Imbalance propagation in metro systems

Abstract:

The unforeseen imbalance between supply and demand in the metro system usually propagates along the running direction, which increases passengers’ travel costs and even leads to social and economic loss. Although existing studies have analyzed the train delays and over-crowdedness situations, none of them have extracted the theoretical nature of disruptions, i.e., the imbalance between vehicle supply and passenger demand. Moreover, the variance of propagation caused by the imbalance occurrence time, the imbalance type, and the level of primary imbalance has not been examined. With these concerns, this paper proposes a two-layer imbalance propagation model for metro systems based on automatic fare collection data, where the affected time scope, the affected space scope, and the spatial-temporal extra waiting cost are outputted to describe the propagation mechanism. The lower-layer model calculates the passengers’ latest arrival time matrix for boarding each train. This matrix is an essential input parameter of the upper-layer imbalance propagation model, where the real-time extra waiting cost for each platform under disruptions is estimated. The proposed model is applied to a real-world metro line of Shenzhen metro to analyze its propagation characteristics, and some managerial insights are summarized.