What i noticed, besides everything is said here, is that cities (no matter where ur bus/tramlines go) will tend to expand around the trainstation. Even on the OTHER side of it (that people need to walk all around the station to get there).
This makes no sense as there are mostly numerous bus and tramlines going everywhere in the town. Building houses near those tram/bus lines would make much more sense as they need to travel shorter to any given destination on the map (even in the same town).
Ive played alot of games and still some things about city growth are not clear to me, or just do not make sense.