Center for Psychological Science at Zhejiang University, Hangzhou, Zhejiang Province, China.
Southern Medical University, Guangzhou, Guangdong Province, China.
PLoS One. 2017 Oct 17;12(10):e0185347. doi: 10.1371/journal.pone.0185347. eCollection 2017.
Speed estimation of drivers' own vehicles and other vehicles on the road is an important task for drivers and is also crucial to the roadway safety. The objective of the study was to examine the effects of multiple factors such as image scale, speed, road type, driving experience, and gender on the speed perception of drivers' own vehicles.
Thirty participants consisted of 17 males and 13 females, including 13 without driving experience. All participants estimated the driving speed of 192 5-second video clips, which were selected from naturalistic driving recordings. The recorded driving speeds were evenly distributed across the entire range from 5mph to 65mph. Half of the selected video clips were recorded on wide roads and another half were recorded on comparatively narrow roads. Video clips were played on a large screen, with each clip shown in one of 4 image scales (100%, 75%, 50%, and 38% of the actual field of view in the real world).
Speed estimates were most accurate for the smallest image size (38% of the actual field of view). As the image size increased, the driving speed was increasingly underestimated. Participants with driving experience accurately estimated the driving speed on both wide and narrow roads whereas those without driving experience had greater underestimates on wider roads. Speeds were most accurately estimated within the range 25-35mph, but the speeds slower than the range tend to be overestimated and the speeds faster than the range are more likely to be underestimated. While males and females showed the same pattern across speed groups, females have greater estimation errors at the highest and lowest speed groups. Participants without driving experience showed increasing underestimation of speed as driving speed increased whereas participants with driving experience primarily underestimated the highest speeds.
The present study shows the effect of multidimensional influential factors on perceived vehicle speed from drivers' perspective. The results also have implications for driving simulation scenario design, driving simulator setup, and the assessment of speed control in simulated and naturalistic environments.
估计驾驶员自身车辆和道路上其他车辆的速度是驾驶员的一项重要任务，对道路安全也至关重要。本研究的目的是检验多种因素（如图像比例、速度、道路类型、驾驶经验和性别）对驾驶员自身车辆速度感知的影响。
30 名参与者包括 17 名男性和 13 名女性，其中 13 名无驾驶经验。所有参与者估计了 192 个 5 秒视频片段的行驶速度，这些片段选自自然驾驶记录。记录的行驶速度均匀分布在 5 英里/小时至 65 英里/小时的整个范围内。所选视频片段的一半是在宽阔的道路上录制的，另一半是在相对狭窄的道路上录制的。视频片段在大屏幕上播放，每个片段以 4 种图像比例（实际视野的 100%、75%、50%和 38%）之一显示。
最小图像尺寸（实际视野的 38%）下的速度估计最准确。随着图像尺寸的增加，行驶速度被越来越低估。有驾驶经验的参与者准确估计了宽阔和狭窄道路上的行驶速度，而无驾驶经验的参与者在宽阔道路上的低估幅度更大。速度在 25-35 英里/小时范围内估计最准确，但速度低于该范围时往往被高估，速度高于该范围时更可能被低估。虽然男性和女性在各速度组中表现出相同的模式，但女性在最高和最低速度组中的估计误差更大。无驾驶经验的参与者随着行驶速度的增加，对速度的低估程度逐渐增加，而有驾驶经验的参与者主要低估最高速度。
本研究从驾驶员的角度展示了多维影响因素对感知车速的影响。研究结果还对驾驶模拟场景设计、驾驶模拟器设置以及模拟和自然环境中的速度控制评估具有启示意义。
