# System Dynamics Modeling for Estimating the Locations of Road Icing Using GIS
## 5 Conclusions  
In this study, modeling was performed through the system dynamics theory to estimate the amount and location of road icing, and the results were simulated on the geographic information system (GIS). In the system dynamics model, the amount of road icing per unit area (1 m\({}^{2}\)) was modeled by combining block diagrams in the causal order. In this model applied per unit area, the amount and location of road icing for 14 h were simulated by calculating numerical values differently depending on the specific values (spatial and meteorological data) of each road section. The upper tailed test through the \(p\)-value was then conducted in vulnerable areas where actual freezing traffic accidents occurred, and the alternative hypothesis that the model properly simulates the generation of thin ice in vulnerable areas was adopted. Through this hypothesis testing, it could be estimated that the model properly simulates the actual occurrence of road icing. Research was conducted on estimating the occurrence of road icing through modeling in vulnerable areas, but freezing traffic accidents are caused by many factors, such as the presence of slopes, signals, and curves, as well as a simple degree of freezing on the road. In other words, although the model estimates the amount and location of road icing, it has limitations in accurately selecting places vulnerable to traffic accidents due to the omission of additional vulnerability factors. If calculation is performed by adding the factors described above, such as slopes, signals, and curves, it will be possible to estimate traffic accident vulnerability more accurately. The results can also be compared with the data of actual points where traffic accidents occurred. In the future, it is necessary to conduct further research on vulnerability by superimposing these factors in the form of a layer on GIS or calculating them along with parameters in the system dynamics theory. This study is significant, as the location and amount of road icing are simulated prior to risk evaluation. In addition, the results of this study can be useful data for government agencies (e.g., road traffic authority) in managing traffic accidents caused by road icing. If factors are reinforced and more accurate vulnerability assessment is performed in the future, it will be possible to reduce manpower wasted for surveys on vulnerable sections by selecting points where damage from road icing is expected in advance. It will also be possible to efficiently implement structural and non-structural measures at more accurate points. Conceptualization, S.-B.H. and H.-S.Y. ; methodology, S.-B.H. and H.-S.Y. ; software, S.-B.H. and C.-H.K. ; validation, S.-B.H., H.-S.Y. and C.-H.K. ; formal analysis, S.-B.H. ; investigation, B.-W.L. ; resources, H.-S.Y. ; data curation, S.-B.H. ; writing--original draft preparation, S.-B.H. and H.-S.Y. ; writing--review and editing, S.-B.H. and H.-S.Y. ; visualization, S.-B.H. ; supervision, H.-S.Y. ; project administration, H.-S.Y. ; funding acquisition, H.-S.Y. and B.-W.L. All authors have read and agreed to the published version of the manuscript. This work was supported by the Korea Environmental Industry & Technology Institute (KEITI) through Environmental R&D Project on the Disaster Prevention of Environmental Facilities Program funded by Korea Ministry of Environment (MOE) (No. 2020002860001). Not applicable. The data presented in this study are openly available in reference [5; 39].