PURPOSE: To continuously picture display the condition of a car for an arbitrary time, by selecting an arbitrary car without regard to the car's location and the transition of sections when a travelling course is suitably partitioned and the car is centralizing monitored by a data transmission circuit and a picture transmission circuit.

CONSTITUTION: A car travels on the sides of signal transmission courses 6M...6A, 6B laid along a private travelling course. When the number of the car 1 is designated to a car select device 10, the select device 10 transmits the demand of picture display and the designated number of the car to a multiplex communication controller 8. The multiplex communication controller 8 varies the content of data so that the starting of picture transmission be indicated in command data sent to the car 1, and puts out a command of changing over circuits so that a picture signal from a ground transmitter-receiver 7A corresponding to a section, at where the car 1 exists, be projected onto a monitor TV 11. When the car 1 normally receives command data, a command of starting sending of the picture signal is put out to a device 4 of converting the picture signal