## 5 Discussion  
In this paper, a calculation method for the transition area length was proposed. Based on the results of our theoretical calculations, naturalistic driving experiments were con  
Figure 11: Distribution of vehicle deceleration points under different lane closure forms. Figure 12: Distribution of distance traveled by reducing the driving workload to normal levels under different lane closure forms. ducted with 48 participants in 12 scenarios involving 3 lane closure forms and 4 transition area lengths. The speed limit of the experimental road was low, speeding was observed in different areas, the number of aggressive and conservative drivers in the work area was significantly higher than that of ordinary drivers, and drivers in the left lane were more aggressive than those in the right lane. This resulted in vehicle speeds being too high or too low, under the combined impact of factors such as the transition area length, the speed difference, and speed dispersion between adjacent areas were increased. [PERSON] et al. used sequential g-estimation and other methods to study the relationship between vehicle speed and traffic conflicts in work zones, and the results indicated that when the vehicle running speed was \(\geq\) 90 km/h, the reduction in the speed limit contributed to traffic safety in work zones. When the vehicle running speed was <90 km/h, the reduction in the speed limit did not have a significant impact on traffic safety in work zones. Meanwhile, optimizing work zone configurations to induce driving behaviors was found to effectively reduce traffic safety risks [35]. Therefore, a reasonable variable speed limit strategy should be adopted based on the specific conditions of the work zone [36] to appropriately reduce the overall vehicle running speed in the work zone while optimizing work zone configurations, reducing the speed difference and speed dispersion of adjacent areas, and ensuring traffic safety. Closed lane widths, work zone speed limits, and traffic volumes in closed lanes and adjacent lanes are the primary factors in determining the transition zone length. Our experimental results indicated that transition zone length, driving behavior, and lane closure form all have an impact on the driving workload and vehicle speed in the work zone. This experiment was conducted under free-flow conditions, and previous studies have indicated that the driving workload while merging is positively correlated with traffic volume [37], and an increase in traffic volume can lead to a decrease in vehicle speed. Part of the work zone can be borrowed from the opposite lane to form a cross-work zone, with short intervals between the transition area and median opening, which can result in a rapid rise in driving workloads within a short period of time, increasing traffic safety risks. Changes in road conditions, reduced numbers of lanes, and reduced speed limits in work zones have resulted in a decrease in capacity [38]. It was found that with a speed limit of 60 km/h, the capacity of 4 \(\to\) 3, 3 \(\to\) 2, and 2 \(\to\) 1 transition areas was 1570, 1550, and 1610 pcu/h-ln, and the maximum capacity of the median opening was 1600 pcu/h-ln. Therefore, when establishing the transition area, it is necessary to fully consider the relationships between different affecting factors and the transition area length, maintain a relatively stable driving workload, and avoid a significant increase in the driving workload in a short period of time. Attention should be paid to differences in the capacity of different areas to avoid the phenomenon of \"double bottlenecks\". When evaluating accident risk in work zones, due to the difficulty in obtaining accident data, the traditional method of predicting accident probability based on traffic accident data cannot effectively observe and measure all accident causes. [PERSON] et al.