A server assigns a vehicle to be provided with a vehicle sharing service to a user based on the received at least one piece of schedule information and position information of a plurality of the vehicles when at least one of schedule information of the user and use information of a vehicle sharing service is received by a terminal for the user. The server operates a communication device to transmit identification information of the assigned vehicle to the terminal for the user, and operates the communication device to transmit user information to the assigned vehicle.