Research On The Influence Of Awning On The Visual Characteristics Of Drivers In Tunnel Entrance And Exit

In recent years,traffic accidents happened frequently at tunnel,which has become a public concern.There are at least two reasons accounted for this issue.On the one hand,drivers are often susceptible to environmental influences,resulting in operational errors.On the other hand,the unique light environment at tunnel,especially at the entrance and exit of tunnels,have a great effect on drivers' driving performance.Due to the special driving environment of tunnel,there are undesirable phenomena such as “black hole effect”,“white hole effect”,“stroboscopic effect” and “zebra effect”,leading to visual discomfort and even momentary blindness.At present,China mainly regulates the entrance and exit of tunnels and the lighting inside tunnels according to the "Design Rules for Highway Tunnel Lighting".Enhancing light is a practical Reinforced lighting is a practical way to alleviate the problem of tunnel light environment,but it often increases the cost of road maintenance.Setting an awning at the tunnel entrance and exit is often a suitable option.The awning can not only construct a good brightness transition zone,alleviating the problem of light and dark adaptation of the tunnel entrance,reducing the burden on the driver,improving road safety,but also reduce the number of lamps of enhance lighting section,reducing power consumption,and help build an environmentalfriendly tunnel.Considering that the main purpose of setting up the awning is to improve the visual characteristics of the driver when entering and exiting the tunnel,it is necessary to explore the necessity of setting up the awning at the entrance and exit of the tunnel and its influence on the driver visual characteristics.This paper intends to analyze and study the influence of the setting of the tunnel entrance and exit awning on the visual characteristics of the driver from the perspective of the driver.Collecting driver's eye movement data,cardiac physiological data and vehicle operation data by real-time vehicle operation data acquisition platform to analyze the influences of awning setting on the driver's basic eye movement characteristics,the driver's visual shading adaptation characteristics,visual dynamic searching characteristics and driver's gaze transfer characteristics.The result of this research have shown that the awning has a significant impact on the basic eye movement characteristics of the driver.Compared with the tunnel without the awning,the gaze time and the proportion of gaze increase and the number of blinks decreases at the entrance and exit of tunnel with awning.The awning alerts the driver to concentrate on driving tasks.As for light and dark adaptation characteristics,the improvement effect of entrance awning is slightly better than that of the exit awning.After the entrance awning is set,the visual impact of the tunnel light environment on the driver is effectively alleviated.The driver's visual adaptation time is shortened,and the tunnel light environment of the tunnel entrance section can be more quickly adapted.The exit awning offers the driver longer adjustment time to ensure that the driver can safely drive out of the tunnel.In terms of the driver's dynamic visual characteristics,the setting of the awning has little influence on the driver's gaze concentration area;it has a positive guiding effect on the driver's visual search breadth,and the entrance awning makes the driver's visual search breadth narrow and the visual breadth shrinkage rate is-0.03,which is improved compared to the non-awning case with the visual breadth shrinkage rate-0.01.And the exit awning can also improve the driver's visual search breadth,the extend rate is increased from 0.008 of the tunnel exit without awning to 0.025 of the tunnel exit with awning,which helps the driver search a wider space in bright environment;it has little effect on the main form of the driver's gaze transfer characteristics.Regardless of whether the entrance and exit tunnel has an awning,the two transfer is the main visual transfer mode.The research results can provide theoretical guidance for the awning design,and theoretical basis and objective evaluation for the awning setting to promote the safe development of the transportation system.