Business Spur I-90 - Sioux Falls

bs-090-sd-115-s-after-34th-st-n — This assembly for Business Spur I-90/SD 115 south was located on Cliff Avenue southbound by St. Michaels Cemetery. The business route was relocated from Cliff Avenue south of Benson Road, and North Drive west to Minnesota Avenue in the early 2000s. The change took place when Cliff Avenue was widened and realigned south of 34th Street North. Photo by Ed Wilson (08/00).

Uniquely signed as “Downtown Spur” I-90, the Sioux Falls business spur extends south from Exit 399 to the city center along a 5.1 mile course. Cosigned with South Dakota 115, the route utilizes portions of old U.S. 77 along a route using Cliff Avenue, Benson Road and Minnesota Avenue. Business Spur I-90 south ends at the one-way couplet of 10th Street and 11th Streets in Downtown Sioux Falls, where Business Spur I-29 ends from the west and Business Loop I-229 makes a 90 degree turn from Minnesota Avenue (SD 115) onto the couplet of 10th & 11th Streets. The northbound direction of the business spur is generally signed with trailblazers for Interstate 90 in lieu of business route markers.

According to Brad Schwartze, in 2006 SD 42 and SD 115, along with the cosigned Business Loops/Spurs for I-29, I-90 and I-229, within the city of Sioux Falls were turned over to the municipality for maintenance. South Dakota DOT’s Transportation Inventory Management group indicated that these actions occurred so that the city could overtake traffic management along the respective routes. The state and business spur designations remained signed, although with less attention under city maintenance.

The old alignment of U.S. 77 through Sioux Falls took Minnesota Avenue (SD 115) to North Drive, which it followed northeast to Cliff Avenue. This changed when the eastern most section of North Drive permanently closed, severing the connection with Cliff Avenue.

Updated August 1, 2026