## 5 Conclusions
(b) In the four conditions of static state (driving in a fog-free environment in the daytime, driving in a dense fog environment without guiding lamps, and driving in a dense fog environment with guiding lamps) the drivers generally showed the following characteristics: The highest blood pressure and heart rate values were obtained in the condition of driving in a dense fog environment without guiding lamps, followed by the condition of driving in a dense fog environment with guiding lamps. Thus, it can be seen that dense fog environments have an influence on drivers' blood pressure and heart rate and that guiding lamps in dense fog environments can alleviate the increase in drivers' blood pressure and heart rate; it can be assumed that guiding lamps in foggy environments can compensate for drivers' loss of visual information and increase visual information input to their eyes. (4) Given the imperative of ensuring experimental safety, the extant research on traffic guidance for foggy expressway sections predominantly employs driving simulators for indoor simulation testing. Such an approach yields data that may not accurately reflect the conditions present on actual foggy expressway sections. This study distinguishes itself by conducting real-vehicle experiments within authentic expressway settings, thereby endowing the research outcomes with heightened credibility. However, due to the unique nature and extended duration of these experiments, it was not feasible to comprehensively account for the influence of road surface parameters and variations in road geometric alignment on driver behavior. Future research endeavors will integrate variables such as expressway surface friction coefficients and road geometric structures. The findings of this paper are poised to offer theoretical substantiation for the necessity of deploying traffic safety guidance devices in response to sudden low-visibility conditions both nationally and internationally. Furthermore, the study provides insights into the psychological impact of low-visibility conditions on drivers and can inform the development of guidelines for the placement of guidance lights. Study conception and design: X.L. ; analysis and interpretation of results: Q.S. and X.L. ; draft manuscript preparation: Q.S. and X.L. ; investigation, X.L. All authors have read and agreed to the published version of the manuscript. This research was supported by the National Natural Science Foundation of China (Grant No. 52102408); the project of Science and Technology Research Program of Chongqing Education Commission of China (No. KJZD-K202400710); the Research Project of Chongqing Municipal Education Commission of Science and Technology (No. kjqn202000750); the open fund of Changsha University of Science and Technology Transportation Engineering and Surveying Science and Technology Research Base (No. kfj210704) and the Research Project on Higher Education Teaching Reform of Chongqing Education Commission (No. 234145). Not applicable. All data included in this study are available upon request by contact with the corresponding author after publication of this article. The authors declare no conflicts of interest. Notation  
The input information variable of the human visual system  
The output information variable of the human visual system