I-90 Exit 406 Interchange Modification Study and Environmental Assessment

Public Comment Summaries

Public Information Meeting #2 Materials

January 23, 2017

Initial Concept Figures

In response to feedback received at the first public meeting and further study, the study team developed an initial range of I-90 Exit 406 interchange (11 concept figures) and SD 11/Splitrock Boulevard corridor (4 concept figures) alternatives.  Each concept is noted as being carried forward or eliminated from contention by the study advisory team prior to developing the Build Alternative figures.

Build Alternative Figures

The following figures depict those concepts that were carried forward by the study advisory team for further design refinement and analysis, referred to as the Build Alternatives.  The Study Advisory Team is seeking your feedback on the following Build Alternatives for any additional refinement and to aid in further screening of Build Alternatives towards the identification of proposed improvements.

Interchange Build Alternatives

  • Standard Diamond
  • Standard Diamond (shifted west)
  • Standard Diamond with Roundabouts (shifted west)
  • Diverging Diamond Interchange
  • Interchange Summary

SD 11/Splitrock Blvd Build Corridors

  • South of I-90
    • 5-Lane Undivided
    • 4-Lane Divided
    • Backage Road Sub-Alternatives
  • North of I-90
    • Retain Existing with Potential Improvements at Hemlock Blvd Intersection
    • Hemlock Blvd Intersection Sub-Alternatives
  • Corridor Summary

Other Misc. Meeting Display Boards

  • Schedule
  • Predictive Crash Analysis
  • Environmental Resources
  • Contact Information

Project Overview

The South Dakota Department of Transportation (SDDOT), City of Brandon, Sioux Falls Metropolitan Planning Organization (MPO), and Federal Highway Administration (FHWA), have identified a need to revisit and further study the originally proposed alternatives and other potential improvements to the 1-90 Exit 406 interchange. The study includes an Interchange Modification Justification Report (IMJR) and associated environmental investigation.

Study Overview

Public Information Meeting #1


Steve Gramm
SDDOT Project Manager

Jon Wiegand
Consultant Project Manager

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