CONFIDENCE INTERVALS AND THE SOCIAL VALUE OF TRAVEL TIME SAVINGS

This paper builds on the main results of a three year research project whose aim was to recommend social values of time to the Chilean government. Since the publication of the British value of time study a whole new information was generated on the subject both in Chile and elsewhere and this was reviewed in depth during the project. The paper has two general objectives: first, to introduce a practical form to define confidence intervals on SVT's estimated from discrete choice models, taking into account its random nature; this could allow in turn for better sensitivity testing of projects where travel time savings take undue importance. Second, to present a practical approach for the definition of VT's in the presence of large variations in the SVT's and its associated confidence intervals, as was found in our research. The rest of the paper is organised as follows. In section 2, some analytical aspects of the SVT confidence interval construction method are discussed. In section 3, the information used is described and a new methodology presented to define consistent VT's for urban, interurban and air trips. Finally, in section 4 some comments are made about the recommended values and its relation with the experimental data. (A) For the covering abstract see IRRD 880168.

Language

  • English

Media Info

  • Features: References;
  • Pagination: p. 119-30

Subject/Index Terms

Filing Info

  • Accession Number: 00724202
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • ISBN: 0-86050-283-X
  • Files: ITRD
  • Created Date: Aug 19 1996 12:00AM