permissive working
A system allowing more than one train at a time to be on the same line in a block…A system allowing more than one train at a time to be on the same line in a block section, a signal section, or a dead-end platform line.
Meaning
1 senses(UK, uncountable)A system allowing more than one train at a time to be on the same line in a block section, a signal section, or a dead-end platform line.
Lessons for this word
1 lessons- A1Countable and uncountable nouns — Because it can be uncountable