It is acknowledged that COBA is not appropriate for the evaluation of strategic or urban highway schemes involving redistribution or complex re-routeing due to capacity limitations. This paper outlines the development of the main features of surpass which uses, as far as possible, the methodology adopted in COBA to evaluate the cost implications of the different levels of flow. The authors establish a relationship between user benefits and traffic flow levels. The results from surpass are compared with those of more simplistic approaches: these include the calculation of benefits for a single year and extension using growth factors, calculation of benefits for two separate years and interpolation, plotting a graph of annual benefits against time from a series of calculations. It was found that the estimation of benefits by surpass was more accurate than by any other method outlined. The surpass technique produces a robust estimate of net present value for a scheme using the consumer surplus formulation, but requiring the minimum number of full model runs. (TRRL)

  • Availability:
  • Corporate Authors:

    Printerhall Limited

    29 Newmart Street
    London W1P 3PE,   England 
  • Authors:
    • Wyley, W J
    • GOODWIN, R P
  • Publication Date: 1980-2

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Filing Info

  • Accession Number: 00323125
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Files: ITRD, TRIS
  • Created Date: May 21 1981 12:00AM