Slide One


I-495 & I-270 Managed Lanes Study

Draft Environmental Impact Statement (DEIS)

Date Published July 10, 2020

MDOT SHA and FHWA concluded the extended public comment period for the I-495 & I-270 Managed Lanes Study DEIS which was open for 123 days from July 10, 2020 until 11:59 p.m., November 9, 2020.

Related extended public comment periods for the JPA for the Alteration of Any Floodplain, Waterway, Tidal or Nontidal Wetland in Maryland by the Maryland Department of the Environment (MDE) and U.S. Army Corps of Engineers (USACE) have also concluded.

Comments were accepted during the extended comment period through multiple methods including oral testimony, online comment form, email, and letter. MDOT SHA and FHWA will review and consider all comments received, perform additional analyses, as needed, and respond to substantive comments in the Study’s Final Environmental Impact Statement (FEIS).

To view mapping of the Build Alternatives analyzed in the DEIS and the environmental resources along the study corridors, review the interactive map here.


FHWA and MDOT SHA have completed the Draft Environmental Impact Statement (DEIS) and Draft Section 4(f) Evaluation for the I-495 & I-270 Managed Lanes Study, with the Notice of Availability published in the Federal Register on July 10, 2020. The DEIS includes traffic, environmental, engineering, and financial analyses of the Build Alternatives and the No Build Alternative. The DEIS comment period provided an opportunity for the public, interest groups and other agencies to review and provide comment on the proposed federal action and the adverse and beneficial environmental impacts and proposed mitigation for unavoidable impacts. Comments were also accepted on the Joint Federal/State Application (JPA) for the Alteration of Any Floodplain, Waterway, Tidal or Nontidal Wetland in Maryland. USACE is responsible for reviewing the JPA per the Clean Water Act, Section 404(b)(1) and MDE is responsible for reviewing the Application per Environment Article §5-503 and §5-906, Annotated Code of Maryland.

FHWA, MDOT SHA, and the Maryland Department of the Environment (MDE) conducted six Joint Public Hearings for the public to provide oral testimony on the DEIS and JPA. Virtual public hearings were held on August 18, 20, 25 and September 3, 2020. The U.S. Army Corps of Engineers (USACE) participated in the August 25 virtual public hearing to meet the Department of the Army requirements. Two in-person public hearings were held in Prince George’s and Montgomery counties on September 1 and 10, 2020, respectively.

Stay up to date on the I-495 & I-270 Managed Lanes Study by checking the program website and feel free to reach out to the I-495 & I-270 Managed Lanes Study team by methods found here.

View the DEIS Documents

FHWA and MDOT SHA have completed the Draft Environmental Impact Statement (DEIS) and Draft Section 4(f) Evaluation for the Managed Lanes Study, with the Notice of Availability published in the Federal Register on July 10, 2020. The Draft Environmental Impact Statement or DEIS provides a summary of the 19 technical reports and contains ten chapters.

Executive Summary also available in AmharicFrench, and Spanish.

DEIS Document by Chapter

Signature Page, Title Page, and Table of Contents

Executive Summary of the DEIS

Chapter 1 presents the Study’s Purpose and Need

Chapter 2 presents the alternatives development and analysis

Chapter 3 presents the existing and future traffic conditions and the results from the traffic operational analyses

Chapter 4 presents the existing environmental conditions (affected environment), the anticipated effects to the resources (environmental consequences), and measures to avoid, minimize, and mitigate potential environmental effects, where applicable.

Chapter 5 presents a summary of the Draft Section 4(f) Evaluation, which discusses the potential effects to significant public parks, recreational areas, and historic properties in compliance with Section 4(f) of the US Department of Transportation (USDOT) Act of 1966.

Chapter 6 presents the Executive Order 13807: Establishing Discipline and Accountability in the Environmental Review and Permitting Process for Infrastructure Projects that requires Federal agencies to process environmental reviews and authorization decisions for major infrastructure projects as “One Federal Decision.”

Chapter 7 presents a summary of the public outreach and agency coordination for the Study that has occurred, to date.

