Studies conducted in 2004 put the total cost of the project at Euros
4.1 million, which included Euros 2.03 billion for a 60km high-speed
line from Wendlingen to Ulm. However, a new study has revised the cost
of this link to around €2.89 billion.

The state of Baden-Württemberg has committed Euros 950 million to the
project and previously said it would not commit any more funding,
although premier Mr Stephan Mappus says the revised budget is
"manageable and justifiable."

Stuttgart 21 entails the construction of a new valley crossing in
Stuttgart city centre. A 9.5km tunnel will link the main station and
the new airport station, joining a new 10km line to Wendlingen where
trains will run onto the new line to Ulm.

A second tunnel will run under the south side of the city to
Obertürkheim, where it will emerge to join the existing line to
Esslingen. The S-Bahn lines from main station to Stuttgart North and
Bad Cannstatt will also be refurbished, and new holding sidings will be
built at Untertürkheim. A new chord south of Vaihingen will allow
trains arriving from the Singen direction to serve the airport station
and run into the main station from the south.

Construction work has already begun near the existing Stuttgart Main
Station, but the complexity of the project means it will not be
completed until 2019.

From the outset Stuttgart 21 has been a controversial project and it remains the subject of regular protests in the city.