List of Interstate Highways in Iowa

Interstate Highways in Iowa form a network of freeways that cross the state.

Interstate Highways of the Iowa Primary Highway System
Highway markers for I-80, I-380, and I-35 Bus. Loop
System information
Formed	August 14, 1957[1]
Highway names
Interstates	Interstate X (I-X)
Business Loops:	Interstate X Business (I-X Bus.)
System links
Iowa Primary Highway System Interstate U.S. State Secondary Scenic

System map

Primary Interstates

Number	Length (mi)	Length (km)	Southern or western terminus	Northern or eastern terminus	Formed	Removed
I-29	151.826	244.340	I-29 at Hamburg	I-29 at Sioux City	1958	current
I-35	218.432	351.532	I-35 near Lamoni	I-35 near Albert Lea, Minn.	1958	current
I-74	5.386	8.668	I-80 at Davenport	I-74 / US 6 at Bettendorf	1968	current
I-80	306.268	492.891	I-80 at Council Bluffs	I-80 at LeClaire	1958	current

• Primary Interstates
• 
  I-29 crossing over the mouth of the Floyd River
• 
  I-35 approaching exit 182
• 
  Exit 68 to Iowa Highway 5 on I-35 south of West Des Moines
• 
  The Interstate 74 Bridge carrying I-74 across the Mississippi River
• 
  I-80 in western Iowa near Walnut
• 
  Traffic congestion on I‑35 / I‑80 during the Iowa flood of 2008

Auxiliary Interstates

Number	Length (mi)	Length (km)	Southern or western terminus	Northern or eastern terminus	Formed	Removed	Notes
I-80N	16.565	26.659	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	13.816	22.235	I-35 / I-80 at West Des Moines	I-35 / I-80 at Des Moines	1961	current
I-280	9.581	15.419	I-80 / US 6 at Davenport	I-280 at Rock Island, Ill.	1973	current
I-380	73.080	117.611	I-80 / U.S. Route 218 / Iowa 27 near Coralville	US 218 at Waterloo	1973	current
I-480	0.721	1.160	I-480 / US 6 at Council Bluffs	I-29 / US 6 at Council Bluffs	1966	current
I-680	3.169	5.100	I-680 at Omaha, Neb.	I-29 near Crescent	1966	current
I-880	16.565	26.659	I-29 at Loveland	I-80 near Neola	2019	current	Replaced a portion of I-680
Former

• Auxiliary Interstates
• 
  I‑235 crossing the Des Moines River in Des Moines, Iowa
• 
  The Edna M. Griffin Memorial Bridge carrying I‑235 across the Des Moines River
• 
  The I‑480 bridge over the Missouri River between Council Bluffs, Iowa and Downtown Omaha, Nebraska
• 
  I‑280 crosses the Mississippi River over the Baker Bridge.

Business routes

Number	Length (mi)	Length (km)	Southern or western terminus	Northern or eastern terminus	Cities	Formed	Removed
I-35 Business Loop	—	—	I-35 / US 30 in Ames	I-35 in Ames	Ames	—	—
I-35 Business Loop	—	—	I-35 / US 18 in Clear Lake	I-35 / US 18 / Iowa 122 in Clear Lake	Clear Lake	—	—

References

1. Official Route Numbering for the National System of Interstate and Defense Highways (Map). American Association of State Highway Officials. August 14, 1957.

External links

• The Iowa Highways Page by Jason Hancock
• Interstate Guide