The permanent way is the track and everything that carries it. Maintain the permanent way.
It was named to distinguish it from the temporary track a contractor laid while building. The permanent way includes the ballast and the formation as well as the rails.
1nounpermanent wayThe track and everything that carries it.
“The permanent way on that line was relaid in 1974.”
permanent way is a track.
Named in contrast to the temporary way, the light track a contractor used during construction.
permanent (contrasted with the temporary way of a contractor) + way (as in railway)
Etymology from Wiktionary, CC BY-SA
Practised in Railways