Optimization Of Parameters Of Road Facilities On Horizontal Curves Under The Influence Of Visibility

In recent years,the number of motor vehicles has continuously increased in our country,and traffic accidents and death rates are consistently high.Due to the large regional climate variability in our country,there is a great hidden danger to driving safety in areas with low visibility,such as rainy and foggy weather.The design parameters of the horizontal curve road stipulated in the current technical standards of Highway Engineering in China,only considering the stability of the vehicles dynamics,has some limitations.This paper optimizes the road facilities parameters of the horizontal curved section based on the visibility in rainy days.The topic of this thesis comes from the National Natural Science Foundation of China of “Accident Risk Assessment of Highway Traffic Flow and Optimization of Safety Design Parameters under the Influence of Visibility(NO.51578207)”.Firstly,a safe speed limit calculation model was constructed based on the analysis of the driving distance on horizontal curves,and considering the environmental visibility and other parameters under the influence of rainy days,which is suit to the horizontal road curve section in the rainy area.According to the results of the model calculation,the limit radius of horizontal curve in rainy area can be optimized.Meanwhile,the corresponding speed limit design values for different horizontal alignment segments are given for different rainfall intensities.Secondly,referencing the existing research results,the geometric equation of the horizontal curve section and the driver sight line were constructed for optimizating the set method of chevron,considering the impact of visibility on driver sight line,and utilizing the geometric parameters of the horizontal curve.Finally,simulation experiments are carried out with driving simulator.The experimental results show that the calculation results obtained from the geometric model of the horizontal curve and the driver sight line to set chevron,can effectively reduce the running speed of the vehicle in the curve section,keep the current lane track,and improve the accuracy of driver sensing when the front alignment curve changes.Through this research,utilizing electronic traffic sign technology in future,the interval between alignment inducing sign can adjust according to different weather conditions,which effectively improve the construction of road traffic safety facilities in our country,and provide new research ideas for reasonable speed limit of horizontal curve sections and road parameter optimization theory research.