6.2 Freight Traffic Assignment Problems ([TAPs])......
Freight [TAPs] amount to determining a least-cost routing of goods over an existing network of transport services from their origins (e.g. manufacturing plants) to their destinations (e.g. retail outlets). In a sense, the demand allocation problems illustrated in Chapter 3 are particular freight [TAPs]. From a mathematical point of view, [TAPs] can be casted as network flow (NF) problems. NF problems include, as special cases, several remarkable network optimization problems, such as the shortest path problem and the transportation problem.