Relationships amongst three functions, which may be defined in terms of the parameter alpha of the single parameter gravity model, are discussed. The functions are the entropy h (which is interpreted as a measure of the interactivity in the transportation system), the accessibility F (a generalization of Hansen's accessibility index), and C (the mean trip cost). It is shown that the derivative of h with respect to C exists and is equal to alpha, and the existence is established of a one-to-one correspondence between F and h. /Author/TRRL/

  • Corporate Authors:

    Pergamon Press, Incorporated

    Maxwell House, Fairview Park
    Elmsford, NY  United States  10523
  • Authors:
    • Erlander, S
    • STEWART, N F
  • Publication Date: 1978-8

Media Info

  • Features: References;
  • Pagination: p. 291-293
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00188278
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: ITRD, TRIS
  • Created Date: Apr 12 1979 12:00AM