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.