Hi Pitkin.
From my own surveyor route/session experience, you cannot move a stretch of track if there is some vehicle on the stretch of track. Only stretch of track with no vehicle on it can be moved. So surveyor or edit mode has already some protection mechanism to avoid breaking by error some tracks.
Regards.
Pierre.
Good point. I have experienced from time to time 2 traincars that are overlapping each other. This was from trying to reuse older sessions. I assumed the session stores the coordinates of each car.