Fig 1.
Employee railroad incidents in the United States (2015–2024).
Source: NSC Injury Facts (2024).
Fig 2.
Examples of accident evidence from investigation reports.
(Left) Signal equipment room terminal block before and after the accident. (Right) Condition of the accident train at the time of the incident. Source: Aviation and Railway Accident Investigation Board (ARAIB), Republic of Korea. Images reproduced for illustrative purposes.
Table 1.
Basis for defining categories (C1–C8) from prior human error classifications.
Table 2.
Operational definitions and report-based evidence for coding categories (C1–C8).
Table 3.
Inter-rater agreement for human error categories (Cohen’s kappa).
Fig 3.
Workflow for extracting, categorizing, and coding accident report data.
Table 4.
Descriptive statistics of variables (N = 105).
Fig 4.
Distribution of accident cost before and after log transformation.
Fig 5.
Q–Q plots of accident cost before and after log transformation.
Table 5.
VIF results for human error variables (C1–C8).
Fig 6.
Pairwise phi correlations among C1–C8 shown as a heatmap and a correlation matrix.
Table 6.
Comparison of distributional specifications for accident cost.
Table 7.
Robustness checks using regularized log-linear models.
Table 8.
Baseline regression results (Gamma GLM).