Chapter 8 presents the List of Preparers of the DEIS

Chapter 9 presents the Distribution List of agencies, organizations, and persons to whom the DEIS was made available for review and comment.

Chapter 10 presents the references for the DEIS.

DEIS Technical Reports

To review the 19 supporting DEIS Technical Reports click on the report titles below.  Note, unless otherwise listed the appendices supporting each DEIS Technical Report are include in the single file for viewing, if applicable. In cases where the files are large, they have been broken up into smaller file sizes for viewing.

APPENDIX A Purpose and Need Statement

Alternatives Technical Report

Appendix A & B: MD 200 Diversion Alternatives Analysis Results Paper and Alternative 9 Modified Preliminary Evaluation

APPENDIX C Traffic Technical Report
APPENDIX D Environmental Resource Mapping
APPENDIX E Community Effects Assessment/ Environmental Justice Technical Report
APPENDIX F Draft Section 4(f) Evaluation

Cultural Resources Technical Report (Redacted)

Volume 1:    Overview and Effects Assessment

Volume 2:    Archaeological and Historic Architectural Gap Analysis and Assessment

Volume 3 Part 1:    Architectural Resources Evaluation Technical Report 

Volume 3 Part 2

Volume 3 Part 3

Volume 4:    Phase I Archaeological Investigation

Volume 5:    Phase II Archaeological Evaluation at Sites 18PR750, 18MO749, and 18MO751 for the I-495 & I-270 Managed Lanes

Volume 6:    Phase I Archaeological Survey, Intensive Phase I Archaeological Survey of 44FX0373, and Phase II Archaeological Evaluation at Sites 44FX0374, 44FX0379, 44FX0381, 44FX0389, 44FX3160, and 44FX3900 Within the George Washington Memorial Parkway for the I-495 Northern Extension (NEXT) Project and the I-495/I-270 Managed Lanes Study, Fairfax County, Virginia

APPENDIX H Draft Section 106 Programmatic Agreement
APPENDIX I Air Quality Technical Report
APPENDIX J Noise Analysis Technical Report

Hazardous Materials Technical Report

Appendix A: Priority Table

Appendix B: 700-foot Scale Sites of Concern Maps

Appendix C: 200-foot Scale Potential Environmental Concerns Maps

Appendix D: EDR Report

Appendix E: MDE Records

Appendix F: Photo Log


Natural Resources Technical Report

Appendix A: Impact Tables

Appendix B: Natural Resources Inventory Maps

Appendix C: Soil Tables

Appendix D: Overview and Key Maps

Appendix E: Delineated Features Table

Appendix F: Delineated Features Maps

Appendix G Part 1: Field Datasheets 

Appendix G Part 2

Appendix H Part 1: Photo Documentation 

Appendix H Part 2

Appendix H Part 3

Appendix I: NPS Property Additional Information

Appendix J: Wetland Functions and Values Table

Appendix K: Aquatic Biota and Surface Water Sampling Monitoring Map

Appendix L: Wildlife Table

Appendix M: Aquatic Biota Monitoring Table

Appendix N: Agency Correspondence

Appendix O: Sampled Fish Table

Appendix P: Bridge Survey Report Northern Long Eared Bat and Indiana Bat

Appendix Q: Unique and Sensitive Areas Map

Appendix R: RTE Plant Species Survey

APPENDIX M Avoidance, Minimization & Impacts Report (AMR)
APPENDIX N Draft Compensatory Mitigation Plan
APPENDIX O Indirect and Cumulative Effects Technical Report
APPENDIX P Public Involvement & Agency Coordination Technical Report
APPENDIX Q Conceptual Mitigation Plan
APPENDIX R Joint Permit Application
APPENDIX S Environmental Assessment Form

DEIS and JPA In-Person Document Availability

Hard copies of the DEIS, supporting technical reports and the JPA were available for review in multiple locations in Montgomery and Prince George’s counties, as well as one in Fairfax, Virginia and one in Washington, D.C. from July 10, 2020 through November 9, 2020. While no longer available in-person, the DEIS and JPA will continue to be available online.