PURPOSES : This study was conducted to prevent road thinning ice caused by abnormal weather conditions. METHODS : The appropriate amount of de-icer spread rate was verified by presenting the appropriate amount of snow removal agent spraying criteria for the thickness of the water film, owing to abnormal weather phenomena (fog, frost), and applying the standards to the site. Furthermore, we present a method to utilize residual salt, by quantifying the surface state changes according to the amount of deicer. RESULTS : Precautionary spread experiments to prevent road thin ice caused by abnormal weather conditions, indicated no freezing from 7.6g/m2 at 2℃-4℃ but 11.1g/m2 was suggested as a step higher considering external environmental variables. The amount of spraying was presented in two sections of rainfall(freezing rain). It is 17.7g/m2 at 0-7℃, 33.3g/m2 at -7~ -15℃, and 44.4g/m2 and 51.1g/m2 at non-urban, respectively. CONCLUSIONS : The criteria were divided into air temperature and road temperature standards, so that they could be distributed according to the temperature standards that meet the conditions, and the criteria presented were confirmed to be effective in preventing road thinning ice. If the road manager adopts Safety Line, which is suggested by utilizing the amount of residual salt on the road, it is believed that it can help determine the additional deicer.

This study tries to reveal abnormal trends in climate change from 60 stations in Korea during 1981-2010 by comparisons to the standard station, Chupungnyeong station. Trends in climate change from station with the abnormalities, and their implication and causes are also discussed. Although Wando, Wonju, Mungyeong and Mokpo stations show the most abnormalities, normal trends in climate change from some climate data are also found from Mokpo station. On the other hand, some climate data from Suwon, Jeonju, Jinju, Icheon and Geumsan stations indicate the most normalities. It should be noted that variabilities of climate data are largely different, indicating that clear trends in climate change may not be extracted. The fact that some stations with the abnormalities from some climate data also show the normalities should be also noted. This study suggests that most stations with the most abnormalities may be relevant to relocation of station.