Efficient Circulation of Railway Rolling Stock.

Railway rolling stock is one of the most significant cost components for operators of passenger trains. The efficient circulation of rolling stock is therefore one of the main objectives pursued in practice. This paper focuses on the determination of appropriate numbers of train units of different types together with their efficient circulation on a single line. To utilize the train units on this line in an efficient way, they are coupled to or uncoupled from the trains in certain stations according to the passengers’ seat demand in peak and off-peak hours. Because coupling and uncoupling train units must respect specific rules related to the shunting possibilities in the stations, it is important to take into account the order of the train units in the trains. This aspect strongly increases the complexity of the rolling stock circulation problem. This paper presents a solution approach based on an integer multicommodity flow model with several additional constraints related to the shunting processes at the stations. The approach is applied to a real-life case study based on the timetable of NS Reizigers, the main Dutch operator of passenger trains