Car handling, and hence, safety, is affected by the way we estimate speed. Speed, however, is often underestimated in degraded visual environments, including virtual environments such as driving simulators. In simulators the visual and physical motion are typically incongruent as limited by quality and amplitude, respectively, which may cause a negative transfer of training. To improve the (training) quality of simulators and make them feel more real, it would be helpful to fill a knowledge gap on in-car speed perception as affected by real and virtual views, within a single group of subjects. We did so by testing whether estimations of speed in terms of km/h could be a valid metric for that purpose. We therefore exposed 17 subjects, seated as passengers in the front of a car on a straight road to four experimental conditions: (1) driving with a real out-the-window view, (2) driving with a live video view, (3) standing still watching pre-recorded video's, and (4) driving with eyes closed. Field-of-view was made equal in all conditions. Speeds tested ranged between 20 and 60 km/h. On average, speed was estimated 5 km/h less than actual, while we did not find a statistically significant difference between the four conditions tested. These results seem to contradict previous observations on motion perception, in particular in simulators, that have been ascribed to the quality of the visuals used. This finding may yet be explained by the assumption that speed estimations in terms of km/h are dominated by (conscious) cognitive processes, while visual-vestibular coherence between visual and physical motion, is dominated by (unconscious) sensorial driven perceptual processes. This disqualifies perceived speed as a valid metric for studying motion perception related to the optimisation of simulators.

中文翻译：

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具有真实、虚拟和无视图的车内速度估算

汽车的操控性和安全性受到我们估算速度的方式的影响。然而，在退化的视觉环境（包括驾驶模拟器等虚拟环境）中，速度往往被低估。在模拟器中，由于质量和幅度的限制，视觉和物理运动通常不一致，这可能会导致训练的负面转移。为了提高模拟器的（训练）质量并使它们感觉更真实，在一组主题中填补受真实和虚拟视图影响的车内速度感知的知识空白将是有帮助的。为此，我们测试了以公里/小时为单位的速度估计值是否是一个有效的指标。因此，我们将 17 名受试者（作为乘客坐在汽车前部）暴露在四种实验条件下：(1) 以真实的窗外风景驾驶，(2) 以实时视频视图驾驶，(3) 站着观看预先录制的视频，以及 (4) 闭眼驾驶。视野在所有条件下均相等。测试的速度范围在 20 到 60 公里/小时之间。平均而言，估计速度比实际速度低 5 公里/小时，而我们没有发现四种测试条件之间存在统计学上的显着差异。这些结果似乎与之前对运动感知的观察结果相矛盾，特别是在模拟器中，这归因于所使用的视觉质量。这一发现可能还可以通过以下假设来解释：以公里/小时为单位的速度估计由（有意识的）认知过程主导，而视觉和物理运动之间的视觉-前庭一致性，由（无意识的）感官驱动的感知过程主导。这使得感知速度无法作为研究与模拟器优化相关的运动感知的有效指标。