Investigating effects of temperature and CO 2 on driver drowsiness in the context of conditional automated driving
通过驾驶模拟实验，研究了车内温度（22.5°C、25°C、27.5°C）和二氧化碳浓度（4200、1200 ppm）如何影响条件自动驾驶下驾驶员的困倦程度和生理反应，发现低温降低困倦，高二氧化碳抑制心血管活动但主观无感。
With the introduction of conditional automated driving, drivers are freed from continuous control but must remain alert for takeover requests. This study examines how in-cabin temperature (22.5 °C, 25 °C and 27.5 °C) and CO2 (4200 and 1200 ppm) influence driver drowsiness and physiological responses under conditional automated driving. A driving simulator experiment involving 60 participants was conducted, collecting subjective ratings, eye-tracking and physiological data. Results showed that cooler temperatures were associated with lower drowsiness levels compared to neutral temperatures. However, physiological responses may mainly reflect thermoregulation when temperature varies, obscuring drowsiness-related changes. Further, although CO2 concentration did not significantly affect subjective drowsiness, higher CO2 levels attenuated cardiovascular and autonomic activity, suggesting CO2 effects on physiological responses can emerge before conscious awareness. These findings suggest that climate control systems in automated vehicles should balance comfort, efficiency and driver alertness, while physiology-based driver monitoring systems should incorporate environmental data to detect drowsiness earlier.