Interstates by State
This list breaks down the Interstate-Guide by states (and the District of Columbia) and including current, former, future and unsigned routes. Interstate mileage statistics provided for each state and D.C. were obtained from the December 31, 2018 Interstate Route Log and Finders List.
Alabama | 12 active routes | 1,145.49 mi.
Alaska | 4 active routes | 1,082.22 mi.
Arizona | 6 active routes | 1,168.64 mi.
Arkansas | 10 active routes | 747.12 mi.
California | 12 active routes | 2,457.34 mi.
- I-5, I-8, I-10, I-15, I-40, I-80
- I-105, I-205, I-305, I-405, I-505, I-605, I-805, I-905, I-110, I-210, I-710, I-215, I-238, I-280, I-380, I-580, I-680, I-780, I-880, I-980
Colorado | 5 active routes | 951.85 mi.
Connecticut | 8 active routes | 346.17 mi.
Delaware | 3 active routes | 40.61 mi.
District of Columbia | 5 active routes | 12.27 mi.
Florida | 12 active routes | 1,497.58 mi.
Georgia | 15 active routes | 1,253.19 mi.
- I-16, I-20, I-59, I-75, I-85, I-95
- I-516, I-420, I-520, I-475, I-575, I-675, I-185, I-285, I-485, I-985
Hawaii | 4 active routes | 54.91 mi.
Idaho | 5 active routes | 611.76 mi.
It was determined by the city of Chicago that the Chicago Skyway was never formally included in the Interstate Highway System in 1999. As such, trailblazers were posted in lieu of confirming markers along the toll road.
Interstates are commonly dedicated as war memorial highways throughout the United States. One such designation is the Purple Heart Trail, which originates at a monument in Mt. Vernon, Virginia. Purple Heart Trail routes include I-5 in California, I-35 in Texas and I-95 between Augusta and Holton, Maine.
Prior to 2010, IH 110 was one of a handful of unmarked routes in the Interstate system.
Illinois | 24 active routes | 2,203.42 mi.
- I-24, I-39, I-55, I-57, I-64, I-70, I-72, I-74, I-80, I-88, I-90, I-94
- I-155, I-255, I-355, I-270, I-172, I-474, I-180, I-280, I-190, I-290, I-390, I-490, I-294, I-494
Indiana | 14 active routes | 1,306.52 mi.
Iowa | 10 active routes | 781.24 mi.
Kansas | 9 active routes | 874.34 mi.
Kentucky | 11 active routes | 913.20 mi.
Louisiana | 13 active routes | 933.84 mi.
Maine | 5 active routes | 366.54 mi.
Maryland | 16 active routes | 480.09 mi.
- I-68, I-70, I-81, I-83, I-95, I-97
- I-170, I-270, I-370, I-195, I-295, I-395, I-495, I-595, I-695, I-795, I-895
Massachusetts | 13 active routes | 565.63 mi.
Michigan | 13 active routes | 1,240.96 mi.
Minnesota | 9 active routes | 912.73 mi.
Mississippi | 9 active routes | 831.47 mi.
Missouri | 18 active routes | 1,386.23 mi.
- I-29, I-35, I-44, I-49, I-55, I-57, I-64, I-70, I-72
- I-229, I-435, I-635, I-155, I-255, I-364, I-170, I-270, I-370, I-470, I-570, I-670
Montana | 5 active routes | 1,191.23 mi.
Nebraska | 6 active routes | 481.66 mi.
Nevada | 6 active routes | 623.79 mi.
New Hampshire | 5 active routes | 224.54 mi.
New Jersey | 10 active routes | 431.36 mi.
New Mexico | 3 active routes | 999.90 mi.
New York | 31 active routes | 1,730.34 mi.
- I-78, I-81, I-84, I-86, I-87, I-88, I-90, I-95, I-99
- I-278, I-478, I-678, I-878, I-481, I-781, I-684, I-287, I-587, I-687, I-787, I-190, I-290, I-390, I-490, I-590, I-690, I-790, I-890, I-990, I-295, I-495, I-695, I-895
North Carolina | 19 active routes# | 1,337.30 mi.
- I-26, I-40, I-42, I-73, I-74, I-77, I-85, I-87, I-95
- I-140, I-240, I-440, I-540, I-840, I-274, I-277, I-285, I-485, I-587, I-785, I-885, I-295, I-495, I-795
North Dakota | 3 active routes | 571.13 mi.
Ohio | 21 active routes | 1,572.35 mi.
- I-70, I-71, I-74, I-75, I-76, I-77, I-80, I-90
- I-270, I-470, I-670, I-271, I-471, I-275, I-475, I-675, I-277, I-280, I-480, I-680, I-490
Oklahoma | 7 active routes | 930.16 mi.
Oregon | 6 active routes | 727.41 mi.
Pennsylvania | 23 active routes## | 1,862.21 mi.
- I-70, I-76, I-78, I-79, I-80, I-81, I-83, I-84, I-86, I-90, I-95, I-99
- I-176, I-276, I-376, I-476, I-576, I-676, I-279, I-579, I-178, I-378, I-180, I-380, I-283, I-295
Puerto Rico | 3 active routes | 249.77 mi.
Rhode Island | 3 active routes | 68.53 mi.
South Carolina | 11 active routes | 850.80 mi.
South Dakota | 4 active routes | 678.31 mi.
Tennessee | 17 active routes### | 1,959.54 mi.
- I-24, I-26, I-40, I-55, I-65, I-69, I-81
- I-124, I-140, I-240, I-440, I-640, I-840, I-155, I-265, I-269, I-275, I-181
Texas | 25 active routes | 3,501.15 mi.
- I-2, I-10, I-14, I-20, I-27, I-30, I-35, I-35E, I-35W, I-37, I-40, I-44, I-45, I-69
- I-110, I-410, I-610, I-820, I-635, I-345, I-69C, I-69E, I-69W, I-169, I-369
Utah | 5 active routes | 938.00 mi.
Vermont | 4 active routes | 320.22 mi.
Virginia | 16 active routes | 1,117.23 mi.
- I-64, I-66, I-73, I-77, I-81, I-85, I-95
- I-264, I-464, I-564, I-664, I-381, I-581, I-785, I-195, I-295, I-395, I-495, I-895
Washington | 7 active routes | 763.67 mi.
West Virginia | 7 active routes | 549.05 mi.
Wisconsin | 7 active routes | 741.80 mi.
Wyoming | 4 active routes | 913.60 mi.
# – I-495 was renumbered as I-87 in 2016
## – I-295 was established over a portion of I-95 in Bucks County in 2018
### – The remainder of I-181 was renumbered as an extension of I-26 in 2005.
Page updated April 11, 2019.