Translation:From the bridge one can see the railway station.
In America, a "railroad" station and a "railway" station are exactly the same thing. The former is actaully used far more often.
Something is done from that bridge. Without "si" the bridge sees the train station, but you have to remove "dal" too. They come together in the sentence.
E.g. Dalla mia finestra si vede la Luna. La mia finestra vede la Luna.
Why is 'the train station is seen from the bridge' wrong? Not a literal but it avoids using 'can' which is not in the Italian and therefore not literal either.
Absolutely! 'one' is very uncommon in British English and pretty formal as others have said
Why do I need the one formulation? Why can't I use: The trainstation is visible from the bridge? It seems more natural for me as la stazione is the subject of the sentance.
Why can't it be translated as "From the bridge, one sees the railway station."