| Accidents occurred frequently and severely in urban underpass tunnels.Therefore,it is urgent to study the traffic safety about urban underpass tunnels.When a vehicle passes through an urban underpass tunnel quickly,the uphill and downhill section of its portals and the semi-enclosed tunnel structure will exert certain psychological pressure on the driver,thus affecting traffic safety.Therefore,in this research,a real vehicle experiment for urban underpass tunnel was designed to explore the changing law of drivers' behavior and physiological characteristics in different sections of urban underpass tunnel(longitudinal slope section,entrance and exit section,internal section).Specifically,the main contents are as follows:(1)A real vehicle experiment was carried out.Considering the impact of longitudinal slope section and accident situation of urban underpass tunnel synthetically,eight typical urban underpass tunnels of Hefei No.1 Ring Road in Hefei City were selected as experimental sections.A total of 32 drivers' behavior and physiological indicators,such as pupil area,heart rate and driving speed,were collected.(2)The traffic safety parameters of longitudinal slope section of urban underpass tunnel were optimized.The relationship between slope,speed and drivers' heart rate growth of longitudinal slope section of urban underpass tunnels has been emphatically studied.Specifically,the influence of slope on speed and drivers' heart rate was explored,and Post Hoc Analysis method was carried out afterwards to compare whether the influence of different slope range on vehicle speed and drivers' heart rate was significant.Then,the regression analysis method was used to establish the relationship models between longitudinal slope and speed,longitudinal slope and drivers' heart rate growth respectively,and to quantitatively analyze the change rule of drivers' heart rate growth and vehicle speed with slope.In addition,the comfort threshold of drivers' heart rate growth for urban underpass tunnel was proposed,and based on this threshold,the reference values of maximum safe slope and maximum safe driving speed for urban underpass tunnel were proposed.(3)The traffic safety parameters at the portals of urban underpass tunnels were optimized.Based on the velocity of the pupil area change,the drivers' light and dark adaptation time index at the urban underpass tunnel portals was established.The effect of illumination change and slope on drivers' light and dark adaptation time was analyzed,and a quantitative model for the relationship between slope,maximum illumination transition and drivers' light and dark adaptation time at urban underpass tunnel portals was constructed.In addition,the sensitivity of the independent variables(maximum illumination transition and slope)in the model was analyzed using a single factor sensitivity analysis method.Finally,the drivers' stopping sight distance was optimized based on the light and dark adaptation time,which provides a strong reference for traffic safety design and the management of urban underpass tunnel portals.(4)The traffic safety parameters of the inner section of urban underpass tunnel were optimized.The relationship between illumination in the inner section tunnel and drivers' heart rate growth,pupil diameter and speed respectively has been emphatically studied.To explore the effects of illumination on drivers' heart rate growth,pupil diameter and vehicle speed.The relationship between illumination and drivers' heart rate growth,pupil diameter and vehicle speed was quantified.Then,based on the ROC discriminant model of drivers' physiological comfort,the proposed illumination design value of the inner section of urban underpass tunnel was proposed.Finally,based on the proposed illumination value,the recommended speed value of the inner section of urban underpass tunnel was proposed. |
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