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.