SEIS Process

A Supplemental Environmental Impact Statement, or SEIS, reviews the findings of an existing Environmental Impact Statement, or EIS. An EIS is required for projects with major impacts on the natural and human environment by the National Environmental Policy Act of 1969 (NEPA).

An SEIS allows agencies and the public to consider the impacts of significant changes and/or planned improvements to a project for which the NEPA process had previously been completed.


SEIS Flow Chart 2020
  • Notice of Intent
    Notice of Intent
    The NOI published on July 7, 2017 regarding the I-94 project indicated that an SEIS was necessary because changes to the project have been proposed that may result in impacts not evaluated in the 2004 Final EIS.
  • Notice of Intent
    Draft SEIS

    The DSEIS was published in August 2019 for a 45-day review period, which ended on October 31, 2019. Comments from the public, stakeholders and agencies will be addressed in the Combined Final SEIS and Record of Decision (Combined FSEIS and ROD).

    The DSEIS addresses modifications to the previously approved 2005 design. The intent of the document is to provide full disclosure of the environmental effects of the Project to the government and to the public. The DSEIS considers how the modifications might impact a variety of resources, including air quality, historic and archaeological resources, parks, trails, plants and animals. The DSEIS also reviews the purpose and need for improvements and describes the alternatives that were considered. Analysis of the potential effects on community services, traffic through neighborhoods, noise and vibration impacts, aesthetics, effects on minority and low-income populations and the indirect effects of the project are also included.

    The proposed modifications, first presented for public comment at the November 2016 open house meetings, were developed to address changes in the city of Detroit that have occurred over the past decade. Overall, the focus of the design modifications is to:

    • Better use existing city streets as local connections instead of building new, continuous service drives adjacent to the freeway as proposed in the original plan
    • Modify local access ramps to and from I-94, M-10 and I-75
    • Add “Complete Streets” bridges to provide multi-modal access, making them user-friendly for cars, bikes and pedestrians with wider walkways/paths separated from traffic and landscaping

    The DSEIS was posted for public review and comment on September 13, 2019 and was available for a 45-day public comment period. MDOT also held public hearings on October 10, 2019 to solicit public and agency comments on the DSEIS. The deadline for comments on the DSEIS was October 31, 2019.

    After circulation of the DSEIS, and consideration of the comments received, the Federal Highway Administration (FHWA) may issue a Combined Final Supplemental Environmental Impact Statement and Record of Decision (Combined FSEIS and ROD) document, unless statutory criteria or practicability considerations preclude issuance of the combined document.

  • Notice of Intent
    Combined FSEIS and ROD and FSEIS Errata Sheet
    Comments received on the DSEIS were minor and responses to those comments are limited to factual corrections and clarifications. As such, FHWA will issue a "Combined Final Supplemental Environmental Impact Statement and Record of Decision" document with an Errata Sheet and responses to comments received during the comment period.