The Minimum Fleetsize for a Suburban Railway System

A mathematical method is developed for minimizing the number of railcars that is needed for the peak operations of a suburban railway system by cutting railcars back from stations along the lines in an optimum way. A secondary objective is the minimization of the total driver time. A mathematical proof is given of the fact that the total number of railcars required is equal to the maximum number of railcars simultaneously in operation; and this theorem leads to the formulation of the minimization problem as a set of linear zero-one-programs. A case study demonstrates the practical usefulness of the method by applying it to an existing railway system.