## 3 Results and Discussion
Among the road sections where the average number of accidents is between 3.1 and 4.5, a few of them are icy and have low slopes, some of them are snowy and have medium slopes, and a significant portion of them are wet and have high slopes. On road sections where the average number of accidents is below 3, some of them are snowy and have low slopes, some of them are wet and have medium slopes, and some of them are wet and have low slopes. Accordingly, the road sections with the highest accident risk have icy road surfaces and high slopes. The second highest risk of accidents was found in sections where few road surfaces were icy and the slope was moderate, and in sections where many road surfaces were snowy and the slope was high. When all the accident data were evaluated together, it was determined that the most effective factor is the slope of the road, and the second most effective factor is icy conditions. After the accident density map was created for the study area, the most common accident by types of occurrence were determined for each road condition class. Determining the types of accidents is very important for determining the measures that can be taken to prevent these accidents. Table 2 below shows the top three most common types of accidents in each road class and the frequency of occurrence in percentages. Figure 6: Accident risk intensity map for Erzurum during winter months. When the most common type of accident in each road condition was analyzed, it was seen that rear-end collisions are more common, especially on icy road sections. On the other hand, side-impact collisions are more common on road sections with high slopes, and pedestrian collisions are more common on wet road sections. These results are very important for taking precautions against traffic accidents that occur in winter months. In these conditions where the risk of accidents is high during winter months, regulations can significantly reduce accidents. One of the most important steps to be taken by local governments can be the installation of speed breakers in a downhill direction in sections with high slopes. In addition, since side impacts are more common on these road sections, converting them into divided roads may also reduce the likelihood of accidents. Heated anti-icing systems, an application of intelligent transportation systems, can be installed on road sections where the possibility of ice is high. In this system, snow and ice can be prevented by automatically operating the heating cables placed under the road surface according to weather conditions. In wet road sections where pedestrian accidents are high, drainage systems can be applied to speed up the drainage of water from the road surface. The construction of pedestrian underpasses or overpasses to prevent pedestrian accidents can also significantly reduce the risk of accidents. In addition, it is possible to significantly reduce accidents using various warning signs in all sections where the risk of accidents is high. Our analysis highlights that road grade, particularly steep slopes, significantly influences accident risk, a finding supported by the accident risk density map. Steep downhill segments are prone to higher accident rates due to factors such as increased vehicle speeds, reduced braking efficiency and traction challenges. These risks are particularly pronounced for heavy vehicles, which face greater braking difficulties, especially on icy or wet road surfaces. Previous studies have emphasized the critical role of grade in crash severity and frequency, particularly in high-risk zones, such as mountainous highways and steep urban corridors. In this study, road grade has been identified as the most influential factor in accident risk, followed by surface conditions, such as ice or wetness. These findings underscore the necessity of targeted safety measures, including the installation of speed breakers, the application of anti-icing systems, and the implementation of runaway truck ramps on steep segments.