An improved mixed integer program for single allocation hub location problems with stepwise cost function

Recently, a new model for the uncapacitated single allocation p‐hub median problem was defined, which uses a more realistic cost structure. Instead of measuring the transport costs as a linear function of the volume, integer variables for the number of used vehicles are introduced. This leads to a more precise model if the number of vehicles is low and capacity utilization plays a major role. We will introduce a new mixed integer program formulation of the problem that uses fewer variables but more constraints. This study shows its numerical advantages.