Optimizing Rolling Stock Deadhead Routing Problem before Operation Period of Urban Rail Transit Line

In an urban rail transit line, many trains that run during the initial operation period require to be served by rolling stocks that depart from depots. Hence, before the operation period, these rolling stocks consecutively leave depots, and run without passengers to the origin station where they serve as operating trains using either a direct or an indirect route. This paper investigated the rolling stock scheduling problem with multiple line plans, multiple depots and multiple rolling stocks, assigning the origin depot and corresponding deadhead route for the rolling stock required by each train during the initial operation period. By considering the depot maintenance capacity and departure capacity as well as the switchback station capacity, a mixed integer linear programming model was built to minimize the total deadhead mileage. The size of the model is polynomial with respect to the number of depots, switch stations and trains, with which large-scale problems can be quickly solved to optimality by commercial optimization solvers. The computational results demonstrate that the optimization approach is better than the empirical method used in practice in terms of solution quality, while opening closed switchback stations or prolonging available depot departure time are expected to further shorten the total rolling stock deadhead mileage. © 2018, Department of Journal of the China Railway Society. All right reserved.