Train service replanning in urban rail transit system: An integrated operation mode that combines express/local and short-turning strategies

Abstract

With the expansion of urban rail network, traditional train operation mode is gradually difficult to meet the complex and changeable passenger demand. This paper focuses on an integrated train operation mode that combines express/local strategy and short-turning strategy and explores its applicability in the urban rail transit system. Considering that the traditional train service replanning method is hard to implemented in this special mode due to the complexity of its stopping patterns, train types, and turnaround patterns, all types of train in this mode are categorized into 4 cases and the potential passenger transfer choices are explores at first. Then, a service replanning model aiming at reducing both the passenger travel time as well as the train operation cost is proposed. A bi-stage adaptive NSGA-II algorithm is designed to deal with this mix integer nonlinear programming problem. Finally, numerical examples from Nanjing Metro Line S6 verify the effectiveness of the algorithm and the proposed model. Comparisons between this special mode and other modes such as all-stop mode, short-turning mode, and express/local mode are further made. The results indicate that the proposed integrated mode combines the advantages of other modes and can reduce 15.3% train operation cost as well as 2.8% passenger travel time, which is suitable to operate in urban rail transit.