To inform a driver of a train approaching a railroad crossing of the situation of a railroad crossing by processing a color image signal from a color camera, performing operation for detecting an obstacle in the crossing based on its output and using a crossing control signal for controlling the output from it and opening/closing of the crossing.

A color camera for monitoring 10 is mounted at the position where the entire crossing way can be monitored and puts out a color image signal S10 to an AD converter 13 and a controlling means 12. The AD converter 13 converts a color image signal S10, which is an analogue signal to a digital color image signal S13. An image processing signal S14A obtained by processing the image signal based on the image signal S13 is put out to an operating means 15, and an image processing signal S14B is put out to a sending means 19. The sending means 19 sends out and processes the image processing signal S14B based on a control signal Sd from the controlling means 12 and sends out a sending signal S19 to a train approaching the crossing or a train which sent out a communication control signal. A driver of the train can determine the state of the crossing way.