# Revealing the Spatial Pattern of Weather-Related Road Traffic Crashes in Slovenia
## 4 Discussion  
Owing to decreased traveling time and increased mobility, motor vehicles provide many benefits for individuals and society [1]. However, their widespread use is negatively affecting the quality of the living environment and poses a threat in the form of traffic crashes, which are still the leading cause of death for children and young adults [41; 42]. The increased use of vehicles and more frequent extreme weather events, because of climate change, can thus result in higher road traffic crash risk, despite an improvement in worldwide numbers [43]. The Slovenian road traffic crash database revealed a similar frequency distribution of road traffic crashes in adverse weather conditions as reported in other European countries. Fortunately, general trends for these unpleasant events are, on both levels (national and European), clearly negative [44]. However, [PERSON] and [PERSON] [45] concluded that road traffic crashes are spatiotemporal events along road networks, which can be influenced by many varying factors, including weather. Because Slovenia lies at the conjunction of different climatic zones characterized by differences in weather phenomena, which further modify traffic safety, significant regional differences in road traffic crash frequency were expected. Other studies across the Globe [11; 12; 43; 44; 46; 47] have confirmed the impact of weather (as a direct or indirect cause) on road traffic crashes, especially during heavy precipitation. Slovenia is not an exception; rainy and snowy weather conditions lie behind the highest share of road traffic crashes in adverse weather. The municipal level road traffic crash trend analysis, based on 13 time windows (2006-2018), additionally confirmed this fact. However, the road traffic crash hot spot pattern in Slovenia was the most unusual in windy and foggy weather conditions. Moreover, this unique hot spot pattern was detected in the four Slovenian municipalities with the highest traffic load and crash frequency (Ljubljana, Maribor, Celje, and Koper) on the local road segment level [48]. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Weather Situation**} & \multirow{2}{*}{**Variable**} & \multirow{2}{*}{**Variable**} & \multirow{2}{*}{**Deviance**} & \multirow{2}{*}{**MAE**} & \multirow{2}{*}{**Moran’s Index**} & \multirow{2}{*}{**_p_-Value**} \\  & & & **Importance (\%)** & & & **(\%)** & \\ \hline \multirow{4}{*}{Rain} & F3 & 36 & & & & & \\  & F1 & 17 & & & & & \\  & CHI & 17 & & & & & \\  & F2 & 16 & & & & & \\  & MDC & 15 & & & & & \\ \hline \multirow{4}{*}{Snow} & F3 & 39 & & & & & \\  & F1 & 21 & & & & & \\  & CHI & 17 & & 41 & 1.23 & \(-\)0.142 & 0.472 \\  & F2 & 12 & & & & & \\  & MDC & 11 & & & & & \\ \hline \multirow{4}{*}{Wind} & CHI & 32 & & & & & \\  & F3 & 25 & & & & & \\  & MDC & 16 & & 48 & 0.08 & 0.157 & 0.376 \\  & F2 & 15 & & & & & \\  & F1 & 12 & & & & & \\ \hline \multirow{4}{*}{Fog} & F3 & 32 & & & & & \\  & CHI & 20 & & & & & \\ \cline{1-1}  & MDC & 18 & & 43 & 0.58 & \(-\)0.091 & 0.635 \\ \cline{1-1}  & F1 & 17 & & & & & \\ \cline{1-1}  & F2 & 13 & & & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Summary statistics for the decision tree models. Weather conditions--despite the great natural and geographical diversity of Slovenia--are not the main cause of traffic crashes, but they are an important modifier, especially in areas with relief diversity. Particularly problematic are areas with narrow valleys, where pools of cold air appear at the bottom, which are associated with more a frequent occurrence of ice or fog. If we add to this the fact that in some areas these roads are the only connections between regional centers so the traffic density is higher (the Drava and Soca valleys), the consequence is a higher probability of traffic crashes. By developing an algorithm to adequately predict spatial patterns of anthropogenic activity, here manifested in the form of road traffic crashes, we can bridge still existing gaps in road traffic safety.