When you get to the other end of the road, the terminal, which in some cases is as far as 300 miles away, what happens is that you go into an unassigned type of service. You do not know when you're coming back.
Lorsqu'on arrive à l'autre bout de la ligne, à la gare, qui dans certains cas peut être à 300 milles de distance, nous sommes en service, mais sans affectation.