The conventional train traffic control system has been focused on safety and punctuality in normal operations. Recently, however, more flexible and adaptive management has been required not only for train regulation, but also for maintenance, and in train-delay situations. An autonomous decentralized train control and management system is proposed to attain both the realtime property for train control such as train traffic and non real-time property for train management such as scheduling. This subsystem has been developed to make these two heterogeneous subsystems to coexist by isolating or coordinating mutually. This system has been applied to the train traffic control and management system for Japanese bullet train line (COSMOS : Computerized Safety Maintenance and Operation system of Shinkansen). The proposed system has been in operation since Nov. 1995, and the effectiveness has been evaluated.