Too sick to take over? − Impact of car sickness on cognitive performance related to driving in the context of automated driving

Car sickness in automated driving is not only a comfort issue but might also negatively affect performance. It could be a safety risk if a car-sick driver has to take over, for example in an emergency situation, and their ability to safely control the vehicle is impaired. Previous studies have shown negative effects of other types of motion sickness, such as sea sickness or simulator sickness, on various cognitive performance measures. This is the first study to investigate the effects of actual car sickness in a real vehicle on several performance requirements relevant to driving. Data from two independent studies with N = 20 and N = 47 participants are reported. In both studies, performance tasks were completed before and after car sickness was induced in a real vehicle ride. These tasks represented different aspects of driving, i.e. a visual search task for visual selection, a simple reaction task for reactions to sudden events, a mental rotation task for visuo-spatial ability and a tracking task for hand-eye coordination. Reaction times were significantly prolonged and hand-eye coordination significantly impaired as symptoms of car sickness increased. Visuo-spatial performance also decreased with increasing car sickness, but not significantly (p = 0.059). Visual search was not negatively affected by car sickness. Subjectively, car sickness reduced the ability to concentrate and increased the subjective effort to complete tasks. The results indicate that actual driving performance may be affected by car sickness. The transferability of the results should be verified in a real driving study.