The ability of individuals to substitute modes of transportation leads to an inability to determine the demand for travel between cities. If one were able to determine those characteristics of each mode which influence the choice decision, one would then be able to arrive at more stable demand functions for each of the travel modes. With a more stable demand for travel function policy decisions could better be made concerning the allocation of public funds, to highways, airports, or rail facilities. The question of choosing between modes and the basis of choosing between modes is closely related to the stability of the demand for travel. Baumel and Quandt, Gronau, McGillivray, and Young have all attempted to derive demand equations for travel modes. However, some of the studies attempted to measure the substitutability of the characteristics influencing the demand for travel, rather each focuses on a determination of the quantity of trips undertaken of each mode between origin i and destination j as a function of characteristics. The purpose of this paper is to provide new evidence bearing on the issue of the degree of substituability of the various travel modes. We begin with a utility function rather than a priori specifying the deamnd equations. In specific we employ a multilevel separable utility function which allows the grouping of various choice characteristics of each mode into subsets or branches from which estimates of the ease of substitution among characteristics of the mode may be obtained. The characteristics which enter the branches for each mode are proxies for cost, comfort, and convenience. Since the specific function is weakly separable and nonlinear, we will obtain nonlinear demand equations for the mode characteristics. Another important advantage of using this approach is that it allows us to ascertain the preference intensity of individuals for certain mode characteristics which influence the choice of one mode over another. Moreover, the estimated budget parameters will allow us to determine the optimal combinations of characteristics to be preferred by consumers, and thus their model choice preferences.

  • Corporate Authors:

    Pergamon Press, Incorporated

    Maxwell House, Fairview Park
    Elmsford, NY  United States  10523
  • Authors:
    • KRAFT, J
    • Kraft, A
  • Publication Date: 1976-2

Media Info

  • Features: References; Tables;
  • Pagination: p. 31-35
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00134766
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Jun 23 1976 12:00AM