• Journal of the Korean Geographical Society
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• v.38 no.4
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• pp.478-489
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• 2003

The existing researches related to the fog have focused on mainly the fog itself and its spatial variation. This study defined the hazardous fog as the fog with visibility under 500 m which caused the severe dangerous situation on roads and might cause traffic accident due to insufficient visibility. This study aimed to develop the hazardous fog index which quantified the degree of danger and included frequency of fog, visibility and its duration. We applied the index to 3 years weather station data in Korea and the results showed the distribution of the hazardous fog and their priority in terms of safety management. This was the first study that introduced the fog index in Korea and that quantified the degree of hazardous fog. These application results were useful for identifying the dangerous area due to hazardous fog and contributing to ensure the safety of eventual road users and road authorities.

• Journal of Korean Society of Transportation
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• v.18 no.5
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• pp.7-16
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• 2000

This paper is focused on verifying time-space repetition of the highway accident and finding the their causes and deterrents. We classify all months into several seasonal groups, develop the model for each seasonal group and analyze the results of these models for Joong-bu highway. The existence of seasonal effect is verified by the analysis or self-organizing map and the accident indices. Agglomerative hierarchical cluster analysis which is used to decide the seasonal groups in accordance with accident patterns, winter group, spring-fall group. and summer group. The accident features of winter group are that the accident rate is high but the severity rate is low. while those of summer group are that the accident rate is low but the severity rate is high. Also, the regression model which is developed to identify the accident Pattern or each seasonal group represents that the season-related factors, such as the amount of rainfall, the amount of snowfall, days of rainfall, days of snowfall etc. are strongly related to the accident pattern of evert seasonal group and among these factors the traffic volume, amount of rainfall. the amount of snowfall and days of freezing importantly affect the local accident Pattern. So, seasonal effect should be considered to the identification of high-risk road section. the development of descriptive and Predictive accident model, the resource allocation model of accident in order to make safety management plan efficient.