In either case a diamond-shaped control signal may be located just before the crossing. In addition to duplicating the indications of the hexagonal signals, it marks the place where the train must stop if the crossing is not secured. The control signals also help pointing out the malfunctioning crossing if a hexagonal signal that covers more than one crossing is showing caution.
YELLOW |
»Crossing is unsecured« |
WHITE BLINK or control signal OFF |
»Crossing is secured« The warning lights for road traffic are flashing and gates (if any) are down. |