## 2 Methodology
### Overview of Data
The analysed 27.2 million train passages have the following characteristics presented in Table 2. The count of the trains was evenly distributed over 12 months in the year 2017, with an average count of 2.3 million train passages per month. Table 2 shows the following characteristics of analysed train passages: train subtype, track type, running time delay, trackwork, train enter status, and day time. Each category of these variables is listed, along with the percentage of observations per category, and reports delay-increase observations within four thresholds (1-4 min, 5-9 min, \(\geq\)10 min, and \(\geq\)1 min). Notably, among all categories, freight trains most frequently faced increases in running time delays. In contrast, when passing the analysed section, commuter trains were less prone to such delay increases. Instead, these commuter trains predominantly experienced reductions in running time delays during the period of study. Scheduled trackwork overlapped with about 0.4% of the train passages, whereas 99.6% of the passages did not pass through scheduled trackwork. 10% of the train passages were on quadruple-track, 52% on double-track, and 39% on single-track. Our sample was composed of 81% passenger trains and 19% freight trains. In total, 29% of the train passages in our sample were ahead of schedule entering the analysed track section, and 43% were behind schedule. Interestingly, trains that entered the section ahead of schedule often encountered a subsequent increase in running time delay. Finally, 86% of the passages occurred in the daytime and 14% at night. Night-time was defined (according to the labour act of Sweden [34]) as the period between 22.00 and 06.00. The total count of observations in the sample is 27,182,178. \begin{table}
\begin{tabular}{l c c c c c c} \hline \hline
**Category** & **Obs.** & **Mean** & **St. Dev.** & **Min** & **Max** \\ \hline Trackwork duration (minutes) & 225,507 & 181 & 207 & 0 & 1439 \\ \hline Train delays (minutes) & 18,948,094 & -0.15 & 5 & -444 & 1447 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Statistical summary of trackwork duration and train delays length. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Variable** & **Category** & **Observations** & **Delay** & **Delay** & **Delay** & **Delay** & **Delay** & **Running** \\  & & **Decrease** & **Decrease** (1–4 min)** & **Decrease** (5–9 min)** & **Decrease** (21 min)** & **Decrease** (21 min)** & **Decrease** & **Time** \\ \hline \multirow{8}{*}{Train type} & Freight & 19\% & 22.5\% & 4.3\% & 4.5\% & 31\% & 43\% & 25\% \\  & Unspecified & 1\% & 24.0\% & 1.7\% & 0.8\% & 26\% & 39\% & 34\% \\  & passenger & 6\% & 22.7\% & 1.4\% & 0.5\% & 25\% & 40\% & 36\% \\  & InterCity & 3\% & 27.8\% & 0.3\% & 0.1\% & 28\% & 14\% & 58\% \\  & Amoruter & 26\% & 13.0\% & 0.4\% & 0.2\% & 14\% & 58\% & 29\% \\  & Regional & 32\% & 20.5\% & 0.9\% & 0.3\% & 22\% & 43\% & 36\% \\  & High-speed & 13\% & 23.9\% & 1.1\% & 0.4\% & 25\% & 33\% & 42\% \\ \hline \multirow{2}{*}{Track type} & Single & 39\% & 20.4\% & 2.2\% & 1.8\% & 24\% & 45\% & 30\% \\  & Double & 52\% & 20.0\% & 1.1\% & 0.8\% & 22\% & 44\% & 34\% \\  & Quadruple & 10\% & 15.1\% & 0.4\% & 0.2\% & 16\% & 45\% & 39\% \\ \hline \multirow{2}{*}{Trackwork} & Yes & 0.4\% & 26.2\% & 2.7\% & 1.8\% & 31\% & 42\% & 27\% \\  & No & 99.6\% & 19.7\% & 1.4\% & 1.1\% & 22\% & 45\% & 33\% \\ \hline \multirow{2}{*}{Train Enter} & Early & 29\% & 27.4\% & 2.7\% & 2.5\% & 33\% & 34\% & 34\% \\  & Late & 43\% & 17.1\% & 1.2\% & 0.8\% & 19\% & 50\% & 31\% \\  & On time & 29\% & 15.8\% & 0.5\% & 0.2\% & 17\% & 47\% & 36\% \\ \hline \multirow{2}{*}{Day time} & Night & 14\% & 20.9\% & 2.1\% & 1.9\% & 25\% & 44\% & 31\% \\  & Day & 86\% & 19.5\% & 1.3\% & 1.0\% & 22\% & 45\% & 34\% \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Characteristics of the analysed sample of train passages.