Abstract: A system is provided for arranging articles in a predetermined sequence. In mail handling applications, the documents destined for local distribution may be segregated as to the respective routes of the postmen and arranged in sequence within each route in accordance with the mail-stops or street addresses. In such a system, the documents are transported by individual mechanical carriers. Temporary high density storage of the documents is provided by a recirculation buffer subsystem. Based upon system priorities, selected carriers may be taken out of buffer storage, independently of the other carriers. The selected carriers are then circulated in a short transit-time loop from which they exit to one or more output racks, where they appear in sequential order.