Research On Safety Reliability Measurement And Improvement Method Of Freeway System

In recent years,due to the introduction of national policies and vigorously,improvement,traffic safety situation in China has been significantly promoted,however,compared with foreign developed countries,the overall traffic safety situation is still grim.As an important part of the national transportation network,the safety of freeway system is closely related to the life and property safety of the public.Therefore,it is necessary to do some analysis and research on the safety of freeway system.Based on the principle of system reliability,this paper studied the safety reliability of freeway system.Taking the Liaoning Freeway as an example,the statistical distribution pattern of the interval between two accidents is established.Besides,constructed the safety reliability measurement model of freeway system based on the interval between two accidents,and proposed safety reliability improvement methods of freeway system which based on all road sections and key road sections.Firstly,this paper analyzed the statistical distribution of the interval between two accidents of the basic section,the main line toll station,the interchange of freeway system and the system itself.Applied the MATLAB software to make optimal distribution fitting of the interval between two accidents.The Pearson chi-square test result determined that the interval between two accidents of freeway system and its subunits obey logarithmic normal distribution.Secondly,based on the applicability of reliability in freeway safety analysis,the definition of safety reliability of freeway system is put forward.In addition,Determined safety reliability indexes and function forms of freeway system and its subunits.On the basis of calibrating the safe operation function,proposed the concept of clear variables based on traffic volume and road length.Finally,constructed safety reliability models which are used in freeway system,the basic section,the main line toll station and the interchange.Then,put forward the safety reliability improvement method s of freeway system which based on all road sections and key road sections.Determined the safety reliability improvement step of freeway system and its sub-units,including calculating the initial safety reliability,determining the distribution coefficient,setting the safety reliability target and identifying the key road section.On this basis,given analysis indexes of safety reliability improvement,and proposed an economic benefit analysis method which based on cost increment.Finally,taking Shenshan Freeway as an example,studied the safety reliability of freeway system.The safety reliability of Shenshan Freeway and its subunits are improved by two methods.Additional,the paper put forward some concrete safety reliability improvement measures,and the improvement effect and economic benefit of two kinds of safety reliability improvement methods are analyzed.The analysis results show that the reliability improvement rate based on key road sections is obviously higher than the reliability improvement rate based on all road sections,but the latter is more economical and worthy of promotion.