A system includes one or more processors, and one or more non-transitory computer-readable media having stored thereon a program, which, when executed, causes the one or more processors to perform a method of a distributed server of a transportation system. A method includes monitoring whether a failure has occurred on a communication network between the distributed server and a central server, searching for another distributed server capable of communicating with the central server, based on a result of the monitoring, and communicating with the central server using the other distributed server.