(I-229) in South Dakota
runs just more than ten miles (16 km) mostly within the city limits of Sioux Falls
, the largest city in the state. It runs from Interstate 29 (in southwest Sioux Falls) to Interstate 90
(in northeast Sioux Falls). In between, the interstate travels through parts of southern and eastern Sioux Falls.
Since its initial construction, I-229 had the distinction of being the only interstate in the country that transitioned directly from a four-lane concrete road to a two-lane gravel road. That ended in 2006 with the paving of 476th Avenue, the northern tip of I-229 continuing beyond the interchange with I-90.
Legally, the route of I-229 is defined at South Dakota Codified Laws § 31-4-210.
I-229 currently has a partially complete cloverleaf at its northern terminus. SDDOT
wants to improve this interchange to provide all movements, or at least improve its overall flow with Interstate 90. The discussion is merely on improving the interchange and not about extending the highway further north.
The entire route is in Sioux Falls