Development of the 8th Edition of AASHTO's A Policy on the Geometric Design of Highways and Streets (Green Book)

AASHTO’s A Policy on Geometric Design for Rural Highways (the Blue Book, first published in 1954) and A Policy on Arterial Highways in Urban Areas (the Red Book, first published in 1957) were early nationally recognized standards for geometric design. In 1984, the Blue Book and Red Book were combined to create the first edition of AASHTO’s A Policy on the Geometric Design of Highways and Streets (commonly known as the Green Book). The 1984 Green Book was organized around roadway Functional Classification (Local, Collector or Arterial) and broad Context Classification (Urban or Rural) with design criteria based primarily on motor vehicles. Subsequent Green Book editions retained this basic framework for geometric design guidance. While the basic 10 chapter framework in the Green Book has served practitioners well for new construction or new location projects, it lacks the guidance needed for today’s challenging projects where transportation professionals must balance safety, mobility, and other concerns for all modes of travel. Public works projects are more sensitive to funding than ever before and cost magnitude and cost effectiveness often play large roles in scoping projects. In some locations, especially constrained ones, designing to recommended Green Book criteria is neither feasible nor necessary and a flexible approach can produce a better performing design that is sensitive to the context, environment, and the needs of all of the users of the facility. Design decisions made must consider the effects on safety, mobility, reliability, resilience, accessibility, equity, public health, the environment, land use, and other factors and the rationale for these decisions be clear to the public. The objective of this research is to develop a draft 8th Edition Green Book (GB8) suitable for balloting through AASHTO processes.


  • English


  • Status: Active
  • Funding: $1000000
  • Contract Numbers:

    Project 07-29

  • 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:

    Deng, Zuxuan

  • Performing Organizations:

    Texas A&M Transportation Institute (TTI)

    400 Harvey Mitchell Parkway South
    Suite 300
    College Station, TX  United States  77845-4375
  • Principal Investigators:

    Potts, Ingrid

  • Start Date: 20210510
  • Expected Completion Date: 20241031
  • Actual Completion Date: 0

Subject/Index Terms

Filing Info

  • Accession Number: 01739647
  • Record Type: Research project
  • Source Agency: Transportation Research Board
  • Contract Numbers: Project 07-29
  • Files: TRB, RIP
  • Created Date: May 20 2020 6:31PM