Visual Adaptation Mechanism In Urban Tunnel Exit Driving

Due to the dim and irregular light in urban tunnels,it has great obstacles to drivers’ visual perception and decision-making,so driving in urban tunnels is more dangerous.There are usually many considerations in terms of speed,tunnel length,tunnel lighting and so on.However,traffic accidents still occur frequently in the tunnel section,especially at the entrance and exit of the tunnel.The biggest reason is the sharp change of light near the entrance and exit of the tunnel,which has an important impact on the visual perception,timely decision-making and driving behavior of drivers.Therefore,it is of great practical value to study the visual adaptation mechanism to brightness in the process of urban tunnel exit driving.In this paper,the driving videos collected in advance near the exit of the urban tunnel are used to design a laboratory simulation driving experiment,and the eye movement and EEG data are collected simultaneously to analyze the influence of the brightness change in a period of time before and after the exit of the urban tunnel on the eye movement and EEG signals of drivers,and to explore the cognitive psychological mechanism of drivers in the process of brightness adaptation near the exit of the tunnel.The relationship between eye movement and EEG signals and the changes of internal and external brightness of urban tunnel exits is analyzed from the aspects of pupil diameter,gaze feature,saccade feature,EEG frequency band and EEG feature quantity.The results are as follows:(1)The brightness began to increase at the third second before the exit of the tunnel,and the pupil diameter began to contract accordingly.The pupil diameter contracted to the minimum value 1.5 seconds after the exit of the tunnel,and the light adaptation process was completed within 4.5 seconds;(2)Near the exit of urban tunnels,drivers’ fixation points are concentrated in the vertical level,mainly focusing on the tunnel road surface and the intersection farther outside the tunnel;(3)The saccade index reflects the influence caused by the change of brightness.The closer the distance to the exit of the tunnel,the greater the saccade amplitude,which basically remains unchanged after exiting the tunnel,and the difference of saccade speed is not significant;(4)The onset time and duration of drivers’ EEG signals in different frequency bands were different in response to brightness changes.(5)Combined with the relationship between EEG feature quantity and eye movement feature quantity in time,this paper establishes the dynamic time delay model of EEG signal in each frequency band and pupil diameter,further discusses the visual cognitive psychological mechanism near the entrance and exit of the tunnel,and based on this,puts forward constructive guidance suggestions for driving safety at the exit of the urban tunnel.The results of this paper on the visual adaptation mechanism in the process of driving at the exit of urban tunnels are helpful to deepen our understanding of the human visual brain mechanism,and can provide useful reference for the lighting design,speed design,and visual perception and cognitive training of drivers at the entrance of urban tunnels.