## 4 Results
### Conflict Analysis through PCRI Using the ORED  
Due to the significant disparities in weight, size, and braking characteristics between trucks and cars, distinct differences in their driving behaviors and traffic flow characteristics emerge. By analyzing conflicts differentiated by vehicle type, insights into the varying behaviors and risks across vehicle types in traffic incidents can be gained. Authorities can tailor traffic management and control strategies to conflict characteristics of different vehicle types, thereby optimizing traffic policies and urban planning. The conflict analysis considering cars and trucks in this part utilizes the ORED. The number of cars in each video, along with the proportion of trucks, is illustrated in Figure 16. The proportion of trucks mostly ranges between 0.3 and 0.4. The average proportion of trucks across all videos is 0.341. Compared to other datasets, such as highD where trucks constitute 23%, this dataset has a higher truck proportion of 34.1%, indicating a more substantial representation of trucks. Table 4 displays the proportion of trucks on each lane in all videos. The distribution of trucks across different lanes follows a certain pattern, with a higher proportion of trucks on the middle lanes, slightly lower on the inner lanes, and the proportion of trucks nearly zero on the innermost lane. Therefore, conflicts between trucks and other vehicles are more likely to occur in the middle lanes. A total of 646 conflicts are identified from the OREDS using PCRI, with an average of 14 conflicts detected per video. Additionally, the frame number that aligns with the lowest PCRI value is pinpointed, indicating the highest risk moment between the two vehicles. At the moment of highest risk, the continuous midpoint coordinates of the two vehicles' positions are considered as the location where the conflict occurs, on the video frame, the difference in horizontal and vertical coordinates between the two vehicles reflects the proximity of the conflict. The difference in vehicle speeds along the lane direction at that moment is also calculated. Figure 15: The change trends of TTR and TRSD. Figure 17 depicts the spatial distribution of conflict locations. In this Figure, conflicts most frequently occur at the intersection of the on-ramp and the mainline, as well as on the section of road between 0 m to 100 m on lanes 2 and 3. This is because, at the merging area, the vehicles from the on-ramp merge into the mainline, leading to conflicts with vehicles on the mainline. Additionally, due to the high volume of vehicles merging from the on-ramp, queuing and overtaking behavior occur as vehicles enter the mainline, resulting in frequent conflicts among vehicles merging from the on-ramp as well. And lane 3, characterized by the highest truck density, encounters increased conflict risk attributed to trucks' longer stopping distances relative to cars, particularly under similar speed conditions. Figure 18 shows the distribution of the difference in horizontal and vertical coordinates between two conflict patterns. Analysis of the scatter distribution in this figure allows for the classification of conflict into two primary types. The first type is predominantly clustered around the coordinate (0, 4), indicating that conflicts occur when both vehicles are on the same road section yet maintain a horizontal separation of about 4 m. This suggests that these conflicts arise when vehicles are closely aligned along the roadway but with a notable gap in the perpendicular direction to the traffic lane. The cause of such conflicts is more likely due to the lead vehicle overtaking and changing lanes in the process, leading to potential lane-changing conflicts [52; 53]. There are a total of 368 instances in this category, accounting for 56.9% of the total. The second type is concentrated around the coordinate (15, 0), likely occurring in scenarios where vehicles are following each other on the same lane, or the lead vehicle changes lanes to the lane of the front vehicle without overtaking.