## 6 Conclusions  
This paper was based on a calculation model for establishing the transition area length. Through naturalistic driving experiments, the impact of the transition area on the driving workload and driving behavior was studied, and the following conclusions were obtained:  
1. Based on the driving behavior of vehicles merging into the transition area, the relationship between the critical gap and the distance traveled in the transition area was analyzed. The gap acceptance theory was used to establish a calculation method for the transition area length, and the calculated transition area length was obtained under different closed lane widths, speed limits, and traffic volumes.
2. Based on the results of our theoretical calculations, naturalistic driving experiments were conducted with 48 participants in 12 scenarios involving 3 lane closure forms and 4 transition area lengths, and the relationship of transition area with driving workload and vehicle speed was determined. A transition area that was too short or too long increased traffic safety risks; overall, the experimental results were consistent with the theoretical calculation length, and the theoretical calculation model was reliable. When the speed limit in the work zone was 60 km/h, a transition zone length of 120-160 m was more reasonable.
3. The relationship of lane closure form and driving behavior with the driving workload and vehicle speed in the transition area was analyzed. Compared to unaffected straight-through vehicles, merging vehicles and vehicles affected by merging have lower speeds, higher driving workloads, and increased traffic safety risks. An increase in the number of lanes in the transition area will result in increased driving workloads and vehicle speeds.
4. Based on the changes in vehicle deceleration points and driving workloads, the affected area of the transition area was obtained. When the speed limit was 60 km/h, the upstream affected transition areas with four, three, and two lanes were 1000 m, 850 m, and 700 m, and the downstream affected areas were 450 m, 400 m, and 350 m. In practical applications, the length and configuration of the transition area should be comprehensively determined based on the closed lane width, speed limit, traffic volume, number of lanes, driving behavior, and other factors.  
This article only conducted a naturalistic driving experiment with a speed limit of 60 km/h. Further research should be carried out on the impact of transition areas under other speed limits and work zone configurations.  
Conceptualization, J.H.; methodology, S.M.; writing, S.M. and R.W.; visualization, S.M.; supervision, J.H. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the key field research and development plan projects of the Department of Science and Technology of Guangdong Province (No. 2022B0101070001).  
Not applicable.  
The data generated in this study are available upon request.  
**Acknowledgments:** The authors would like to thank all the participants in the experiments. The authors also gratefully acknowledge the support provided by [PERSON] and [PERSON].  
**Conflicts of Interest:** The authors declare no conflict of interest.