The multiple frequency delivery operations in the time-definite delivery industry

The pure hub-and-spoke network is an efficient network structure for time-definite freight delivery common carriers. Centres perform pickup and delivery functions, while hubs consolidate partial loads. This substantially reduces the transportation costs with only a small increase in the handling cost. In Taiwan, as well as in the US, carriers run their delivery operations once a day. As a result, the feeder fleet is under-utilized. This research studied the impact of multiple frequency delivery operations on the feeder fleet size. We formulated line-haul operations planning for multiple frequency delivery operations as an integer programme. We developed an α-optimal implicit enumeration algorithm and used two small networks from the third largest carrier in Taiwan for numerical testing. The results demonstrated a smaller feeder fleet size compared with the single frequency delivery operations.