- Trial period: From January 23, 2022 to January 22, 2023.
- During weekends/holidays (all day) and weekdays (10:00-16:00, 22:00-end of service), passengers with double basses may enter/exit from stations on the Tamsui-Xinyi Line (excluding Daan Station), Songshan-Xindian Line (excluding Nanjing Fuxing Station), Zhonghe-Xinlu Line (excluding Zhongxiao Xinsheng Station), and Bannan Line (excluding Zhongxiao Fuxing and Zhongxiao Xinsheng). These passengers will not be permitted access to any other stations.
- Passengers with double basses are required to purchase a Single-Journey Ticket for Double Bass at information counters, which costs NT$80 for one trip of unlimited distance for a single passenger and double bass. Service staff shall guide the passenger to enter and exit the station through the Group Ticket/One-day Pass Entrance/Exit.