Intrazonal or Interzonal? Improving Intrazonal Travel Forecast in a Four-Step Travel Demand Model

Conventional four-step travel demand models, used by virtually all metropolitan planning organizations (MPOs), state departments of transportation, and local planning agencies, are the basis for long-range transportation planning in the United States. Trip distribution – whether the trip is intrazonal (internal) or interzonal (external) – is one of the essential steps in travel demand forecasting. However, the current intrazonal forecasts based on a gravity model involve flawed assumptions, primarily due to a lack of consideration of differences in land use and street network patterns. In this study, the authors first survey 25 MPOs about how they model intrazonal travel and find the state of the practice to be dominated by the gravity model. Using travel data from 31 diverse regions in the U.S., the authors then develop an approach to enhance the conventional model by including more built environment D variables and by using multilevel logistic regression. The models’ predictive capability is confirmed using k-fold cross-validation. The study results provide practical implications for state and local planning and transportation agencies with better accuracy and generalizability.

  • Supplemental Notes:
    • This paper was sponsored by TRB committee ADB40 Standing Committee on Transportation Demand Forecasting.
  • Corporate Authors:

    Transportation Research Board

  • Authors:
  • Conference:
  • Date: 2019


  • English

Media Info

  • Media Type: Digital/other
  • Features: Figures; References; Tables;
  • Pagination: 20p

Subject/Index Terms

Filing Info

  • Accession Number: 01697408
  • Record Type: Publication
  • Report/Paper Numbers: 19-00127
  • Files: TRIS, TRB, ATRI
  • Created Date: Dec 7 2018 9:26AM