Assertion: railway's line | /r/HasProperty | clear
Facets:
value: far ahead
type: DEGREE
value: usually
type: DEGREE
Source sentences:
text: As the train approaches the junction signal, the signal may 'step up' to a less restrictive aspect (single yellow, two yellows or green.) depending on how far ahead the line is clear.
text: The stop signal consists of a red, square-ended arm, with a vertical white stripe typically 9-12 inches (230–300 mm) from the end, and advises the driver whether the line immediately ahead is clear or not.
text: and, when pulled off, allows the driver to proceed cautiously for as far as the line is clear (or to the next stop signal).
text: For a signalman to accept a train, both his block section and the line for a quarter mile inside his outer home signal must usually be clear; the quarter mile is a precaution in case the driver fails to stop in time for the outer home signal.
text: A "Proceed On Sight Authority" is only shown in conjunction with a red main aspect on a main signal and when operated the two white lights in the subsidiary signal flash on and off together to warn the driver he is proceeding under caution only as far as the line can be seen to be clear.