Identifying the occurrence characteristics and main causes of icy roads traffic accidents through analysis of traffic accident statistical data and past traffic accident investigation data

In Korea, every year, numerous casualties occur due to traffic accidents caused by icy roads during the winter. Accordingly, in this study, the characteristics and main causes of icy roads traffic accidents were derived through road traffic accident statistics and analysis of major accident cases that occurred in the past, and implications for reducing icy roads traffic accidents were derived. To this end, first, 2,147,503 traffic accident statistics that occurred over the past 10 years (2014-2023) were extracted from the Traffic Accident Analysis System(TAAS) operated by the Korea Road Traffic Authority. Based on the extracted statistical data, the characteristics of icy roads traffic accidents were analyzed by categorizing them by time zones(one-hour intervals), road types(7 such as highways, national roads and etc.), road forms(12 such as bridges, tunnels and etc.), and road conditions (7 such as dryness, icy and etc.). As a result of the analysis, the proportion of traffic accidents caused by icy was found to be not high at 0.76% of all traffic accidents. On the other hand, the fatality rate of icy roads traffic accidents was 2.3%, which was about 1.35 times higher than that of general traffic accidents, which was 1.7%. According to the analysis by time zone, unlike general traffic accidents, icy roads traffic accidents occurred at the highest rate(20.8%) between 8 and 10 a.m., and the fatality rate was the highest at 5.1% between 4 and 6 a.m. The reason for this is that in winter, sunrise is late, so the roads remain icy until the morning rush hour, and at the same time, traffic volume increases in these circumstances, which leads to many accidents. By road type, the largest number of accidents, 5,479(33.7%), occurred on city-operated roads, and the fatality rate was highest in accidents occurring on highways at 7.9%. One of the reasons why fatality rates are highest on highways is generally believed to be because of the high speeds of vehicles traveling on them. The results of the analysis by road forms show that the most accidents occurred in other single roads(57.9%), however, the fatality rate was highest in tunnels(8.3%). The reason for the high fatality rate in tunnels is believed to be that it is difficult to evacuate due to spatial constraints in the event of chain collisions and fires caused by a primary icy roads traffic accident. In addition, the investigation data were collected and analyzed on six accidents with large damage or social issues among icy roads traffic accidents over the past 10 years. The analysis results showed that the common main causes of accidents were drivers’ violation of speed limits in dangerous environments with icy roads, lack of installation of anti-icing and slipping facilities, and a number of traffic accidents caused by freezing in sections not designated as vulnerable to freezing. Finally, three implications for reducing icy roads traffic accidents were derived and the results will be provided to the TF currently being jointly conducted by ministries to establish measures to reduce icy roads traffic accidents.