Research On Highway Traffic Risk Assessment And Control Strategy Based On Vehicle Speed Dispersion

Economic development stimulates the rapid improvement of the transportation industry's entire life cycle process from planning,construction to construction and maintenance.As one of the five main modes of transportation,road transportation,together with railways,water transportation,aviation,and pipelines,controls the lifeblood of national road network construction.In recent years,related technologies for highway network construction have reached the world's top level.China's highway network has become saturated,and with it,a series of problems have arisen.Increasing accident rates caused by natural or man-made disasters,inadequate management levels,and traffic congestion caused by saturated traffic flow have become major issues that need to be addressed.Among them,the accident rate,which is directly related to the lives of the people,deserves more attention.There are many reasons that affect the accident rate.The discrete speed is the main reason for the increase in the accident rate.Therefore,the exploration of the impact of the discrete speed on the traffic safety is the key to guaranteeing the life safety of travelers.This paper studies the relationship between the discrete characteristics of highway speeds,traffic conflicts,and traffic safety risks,and conducts safety control from two aspects: reducing the speed dispersion and preventing traffic conflicts,to effectively improve the safety of highway vehicles.Through video survey data,collect relevant parameters such as road traffic flow,traffic composition,vehicle running speed,explore the operating rules of vehicles in different lanes,and explore the impact of traffic flow,vehicle proportion,and speed distribution on discrete characteristics of vehicle speed.By adopting research methods of qualitative analysis,quantitative research,mathematical modeling,case verification and countermeasure research,a highway traffic safety risk assessment model under the background of speed dispersion is constructed and reasonable speed limit values and safety improvement measures are proposed.The work of this paper mainly includes the following four aspects:(1)Based on the measured data,this paper preliminary analyzes the spatial and temporal distribution characteristics of traffic flow parameters such as traffic flow,vehicle proportion,and speed.The effects of traffic flow,speed distribution,and vehicle model ratio on the discrete characteristics of vehicle speed were further explored to provide data support and theoretical basis for the subsequent research on the correlation between vehicle speed dispersion and traffic conflict.(2)Introduce the method of traffic conflict technology to make up for the shortcomings of lack of accident data.Based on traffic conflict data collected from survey videos,The correlation between the factors that influence the discrete characteristics of vehicle speed and the severity of traffic conflicts has been studied.And the correlation between the feature of discrete speeds and the severity of traffic conflicts has been further studied.Multivariate Logistic regression prediction analysis model was used to predict the overall level of rear-end collision,lateral conflict and traffic conflict.(3)Introduce fault trees and Bayesian networks,construct a Bayesian network model based on fault trees,set model variables and corresponding value ranges,and construct a Bayesian network assessment structure diagram of traffic risk,and give the traffic risk assessment process.The data collected from the entrance of Kunming International Airport Expressway Dabanqiao—the internal road exit of the airport correspond to the corresponding value range of the traffic risk assessment model,and the corresponding traffic risk assessment and index sensitivity analysis are carried out.(4)The improvement of highway traffic risk is mainly studied from two aspects: reducing the speed dispersion and reducing traffic conflicts.In terms of reducing the degree of speed dispersion,the establishment of an early warning induction system is used to control the entry of large vehicles into the expressway lanes in real time.Strengthening lane management is used to guide and restrict different models.Limiting the speed of the vehicle is used to ensure that the flow speed tends to be consistent.In terms of preventing traffic conflicts,real-time warnings and improvement suggestions are mainly provided in terms of early warning of safe distances and the design of auxiliary facilities for distances.The research results obtained in this paper can provide reference for traffic management departments to formulate management strategies and safety supervision of large-vehicle traffic limitation and speed control.It will help improve the operational safety status of the entire highway system.