APPROACH TO THE EVALUATION OF CHANGES IN TRAVEL UNRELIABILITY: A "SAFETY MARGIN" HYPOTHESIS

Even where unreliability has been recognized as a significant component in the generalized cost of trip-making, few attempts have been made to quantify it in the evaluation of transport improvements. This neglect is perhaps explained by the difficulty of observing a suitable "trade-off" situation in which transport users can trade money directly or indirectly for improved reliability of their transport modes. This article investigates the characteristics of a possible trade-off which might be made by commuters-the allowance of extra time for traveling in order to avoid unpredictable lateness at destination. The form of the costs of a response to unreliability of this nature is considered within a more general framework of the allocation of time under uncertainty or risk conditions. Certain other approaches to the evaluation of travel unreliability are reviewed and a brief outline is given to a current research project which attempts to test the applicability of the "safety margin" in London commuters' timing of the trips that they take to work.

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/00494488
• Corporate Authors:

  Elsevier

  Radarweg 29
  Amsterdam,   Netherlands  1043 NX
• Authors:
  • Knight, T
• Publication Date: 1974-12

Media Info

• Features: References;
• Pagination: p. 393-408
• Serial:
  • Transportation (Netherlands)
  • Volume: 3
  • Issue Number: 4
  • Publisher: Martinus Nijhoff Publishers
  • ISSN: 0049-4488

Subject/Index Terms

• TRT Terms: Alternatives analysis; Commuter service; Commuters; Hazards; Mode choice; Passenger service; Quality of service; Reliability; Risk assessment; Travel budgets; Travel costs; Travel demand; Travel time; Uncertainty; Work trips
• Uncontrolled Terms: Passenger demand
• Subject Areas: Highways; Operations and Traffic Management; Passenger Transportation; Railroads; Safety and Human Factors; Society;

Filing Info

• Accession Number: 00095251
• Record Type: Publication
• Source Agency: Engineering Index
• Files: TRIS
• Created Date: Jul 15 1975 12:00AM