The research of data analysing method on urban expressway interchanges

The interchanges are the important facilities of the urban expressways, in order to offer basic theory for the research of capacity of interchanges, according to the field data, using statistic method to research the data statistic interval based on the speed characteristics and the characteristics of speed standard deviation, then to research the requirement of sample size based on mathematic principle. The results are useful to the research of capacity of urban expressway interchanges.