城市快速路高架桥段行驶视觉空间的结构特征与行车安全

视觉疲劳是驾驶人在高速行车过程中致命的交通安全隐患,对驾驶人行驶视觉空间的结构特征进行数量化分析,是研究驾驶视觉和行车安全的重要途径.针对城市快速路高架桥比例高和视觉环境单一等特点,用车载等距变距自动成像技术对高架桥段驾驶人行驶视觉空间进行还原模拟实验,采用数值计算对普通高架桥段和特殊零界面高架桥段行驶视觉空间的结构特征进行分析比对,确定两种典型空间的视觉要素构成与变化频率.实验结果表明,除天际背景外城市高架路行驶视觉空间内的视觉要素均低于普通城市道路；普通高架桥段的主要视觉要素为空旷天际背景的桥面,其次为右侧沿街建筑,且分布均衡单一,易导致驾驶人视觉疲劳；零界面高架桥段的视觉要素较长时间处于匮乏状态,易引发驾驶人焦虑、恐慌和不稳定感等负面驾驶心理.通过交通安全设施的合理设计引导驾驶员视线适时收放可有效缓解驾驶人的视觉疲劳,增加视觉对象作为高程参照是消除零界面桥段负面驾驶心理的最直接手段.

Driving safety and structural characteristics of driving visual space in the viaduct section of an urban expressway

Visual fatigue is a fatal traffic safety hazard for drivers in the process of high-speed driving. Therefore, the analysis of the driving visual space of the driver in a quantitative way is an important path to reveal the relationship between driving safety and driving visual behavior. In response to these characteristics, such as a monotonous visual environment and a high proportion of viaducts in the urban expressway, this research adopted the automatic imaging technology of vehicle-mounted isometric and variable-distance for the simulation experiment, and the numerical analysis method is used to analyze the structural characteristics of the driving visual space between the common viaduct section and the zero-interface viaduct section in the urban expressway, to determine the composition and frequency of visual elements in the two typical spaces. Results show that the visual elements of the urban viaduct section are lower than the common urban roads in addition to the sky background. The main visual elements of the viaduct section are the bridge pavement with the sky as the background and the right-side street building, and the distribution of these elements is too balanced and simplification, thereby causing visual fatigue of the driver. In addition, the visual elements of the zero-interface viaduct section are in a state of scarcity for a long time, which is easy to cause negative driving psychology, such as anxiety, panic and instability. The reasonable design of traffic safety facilities to guide the driver''s sight at the right time can effectively alleviate the driver''s visual fatigue, and increasing the visual elements as the elevation reference is the most direct measure to eliminate the negative driving psychology of the zero-interface viaduct section.