Influence Of Upstream Tunnel Length On Physiological Load Of Downstream Tunnel Drivers

Highway tunnel group is accident-prone because of its special structure and driving environment.On the one hand,drivers driving in tunnel group will experience the process of light adaptation,dark adaptation and overlapping of light and dark adaptation due to the continuous change of light environment,which will bring visual burden to drivers.On the other hand,the upstream tunnel is too long,resulting in long-term sleepiness and fatigue for drivers in the dark environment.Therefore,compared with ordinary sections,the traffic accident rate of tunnel group is higher.In order to investigate the influence of upstream tunnel length on physiological load of drivers in each section of downstream tunnel group.The characteristics of eye movement,electrocardiogram and electroencephalogram of drivers in different tunnel groups were investigated by carrying out real car experiments.The comprehensive physiological load evaluation model of tunnel group drivers was built to evaluate the physiological load of each section in the middle and downstream of the tunnel group with different length of the upstream tunnel and its influence on the physiological load of the downstream tunnel group,and corresponding improvement measures for the downstream tunnel were proposed.The main research contents and conclusions of this paper are as follows:(1)According to the literature research,the continuous change of light and shade in the tunnel cluster environment will continuously increase the visual load of drivers,and also have a negative impact on the physiological response of drivers.In particular,the light environment of the upstream and downstream tunnel connection sections of the tunnel group changes dramatically,and the upstream tunnel of different lengths will bring different degrees of physiological load to drivers in the tunnel group connection sections.(2)Two or more consecutive tunnels with a distance less than 500 m are defined as tunnel groups by analyzing the optical environment characteristics of tunnel groups and drivers’ visual characteristics when driving tunnel groups.The tunnel group is divided into upstream tunnel entrance section,upstream tunnel middle section,upstream tunnel exit section,connection section,downstream tunnel entrance section,downstream tunnel middle section,and downstream tunnel exit section,which provides a basis for the subsequent analysis of the influence brought by the upstream tunnel length.(3)The pupil-area,pupil-area change rate,heart rate,SDNN,average β-wave power,(α+θ)/β change trend of drivers with upstream tunnel length were collected and analyzed through real vehicle test.The independence analysis is used to test the difference of the downstream tunnel segments with the length of the upstream tunnel.(4)Based on the principal component analysis method,the driver’s comprehensive load equation in the tunnel groups with different upstream tunnel lengths is constructed,and the comprehensive load value of each section of the downstream tunnel of the three tunnel groups is compared,and the conclusion is drawn: With the increase of the upstream tunnel length,the growth rate of comprehensive physiological load in the downstream entrance section of the tunnel group will be faster and the comprehensive physiological load in the middle section of the downstream will increase with the increase of the upstream tunnel length.Therefore,it is concluded that the entrance section of the downstream tunnel is a bad section of the downstream tunnel,and it is necessary to optimize the design of light environment to reduce the physiological load of drivers.Based on the analysis of the current situation of improving the technology of tunnel entrance section,reasonable improvement measures outside and inside the downstream tunnel entrance are put forward from the perspectives of cost and applicability.