Interstate 129

Interstate 129 marker
Interstate 129
Map
I-129 highlighted in red
Route information
Auxiliary route of I-29
Length3.50 mi[1][2] (5.63 km)
Nebraska: 3.21 mi (5.17 km)
Iowa: 0.286 mi (460 m)
ExistedNovember 22, 1976[3]–present
NHSEntire route
Major junctions
West end US 20 in South Sioux City, Nebraska
Major intersections US 75 / US 77 in South Sioux City, Nebraska
East end I-29 / US 20 / US 75 in Sioux City, Iowa
Location
CountryUnited States
States
Counties
Highway system
N-128NE N-133
Iowa 128IA Iowa 130

Interstate 129 (I-129) is an auxiliary Interstate Highway which connects South Sioux City, Nebraska, to I-29 in Sioux City, Iowa. Opened in 1976, I-129 is a 3.5-mile-long (5.6 km) route, running 3.21 miles (5.17 km) in Nebraska. At 0.286 miles (0.460 km), I-129 is the shortest highway in the state of Iowa. All of the route's length is concurrent with U.S. Route 20 (US 20) and most of its length is concurrent with US 75.

  1. ^ "Nebraska Highway Reference Log Book" (PDF). Nebraska Department of Roads. 2015. p. 270. Archived from the original (PDF) on January 2, 2017. Retrieved January 8, 2017.
  2. ^ "Road Network (Portal)" (ESRI shapefile). Ames: Iowa Department of Transportation. April 9, 2021. Retrieved April 18, 2021.
  3. ^ Iowa Department of Transportation. The National System of Interstate Defense Highways: 1956–1996.