| Grassland highway has the characteristics of simple line shape,small traffic volume,few towns passing through,single road landscape,large proportion of long straight lines,imperfect traffic engineering facilities,etc.Drivers are less stimulated by information during driving,which leads to low switching frequency of driver operation,easy to induce fatigue state of drivers and even lead to distracted driving.Through the preliminary investigation,it was found that the grassland highway has the problem of lack of traffic sign information,which is also the main cause of traffic accidents.Traffic signs,as the infrastructure of highway engineering,provide drivers with road environmental information.Different traffic signs contain different information with different importance.Drivers pay more attention to traffic signs with higher information importance according to their own demand for traffic sign information,and perceive,judge and process all kinds of information to finally realize purposeful operation.Once the information content of traffic signs is set unreasonably,the judgment ability and driving behavior of drivers will be affected,and even wrong reactions will occur,leading to traffic accidents.The quantification of traffic sign information is the basis for the reasonable setting of traffic signs.At present,the research on quantitative methods of traffic signs is only evaluated from objective factors such as characters and colors,but not from the subjective perspective of drivers.Based on the above problems,this paper aims at the present situation of grassland highway traffic sign information,based on information theory,uses physiological experiment method,studies the driver’s attention to the prohibition sign information from the perspective of driver’s visual characteristics,puts forward the attention model,and determines the effective information amount of the prohibition sign by using the driver’s attention to the prohibition sign information.The main conclusions of this paper are as follows:(1)Through the investigation and statistics of typical secondary grassland road traffic signs,the information of various factors of grassland road traffic signs is analyzed and summarized,and the basic information of grassland road ban signs is determined.The basic information of speed limit signs is 17bits,that of load limit signs is 22.4bits,and that of yield signs is 15.9bits.(2)The driver’s attention Cn to the prohibition sign information is proposed.The index includes the sub-percentage of video injection in the region of interest,the percentage of fixation time in the region of interest and the pupil diameter.The sub-percentage of video injection in the region of interest has a high correlation with the percentage of fixation time in the region of interest,while the pupil diameter has no correlation with the sub-percentage of video injection in the region of interest and the percentage of fixation time in the region of interest.And through verification,the Cn function relation of all kinds of ban signs is revised,and the attention index of all kinds of ban signs is calculated,in which the attention of speed limit signs is 42%,that of load limit signs is 40%,and that of line signs is 48%.(3)Using the driver’s subjective attention Cn to the information of the ban sign,the objective information amount of the ban sign is corrected,and the effective information amount of the ban sign is determined.The effective information amount of the speed limit sign is 7.16bits,the effective information amount of the load limit sign is 8.96bits,and the effective information amount of the line sign is 7.63bits.(4)A quantitative method of grassland highway ban sign information is proposed.Based on information theory,from the perspective of driver’s gaze behavior,the information attention parameter is introduced to modify the traditional information quantitative model.The quantification method is not only applicable to ban signs,but also applicable to other traffic signs. |
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