The main sources of error throughout the mathematical modelling process are identified and the accuracy of output from each stage is evaluated using a combination of theoretical and empirical approaches. Errors in forecasting input parameters and the use of calibration adjustments are both considered briefly. The significance of the accuracy of various outputs is discussed in detail. It is concluded that output is inadequate for most design purposes and that evaluative techniques are so sensitive to small modelling errors that little reliability can be attached to even comparative studies. Because modelling results create an illusion of accuracy and objectivity, they are frequently used to justify proposals in whose formulation modelling has played little part. Arguments are advanced for the more discriminating use of modelling in transport studies and for more emphasis on data collection as a direct aid to decision-making. /TRRL/

  • Availability:
  • Corporate Authors:

    Printerhall Limited

    29 Newmart Street
    London W1P 3PE,   England 
  • Authors:
    • Robbins, J
  • Publication Date: 1978-1

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00177203
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Report/Paper Numbers: HS-022 745
  • Files: ITRD, TRIS
  • Created Date: Jul 19 1978 12:00AM