Study On The Impact Of Mountain Freeway Tunnel Entrance Environment On Drivers' Physiology And Behavior

With the development of the road transportation,China has become the country with the most tunnel and the fastest construction speed in the world.However,the mountainous freeway tunnel entrance exists some defeciencies such as irregular road aligment,illumination variation,which would probably impact on drivers' physiology and behavior,thus affecting traffic safety.The traffic accident statistics show that the driver-related accidents accounted for about 80% of the total number of accidents.Therefore,taking the drivers' physiology and behavior under tunnel entrance as the object of this study,this paper aims to reveal the influence of the environmental factors of the tunnel entrance on the drivers' ECG and behavior,and develop the tunnel entrance risk prediction model and provide the tunnel safety improvement countermeasures.First of all,based on the study of the environmental and traffic accident characteristics of mountainous freeway tunnels,we choose the posted speed limit,road aligment and illumination as the performance parameters of the tunnel entrance environment.Through researching the relationship among the tunnel entrance environment,the driver's physiological,behavioral stimulus and effect is established,which is the theoretical foundation for the research.Base on this theory,the rate of heart rate is selected as the physiological evaluation index,velocity,speed difference,acceleration and acceleration disturbance are selected as the driving behavior index to study the influence of the tunnel entrance environment on the driver's physiology and behavior.Secondly,based on the measured data,the statistical knowledge is used to analyze the changing characteristics of the driver's heart rate,vehicle speed and acceleration in the tunnel entrance,and the influence of the tunnel entrance environment on the driver's physiology and behavior is studied.The results show that the driver 's heart rate is higher,the speed is lower,the speed difference is larger and the acceleration interference is larger at the tunnel of speed limit 60km/h than that of speed limit 80km/h.Under the same speed limit conditions,slope,flat curve radius,illumination significantly influence on the driver's heart rate and vehicle speed,acceleration.Then,the paper explores the relationship between driving physiology and driving behavior,and demonstrates their correlation,and constructs the regression model of speed and heart rate growth rate under SL80 and SL60.Based on the study of the influence of the tunnel entrance environment on the driver's physiology and behavior,the factors such as the rate of heart rate growth,the average speed,the speed difference and the acceleration disturbance were selected from the perspective of driver's physiology and behavior,and the entropy method was used to evaluate the tunnel dangerous degree and demarcate the indicators.Finally,based on the tunnel risk assessment method,we select slope,flat curve radius and the illumination as the input,the risk as the output to construct the multiple regression and BP neural network.The BP neural network prediction accuracy is higher by multiple regression analysis and BP neural network prediction model,and the multiple regression can judge the influence degree of each environmental parameter on the risk degree according to the regression coefficient.Through compare two models,BP neural network prediction accuracy is higher,and multiple regression can determine the impact of environmental parameters on the risk based on the regression coefficient.By analyzing the influence of environmental factors on the risk of tunnel import,the improvement measures of tunnel entrance environment are put forward from three aspects: reasonable speed limit,linear safety design and import dimming.The research results will help improve the road traffic safety management.