Study On The Driver’s Dynamic Visual Characteristics Of Prairie Highway Field Landscape

The human-machine environmental system consists of people, vehicle, road and environment, and people are the core element within it. Highway landscape, a crucial and critical part of highway traffic man-machine environmental system, stimulates driver’s vision, which directly affects their psychology and physiology states, driving behaviors and fatigue levels. Accounting for 73.3% of the total area in Inner Mongolia autonomous region, grassland constitutes the main landscape type, and most of built and building roads are located in this area. Generally, highways in grassland have typical characteristics, such as small change of landform, few towns and villages passing by, simple alignment, large sight distance and monotonous landscape, etc. So the low switching frequency and little visual stimulus when driving on the grassland highways often drags the driver into an unreasonable monotonous state, and it easily results in the psychological and physical fatigue with slower response, lower attention, increasing speed and distance estimation deviation and decreasing the ability of perception and processing information, all of them pose a serious threat to drivers’ safety. Thus, research on driver’s dynamic visual characteristic can be beneficial for the design and optimization of highway landscape based on the environment of the prairie-highway, which also promotes the driving comfort level, reduces drivers’ fatigue as well as strengthens the traffic safety. As a result, this study performs great practical significance.In this paper, 5 kinds of landscape are surveyed within prairie highways in Inner Mongolia and sorted by the method of comprehensive classification. Some appropriate eye movement indexes are determined based on the theory of visual physiology and psychology and practical eye movement data collected through real driving test on prairie highways. This dissertation aims to study the impact of grassland highway landscape on driver’s dynamic visual features by analyzing each driver’s eye movement indicators and exploring the law of eye movement in different landscape environment. Also, the quality of prairie highway landscape is evaluated with the methods of combination of quantitative and qualitative so as to verify the characteristics of the monotonous landscape, which sets a solid foundation to optimize the human-machine environmental system of grassland highway.Through the research on the effect of different landscape environment of prairie highway on the driver’s dynamic visual characteristics, some conclusions can be concluded as followings:(1) Due to large difference in the region, landscape and road alignment of prairie highway, landscape environment of prairie highway is divided into five kinds by comprehensive classification such as respectively typical grassland landscape, half desertification grassland landscape, hilly area landscape, severe degradation grassland landscape and wetland grassland landscape.(2) The pupil area change rate of diver is mainly concentrated in the range of 0 ~ 10% and the blink duration of diver is mainly concentrated in the range of 150 ~ 300 ms under five kinds of landscape environment of prairie highway. It is shown that the impact of the different types of landscape on driver’s pupil area and blink duration is not obvious.(3) The saccade amplitude is mainly concentrated in the range of 5 ° ~ 20 ° range in hilly area landscape and wetland grassland landscape, others is in the range of 0° ~ 10 °. It is shown that the impact of the different types of landscape on driver’s saccade amplitude is significant.(4) The driver’s average fixation duration is longer in typical grassland landscape, half desertification grassland landscape and wetland grassland landscape. But it is shorter in hilly area grassland landscape and severe degradation grassland landscape(338 ms). It is shown that the impact of the different types of landscape on driver’s the fixation duration is significant.(5) The visual quality is poorer in the typical grassland landscape, half desertification grassland landscape and severe degradation grassland landscape, but the visual quality is better in the hilly area grassland landscape and wetland grassland landscape.(6) The typical grassland landscape and half desertification grassland landscape are accounted for more than 80% and others is less proportion in the road region landscape of the prairie highway. In consequence, the road region landscape quality of the prairie highway is overall poorer, which easily leads to fatigue of the driver and seriously threats driving safety.