Study On Optimization Of Highway Tunnel Entrance Landscape Based On Dynamic Visual Law

Highway tunnel is a kind of special tubular structure which has two opening ends and closed middle,this is bound to cause such traffic safety problems:the illumination inside tunnel is lower than outside at daytime,illumination inside tunnel is higher than outside at night,tunnel illumination inside and outside always have large differences,also vehicles travel in confined spaces,the fire encountered is not easy to extinguish.Driver is the most dominant in interactive system of driver,vehicle,road and environment,as driver is the only operator and experiencer of highway environment,so the driver must be one of the main factors of road traffic safety.According to the the previous research data,more than 90% of accidents are directly or indirectly caused by the driver.Drivers get traffic informations with the sense organs,80% of the traffic informations is obtained by visual organ and more than 95% are dynamic visual informations,as a result,the key traffic information is dynamic visual information,and dynamic visual information is the foundation of road safety research.So this thesis focuses on the research of how tunnel entrance landscapes influence dynamic visual characteristics and the optimization of tunnel entrance landscapes has a very important significance on highway construction.People use hue,lightness and purity to identify and distinguish the color,which are the basic properties of color,so these are called three attributes or three elements of color.The basic properties of the tunnel entrance landscape color are also hue,lightness and purity.According to the comparison between the photoes of tunnel entrance landscape at different times,the best color identification element of tunnel entrance landscapes should be the lightness.The environments inside and outside of tunnel entrance change suddenly,light intensity also occurs significant change,these huge differences inevitably lead to great dynamic vision changes of driver.Dynamic visual feature parameters can measure these changes,so in this thesis,it is the most appropriate to select pupil size as a measure of driver visual comfort index in the process of entering the tunnel.We choose to use eye tracker to record the changes of driver's dynamic visual data in the process of entering the tunnel.According to the data of test driver's pupil area,we can get dynamic visual data change regulation in the process of different time entering the tunnel entrance at different times.According to the tunnel experiment results of different times,in sunny morning and afternoon or at cloudy noon,the landscape color lightness is moderate,the truth and visibility of color is the best,meanwhile the driver's dynamic vision in the process of entering the tunnel entrance is most comfort,and safety is best;at sunny noon the landscape color lightness is high,the color isn't quite true to the original,so driver's dynamic vision is not comfortable,and changes in pupil size have a small range of fluctuation;in sunny evening,cloudy morning or afternoon,the landscape color lightness is very low,the color isn't quite true to the original,so the driver's dynamic visual comfort is the worst,there is a wide range of changes in pupil size.Finally providing optimal illumination of the road,different lightness of the landscape is optimized,meanwhile,different lightness of landscape and brightness contrast card are corresponding.