Interstate 380 (Iowa)

Interstate 380
Iowa's Interstate Highways with I-380 highlighted in red.
Route information
Auxiliary route of I-80
Maintained by Iowa DOT
Length:	73.080 mi (117.611 km)
Existed:	ca. September 19, 1973 – present
History:	Under construction 1973–1985
Major junctions
South end:	I-80 / US 218 / Iowa 27 near Iowa City
	US 30 in Cedar Rapids US 151 Business in Cedar Rapids US 20 in Black Hawk County
North end:	US 218 in Waterloo
Highway system
Interstate Highway System Main Auxiliary Suffixed Business Future Iowa Primary Highway System Interstate U.S. State Secondary Scenic ← Iowa 376 Iowa 404 →

Interstate 380 (I-380) is a 73-mile (117 km) auxiliary Interstate Highway in eastern Iowa. The route extends from Interstate 80 near Coralville to Waterloo. I-380 connects the cities of Cedar Rapids and Waterloo, the state's second- and sixth-largest cities, respectively, to the Interstate Highway System. Except for its last 1 ¹⁄₂ miles (2.4 km) north of U.S. Route 20 (US 20), I-380 runs concurrent with Iowa Highway 27, which represents Iowa's portion of the 560-mile (900 km) Avenue of the Saints Highway connecting St. Louis, Missouri, with St. Paul, Minnesota.

Construction of I-380 took 12 years to complete, ending in 1985. After the interstate opened, US 218 was moved onto the new freeway. In the 1990s, the I-380 corridor was selected as part of the Avenue of the Saints corridor, which Iowa designated as Iowa Highway 27 in 2001. I-380 has been affected by two major floods, the Great Flood of 1993 and the Iowa flood of 2008, both of which closed the road at the Iowa River for two weeks.

Interstate 380 begins at a cloverleaf interchange where US 218 and Iowa 27 cross Interstate 80 in Coralville in Johnson County. From the interchange, I-380, US 218, and Iowa 27, the route assigned to the Avenue of the Saints Highway in Iowa, run together towards Cedar Rapids. The interstate heads north and serves North Liberty. North of North Liberty, the freeway runs parallel to the former routing of US 218 and Iowa 965; here the two highways cross the Iowa River. After crossing into Linn County, the three routes enter the Cedar Rapids city limits near The Eastern Iowa Airport. Three miles (4.8 km) north of the airport, I-380 intersects US 30 and US 151 at a cloverstack interchange. At this interchange, US 218 splits away from I-380 and Iowa 27.