US 51 (Stoughton Road) North Study – Environmental information

Final Environmental Assessment (EA) and Finding of No Significant Impact (FONSI) | What is the National Environmental Policy Act (NEPA) | What is an environmental assessment?

Final Environmental Assessment (EA) and Finding of No Significant Impact (FONSI)

The Federal Highway Administration and the Wisconsin Department of Transportation signed the EA/FONSI for the US 51 (Stoughton Road) North Corridor Study on July 21, 2025.

The EA/FONSI selects the preferred alternative for the corridor, presents the basis for that decision and provides information on mitigation measures that will be taken to offset impacts. The EA/FONSI is the final environmental approval needed before proceeding to final design and construction. Modifications to the project design as well as new and updated project information are included in the EA/FONSI. It also reports the results of the March 2025 public hearing. Changes to the original EA, signed prior to the public hearing, are highlighted yellow.

Main Sections

• Section 1 - Environmental Document Availability and Hearing Summary
  
• Section 2 - EA Template
  
• Section 3 - Factor sheets
  
• Section 4 - Maps

Appendices

• Appendix A - Process Initiation letter
  
• Appendix B - Transportation Improvement Program documents
• Appendix C - Purpose and need report
• Appendix D - Alternatives screening technical report
• Appendix E - Proposed corridor typical sections
• Appendix F - [Revoked]
  
• Appendix G - [Revoked]
  
• Appendix H - Public surveys
  
• Appendix I - Public involvement documentation
• Appendix J - City of Madison coordination
• Appendix K - Bicycle and pedestrian workshop documentation
• Appendix L - Dane County Regional Airport coordination
• Appendix M - Agency coordination
• Appendix N - Conceptual relocation plan
  
• Appendix O - Runway protection zone analysis memo
  
• Appendix P - Temporary occupancy letter
• Appendix Q - [Revoked]
  

The original EA for the US 51 North study was signed by FHWA and WisDOT on December 9, 2024. The original published version can be found here.

WisDOT works to balance the department’s transportation responsibilities with environmental impacts, avoiding and minimizing such impacts when possible. When avoidance or minimization is not possible, the department works to mitigate environmental impacts where appropriate. Click the following link to learn more about WisDOT’s environmental processes: wisconsindot.gov/Pages/doing-bus/eng-consultants/cnslt-rsrces/environment/default.aspx

What is the National Environmental Policy Act (NEPA)?

Signed into law on Jan. 1, 1970, NEPA requires federal agencies to assess the environmental effects of their proposed actions prior to making decisions. The range of actions NEPA covers is broad and includes constructing highways and other publicly owned facilities. Agencies use the NEPA process to evaluate the environmental and related social and economic effects of their proposed actions, and they provide opportunities for public review and comment on those evaluations.

What is the environmental assessment?

An environmental assessment determines whether a federal action has the potential to cause significant effects on the environment. Generally, an environmental assessment includes a brief discussion of:

• The purpose and need for the proposed action
• A range of improvement alternatives
• The environmental impacts of the proposed action and alternatives
• A listing of agencies and persons consulted

Based on the environmental assessment, the following actions can occur:

• If FHWA determines that the action will not have significant environmental impacts, the agency will issue a Finding of No Significant Impact (FONSI). A FONSI is a document that presents the reasons why an agency has concluded that no significant environmental impacts are projected to occur upon implementation of the action.
• If the FHWA determines that the environmental impacts of a proposed federal action will be significant, WisDOT will prepare an environmental impact statement.