The purpose of this report is to develop analytical models that may be used to determine the size and number of trucks required to provide a given service level at the lowest possible cost. Two models are presented, they are: 1. The Simulation-Linear Program Truck Selection Model: This model employs simulation to determine the number of miles driven and linear programming to minimize the “total cost objective function.” 2. The Truck Salesman's Truck Selection Model: This model is less accurate than the “Simulation-L.P.” model but is also less laborious and easier to use. It applies “trial and error” solutions to the L.P. objective function and uses other equations developed for the Simulation-L.P. model to make these solutions as accurate as possible. The two models have been used on a number of case studies and similar results have been obtained. Thus, it is hypothesized that because the results are similar the models must be correct.The report concludes with a discussion of some of the nonquantifiable problems that may be encountered when rationalizing a truck fleet.