Several studies by other researchers to determine which aspects of a bus service are regarded by users as important are discussed. These usually show that reliability is high on list of people's preferences. Although reliability can be defined in a number of ways, the index of reliability most commonly used has been that of the average waiting time of passengers. This paper takes sixteen possible indices of reliability in three, not wholly distinct, groups: those pertaining to the operator, those of relevance to the passenger, and those which do not presuppose either standpoint. Each index is discussed separately and then compared with other indices to show which ones are different expressions of the same quantity and which can be thought of as fundamental. A selection of representative indices is then used in two ways: analytically, to show how a given change in the operation of a route would be indicated by several indices; empirically, by applying the indices to sets of data to show typical values; and by seeing how various indices have been used in a number of bus studies, mostly carried out in the 1970's. As a conclusion, it is pointed out that a number of aspects of reliability may be treated by the same action on the part of the operator,but that in any assessment of this action, how much of an improvement is indicated will depend on which index is used. The essence of reliability lies in the principle well established in the bus industry, of keeping to a schedule, published or unpublished, which is usually designed to maintain even headways between buses where the service is at all frequent. /Author/

  • Corporate Authors:

    Newcastle-Upon-Tyne University, England

    Transport Operations Group
    Newcastle-Upon-Tyne, Northumberland,   England 
  • Authors:
    • Chapman, R A
  • Publication Date: 1976-3

Media Info

  • Features: Figures; References; Tables;
  • Pagination: 35 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00139312
  • Record Type: Publication
  • Report/Paper Numbers: No. 18 Work Paper
  • Files: TRIS
  • Created Date: Sep 16 1981 12:00AM