I have just enjoyed reading the posts in this thread. I had a Driver Interview last month, but I had also a week before had an interview for Conductor. I had by the time of the interview been told that the Conductor interview was successful. I didn't get the Driver position, but now have experience of having had an interview. I am looking forward to starting my training on 2nd November.
I will say, turn up smart. On Time, and just be yourself. Don't try and be a know it all. Some answers you won't even know, until you've actually started, but they're not trying to catch you out. Above all be honest as well.
I was asked if I had applied for other positions at the TOC, and I was honest and said yes, because it could have been checked. But I got the job anyway.
I now have a foot in the door, and can re-apply for a driver position in the future should I wish to do so.
Good Luck.