Abstract: The time headway characteristics from the weaving area to the merging area are researched based on the actual data surveyed on a half-clover interchange in Guangzhou city for analyzing the influence of weaving areas on merging areas time headway distribution,and the difference between the time headway distribution in the merging area of the urban expressway interchange and that in the merging area of freeways is researched,then a absolute value WEIBULL distribution model is set up to simulate the time headway distribution of merging area under the influence of the weaving area on the merging area of urban expressway interchanges,after figure simulation and data test,the model is proved to be feasible by the figure simulation and data test.