An Improved Prim Algorithm for Connection Scheme of Last Train in Urban Mass Transit Network

In the network operation stage of urban mass transit, the connection relations between lines can effectively improve travel accessibility. As the last opportunity to travel on the same day, whether the last train can achieve transfer will directly affect passengers’ travel experiences. It is an important work to make the connection scheme of the last train, which needs to take the network structure, the trend, and the volume of passenger flow into overall consideration. This paper analyzes the characters of the last train connection, including the connection structure and the accessible form. Then, we establish a scheme model and define the objectives, the constraints, and the decision data source, and transform it into a graph theory problem. Taking an urban mass transit network as an example, we demonstrate the solution process by using an improved Prim algorithm. Finally, the main aspects and methods of initial scheme optimization are proposed.