## 2 Materials and Methods
### Methods
#### 2.2.3 Determining the Expected Impact of Occurrences by Category  
Only those occurrences that emerged due to human error were considered for the calculation of the average impacts of occurrences following the conclusions of [22]. The categories of occurrences listed in Table 2 are, therefore, considered for the current research. Using the data contained in the Database of Occurrences [3] and the unit impacts of occurrences presented in the previous part of the text, the expected overall socioeconomic impacts of individual categories of occurrences were determined using Relation (1). The overall socioeconomic impacts include the following items:  
* Impacts on health,
* Delay of passenger trains,
* Delay of freight trains, and
* Total costs. The presented research made use of selected occurrences on two levels. The first level included occurrences taken from the Database of Occurrences [3] (adjusted for occurrences at railway crossings and suicides), whatever the cause; the second level included occurrences caused by human error. A detailed evaluation of individual categories of occurrences was described in [23]; the expected impacts of individual categories of occurrences are summarized in Table 3. \begin{table}
\begin{tabular}{c l} \hline \hline
**Designation** & **Description** \\ \hline A1 & Collision of railway vehicles, resulting in death or injury to at least 5 persons or large-scale damage. \\ \hline A2 & Derailment of a rail vehicle, resulting in death or injury to at least 5 persons or large-scale damage. \\ \hline A3 & Collision of a rail vehicle with an obstacle in the passage, resulting in death or injury to at least 5 persons or large-scale damage. \\ \hline B1 & Collision of railway vehicles, resulting in minor consequences rather than a serious accident. \\ \hline B2 & Derailment of a rail vehicle, resulting in minor consequences rather than a serious accident. \\ \hline B3 & Collision of a rail vehicle with an obstacle in the passage, resulting in minor consequences rather than a serious accident. \\ \hline C1 & Collision of railway vehicles, resulting in minor consequences rather than a serious accident or accident. \\ \hline C2 & Derailment of a rail vehicle, resulting in minor consequences rather than a serious accident or accident. \\ \hline C3 & Collision of a rail vehicle with an obstacle in the passage, resulting in minor consequences rather than a serious accident or accident. \\ \hline C6 & Unauthorized movement of the rail vehicle behind a signaling device prohibiting driving, resulting in minor consequences rather than an accident. \\ \hline C12 & Unsecured movement of a rail vehicle, resulting in minor consequences rather than an accident. \\ \hline C16 & Failure of signaling systems, resulting in minor consequences rather than an accident. \\ \hline C19 & Unspecified incident arising in connection with the movement of the rail vehicle, resulting in minor consequences rather than an accident. \\ \hline \hline \end{tabular} Source: Database of Occurrences 2009–2018 [3].  
\end{table} 
Table 2: Categories of occurrences. \begin{table}
\begin{tabular}{c c} \hline \hline \multirow{2}{*}{**Category**} & \multicolumn{2}{c}{**Expected Impact Per Occurrence (EUR)**} \\ \cline{2-3}  & **Cause—Human Factor** \\ \hline A1 & 742,138 \\ A2 & 983,734 \\ A3 & 2,672,916 \\ B1 & 105,200 \\ B2 & 59,398 \\ B3 & 74,056 \\ C1 & 5880 \\ C2 & 3797 \\ C3 & 4202 \\ C6 & 2464 \\ C12 & 3325 \\ C19 & 4422 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Average total economic impacts per occurrence by category. The presented methodological part resulted from the current research that is focused on the evaluation of the socioeconomic impacts associated with occurrence emergence in railway infrastructure in order to consider the increase in the safety and reliability of the railway in the socioeconomic evaluation of railway infrastructure projects.