Interstate 90 - Exit 406 (Brandon)
Project Summary:
This project includes the reconstruction of exit 406 (Brandon) with added lighting, signals, and mainline Interstate work. This project also includes three structure replacements.
The interchange will be reconstructed as a diverging diamond configuration.
Westbound Interstate 90 lanes (along with the railroad structure on I90) will be reconstructed in 2024 and the eastbound lanes (and railroad structure in 2025). The interchange itself and new structure over I90 will be reconstructed between 2024 and 2025.
S.D. Highway 11 traffic will be maintained across Interstate 90 during construction.
The westbound on-ramp and eastbound off-ramp are expected to be open to traffic for the majority of the project. Closures for the westbound off-ramp and eastbound on-ramp are planned for 2025.
Work will extend on S.D. Highway 11 down to Redwood Boulevard. That work includes adding a shared use path on the west side, approach and side street work, a retaining wall on the east side north of Ash St, and other items.
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Project Updates:
April 20, 2026:
Anticipated Work May 2026:
Rolling closures will occur on Interstate 90 to grind rumble strips on the shoulders of both eastbound and westbound lanes.
Minor traffic diversions are also anticipated on S.D. Highway 11 and at the Interstate 90 exit to accommodate extended utility work on the south end of the exit bridge and at the intersection of Redwood Boulevard and S.D. Highway 11 for signal updates.
Additional lane closures on Interstate 90 may occur for power line relocation by Xcel Energy and for final grading at the railroad structures. Some of this work may extend into June.
April 2026 Completed Work:
Pavement markings were completed throughout the project.
Navigating a DDI:
Sample video of how to drive a DDI (sample provided demonstrates the DDI located at 41st Street in Sioux Falls which features three lanes). I-29 41st St DDI Animation - YouTube
Drivers follow the signs, signals and pavement markings to cross through the intersection at the first set of traffic lights. Traffic appears as if on a one-way street.
All left turns onto the freeway are free flow, meaning vehicles do not have to stop to access the ramp.
Vehicles going straight simply proceed through a second set of traffic lights.
Pedestrians travel on designated walkways and cross only at the crosswalks.
Bicyclists may choose to use the bike lane or pedestrian walkways and crosswalks.