Trains off track?

With Brumby promising millions spent on new trains the question remains, can the archaic rails hold them? According to information ripped from the depths of my own trivium (as in I can't remember where I heard this) the majority of Melbourne's trains are incapable of even nearing top speeds on inner city tracks, in fact they travel well below required speeds. The tracks look old so this sounds feasible however trying to get a hold of such information could be a logistical nightmare. It would be incredibly interesting to know how old the tracks are and what safe speed is in fact possible atop them. Does anyone have suggestions as to where to find out if 'engineering' type info about melbournes public transport system. I'll keep looking but help would be appreciated. Thanks,
Lachlan

I imagine that there is the information the government releases, the info that Connex releases and then theres the truth. It might be worth combing the vic.gov website and the connex website and compare the details.. I'll have a look into it as well.