Optimizing the train timetable considering cross-line operation in the urban rail transit network

Cross-line operation stands out as one of the emerging new metro operations. This paper investigates the cooperative optimization of cross-line train stopping/overtaking schemes, and train timetables on the metro network under cross-line operation. To describe passengers’ traveling process, a travel path alternative set generation method based on rational passengers is proposed, which proactively distinguishes the travel paths of passengers. For a given passenger travel path, the paper adopts a passenger pre-classification method, dividing passengers into four groups, to separately calculate their travel time. The model’s optimization objective is to minimize the travel time of passengers across the entire network. To enhance the efficiency of the model solution, a two-stage algorithm with a search strategy is introduced. To demonstrate the correctness of the model and the effectiveness of the algorithm, the model is applied to a network comprising 4 lines and 39 stations. Comparing with split-line operation, the results demonstrate that cross-line operations can achieve an approximate 11.32% reduction in network-wide passenger travel time and a substantial 67.09% reduction in network-wide transfer flow. Finally, this paper conducts a set of sensitivity analyses to summarize the characteristics of cross-line train operation and provides recommended combinations for passengers choosing the train service.