Yes thank you for the information that the Burma Railway was real, I had a similar story from one of my previous neighbours many many years ago who helped build it. I say helped without the usual implication of willingness and cooperation that that word implies.
The film depicts the construction of the Burma Railway for its historical setting. The bridge shown was fictitious, including the location, the name and the construction and a quick comparison of photographs should confirm this fairly readily.
Even if that trestle bridge qualifies, it is more the exception than the rule, other formats of bridge were far more popular in Europe and the other theatres of combat.
Think about it for a minute, what would be more fun to fly under and also attack, a wooden trestle bridge or something like the Ludendorff or the Arnhem Bridge?