For　the　shortage　of　previous　studies　on　urban　expressway　weaving　segments,　the　capacity　of　them　is　studied　using　traffic　simulation　method.　It　is　indicated　and　verified　that　the　capacity　of　urban　expressway　weaving　segments　has　a　great　relationship　with　the　source　and　distribution　of　weaving　and　non-weaving　flows.　Subsequently,　using　the　calibrated　simulation　model,　capacity　values　of　urban　expressway　weaving　segments　have　been　estimated,　in　which　capacity　values　of　weaving　segments　shorter　than　150　m　that　it　is　not　considered　in　the　Highway　Capacity　Manual　(HCM)　2000　are　also　included.　In　addition,　it　is　demonstrated　that　the　proposed　model　capacity　estimates　are　consistent　with　field　data　while　the　HCM　procedures　tend　to　overestimate　the　capacity　of　weaving　segments　significantly.　(C)　2012　Published　by　Elsevier　B.V.　Selection　and/or　peer　review　under　responsibility　of　Beijing　Jiaotong　University　[BJU],　Systems　Engineering　Society　of　China　(SESC)