Exploration of Travel Patterns of Intercity Metro Passengers—A Case Study in Changsha–Zhuzhou–Xiangtan Metropolitan Area, China

(1) Background: Rapid urban growth in China has extended rail systems to neighboring cities to meet intercity travel needs, making it important to understand intercity travel patterns. (2) Methods: Taking the Changsha–Zhuzhou–Xiangtan Intercity Metro Xihuan Line as an example, intercity ridership patterns are analyzed. A Gaussian mixture model is applied to cluster ridership into groups based on travel time and stay time, respectively, and their travel patterns are examined. (3) Results: Weekdays display distinct commuting patterns with morning and evening peaks. On weekends, peak travel times are quite different. Based on travel time, intercity ridership is divided into two groups. The short-travel-time group primarily travels for residential demand, while the long-travel-time group is mainly for leisure. No significant differences were found in weekday and weekend patterns. Based on stay time, ridership is categorized into two groups. Most trips are round trips on the same day, but overnight ridership is higher on weekends. On weekends, the intercity ridership groups with tourism as their travel purpose on weekends have different stay modes, but their main travel destinations are similar. On weekdays, there are large differences in the distribution of main travel destinations between the short-stay-time group and the long-stay-time group, and their travel purposes are more diverse.