Travel lit book about a man revisiting a train journey?

I sat next to man on a plane who told me he was reading a travel literature book written by a man, and he was re-doing a long train journey. He had done and written the same journey years ago (20 years?!) and was revisiting all the places again in the new book. Unfortunatley i cant remember where he went, defenatley east, maybe indian asia that region? Really would appreciate it if someone could help me work oit the author or the name of one of the books!