Design

Geometric Design

Title 23 USC 109 provides that design standards for projects on the National Highway System (NHS) must be approved by the Secretary of the U.S. Department of Transportation in cooperation with the State highway departments. The Secretary has delegated this authority to the Federal Highway Administrator.

The State highway departments, working through the American Association of State Highway and Transportation Officials (AASHTO) develop design standards through a series of committees and task forces. FHWA contributes to the development of the design standards through membership on these working units, sponsoring and participating in research efforts, and many other initiatives. Following development of the design standards, FHWA uses a formal rulemaking process to adopt those it considers suitable for application on the NHS.

Regulations

• Design Standards for Highways Final Rule (01/03/2022)

Policy

• Federal Register Notice: Revision of Thirteen Controlling Criteria for Design and Documentation of Design Exceptions (05/05/2016)
• Memo: Revisions to the Controlling Criteria for Design and Documentation for Design Exceptions (05/05/2016)
• FHWA Policy on Permissible Project Related Activities During the NEPA Process (Order 6640.1A) (10/01/2010)

Guidance

• Design Decision Documentation and Mitigation Strategies for Design Exceptions (March 2024)
• Design Standards, FAST Act and Infrastructure Investment and Jobs Act (IIJA) Provisions Memo (11/16/2023)
  Questions and Answers - Section 1404 of the FAST Act, Section 11129 of the IIJA (06/10/2024)
• Review of State Geometric Design Procedures or Design Criteria for Resurfacing, Restoration, and Rehabilitation Projects on the NHS (March 1, 2023)
• Level of Service on the National Highway System (05/06/2016)
• Supplement to the 2013 DOJ/DOT Joint Technical Assistance on the Title II of the Americans with Disabilities Act Requirements To Provide Curb Ramps when Streets, Roads, or Highways are Altered through Resurfacing (December 1, 2015)
• Relationship between Design Speed and Posted Speed (10/07/2015)
• Department of Justice/Transportation Joint Technical Assistance on the Title II of the Americans with Disabilities Act Requirements to Provide Curb Ramps when Streets Roads or Highways are Altered through Resurfacing Guidance (June, 2013)
• Coordination of Vertical Clearance Design Exceptions on the Interstate System (04/15/2009)
• Americans with Disabilities Act (ADA) Accessibility Guidelines and Detectable Warnings (07/30/2004)
• Guidelines for Preparation of Plans, Specifications, and Estimates (FAPG Non-Regulatory Guidance 23 CFR 630B) (12/09/1991)
• Guidance on NHS Design Standards and Design Exceptions
• Transportation Enhancement Activities - Guidance
• AASHTO Roadside Design Guide 4th Edition (06/26/2012) The purpose of this memo is three-fold: reiterate the status of the RDG for FHWA, summarize significant changes in the RDG 4th edition, and add Frequently Asked Questions to our website.

Information

• RRR (freeways) and 2018 Green Book (1/3/2022)
• 2018 Green Book (05/10/2019) (Archived)
• 2016 Interstate Standards (11/06/2018)
• Evolving Geometric Design Decision-Making in the United States (June, 2015)
• Illinois DOT Guidelines for Reducing Wrong-Way Crashes on (May, 2014)
• NTSB Highway Accident Reports (08/01/2007)
• ADAAG Detectable Warnings (05/06/2002)
• Research and Guidance Report: Designing Sidewalks and Trails for Access, Part II, Best Practices Design Guide (11/20/2001)
• Clear Zone and Horizontal Clearance Frequently Asked Questions
• FHWA Safety resources on wrong-way crashes
• Pedestrians and Accessible Design
• Safety Office information related to Geometric Design
• Meeting Performance Priorities in the U.S. Through Geometric Design (US Country Report; June, 2020) (12/26/2019)

Webinars

• Webinar Slides showing changes to 23 CFR Part 625 (1/20/2022)
• Webinar on Revisions to Controlling Criteria for Design (05/16/2016)

Archive

• Design Standards and Section 1404 of the FAST Act (10/06/2016) (Superseded)
• 2011 Green Book (11/12/2015)
• Mitigation Strategies for Design Exceptions (05/01/2014)
• A Policy on Design Standards - Interstate System, January 2005 (05/08/2006)
• Information on Application of Design Standards, Uniform Federal Accessibility Standards, and Bridges (23 CFR 625 Non-regulatory supplement) (03/01/2005)
• Design Standards for Projects on the National Highway System (2004 Green Book) (02/23/2005)
• AASHTO - A Policy on Geometric Design of Highways and Streets (2004 Greenbook) (2004)
• New Design Standards for Projects on the National Highway System (2001 Green Book) (02/15/2002)
• Operational Analysis of Access Points to the Interstate System (08/21/2001)
• The 2001 Green Book Changes - Additions
• Developing Geometric Design Criteria and Processes for Nonfreeway RRR Projects (T 5040.28) (10/17/1988)
• Implementation of New AASHTO Green Book (05/13/1986)

Projects off the NHS

Title 23 USC 109 provides that projects (other than highway projects on the NHS) shall be designed, constructed, operated, and maintained in accordance with State laws, regulations, directives, safety standards, design standards, and construction standards.