I-229 Exits 3 & 4, Sioux Falls, SD

a flyover of a worksite for Infrastructure Design Group Inc

The South Dakota Department of Transportation (SDDOT) & the City of Sioux Falls are working together to complete the planning, design, and construction of the Exit 3 interchange, along with portions of corresponding Minnesota Avenue.

InfrastructureDG, SEH, Inc., & Confluence are teamed together on the planning & design phases of the project.  This project includes a new single point urban interchange, including new ramps, reconstructed mainline I-229, two new bridges, improvements to Minnesota Avenue, & adjacent businesses, pedestrian tunnels, and realignment of a segment of the Sioux Falls Recreational Trail.  The scope of this project includes river hydraulic analysis for Exit 3.  It also includes analysis and design of compensatory storage for any fill placed within the floodplain.  The project involves preparation of IMJRs, NEPA documentation, topographic surveys, and subsurface utility engineering & exploration. The study phase of the project looked at different interchange design alternatives for the interchange as well as improvements to Minnesota Avenue from the Big Sioux River north to 37th Street.

Working closely with the SDDOT & the City of Sioux Falls, the team works through the challenges of preliminary & final design while maintaining the overall project schedule.  This coordination is vital as the successful completion of Exit 3 includes design elements that must work together.  This coordination is currently happening with our team designing traffic control for the Exit 4 interchange while considering traffic control for Exit 3 to provide for reusing Exit 4’s temporary bridge on the Exit 3 project. Project scope elements include full topographical & boundary survey of the entire project area, horizontal & vertical geometrics, sanitary sewer & watermain relocations, storm drainage, traffic signals, lighting, pavement markings, traffic control, landscaping design, private utility coordination, public involvement, and coordination with other design professionals.