The National And Provincial Arterial Highway Access Safety Evaluation Methods And Access Management Policy Guarantee Research

Highway access points are places where traffic divergs,merges,crosses and weaves.These places have high density of traffic conflicts and traffic crashes happened frequently.Arterial highway access safety promotion is one of hotspots of road safety study in recent years.Based on the research programs of ‘Access safety evaluation of National highway G205 Jiangsu section',‘Safety evaluation and design of Jiangsu Lin Hai high-grade highway',‘The administrative examination and approval system research about the adding of access driveways in Shanghai arterials',the author had accumulated tremendous data about highway access related crashes,access layout design and access management operation etc.Also the author made a deeper thinking about the safety risk control and evaluation method of highway access.Highway access management is in urgent need of systematic access safety evaluation method and access permit system.This paper put forward to solve the problems through the construction of ‘route level,roadway level and single access point level' highway access safety evaluation system.The paper also introduced the traffic impact analysis technology into the management of highway access point adding.This paper evaluated the safety performance of arterial access spacing on route level,from the aspects of coefficient of variation,kurtosis and cumulative distribution percentage value of access spacing.Several arterial highways in Jiangsu province with the same functional and technical grade were used for comparison.The proposed evaluation method is a promising technique for the future improvement of access spacing standards.This paper put forward to evaluate the safety performance of a certain arterial highway on road section level,from the aspects of access functional classification,land use and access density.The National highway G205 Jiangsu segment was taken as an example.The roadway was divided to eight different sections and evaluated the performance of each aspect.This paper presented a new access weight calculation method based on the combined analysis of traffic speed and lateral offset variation on access point.A driving simulator was used to obtain data with high reliability.The proposed access weight calculation method showed promise for its application in access point design and improvement.On single access point level,this study developed a safety propensity index(SPI)for highway access safety evaluation.Through the use of a structural equation modelling(SEM)approach,safety was quantified in terms of multiple endogenous variables and related to various dimensions of exogenous variables.Latent clustering analysis method was used to tease out key factors from numerous factors that affect access safety.The data provided by highway bureau of Jiangsu province for the National Highway G205 was used for analysis.The main benefits of the approach and the subsequent development of an SPI were:(1)the identification of pertinent variables that effect access point safety;(2)the quantification of safety in the form of an index such that a ranking system could be developed.The continued application of the conceptual and quantitative framework utilized in this study provided an opportunity for researchers to gain new perspectives on safety.In the last chapter,traffic impact analysis method was introduced to the adding of access point in arterials.The three level access safety evaluation system studied above was applied to the access adding safety evaluation process.A case study in Baoshan district,Shanghai was carried out to examine the effectiveness of the method.Beside that several suggestions were given to the administrative examination and approval system of access adding.The systematic safety evaluation method set up in this paper could be applied to highway access safety evaluation in different levels.It is the deepening and development of highway access management technology research and application in China.If further developed,the adopted methodology may assist in access safety related decision making and policy analysis.