In Ticket to Ride: The Heart of Africa, are stations allowed? The rulebook explicitly mentions that the plastic carriage pieces and scoring markers from the main game are to be used, but doesn't appear to mention stations. We played without stations, and completing routes was much more stressful than a standard game.
No, the rules explicitly state what pieces are required from an earlier set:
Anything not mentioned in the above list should be considered surplus to official requirements. Though you could always try playing with stations as an interesting variant!
EDIT: yes, without stations Heart of Africa is a very claustrophobic Ticket to Ride game. But this does seem to have been the intention of the designers, as they've admitted as much in a footnote in the rules booklet:
The rules only have stations for the europe map. None of the maps are broken by playing with stations, however. I have played the following maps with and without stations:
Europe, USA, Africa, Switzerland, India, Asia, and Legendary Asia.
The effect of adding stations is to reduce the stress (and uncompleted tickets).
The USA map is much less cutthroat with stations, but the others only somewhat less.