List of Interstates
Note that the route number of an Interstate Highway is even for roads which are primarily east-west routes, and odd for roads which are primarily north-south.
List of one- and two-digit interstate highways in the United States:
| Interstate 4 | Florida |
| Interstate 5 | California, Oregon, Washington |
| Interstate 8 | Arizona, California |
| Interstate 10 | Alabama, Arizona, California, Florida, Louisiana, Mississippi, New Mexico, Texas |
| Interstate 12 | Louisiana |
| Interstate 15 | Arizona, California, Idaho, Montana, Nevada, Utah |
| Interstate 16 | Georgia |
| Interstate 17 | |
| Interstate 19 | |
| Interstate 20 | |
| Interstate 24 | |
| Interstate 25 | |
| Interstate 26 | |
| Interstate 27 | |
| Interstate 29 | |
| Interstate 30 | |
| Interstate 35 | |
| Interstate 37 | |
| Interstate 39 | |
| Interstate 40 | |
| Interstate 43 | |
| Interstate 44 | |
| Interstate 45 | |
| Interstate 49 | |
| Interstate 55 | |
| Interstate 57 | |
| Interstate 59 | |
| Interstate 64 | |
| Interstate 65 | |
| Interstate 66 | |
| Interstate 68 | |
| Interstate 69 | |
| Interstate 70 | |
| Interstate 71 | |
| Interstate 72 | |
| Interstate 73 | |
| Interstate 74 | |
| Interstate 75 | Florida, Georgia, Kentucky, Ohio, Michigan, Tennessee (See Also: Alligator Alley)
| |
| Interstate 76 | |
| Interstate 77 | |
| Interstate 78 | |
| Interstate 79 | |
| Interstate 80 | |
| Interstate 81 | |
| Interstate 82 | |
| Interstate 83 | |
| Interstate 84 | |
| Interstate 85 | |
| Interstate 86 | |
| Interstate 87 | |
| Interstate 88 | |
| Interstate 89 | |
| Interstate 90 | |
| Interstate 91 | |
| Interstate 93 | |
| Interstate 94 | |
| Interstate 95 | |
| Interstate 96 | |
| Interstate 97 | |
| Interstate 99 | Pennsylvania |
| Interstate 238 | California (an unusual exception to the rules) | |
Hawaii interstates include:
Note: Three-digit interstates (with the exception of I-238) are to be discussed in the same article as the one- or two-digit interstate that the three-digit interstate is a spur or loop of, even if plans to build the connection between the "spur" and the main highway never materialized. For example, I-170 is discussed in the I-70 article, and I-278 in New York and New Jersey is discussed in the I-78 article, even though no connection exists between I-78 and any of its spurs or loops. I-238 is an exception because it is not a loop or spur of any one- or two-digit interstate (no I-38 exists anywhere near I-238).
