Research On Safety Analysis And Improving Of Freeway Based On Reliability

In recent years, traffic safety has been improved in China, however, traffic safety problem of freeway is still not optimistic because of the increasing of motor vehicles population, so it is necessary to continue the research. In this paper, reliability theory was applied to traffic safety research of freeway, such as traffic safety analysis, traffic safety prediction, and the improving of security situation.The concept and calculation method of freeway safety reliability is introduced, and a number of basic data are collected. The similarities between highway system and reliability system and the feasibility of reliability application on freeway safety study are analysed. The concept and calculation method of highway safety reliability are put forward, and the basic data needed for this study are collected and processed.The analysis method of highway safety based on the reliability is proposed. After finishing the basic data, distribution of the time interval between two consecutive accidents is studied. The reliability of each section and toll station is calculated. And taking the reliability as the evaluation index, the safety of the highway is analyzed, and the safety order of sections and toll stations are given.Freeway safety reliability prediction model is established. With the form of logistics model, the per kilometer safety reliability is considered as the dependent variable, and six independent variable are selected from traffic volume and geometric alignment. Then three(six-lane, eight-lane and four-lane) prediction models of section safety reliability are established. And one prediction model is established with safety reliability as the dependent variable, toll station type and lane number as independent variables.At last, the reliability improving method of the road section based on the reliability allocation theory is studied. The target reliability is allocated to each section of the road by using the minimum effort algorithm, and the sections which need to be treated and their treated order are determined. The measures of safety improvement for each freeway are put forward, according to the significant influence factors in the sectin safety reliability prediction model.The research results show that it is feasible and practical to apply the reliability in the study of freeway safety. This method is to study the distribution of the time of the accident, which is continuous distribution. This method can be used in a relatively short period of time to get the distribution of accident data, and can be used to analyze damaged accident data and time inconsistent accident data. This method enriches the theoretical system of highway safety research, gives a new idea or way, and provides reference for the future research.