Identification of AASHTO Context Classifications

NCHRP Research Report 855: An Expanded Functional Classification System for Highways and Streets served as a key reference informing the seventh edition of AASHTO’s A Policy on Geometric Design of Highways and Streets (Green Book). The new Green Book introduces a change in guidance for state transportation officials by introducing a broader set of land use context classifications (i.e., rural, rural town, suburban, urban, and urban core). These context classifications provide a mechanism for better targeting design solutions to specific contexts while providing needed flexibility to address planning and design needs. The AASHTO Committee on Design has begun planning for the eighth edition of the Green Book and envisions a major restructuring. This includes organizing design guidance by the context classifications listed in the seventh edition with the addition of a context classification, "Industrial, Warehouse, or Port Roads." NCHRP Project 15-77, "Aligning Geometric Design with Roadway Context" will be drafting these chapters. Many state, regional, and local transportation and planning agencies are interested in applying the new context classifications in their jurisdictions. The existing research and guidance, however, does not point to specific methodologies or parameters for implementing these context classifications. Research was needed to help agencies proceed efficiently and consistently.  The objective of this research was to develop practical guidance to assist state, regional, and local planners in identifying the appropriate context classification(s) for an area or a transportation project. Critical questions were (1) what are the context(s), (2) how will those context(s) change (spatially and temporally), and (3) what are the implications for the various travel modes.


  • English


  • Status: Completed
  • Contract Numbers:

    Project 15-72

  • 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:

    McKenney, Christopher

  • Performing Organizations:

    University of Kentucky, Lexington

    Lexington, KY  United States  40506-0281
  • Principal Investigators:

    Stamatiadis, Nikiforos

  • Start Date: 20200814
  • Expected Completion Date: 20220318
  • Actual Completion Date: 20220318

Subject/Index Terms

Filing Info

  • Accession Number: 01707637
  • Record Type: Research project
  • Source Agency: Transportation Research Board
  • Contract Numbers: Project 15-72
  • Files: TRB, RIP
  • Created Date: Jun 6 2019 8:00PM