IMPLICATIONS OF RECENT RESEARCH INTO VALUES OF TIME FOR THE CLASSICAL TRANSPORT MODEL, FORECAST AND APPRAISAL

A series of results of VOT experiments has been reported in recent years, all tending to reinforce the findings that VOTs: (1) depend on the size and sign of the time change offered; (2) depend on journey length; and (3) are related to income, but do not grow directly in proportion to income. These experiments have all used similar approaches (SP data), but have at least been confirmed to give results which are stable over time and between countries. Many aspects of traditional transport planning, both forecasting and appraisal, are brought into question if we accept the results at face value. Of particular damage to road planning in recent years is the suggestion that the public shows indifference to time savings less than two or three minutes in scale. Implicitly, the use of (simple) Generalised Cost in forecasting mode, destination and route choice is questioned, as is the conventional approach to appraisal. Defendants of the status-quo have questioned the experimental method itself, its particular method of application in the studies reported, and the very question of whether the VOT measure coming from the experiments (even if correctly applied) are to be equated with the VOT appearing within the Generalised Cost measure. The paper summarises the position, including the evidence and the various points of view that have been expressed by those who have contributed to the debate. The authors conclude with a list of outstanding questions, relating to: (a) the specific issue of the usefulness of the Generalised Cost concept; (b) the directions in which current practice might now move; and (c) the speed and sequence of any movements that might be foreseen. For the covering abstract see ITRD E105584.

Language

  • English

Media Info

  • Features: References;
  • Pagination: p. 209-24
  • Serial:
    • Volume: P434

Subject/Index Terms

Filing Info

  • Accession Number: 00796498
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • ISBN: 0-86050-325-9
  • Files: ITRD
  • Created Date: Aug 2 2000 12:00AM