Abstract: To analyze the effect of lighting conditions on the visual behavior of urban road cyclists, eye movement experiments were conducted by using TobiiGlasses eye-tracking devices under three kinds of conditions: daytime, evening and nighttime. The fixation, scanning, blinking, and pupil indicators of cyclists under three kinds of conditions were compared and analyzed. K-means clustering was used and integrated with scenes to divide gaze regions, and the cyclists gaze transfer probability and stability probability were obtained by Markov chains. Indicators was established to analyze the visual change rate of cyclists. The results show that: cyclists visual field spreads gradually as light fades, and the degree of visual load is inversely proportional to light level. When external lighting weakens, the probability of gaze transfer to distant and brighter objects is higher. In both processes of light fading, cyclists perception and access to hazards decreases more significantly from day to evening, the probability of balancing various regions is slightly higher, and cyclists tension is higher from evening to night.

Key words: traffic engineering; eye-movement characteristics; electric bicycles; Markov chains; light conditions

摘要： 为分析光照条件对城市道路骑行的视觉行为影响，使用TobiiGlasses眼动仪在白天、傍晚和夜晚3种条件下进行眼动实验，对比分析3种条件下骑行者的注视、扫视、眨眼和瞳孔指标；使用K均值聚类并综合场景划分注视区域，使用马尔可夫链得到骑行者的注视转移概率和平稳概率；建立指标分析骑行者的视觉变化率。结果表明：骑行者的视野范围随光照减弱逐渐扩散，视负荷程度与光照度成反比；外部光照减弱时，对远处和亮度更高处的注视转移概率更高；在光照减弱的两个过程中，从白天到傍晚骑行者的认知和获取危险能力下降更明显、对各个区域的兼顾概率略高，从傍晚到晚上骑行者的紧张程度更高。

关键词: 交通工程；眼动特性；电动自行车；马尔可夫链；光照条件