Carolina Diaz-Piedra¹, Francesco Angioi^1,2, Rocío de Oña², Juan de Oña², David Soler-Ortiz¹, Leandro L. Di Stasi^1,3; ¹Mind, Brain, and Behavior Research Center (CIMCYC), University of Granada, Spain, ²TRYSE Research Group, Department of Civil Engineering, University of Granada, Granada, Spain, ³Joint Center University of Granada - Spanish Army Training and Doctrine Command, Spain

Background: Adverse weather is a well-recognized major risk factor for road safety, as it substantially reduces visibility and predictability of road geometry. Conventional road technologies, such as white markings or passive road studs (known as "cat's eyes”), offer limited improvements in visibility. In contrast, smart road technologies (SRT) - such as photoluminescent markings (PRM) and active studs (ARS) - may enhance drivers’ situational awareness by increasing luminance contrast and highlighting potential hazardous situations. However, it remains unclear whether these technologies shape drivers’ visual exploration strategies and, in turn, affect driving performance. Here, we investigated how different technologies affect stationary gaze entropy during nighttime driving under both clear and adverse weather conditions. Methods: Fifty participants (mean age ± SD = 36.88 ± 11.28 years; 23 women) underwent two driving sessions (dry and rainy) each consisting of four driving scenarios (~ 15 min each, one for each technology: white markings, passive road studs, ARS, and PRM). We recorded stationary gaze entropy using the Tobii Glasses 2.0 (50 Hz), driving performance (speed and lateral position), and subjective ratings of complexity with a visual analog scale. Results: Drivers’stationary gaze entropy changed depending on the road technology of the scenario. Such changes were similar in both weather conditions. Post hoc comparisons showed that ARS led to less random (i.e., more stereotyped) visual exploration than classical markings. PRMs did not have such an effect. Finally, while perceived complexity was similar across all scenarios, driving performance improved when driving with PRM. Conclusions: Results show that ARS are valuable visual guidance tools for enhancing driving in poor visibility conditions by increasing drivers’ situational awareness. This study supports the introduction of smart technologies as complementary passive countermeasures to promote better visual strategies, even in adverse weather conditions.

Acknowledgements: This work is part of the Research Project SARAH (PID2022-141935OB-I00; MICIU/AEI/10.13039/501100011033 & ERDF/UE). FA is supported by a Spanish national pre-doctoral FPI research fellowship (PREP2022-000307; MICIU/AEI/10.13039/501100011033 & ESF Investing in your future).