One of the problems facing public transit that the mismatch between metro service capacity and travel demand is becoming serious, especially in some sections with large passenger flow, which has become a bottleneck restricting the development of metro. Under this background, this paper studies the bottleneck section of Nanjing metro service. The following work is mainly done: 1. Proposing a method of using the express bus line to relieve metro passengers. 2. Extracting passenger flow from passengers' card-brush data and assigning it to the metro network to obtain bottleneck sections. 3. Establishing an average saturation model to calculate the most suitable number of express bus stations. The results show that the method can effectively reduce the saturation of cross-section passenger flow in the bottleneck section of the metro and improve passenger travel satisfaction on the basis of ensuring the rational use of metro capacity.
 

Metro Service Capacity, Bottleneck Section, Express Bus Line, Passenger Flow Relief