The author presents his personal views on a reply by Goodwin to his critique of generalised cost published in an earlier copy of this journal. In this reply Goodwin had stressed that it would be quite wrong to obscure the weaknesses in current practice, and pointed out drawbacks in the regional highway traffic model that the Department of Transport now seems to favour. Criticisms put forward by Goodwin are discussed by clarification of certain issues related to demand elasticities and the stringent conditions that are required for consistent aggregation. It is suggested that Goodwin is wrong to imply that the only alternative to the confused generalised cost evaluation procedure is through "some sort of points system", and the weaknesses of such systems are indicated. The author considers that, as indicated in his original paper, it is particularly important that research and advice within the Department of Transport should cover the relatively unexplored area, as far as transport planning is concerned, of error and uncertainty in the decision-making process. It is considered essential to modify current British practice so as to eliminate as many as possible of its deficiencies: including the misuse of elasticity measures, the inaccuracies that result from the use of exogenous generalised cost weights, and the confusions that result from the way in which measuring units are used in prediction and evaluation. /TRRL/

  • Availability:
  • Corporate Authors:

    Elsevier Publishing Company, Incorporated

    52 Vanderbilt Avenue
    New York, NY  United States  10017
  • Authors:
    • Grey, A
  • Publication Date: 1978-12

Media Info

  • Features: References;
  • Pagination: p. 417-422
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00195191
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Files: ITRD, TRIS
  • Created Date: Aug 28 1979 12:00AM