ESTIMATING FUTURE COSTS OF OPERATING BUSES

The National Bus Company's system of bus route costing lays down a set of accounting conventions designed to bring order and logic to what would otherwise be diverse costing procedures. It provides a practical method of accounting for past costs and apportioning them to individual routes. It thereby puts on to a uniform footing all cost comparisons between routes that may be necessary for evaluating performance and substantiating claims for subsidy. However, the system is fundamentally retrospective in its application. Serious doubt must therefore be cast on any claim that it is a method of forecasting future costs. Such forecasts may be valid if all that is involved is financial indexation, as might be used for example to predict cost increases resulting from general inflation. But far more often, and more usefully, forecasts are needed that involve operational changes in the bus service. The NBC system is not appropriate for this kind of forecast because it contains no predictive relationships between operational variables and costs. To fill this gap, LOGORU has developed a model that enables bus operators to calculate the effect on costs of forecast small-scale changes in either financial variables (for example an increase in labour costs relative to capital), or operational variables (for example in the ratio of peak to off-peak buses), or both together. This model, which has been formulated in a computer program, TPTCOSTS, is the subject of this report. Some of the details of the inputs and outputs of the computer program are given in the appendices. For consistency, TPTCOSTS preserves as far as possible the conventions of the NBC costing system. However, it also incorporates some options that permit alternative assumptions to be made about the allocation of cost headings to cost categories, and that enable the cost changes likely to result from policy changes to be readily assessed. The program can also be used in conjunction with the LOGORU public transport analysis suite of computer programs, TRANSEPT, thus providing a powerful aid to the practical planning of bus services.(a) /TRRL/

  • Corporate Authors:

    Local Government Operational Research Unit

    201 King's Road
    Reading, Berkshire,   England 
  • Authors:
    • DALY, A J
  • Publication Date: 1976

Media Info

  • Features: Figures; References; Tables;
  • Pagination: 15 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00157382
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Report/Paper Numbers: Report No. T60 Monograph
  • Files: ITRD, TRIS
  • Created Date: Oct 13 1981 12:00AM