A Study On Optimization Method Of Safety Parameters Of Road Intersection In Mountainous City Based On Driver’s Heart Rate

Intersection will produce certain psychological pressure on drivers,and then affect their driving behavior and driving safety.The road conditions in mountainous cities are complex,and the shape of intersections is irregular,which is more influential to drivers.From the driver’s point of view,it is particularly important to study methods to improve the safety of intersections.Based on the design of the vehicle test scheme of typical intersections in mountain cities,the physiological data of drivers are collected,and the physiological characteristics and change rules of drivers in different types of intersections in mountain cities are studied,and the optimization suggestions of design parameters of intersections in mountain cities are put forward,which provides the theoretical basis for improving the safety of intersections in mountain cities.The contents include:①Vehicle test design.Considering the geometric characteristics and the physiological characteristics of drivers’ heart,10 intersections with typical mountain city characteristics were selected as the test road section in Chongqing.Four representative drivers were selected to collect the heart rate and parameters of the intersection.Then the heart rate data of intersection drivers are classified into three-leg intersection and four-leg intersection for subsequent analysis.②Study on the heart rate distribution characteristics and its change mechanism of drivers at road intersections in mountainous cities.Firstly,the research scope of three-leg intersection and four-leg intersection is determined according to the heart rate distribution of drivers at the intersection.Then it focuses on the influence of intersection angle,longitudinal slope and curb radius on the heart rate growth rate of drivers in three-leg intersection and four-leg intersection,and quantitatively analyzes the rules of heart rate growth rate of drivers in mountain city intersection changing with intersection angle and longitudinal slope of the entrance.Finally,the mathematical models of heart rate growth rate,intersection angle and entrance slope are established.③Optimization of safety parameters of road intersections in mountainous cities.Firstly,the concept of psychological comfort is put forward,and the growth rate of driver’s heart rate is taken as its indicator.Then,using the partial correlation analysis and multiple regression analysis,taking the intersection angle and the longitudinal slope of the entrance road as the influencing factors,the psychological comfort models of three-leg intersection and four-leg intersection are established respectively.Then,the psychological comfort threshold and safe driving threshold are determined by the heart rate growth rate of drivers.Finally,based on the threshold conditions,the minimum intersection angle,the maximum uphill slope and the maximum downhill slope of the three-leg intersection and the four-leg intersection are calculated.Based on the physiological characteristics of drivers’ heart,the research results provide reference for the optimization of intersection related design indexes in the current "code for design of urban road engineering".