Visibility is an important factor affecting pedestrian movement and safe evacuation. To investigate the walking characteristics of pedestrians under limited visibilities, a novel measurement method by changing the light transmittance in a suitable lighting environment is proposed to achieve different visibility levels. A series of individual movement experiments were performed under the quantitative control of visibility condition. Stoop-walking behavior was observed at low visibility levels. Besides, pedestrians would stretch out their arms or feet to explore the surrounding environment under invisible conditions. Based on the high-precise trajectories, it is found that the acceleration and relaxation time of individuals increase with the improvement of visual condition. The walking speed of males is significantly larger than that of females at the same visibility level. Moreover, individual speed increases with the improvement of visibility level, but no significant difference is found when the visual distance is larger than 6 m. In addition, individuals prefer to change movement direction rather than reduce the speed to avoid the frontal obstacle or pedestrians under limited visibilities. Furthermore, comparison between previous studies and our work is made, and their differences are also elaborated. The study can help to quantitatively predict pedestrian’s speed and develop movement models for limited visibility situations.

能见度是影响行人移动和安全疏散的重要因素. 为了研究行人在有限能见度下的行走特性，提出了一种通过在合适的照明环境中改变透光率来实现不同能见度的新测量方法。在能见度条件下进行了一系列的个体运动实验。在低能见度水平下观察到弯腰行走行为。此外，行人会在看不见的情况下伸出手臂或脚来探索周围的环境。基于高精度轨迹发现，个体的加速和放松时间随着视觉条件的改善而增加。在能见度相同的情况下，男性的步行速度明显大于女性。而且，个体速度随着能见度的提高而增加，但视距大于6 m时差异不显着。此外，在能见度有限的情况下，个人更喜欢改变运动方向而不是降低速度来避开正面障碍物或行人。此外，对以往的研究与我们的工作进行了比较，并阐述了它们的差异。该研究有助于定量预测行人的速度，并为能见度有限的情况开发运动模型。对以往的研究与我们的工作进行了比较，并阐述了它们的差异。该研究有助于定量预测行人的速度，并为能见度有限的情况开发运动模型。对以往的研究与我们的工作进行了比较，并阐述了它们的差异。该研究有助于定量预测行人的速度，并为能见度有限的情况开发运动模型。