Abstract: Subway parking lines with one train space are widely used in urban rail transit systems. However, in the process of train failure rescue , this method can accommodate only one train owing to their length limitations and will cause extra delay. Conversely, subway parking lines with two train spaces work better in train failure rescue, although higher requirements are imposed on engineering conditions and costs. This study designs eight different types of parking lines with two train spaces based on forms and setting principles of traditional parking lines with one train space, and performs a comparison analysis. Moreover, a railway simulation tool OpenTrack is used to simulate the suitability of parking lines with two train spaces during train failure rescue. Results show that each of the eight types of parking lines has its own applicative situation, and tandem parking lines exhibit better applicability among them. Furthermore, the parking lines with two train spaces can considerably reduce rescue delay time when they are set in the middle of the line away from the car depot. In the situation wherein only train failure rescue is considered, the tandem end-type parking lines are the best choice.

Key words: urban rail transit, subway parking line, train failure rescue, OpenTrack simulation