# Study on the Eye Movement Transfer Characteristics of Drivers Under Different Road Conditions
## 4 Fixation Shift Analysis
### Probability of Fixation Shift  
In the study of drivers' fixation behavior, the probability of one-step shift in fixation under four road sections (turning, straight ahead, uphill, and downhill) reveals the visual focusing patterns and behavioral patterns of drivers in different driving situations, as shown in Figure 9 [24]. In the turning section, the driver's fixation behavior shows strong dynamic changes. Due to the complexity of the road curvature during the turning process, the driver's fixation  
Figure 9: Distribution probabilities of one-step fixation shifts for four roadway segments. (**a**) Turning; (**b**) straight ahead; (**c**) uphill; (**d**) downhill. shift is mainly concentrated between the near front (area 1) and the far front (area 2), while the probability of the shift in fixation to the left and right sides (area 3, area 4) is higher. At this time, the driver needs to continuously monitor the traffic on both sides of the road as well as react to the curvature of the turn, so in the turning section, the driver shifts more frequently from the near front to the far front and both sides of the road. In addition, the relatively low probability of fixation shifts in the rearview mirror and dashboard areas (area 5, area 6) suggests that drivers rely more on direct information from the front and side views and pay relatively less attention to the rear in this section. In the straight ahead section, the driver's fixation behavior was relatively stable and the frequency of fixation shifts was low, mainly concentrated between the far ahead (area 2) and the dashboard (area 6), reflecting the driver's continuous attention to the road outlook and regular checking of the vehicle's condition under simpler driving conditions. Since the road changes less during straight driving and drivers do not need to adjust their fixations frequently, the probability of shifting fixations from the far ahead to the dashboard or rearview mirror is higher, while the probability of shifting fixations from the side view (area 3, area 4) to the far ahead is lower, which indicates that drivers pay less attention to their vehicle surroundings and rely more on the road information in front of them. In the uphill section, drivers' fixation behaviors show strong prospective characteristics, mainly focusing on the near front (area 1) and both sides of the road (areas 3 and 4). During the uphill course, drivers need to pay attention to the changes in the ramp, especially the road surface condition and possible obstacles, so the probability of fixation shifts in the near front and the left and right sides of the road is higher. Drivers will shift from the near front to both sides of the road to ensure safe driving and also periodically check the sight glass (area 5) to assess the condition of the surrounding traffic. The low probability of fixation shifting from the dashboard (area 6) to the near front (area 1) in this roadway shows that drivers pay less attention to vehicle-specific parameters in this condition. In the downhill section, the driver's fixation shift is mainly concentrated between the far ahead (area 2) and the sight glass (area 5), which is closely related to the high attention to vehicle speed and stability during downhill. Due to the inclination and speed change in the ramp, the driver needs to constantly monitor the road condition in the far front and pay attention to the dynamics of the vehicle behind through the rearview mirror. At this time, the frequency of fixation shifts is low and mainly occurs between the far ahead, the rearview mirror, and the dashboard, indicating that drivers pay more attention to driving safety and real-time monitoring of vehicle performance in this road section. The lower probability of shifting from both sides of the road (areas 3 and 4) to the far ahead (area 2) in this section may reflect that drivers pay more attention to the road changes in front of them rather than their surroundings during the downhill process.