| Interstate Highways of the Iowa Primary Highway System | |
|---|---|
   Highway markers for I-80, I-380, and I-35 Bus. Loop | |
 Interstate Highways in Iowa highlighted in red | |
| System information | |
| Formed | August 14, 1957 [1] |
| Highway names | |
| Interstates | Interstate X (I-X) |
| Business Loops: | Interstate X Business (I-X Bus.) |
| System links | |
Interstate Highways in Iowa form a network of freeways that cross the state.
| Number | Length (mi) [2] | Length (km) | Southern or western terminus | Northern or eastern terminus | Formed | Removed | ||
|---|---|---|---|---|---|---|---|---|
 I-29 | 151.941 | 244.525 | I-29 at Hamburg | I-29 at Sioux City | 1958 | current | ||
 I-35 | 218.532 | 351.693 | I-35 near Lamoni | I-35 near Albert Lea, Minn. | 1958 | current | ||
 I-74 | 5.399 | 8.689 | I-80 at Davenport | I-74 / US 6 at Bettendorf | 1968 | current | ||
 I-80 | 306.392 | 493.090 | I-80 at Council Bluffs | I-80 at LeClaire | 1958 | current | ||
| Number | Length (mi) [2] | Length (km) | Southern or western terminus | Northern or eastern terminus | Formed | Removed | Notes | |
|---|---|---|---|---|---|---|---|---|
 I-80N | 17.102 | 27.523 | I-29 at Loveland | I-80 near Neola | 1966 | 1973 | Replaced by I-680; now I-880 | |
 I-129 | 0.286 | 0.460 | I-129 / US 20 / US 75 at Sioux City | I-29 / US 20 / US 75 at Sioux City | 1976 | current | ||
 I-235 | 14.585 | 23.472 | I-35 / I-80 at West Des Moines | I-35 / I-80 at Des Moines | 1961 | current | ||
 I-280 | 9.862 | 15.871 | I-80 / US 6 at Davenport | I-280 at Rock Island, Ill. | 1973 | current | ||
 I-380 | 72.969 | 117.432 | I-80 / U.S. Route 218 / Iowa 27 near Coralville | US 218 at Waterloo | 1973 | current | ||
 I-480 | 0.877 | 1.411 | I-480 / US 6 at Council Bluffs | I-29 / US 6 at Council Bluffs | 1966 | current | ||
 I-680 | 3.353 | 5.396 | I-680 at Omaha, Neb. | I-29 near Crescent | 1966 | current | ||
 I-880 | 17.102 | 27.523 | I-29 at Loveland | I-80 near Neola | 2019 | current | Replaced a portion of I-680 | |
| ||||||||
| Number | Length (mi) [2] | Length (km) | Southern or western terminus | Northern or eastern terminus | Cities | Formed | Removed | |
|---|---|---|---|---|---|---|---|---|
 I-35 Business Loop | 6.927 | 11.148 | I-35 / US 30 in Ames | I-35 in Ames | Ames | 1995 | current | |
| I-35 Business Loop | 2.979 | 4.794 | I-35 / US 18 in Clear Lake | I-35 / US 18 / Iowa 122 in Clear Lake | Clear Lake | 1999 | current | |
Interstate 80 (I-80) is an east–west transcontinental freeway that crosses the United States from downtown San Francisco, California, to Teaneck, New Jersey, in the New York metropolitan area. The highway was designated in 1956 as one of the original routes of the Interstate Highway System; its final segment was opened in 1986. The second-longest Interstate Highway in the United States after I-90, it runs through many major cities, including Oakland, Sacramento, Reno, Salt Lake City, Omaha, Des Moines, and Toledo and passes within 10 miles (16 km) of Chicago, Cleveland, and New York City.
Interstate 35 (I-35) is a major Interstate Highway in the central United States. As with most primary Interstates that end in a five, it is a major cross-country, north–south route. It stretches from Laredo, Texas, near the Mexican border to Duluth, Minnesota, at Minnesota State Highway 61 and 26th Avenue East. The highway splits into I-35E and I-35W in two separate places, the Dallas–Fort Worth metroplex in Texas and at the Minnesota twin cities of Minneapolis–Saint Paul.
U.S. Route 6 (US 6) or U.S. Highway 6 (US 6), also called the Grand Army of the Republic Highway, honoring the American Civil War veterans association, is a main route of the United States Numbered Highway System. While it currently runs east-northeast from Bishop, California, to Provincetown, Massachusetts, the route has been modified several times. The highway's longest-lasting routing, from 1936 to 1964, had its western terminus at Long Beach, California. During this time, US 6 was the longest highway in the country.
