The objective of this study was to compare the development of sleepiness during manual driving versus level 2 partially automated driving, when driving on a motorway in Sweden. The hypothesis was that partially automated driving will lead to higher levels of fatigue due to underload. Eighty-nine drivers were included in the study using a 2 × 2 design with the conditions manual versus partially automated driving and daytime (full sleep) versus night-time (sleep deprived). The results showed that night-time driving led to markedly increased levels of sleepiness in terms of subjective sleepiness ratings, blink durations, PERCLOS, pupil diameter and heart rate. Partially automated driving led to slightly higher subjective sleepiness ratings, longer blink durations, decreased pupil diameter, slower heart rate, and higher EEG alpha and theta activity. However, elevated levels of sleepiness mainly arose from the night-time drives when the sleep pressure was high. During daytime, when the drivers were alert, partially automated driving had little or no detrimental effects on driver fatigue. Whether the negative effects of increased sleepiness during partially automated driving can be compensated by the positive effects of lateral and longitudinal driving support needs to be investigated in further studies.

这项研究的目的是比较瑞典高速公路上手动驾驶与2级半自动驾驶时嗜睡的发展情况。假设是部分自动驾驶会由于欠载而导致更高程度的疲劳。该研究采用了2×2设计，其中包括89个驾驶员，条件是手动驾驶与部分自动驾驶，白天（全睡）与夜间（睡眠不足）。结果表明，夜间驾驶会导致主观嗜睡等级，眨眼时间，PERCLOS，瞳孔直径和心率方面的嗜睡水平显着提高。部分自动驾驶会导致主观嗜睡等级稍高，眨眼时间更长，瞳孔直径减小，心率变慢以及EEGα和theta活性较高。但是，睡眠压力升高主要是由于夜间开车导致的睡眠水平升高。在白天，当驾驶员保持警觉时，部分自动驾驶对驾驶员疲劳的影响很小或没有。在半自动驾驶过程中增加嗜睡的负面影响是否可以通过横向和纵向驾驶支撑的正面影响来弥补，这需要进一步研究。