If you search the threads on this forum, they'd all point to questions as being your typical competency questions i.e. followed rules and procedures, dealt with an emergency, worked alone.
To my surprise, not a single question was asked along those lines. It wasn't what I was expecting. It was more along the lines of: what is your greatest achievement, a time where you had to work hard to overcome a difficulty, delivered excellent customer service. Try to think of answers for your traditional railway competency questions, but also these rather general personal questions about your personality and how you deal with certain instances.
My overriding opinion from the interview was that it was more an interview to gauge your personality for the role, the team/depot and if you'd fit in.. and just your general confidence. Unfortunately I failed and my driver dream is over - I'm just being honest with myself and I'm not cut out to be one.
Another thing was the managers who interviewed me were the most professional and friendly interviewers I have come across, and I've been to many interviews! They did seem as though they're desperately trying their best to get the correct answers from you and are not trying to trick you in any way. If you're a fairly confident person with some wholesome life/work experience, you should be fine. Just don't feel rushed in giving your answers, take your time.. and stick to the STAR technique. STAR is a MUST.