U.S. Route 65 is a north–south United States highway in the southern and midwestern United States. The southern terminus of the route is at U.S. Route 425 in Clayton, Louisiana. The northern terminus is at Interstate 35 just south of Interstate 90 in Albert Lea, Minnesota. Parts of its modern route in Iowa and historic route in Minnesota follow the old Jefferson Highway.
The Avenue of the Saints is a 563-mile-long (906 km) highway in the Midwestern United States that connects St. Louis, Missouri and St. Paul, Minnesota.
U.S. Route 136 is an east-west U.S. highway that is a spur route of U.S. Route 36. It runs from Edison, Nebraska, at U.S. Route 6 and U.S. Route 34 to the Interstate 74/Interstate 465 interchange in Speedway, Indiana. This is a distance of 804 miles (1,294 km). Due to the removal of almost every numbered route in Indianapolis, US 136 never meets its parent, US 36; however, it does come within two miles of it at its interchange with I-465/I-74 at its eastern terminus.
Interstate 235 (I-235) in Iowa is an auxiliary Interstate Highway that runs just north of downtown Des Moines through the heart of the Des Moines metropolitan area. I-235 runs from the junction of I-35 and I-80 in West Des Moines to the separation of the same two Interstates in Ankeny. The highway is approximately 14 miles (23 km) long.
Iowa Highway 2 is a 251-mile-long (404 km) state highway which runs across the southernmost tier of counties in the U.S. state of Iowa. At no point along its route is Iowa 2 more than 15 miles (24 km) from the Missouri state line, except for a small section near its eastern terminus. Iowa 2 stretches across the entire state; from the Missouri River near Nebraska City, Nebraska, to U.S. Highway 61 (US 61) at Fort Madison. Prior to becoming a primary highway, the route was known as the Waubonsie Trail.
Iowa Highway 28 is a 21.73-mile-long (34.97 km) state highway located in south central Iowa. The route begins at Iowa Highway 92 at Martensdale and ends at Interstate 35 / Interstate 80 in Johnston. It is the first major north–south highway east of Interstate 35 in the Des Moines metropolitan area.
Interstate 680 (I-680) in Nebraska and Iowa is the northern bypass of the Omaha–Council Bluffs metropolitan area. I-680 spans 16.49 miles (26.54 km) from its southern end in western Omaha, Nebraska, to its eastern end near Crescent, Iowa. The freeway passes through a diverse range of scenes and terrains—the urban setting of Omaha, the Missouri River and its valley, the rugged Loess Hills, and the farmland of Pottawattamie County, Iowa.
Interstate 74 (I-74) in the US state of Illinois is a major northwest–southeast Interstate Highway that runs across the central portion of the state. It runs from the Iowa state line at the Mississippi River near the city of Rock Island and runs southeast to the Indiana state line east of Danville, a distance of 220.34 miles (354.60 km). The highway runs through the major cities of Champaign, Bloomington, Peoria, and Moline.
U.S. Highway 20 in Iowa is a major east–west artery which runs across the state, separating the northern third of Iowa from the southern two-thirds. It enters Iowa from Nebraska, concurrent with Interstate 129 and U.S Route 75, crossing the Missouri River at Sioux City. US 20 runs in a more-or-less straight line across Iowa, paralleling 42° 27' N. It leaves Iowa in Dubuque by crossing the Mississippi River into Illinois. Since October 2018, US 20 is a four-lane divided highway for its entire length in Iowa.
U.S. Highway 6 (US 6) is an east–west United States Numbered Highway which runs 322 miles (518 km) across the U.S. state of Iowa. The route is signed in places as the Grand Army of the Republic Highway. Like all state highways in Iowa, it is maintained by the Iowa Department of Transportation. The route begins at the Missouri River crossing at Council Bluffs. From there, it travels east through Oakland and Atlantic. North of Atlantic, the highway overlaps Interstate 80 (I-80) until De Soto. Between De Soto and Adel, the highway overlaps US 169 before splitting off to the east toward Des Moines. Through the Des Moines area, the highway runs about one mile (1.6 km) north or south of the I-35/I-80 corridor.
