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 Timeline:

Spring 2024 - Overall Completion Date: June 2026

Minor clean-up work to be completed in 2026

Project Updates:

July 18, 2025:

June 15, 2025 – July 15, 2025, Completed Work: Westbound off-ramp and eastbound on-ramp pavement has been completed and reopened to traffic. Girders have been set on phase two of the exit structure. Most of subgrade gravel has been completed and more eastbound mainline pavement has been completed. Bottom footings at the railroad structure are completed. Various lighting and signal base have been completed.

Anticipated work July 15, 2025 – Aug. 15, 2025: Columns and abutments at the railroad structure are anticipated to be complete along with grading and block wall. The bridge deck on the exit structure should be poured. Eastbound off ramp will be switched for continued work on storm sewer crossings and eastbound pavement will continue to be placed. Removal of existing median crossover and grading on median east of the exit is expected to be complete. Topsoiling of east ramps is also expected to be finished. On SD Hwy 11 traffic islands will begin to take shape and more lighting and signage will be placed.

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July 1, 2025:

Interstate 90 Overnight Lane Closures and Traffic Diversions Planned at Brandon

BRANDON, S.D. – Beginning at 7 p.m. on Wednesday, July 9, 2025, eastbound and westbound lanes of Interstate 90 will be temporarily closed to divert traffic through the on- and off-ramps at exit 406 (Brandon). This traffic diversion will be maintained through the overnight until 7 a.m. on Thursday, July 10, 2025. This traffic pattern switch is being scheduled to set forms for bridge decking.

A second night of lane closures and traffic diversions on I-90 at exit 406 (Brandon) is also possible from 7 p.m. on Thursday, July 10, 2025, through the overnight until 7 a.m. on Friday, July 11, 2025. This second night of the scheduled traffic diversion is to install components to build the bridge deck.

Traffic on S.D. Highway 11 will be maintained during these overnight traffic diversions. Flaggers will be posted to guide Highway 11 traffic as Interstate traffic will not be stopped.

Dates for the traffic diversions are weather dependent and may be rescheduled as needed.