All I can tell you Eagle is that the bloke running the course said that as a surveyor, even if I want to go on to railway land to locate ONE mark I am supposed to contact the nearest ARTC office and arrange for an escort, permit and timetable of trains in the area. Its ridiculous and no surveyor would do that in most cases unless they were spending any decent amount of time in the railway corridor. The railway corridor is in the control of ARTC and is not a crown road.
That being said, you would have to be caught for it to be a problem. Where are you looking at this railway service road Boony?