## Appendix A Descriptive Analysis Results
Single-vehicle accidents with single occupation and personal injury that occurred outside built-up areas between 2012 and 2019 in Austria, broken down by roadway-related variables. \begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Variable**} & \multirow{2}{*}{\begin{tabular}{c} **Casualities** \\ **n** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **Severe** \\ **Casualities** \\ **n** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **P (X \(\cap\) SC)** \\ **\%** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **Fisher's** \\ **Exact Test** \\ **P** \\ \end{tabular} } & \multirow{2}{*}{\
\begin{tabular}{c} **Phi** \\ **Coefficient** \\ **n** \\ \end{tabular} } & \multirow{2}{*}{
\begin{tabular}{c} **MCV** \\ **n** \\ \end{tabular} } \\ \cline{2-2} \cline{6-6}  & & Insufficient vehicle security & 16 & 6 & 0.03\% & 0.040 & 0.015 & 2 \\ \cline{2-6}  & & Insufficient load securing & 6 & 0 & 0.00\% & 0.598 & \(-\)0.008 & 1 \\ \cline{2-6}  & & Technical defects & 102 & 15 & 0.07\% & 0.682 & \(-\)0.004 & 6 \\ \cline{2-6}  & & Vehicle fire & 18 & 11 & 0.05\% & 0.000 & 0.055 & 1 \\ \cline{2-6}  & & Airbag not deployed & 8.138 & 819 & 4.04\% & 0.000 & \(-\)0.149 & 975 \\ \hline \hline \end{tabular}   
Table A3 provides a detailed analysis of roadway-related variables and their impact on the severity of single-vehicle accidents that took place outside built-up areas in Austria between 2012 and 2019. \begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Variable**} & \multirow{2}{*}{\begin{tabular}{c} **Casualities** \\ **n** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **Severe** \\ **Casualities** \\ **n** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **P (X \(\cap\) SC)** \\ **\%** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **Fisher's** \\ **Exact Test** \\ **P** \\ \end{tabular} } & \multirow{2}{*}{\
\begin{tabular}{c} **Phi** \\ **Coefficient** \\ **n** \\ \end{tabular} } & \multirow{2}{*}{
\begin{tabular}{c} **MCV** \\ **n** \\ \end{tabular} } \\ \cline{2-2} \cline{6-6}  & & Driving ban & 2270 & 380 & 1.87\% & 0.833 & \(-\)0.002 & 350 \\ \cline{2-6}  & & 1 & 1 & 0.00\% & 0.169 & 0.016 & 1 \\ \cline{2-6}  & & 10 & 0 & 0.00\% & 1.000 & \(-\)0.003 & 1 \\ \cline{2-6}  & & 2 & 0 & 0.00\% & 1.000 & \(-\)0.004 & 1 \\ \cline{2-6}  & & 30 & 173 & 33 & 0.16\% & 0.479 & 0.005 & 13 \\ \cline{2-6}  & & 40 & 8 & 0.04\% & 0.533 & 0.004 & 6 \\ \cline{2-6}  & & 50 & 505 & 71 & 0.35\% & 0.095 & \(-\)0.012 & 56 \\ \cline{2-6}  & & 60 & 334 & 55 & 0.27\% & 0.877 & \(-\)0.002 & 43 \\ \cline{2-6}  & & 70 & 1421 & 218 & 1.07\% & 0.108 & \(-\)0.011 & 321 \\ \cline{2-6}  & & 80 & 1231 & 192 & 0.95\% & 0.225 & \(-\)0.009 & 222 \\ \cline{2-6}  & & 90 & 3 & 0 & 0.00\% & 1.000 & \(-\)0.005 & 1 \\ \cline{2-6}  & & 100 & 12,292 & 2148 & 10.58\% & 0.008 & 0.019 & 2.232 \\ \cline{2-6}  & & 110 & 35 & 4 & 0.02\% & 0.502 & \(-\)0.006 & 10 \\ \cline{2-6}  & & 120 & 2 & 0 & 0.00\% & 1.000 & \(-\)0.004 & 1 \\ \cline{2-6}  & & 130 & 1983 & 321 & 1.58\% & 0.377 & \(-\)0.006 & 488 \\ \hline \hline \multirow{2}{*}{**Variable**} & Highway & 2593 & 417 & 2.05\% & 0.239 & \(-\)0.008 & 488 \\ \cline{2-6}  & & Expressway & 595 & 80 & 0.39\% & 0.024 & \(-\)0.016 & 82 \\ \cline{2-6}  & & Country road & 14,457 & 2416 & 11.91\% & 0.247 & \(-\)0.008 & 2.232 \\ \cline{2-6}  & & Other roads & 2220 & 463 & 2.28\% & 0.000 & 0.037 & 248 \\ \cline{2-6}  & & Intersection & 439 & 62 & 0.31\% & 0.125 & \(-\)0.011 & 62 \\ \cline{2-6}  & & Roundabout & 68 & 16 & 0.08\% & 0.146 & 0.010 & 11 \\ \hline \hline \end{tabular}   
One of the most significant findings is the relationship between speed limits and accident severity. Accidents occurring in areas with a 100 km/h speed limit show a higher probability of severe casualties, with a phi coefficient of 0.019 and a significant \(p\)-value of 0.008, indicating a moderate positive correlation. Similarly, roads with a 130 km/h speed limit also show a notable frequency of severe accidents, although the correlation is slightly weaker.