## 6 Discussion
### Risk Quantification Method Evaluation
Specifically, \(d\)-\(x\) represents the lateral relative distance between the two vehicles, \(d\)-\(y\) represents the relative distance along the direction of vehicle travel, and \(MRF\) represents the driving risk experienced by the target vehicle from the interacting vehicle. \(MRF\)-\(c\) indicates the driving risk experienced by the target vehicle at the current moment, while \(MRF\)-\(p\) represents the predicted future driving risk experienced by the target vehicle from the interacting vehicle. From Figure 9b, it can be observed that from 5 s to 17 s, as the relative distance between the two vehicles decreased, the driving risk experienced by the target vehicle significantly increased. After 17 s, as the relative distance increases, the driving risk decreases. Between 18 s and 21 s, the interacting vehicle changed lanes into the front lane of the target vehicle. Therefore, the region where the \(MRF\) decreased after 17 s can be divided into two phases: before and after the interacting vehicle merges. Prior to the merge, the \(MRF\) decreased at a faster rate because the interacting vehicle was positioned in the left front of the target vehicle; after the merge, the rate of decrease slowed, as the interacting vehicle was positioned directly in front of the target vehicle. At the same relative distance, the risk generated when the interacting vehicle was directly in front of the target vehicle is greater, which is consistent with real-world observations. Additionally, Figure 9b displays both the current driving risk (\(MRF\)-\(c\)) and the predicted future driving risk (\(MRF\)-\(p\)) for the target vehicle. The root mean square error between \(MRF\)-\(c\) and \(MRF\)-\(p\) was 0.08, and the deviation between \(MRF\)-\(c\) and \(MRF\)-\(p\) was 4.76%. It is evident from Figure 9b that the \(MRF\)-\(c\) and \(MRF\)-\(p\) exhibited consistent trends, with \(MRF\)-\(p\) lying to the left of the \(MRF\)-\(c\) curve. This  
Figure 9: Experimental results of the merging scenario. (**a**) The speed of the vehicles and the driving risk of the target vehicle in the merging scenario. (**b**) The relative distance between vehicles and the driving risk of the target vehicle in the merging scenario. indicates that the _MRF-p_ curve can represent the predicted future driving risk at the current moment, thus validating the effectiveness of the proposed model in the merging scenario. Due to space limitations, a 6 s lane change scenario involving the target vehicle and six other interacting vehicles was selected for detailed illustration, as shown in Figure 10. During the entire process, the target vehicle moved from the left lane to the middle lane (Figure 10b), and interacted with the other six vehicles, leading to a conflict (Figure 10c). Once the target vehicle completed the lane change, it transitioned to a following maneuver (Figure 10d). In Figure 10a, the variation in risk field intensity for each vehicle is depicted. To clearly display and distinguish the risk fields of each vehicle, Figure 10b-d shows the risk fields in front of the interacting vehicles and the front and rear regions of the target vehicle, with areas of a higher risk intensity highlighted.