It meant that the next signal was showing double yellow.
If the signal shows green, the clamp is turned away.
The signal showed them dangerously close to the same coastline.
More than one common signal may show convergences by the parties.
The run/stop signal shows whether the sequence is playing or not.
Then the train accelerated again, despite the signal still showing red.
Even when the track is clear of any other trains, the signal will show an "approach medium" light.
The signal going out on the airways now merely showed talking heads.
As he feared, the signal showed a white light throughout.
After signals show the return to the stable zone, pressure is increased again.