Interstate 35 (I-35) is a north–south Interstate Highway in the United States that runs from Laredo, Texas, to Duluth, Minnesota. In Iowa, the highway runs from south to north through the center of the state, roughly parallel to U.S. Highway 69 (US 69) and US 65. It enters the state near Lamoni from Missouri and continues north through the southern Iowa drift plain. In the Des Moines area, I-35 runs concurrently with I-80, and the two highways bypass Des Moines to the west and north. I-235, the only auxiliary route of I-35, serves the suburbs and downtown Des Moines; it begins and ends at the two interchanges where I-35 and I-80 meet. Near Mason City and Clear Lake, US 18 and Iowa Highway 27 (Iowa 27) overlap with I-35. Shortly after, US 18 splits off to the west in Clear Lake, while Iowa 27 runs with I-35 until they reach the Minnesota state line.
Interstate 80 (I-80) is a transcontinental Interstate Highway in the United States, stretching from San Francisco, California, to Teaneck, New Jersey. In Iowa, the highway travels west to east through the center of the state. It enters the state at the Missouri River in Council Bluffs and heads east through the southern Iowa drift plain. In the Des Moines metropolitan area, I-80 meets up with I-35 and the two routes bypass Des Moines together. On the northern side of Des Moines, the Interstates split and I-80 continues east. In eastern Iowa, it provides access to the University of Iowa in Iowa City. Northwest of the Quad Cities in Walcott is Iowa 80, the world's largest truck stop. I-80 passes along the northern edge of Davenport and Bettendorf and leaves Iowa via the Fred Schwengel Memorial Bridge over the Mississippi River into Illinois.
Interstate 74 (I-74) is the central freeway through the Iowa Quad Cities. It roughly divides Davenport to the west and Bettendorf to the east. The Interstate Highway begins at an interchange with I-80 at the northeastern edge of Davenport and continues into Illinois at the Mississippi River by crossing the I-74 Bridge. The freeway was built in stages during the late 1960s and early 1970s.
U.S. Highway 61 (US 61) is a United States Highway that serves eastern Iowa. It enters the state from Missouri near Keokuk with US 136. North of Keokuk, it is overlapped by US 218 for a few miles. It the follows the course of the Mississippi River past Montrose and Fort Madison. It meets US 34 at Burlington. It passes through Wapello and bypasses Muscatine and Blue Grass on its way toward Davenport. There, it follows Interstate 280 (I-280) and I-80 around the Quad Cities. North of Davenport, it follows a freeway north toward DeWitt where it meets US 30. The highway continues north through Maquoketa and reaches the Dubuque area. There it is joined by US 151 and briefly by US 52. The two highways enter the downtown area on an expressway. Due to the proximity of the Mississippi River and railroad tracks that lie between, the routes have an indirect junction with US 20. The two highways leave the state and enter Wisconsin about one-half mile (800 m) north of the Illinois–Wisconsin state line.
U.S. Highway 34 (US 34) is a United States Highway that runs across the southern third of Iowa. It begins on a bridge over the Missouri River west of Glenwood and travels east where it meets Interstate 29 (I-29) and US 275. Through southwestern Iowa, the highway is, for the most part, a two-lane rural road with at-grade intersections; there are interchanges with US 59 near Emerson and US 71 near Stanton and Villisca. At Osceola, the highway intersects I-35 and US 69. Just east of Ottumwa, where the road meets US 63, the road joins the four-lane Iowa 163 for the remainder of its trek through the state. At Mount Pleasant, it overlaps US 218 and Iowa 27, the Avenue of the Saints Highway. From there, the road heads to the southeast where it crosses the Mississippi River on the Great River Bridge at Burlington.
Interstate 880 (I-880) is an auxiliary Interstate Highway in Iowa. Its route was created in 2019 from a section of I-680 in order to facilitate the movement of I-29 traffic around Council Bluffs in the event of Missouri River flooding. It follows the same routing as Interstate 80N (I-80N), which originally connected I-29 and I-80 from 1966 to 1973.
Iowa Highway 90 was a state highway in central Iowa. The highway was in service to traffic from 1932 through 1981 and took several forms over the years. It began as a spur route from Des Moines to Commerce, now part of West Des Moines. At its greatest extent, it extended from Atlantic to Newton along the historical routing of U.S. Highway 6 (US 6). From 1966 through 1981, the highway existed in its final form—from Interstate 80 (I-80) between Earlham and DeSoto to I-35 on the southern outskirts of West Des Moines.
