A Study On Safety Evaluation Method Of Expressway Interchange Based On IHSDM

With the construction of China's highways,the interchanges are also becoming more and more important.Interchange is an important structure to realize the transformation of vehicles between different freeways.However,due to the constraints of land use and terrain conditions,there are many restrictions on the alignment design of interchange,which leads to poor alignment of interchange.Although the design meets the requirements of relevant specifications,due to the complexity of vehicle driving in the interchange area,the unfavorable alignment will lead to the interchange area becoming the multiple location of the accident.How to effectively protect the traffic safety in the interchange area,reduce the occurrence of traffic accidents,and eliminate the traffic accidents in the design of interchange,has become an urgent problem.Based on 11 interchanges in expressway in Shanxi Province,this study obtained the basic data needed by crashes prediction model through the collection of linear design data,traffic data,crashes data and field investigation.Using data mining anomaly detection and correlation analysis technology to excavate and screen traffic crashes,and develop a linear recognition software based on linear analysis of the crashes location and basic conditions,According to the principle of different combination characteristics between horizontal and vertical alignment,the analysis area is divided into eight basic sections,which provides the foundation for the model establishment.Through the linear one-factor analysis of the main line,ramp and distribution lane,the influence of different factors on the crashes safety is confirmed,and the ideal condition of traffic safety in the interchange area is defined.Under the ideal condition of interchange area,the basic model of crashes prediction(SPF)of main line,ramp,and distribution lane was established respectively by means of regression analysis.And the different linear influencing factors of different sections are analyzed.The crashes correction model(CMF)of circular curve radius and longitudinal slope of the main line,ramp and distribution lane of the interchange area is established.Applying the theory of T test and the theory of F test,the model established in this studywas tested.The accuracy of the main line,ramp and distributing lane model is calibrated and verified..Finally,an expressway interchange in southwestern China has been applied.The results show that the model can be effectively used to evaluate the safety of interchange in China.In this paper,the latest IHSDM software interchange module is applied to the safety evaluation of expressway interchange area in our country.Based on the traffic characteristics of highway crossings in Shanxi Province,the calibration parameters of safety model are calibrated to provide the latest method for the safety evaluation of expressways interchange area in China.The research results can be extended to other regions for the expressway interchanges safety evaluation to provide reference.