When railroad companies introduce new services such as express trains skipping stations, they generally did not have a logical methodology to determine the stations the express train should stop at. This paper proposes a mathematical model to determine the stations that the express train should stop, based on maximization of passenger's satisfaction level. Here, it is assumed that the degree of congestion in the trains represents the passenger's satisfaction. In this model, we discuss the condition of a specific station that some passengers can transfer to the express train. The numerical analysis is based on actual collected data and verifies the approximation of the model in real life situations.