett Tpke. / I-93 in Hooksett
I-393	4.50 mi (7.24 km)	I-93 in Concord	NH 9 in Pembroke
Interstate	Length^[3]	Southern/Western terminus	Northern/Eastern terminus
Interstate 94
Illinois
I-294	53.42 mi (85.97 km)	I-80 / I-94 in South Holland, Illinois	I-94 in Deerfield, Illinois
Michigan
I-194	3.42 mi (5.5 km)	I-94 in Battle Creek	M-66 in Battle Creek
Minnesota
I-394	9.50 mi (15.30 km)	I-494 / US 12 in Minnetonka	4th Street in Minneapolis
I-494	43 mi (69 km)	I-94 / I-694 in Maple Grove	I-94 / I-694 in Woodbury
I-694	31 mi (50 km)	I-94 / I-494 in Maple Grove	I-94 / I-494 in Woodbury
North Dakota
I-194	1.7 mi (2.7 km)	McKenzie Drive near Bismarck	I-94 near Mandan
Wisconsin
I-794	3.75 mi (6.04 km)	I-43 / I-94 in Milwaukee	WIS 794 in Milwaukee
I-894	9.30 mi (14.97 km)	I-94 in Milwaukee	I-43 / I-94 in Milwaukee
Interstate	Length^[3]	Southern/Western terminus	Northern/Eastern terminus
Interstate 95
Connecticut-Massachusetts
I-395	66.63 mi (107.23 km)	I-95 in East Lyme, CT	I-90 in Auburn, MA
Delaware
I-495	11.47 mi (18.46 km)	I-95 / I-295 in Newport	I-95 in Claymont
Delaware-New Jersey
I-295	73.50 mi (118.29 km)	I-95 / I-495 in New Castle, DE	I-95 / US 1 in Lawrence Township (current) I-195 in Hamilton Township (future)
District of Columbia
I-695	1.39 mi (2.24 km)	I-395 in Washington	Pennsylvania Avenue in Washington
Florida
I-195	4.91 mi (7.90 km)	I-95 / SR 112 in Miami	SR 907 in Miami Beach
I-295	35.51 mi (57.15 km)	I-95 / SR 9A in Jacksonville	I-95 / SR 9A in Jacksonville
I-395	1.12 mi (2 km)	I-95	MacArthur Causeway at Watson Island, Miami
I-595	13 mi (20 km)	I-75 / SR 869 in Weston	US 1 in Fort Lauderdale
I-795	Proposed route south of Jacksonville
Maine
I-195	1.55 mi (2.49 km)	I-95 in Saco	SR 5 in Saco
I-295	52 mi (84 km)	I-95 in Scarborough	I-95 in Gardiner
I-395	4.99 mi (8.03 km)	I-95 / US 2 / SR 100 in Bangor	US 1A in Brewer
I-495	3.7 mi (6 km)	I-95 in Portland	I-295 / US 1 in Falmouth
Maryland
I-195	4.88 mi (7.85 km)	I-95 / MD 166 near Catonsville	Baltimore-Washington International Airport
I-395	1.98 mi (3.19 km)	I-95 in South Baltimore	West Pratt Street in Baltimore
I-595	19.97 mi (32 km)	I-95 / I-495 / US 50 near Washington, DC	US 50 / US 301 / MD 70 in Annapolis
I-695	51.46 mi (82.82 km)	Beltway around Baltimore
I-795	8.99 mi (14.47 km)	I-695 in Pikesville	MD 140 in Reisterstown
I-895	11.44 mi (18.41 km)	I-95 near Elkridge	I-95 in Baltimore
Maryland-District of Columbia
I-295	8.05 mi (12.96 km)	I-95 / I-495 near Forest Heights, MD	I-695 in Washington, DC
Maryland-District of Columbia-Virginia
I-495	64.0 mi (103 km)	Beltway around Washington, DC
Massachusetts
I-495	120.74 mi (194.31 km)	I-195 in Wareham	I-95 in Salisbury
New Jersey-Pennsylvania
I-195	34.17 mi (54.99 km)	I-295 in Hamilton Township (current) I-95 / I-276 in Bensalem Township, Pennsylvania (future)	Route 34 in Wall Township
New York
I-295	9.10 mi (14.65 km)	NY 25 in Queens, New York City	Bruckner Interchange in Bronx, New York City
I-495	71.02 mi (114.3 km)	Queens Midtown Tunnel in Manhattan, New York City	CR 58 in Riverhead
I-695	1.3 mi (2.1 km)	I-95 in Bronx, New York City	I-295 in Bronx, New York City
I-895	1.12 mi (1.8 km)	I-278 in Bronx, New York City	I-95 in Bronx, New York City
North Carolina
I-295	Planned route around the west side of Fayetteville
I-795	25.41 mi (40.9 km)	US 70 / US 117 in Goldsboro, NC	I-95 / US 264 in Wilson, NC
Rhode Island-Massachusetts
I-195	40.1 mi (64.5 km)	I-95 in Providence, RI	I-495 / Route 25 in Wareham, MA
I-295	26.58 mi (42.78 km)	I-95 in Warwick, RI	I-95 in Attleboro, MA
Virginia
I-195	3.50 mi (5.63 km)	SR 195 in Richmond	I-64 / I-95 in Richmond
I-295	52.75 mi (84.89 km)	I-95 near Petersburg	I-64 near Short Pump
Virginia-District of Columbia
I-395	13 mi (21 km)	I-95 / I-495 in Springfield, VA	US 50 in Washington, DC
Interstate	Length^[3]	Southern/Western terminus	Northern/Eastern terminus
Interstate 96
Michigan
I-196	81 mi (130.35 km)	I-94 in Benton Harbor	I-96 in Grand Rapids
I-296	3.43 mi (5.52 km)	I-196 in Grand Rapids	I-96 / M-37 in Walker
I-496	11.78 mi (18.96 km)	I-69 / I-96 in Lansing	I-96 in Lansing
I-696	29.24 mi (47.04 km)	I-96 / I-275 / M-5 in Novi	I-94 in Roseville

