Originally Posted by
squawk
As does the Queen, at least on some occasions: I was held back in a carriage at a major London terminus while she disembarked from the front set of doors - having spent the previous hour in the same carriage totally oblivious to her presence (as, I think, was everyone else). This was facilitated by the internal layout of the carriage, and the first class section.
widely reported in the press on a few occasions:
The Queen boards the train back to London from Sandringham | Daily Mail Online