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Journal of Public Transportation

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Transportation -- Reliability, Bus lines -- Evaluation, Bus lines -- Oregon -- Portland


The Transit Capacity and Quality of Service Manual (TCQSM) provides transit agencies with tools for measuring system performance at different levels of operation. Bus service reliability, one of the key performance measures, has become a major concern of both transit operators and users because it significantly affects user experience and service quality perceptions. The objective of this paper is to assess the existing reliability measures proposed by TCQSM and develop new ones at the bus stop level. The latter are not suggested as replacements for the existing measures; rather, they are complementary. Using empirical data from archived Bus Dispatch System (BDS) data in Portland, Oregon, a number of key characteristics of distributions of delay (schedule deviation) and headway deviation are identified. In addition, the proposed reliability measures at the stop level are capable of differentiating between the costs of being early versus late. The results of this study can be implemented in transit operations for use in improving schedules and operations strategies. Also, transit agencies can use the proposed reliability measures to evaluate and prioritize stops for operational improvement purposes.


Copyright 2013 National Center for Transit Research. Journal of Public Transportation is led by a distinguished Editorial Board and produced by CUTR. Initially, the journal is being distributed free to transportation professionals, academicians, libraries, and others.

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