It is an eye watering amount of money. IIRC the TGV line from Lyon to Marseille (about 160 miles) came in at €3,8 billion (which in itself was some way over budget). OK, it was nearly 20 years ago, but we've all been told that inflation has been low over the last 20 years, so the figures being bandied about for HS2 really do seem stratospheric.
The line to Marseille has been hugely successful, and the fact you can get from Paris to Marseille in 3 hours means it has taken 2/3 of the volume from air traffic for the route. Of course, fares have been kept reasonable, which helps, and the péage on the autoroutes tilts the economics in favor of rail if you're travelling alone.
One of the thing I really like about the French national character is the love of "le grand projet". The TGV network is a fine example of this; from a French perspective, high speed inter-city rail travel has been a wonderful thing (when the drivers aren't on strike !!).
It's perhaps a sign that I've gone a bit native in my 31 years here, but I'm always a bit baffled by how much the UK beats itself up over this sort of thing. The current rail infrastructure is largely victorian, and look how well it has served. A really long term view is needed on this. The argument about how much quicker it'll be to get to Birmingham is irrelevant, it's about the increase in capacity. By having separate high speed and lower speed tracks one can run way more services (assuming there is the rolling stock and staff to achieve this...)
I'd be very interested to know the views of the likes of Bob, who really know about railways.
