The duo has been going all out with promotions of their forthcoming release. They were to travel to Delhi as part of the film's promotions.
In a recent conversation, Deepika is said to have expressed her wish to travel by train as she had not done so in a long time.
When Ranbir learnt about her wish, he immediately got on to arrange for it.
Flight tickets to Delhi were cancelled and the team booked an overnight train travel instead.
While both of them have been to Delhi a lot of times, it will be for the first time that they will get on an overnight train to cover the journey.
Ranbir and Deepika are super excited for this trip and will be leaving from Mumbai on Sunday afternoon, said a spokesperson of the film.
The two, who were seen in a train journey briefly in "Yeh Jawaani Hai Deewani", have already planned the things to do on their Mumbai-Delhi trip.
Presented by UTV Motion Pictures and Nadiadwala Grandson Entertainment, and produced by Sajid Nadiadwala, the Imtiaz Ali directed film is slated to release on November 27.