Study on Design Speeds of Metro Inter-stations for Traction Energy Saving and Travel Time Reduction

Abstract

The increment of design speed of metro system will increase train energy cost while reduce passengers’ travel time. To determine reasonable design speeds of different inter-stations in a line, the factors including passenger demand, operation cost and interval distance need to be taken into account. However, the common practice adopts uniform design speed for the whole line, which is unsuitable for the metro line with large variations on distances of different inter-stations. Therefore, this paper proposed a design speed optimization model with given line conditions and train control strategies to minimize the comprehensive cost, including train traction energy and passenger travel time. Case studies on a Beijing metro line show that the overall cost is reduced by 4.57% through allowing varied design speeds across different inter-stations in comparison with a uniform design speed for all inter-stations. Sensitivity analysis shows that when the interval distances are 900 m and 1700 m, the recommended design speeds are 80km/h and 100km/h, respectively.