References

^ ^a ^b "FHWA Route Log and Finder List: Interstate Route Numbering" (CFM). Federal Highway Administration. 2002-10-31. http://www.fhwa.dot.gov/reports/routefinder/index.cfm#s09. Retrieved 2008-02-03.
^ http://en.wikipedia.org/wiki/Interstate_99#Future
^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l ^m ⁿ ^o ^p ^q ^r ^s ^t ^u ^v ^w ^x ^y ^z ^aa ^ab ^ac ^ad ^ae ^af ^ag ^ah ^ai ^aj ^ak ^al ^am ^an ^ao ^ap ^aq ^ar "Route Log and Finder List — Table 2" (CFM). Federal Highway Administration. 2002-10-31. http://www.fhwa.dot.gov/reports/routefinder/table2.cfm. Retrieved 2007-06-02.

External links

3-digit Interstates at Kurumi.com

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	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 - Temporary - Future - Gaps
		Auxiliary			Main - Future - Unsigned
		Other			Standards - Business - Bypassed - Tolled

List of auxiliary Interstate Highways

Terminology and guidelines

Spur route

Bypass

Beltway

Exceptions

Connection discrepancies

Short mainline routes

Auxiliary Interstates

Interstate H-1

Interstate 5

Interstate 10

Interstate 15

Interstate 16

Interstate 20

Interstate 24

Interstate 25

Interstate 26

Interstate 29

Interstate 30

Interstate 35

Interstate 40

Interstate 44

Interstate 45

Interstate 55

Interstate 59

Interstate 64

Interstate 65

Interstate 69

Interstate 70

Interstate 71

Interstate 72

Interstate 74

Interstate 75

Interstate 76 (east)

Interstate 77

Interstate 78

Interstate 79

Interstate 80

Interstate 81

Interstate 82

Interstate 83

Interstate 84 (east)

Interstate 84 (west)

Interstate 85

Interstate 87

Interstate 89

Interstate 90

Interstate 91

Interstate 93

Interstate 94

Interstate 95

Interstate 96

See also

References

External links