Technical Reports

Quantification of the Sensitivity of Two Prevalent Track Inspection Systems

  • 03
  • May
  • 2017
AUTHOR: Federal Railroad Administration
SUBJECT: Rail and Infrastructure Integrity
KEYWORDS: Track inspection, inspection systems, inspection methodologies, optimal inspection, risk-based inspection, signal detection theory
ABSTRACT: This report uses signal detection theory to quantify the sensitivity of two common track inspection systems (manual visual inspection via a hi-rail vehicle and automated track geometry inspection). Quantifying the sensitivity of such systems can provide baseline input data for risk-based, probabilistic track inspection programs, which cannot determine optimal track inspection methodologies without accurate probabilities of detection for various track inspection methods. The results show that there are no overall differences in sensitivity (ability to detect deteriorated or anomalous track conditions) between visual and automated inspection methods. However, there is a strong bias with both systems to indicate “no defect,” which results in a high rate of misses of deteriorated and anomalous track conditions.