Research for AASHTO Standing Committee on Highways. Task 423. Planning for a Comprehensive Update and Restructuring of AASHTO's A Policy on Geometric Design of Highways and Streets (8th Edition)

In 2016, the AASHTO Standing Committee on Highways passed a resolution that the Green Book should provide guidance to state DOTs and other users regarding flexibility in design. The resolution (Direction on Flexibility in Design Standards) also directed the guidance to address designing for a multi-modal transportation system and that changes should be coordinated with other AASHTO publications. The resolution recognized that both short-term and long-term steps would be needed to meet the goals of the resolution. AASHTO recently published the 7th Edition of A Policy on Geometric Design of Highways and Streets (the Green Book). The basic format, structure, and design philosophy are essentially unchanged since the 1984 edition which combined AASHTO’s rural and urban design policies (the Blue Book and Red Book, respectively). It does include some major changes in the Foreword and Chapter 1 that address issues raised in the AASHTO resolution (e.g., separate design approach for new vs. existing alignment, performance-based design, new land use context zones). Some key references for these changes are NCHRP Reports 785, 839, and 855. This project developed a detailed roadmap to develop and implement the 8th Edition of the Green Book that supports a flexible, multimodal, performance-based, and context-sensitive design process. A key element of this work was to identify and engage a diverse set of stakeholders to vet the recommendations in the report, better identify the challenges that will be faced in development and implementation, explore solutions to those challenges, and build support for this radical change. These stakeholders included AASHTO committees dealing with related topics and external stakeholders, including professional societies, such as ITE, AMPO, and NACTO. .


  • English


  • Status: Completed
  • Funding: $99986
  • Contract Numbers:

    Project 20-07, Task 423

  • Sponsor Organizations:

    National Cooperative Highway Research Program

    Transportation Research Board
    500 Fifth Street, NW
    Washington, DC  United States  20001

    American Association of State Highway and Transportation Officials (AASHTO)

    444 North Capitol Street, NW
    Washington, DC  United States  20001

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Project Managers:

    Derr, B

  • Performing Organizations:

    Kittelson and Associates, Incorporated

    610 S.W. Alder Street
    Portland, OR  United States  97205
  • Principal Investigators:

    Ray, Brian

  • Start Date: 20180614
  • Expected Completion Date: 20190613
  • Actual Completion Date: 20190613

Subject/Index Terms

Filing Info

  • Accession Number: 01650689
  • Record Type: Research project
  • Source Agency: Transportation Research Board
  • Contract Numbers: Project 20-07, Task 423
  • Files: TRB, RIP
  • Created Date: Nov 13 2017 7:08PM