Government regulations of a maximum gross vehicle weight of 80,000 lb for U.S. interstate highway travel (U.S. DOT, 2011). Therefore, we denote the maximum trailer payload as Kwt = 25 ton. To determine which of these quantities,Kcu or Kwti, constrains the size of a TL shipment, we must also know the weight and density of the item to be shipped. Let us denote the item weight (in lb) as w, and the item density (in lb/ft3) ass, and therefore, the maximum size of a shipment (in units shipped) via TL is of a motor carrier trailer to be 50,000 lb, or 25 ton, based on U.S. Federal