03/12/2026 | Press release | Distributed by Public on 03/12/2026 12:59
For Immediate Release:
Thursday, March 12, 2026
Contact:
Steve Neumeister, Project Engineer, 605-367-5680
SIOUX FALLS, S.D. - On Monday, March 16, 2026, a season-long lane closure will be installed in the southbound lanes of Interstate 229 at mile marker 0. This lane closure will be placed south of the Interstate 29 northbound on-ramp. The two lanes of I-229 southbound traffic will be reduced to a single lane. This lane closure will remain in place through September 2026.
The lane closure is being placed as part of the I-29 and 85th Street interchange construction project. The intersection project includes construction of a Diverging Diamond Interchange (DDI), structure development work, grading, concrete surfacing, curb and gutter, storm sewer, lighting, signals, permanent signing, and pavement marking.
Traffic control measures will be in place to help guide motorists through the work zone. Motorists are reminded to use caution and reduce their speed while workers and equipment are present.
Business access will be maintained at 85thStreet and Sundowner Avenue and Tall Grass Avenue.
Public Information Meeting:
SDDOT and City of Sioux Falls project staff are holding a public information meeting on Thursday, March 19, 2026, at 5 p.m. at Sioux Falls Lutheran School, located at 6715 S. Boe Ln. The meeting will be informal, with one-on-one discussion with SDDOT and City of Sioux Falls staff, along with displays to discuss the proposed construction project and answer questions.
Featured Project Information:
Find additional information about this project on the SDDOT website at https://dot.sd.gov/85thstreetddi.
Sign Up for Text Notifications:
For updates on MAJOR traffic changes, subscribe to a free text-in service. To subscribe, simply text 85thStreetDDIto 605-566-4041. Subscribers can unsubscribe at any time.
The prime contractor for this $54 million project is T&R Contracting of Sioux Falls, SD. The overall project completion date is November 2027.
About SDDOT:
The mission of the South Dakota Department of Transportation is to provide a safe and efficient public transportation system.
For the latest on road and weather conditions, road closures, construction work zones, commercial vehicle restrictions, and traffic incidents, please visit https://sd511.orgor dial 511.
Read more about the innovative work of the SDDOT at https://dot.sd.gov.
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