TOPIC:

I am playing city builder a few times lately.
When I build a train station in a big city I usually also make a bus depot on the same station (attached).

Then later on I make 1 or 2 extra bus stations and transfer people and mail to the train station. With the transfer order.

Is this allowed and considered normal play?

yes, transfers are allowed, as long stations respect the basics of our rules (mostly rule 7 and 8 ).

Okay thanks. I follow those Rules