Only ever done it once, that was in NSW for the bushfires and we had to cross track with gates down, but there was also a person from the Transport Department there saying that it was a malfunction in the gates and trains had also been stopped from running on the line due to the fires, so doesn't really count.
Wouldn't even think of doing it normal situations, cause if you put it in sport terminology, trains are back 2 back undefeated premiers when playing cars & trucks.