Impact of Detector Configuration on Performance Measurement and Signal Operations

In recent years, automated traffic signal performance measures (ATSPMs) have emerged as a means of developing situational awareness of traffic conditions at intersections and assessing the quality of signal operations. As a growing number of agencies are adopting the technology, there is a need to understand how detector configurations can influence the outcomes of an analysis using ATSPM. Current practices with regard to detector configuration vary considerably from one agency to another; at one extreme, agencies may use one single detector input channel per phase without considering where the detectors are located, whereas at the other extreme, some agencies may utilize all possible channels to observe each individual lane at multiple positions. There are also variations in the design of detection zones (lengths and positions). This study takes on the problem in two parts. The first of these examines the impact of stop bar detection zone length and lane- or approach-based detector assignment on the ability of performance measures to identify accurately whether split failures occur. The second part examines the impact of setback detector distance on the use of a “percentage on green” metric that serves as a proxy measurement of the number of stops. The paper presents recommendations for performance measure calibrations and detector configurations that follow from these outcomes.

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    • The contents of this paper reflect the views of the authors, who are responsible for the facts and the accuracy of the data presented, and do not necessarily reflect the official views or policies of the sponsoring organizations. These contents do not constitute a standard, specification, or regulation. © National Academy of Sciences: Transportation Research Board 2020.
  • Authors:
    • Emtenan, A. M. Tahsin
    • Day, Christopher M
  • Publication Date: 2020-4


  • English

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  • Accession Number: 01733742
  • Record Type: Publication
  • Files: TRIS, TRB, ATRI
  • Created Date: Mar 19 2020 5:19PM