Interstate 380 (Iowa)

Interstate 380
I-380 highlighted in red
Route information
Auxiliary route of I-80
Maintained by Iowa DOT
Length	72.969 mi[1] (117.432 km)
Existed	c. September 19, 1973[2]–present
History	Under construction 1973–1985
NHS	Entire route
Major junctions
South end	I-80 / US 218 / Iowa 27 at Coralville
Major intersections	US 30 / US 151 in Cedar Rapids US 151 Bus. in Cedar Rapids US 20 / Iowa 27 in Black Hawk County
North end	US 218 in Waterloo
Location
Country	United States
State	Iowa
Counties	Johnson Linn Benton Buchanan Black Hawk
Highway system
Interstate Highway System Main Auxiliary Suffixed Business Future Iowa Primary Highway System Interstate US 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 I-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 1.5 miles (2.4 km) north of U.S. Highway 20 (US 20), I-380 runs concurrently with Iowa Highway 27 (Iowa 27), which represents Iowa's portion of the 560-mile (900 km) Avenue of the Saints highway connecting Saint Louis, Missouri, with Saint 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 south of Cedar Rapids. In the 1990s, the I-380 corridor was selected as part of the Avenue of the Saints corridor, which Iowa designated as Iowa 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.