/ Europeén Union will finance the 2nd Warsaw metro line. Good news.
You do not spend billions of dollars duplicating infrastructure in case of an accident. when there are other pressing projects to be built. You keep harping on about paralasis if the cross river link gets shut down has this happened to you ever? didin't think so. Have a look here to have your arguements demolished. The fact that none of the metro lines go to centralna station is ridiculous as is building a metro line to shadow an existing rail line!
The line is to be a classic heavy metro. These are very expensive to build and take a great deal of time to complete. Warsaw can ill afford the cost and time delays. A semi-metro, like Hannover's Stadtbahn, which runs underground in the centre of a city and can use tramway tracks on the outskirts, can be rolled out quickly and could be a cost effective fast cure for Warsaw's traffic problems.
The line between Rondo ONZ and Stadion parallels the PKP Linia Srednicowa cross city line, running some 0.5 kilometre to the North. Warsaw can't afford this duplicated capacity. The City needs an East-West metro line running further to the North and crossing Krakowskie Przedmiescie at a point where it could serve the University and the Old Town.
The line won't be completed in time for Euro 2012 football championships which completely negates the reason for adopting current southerly route to serve the new sport stadium which is already served by Stadion station.