I've been a driver now for nearly 34 years (or on the footplate anyway) and my last interview on changing from a FOC (Freight) to a TOC was 15 years ago.
I know it would be a slightly different interview, depending on if your already railway or from outside the industry.
I can't see the interview at this stage being too in-depth but they do like to here that you've at least done some homework and found out what you can about the company and there aspirations, it at least shows an interest and not just about the pay packet.
They will ask you why them!
So do your homework, be confident and just answer truthfully to the best of your knowledge.
There only human (I think) and not there to trick you.
Good luck with the interview.