1. The modernization of the existing line fails to meet the future needs of freight traffic and to maximize its shift from road to rail.
- The upper Maurienne and Susa valleys have very steep slopes (up to 3.3%, i.e almost three times the recommended 1.2% limit for heavy freight trains) imposing strong limitations on operation and higher additional power costs.
- At its highest point, the existing railway line reaches an altitude of 1300 m. As a result, up to two traction units and one pusher unit are required on the upward journey and the train loads have to be limited (one should not forget that trains have to slow down on the descent).
- The winding route across the Alps also seriously slows down the trains (30km/h in some stretches, i.e almost the same as the original speed).
- The current rail safety advocates the need for double tube tunneling instead of single tube tunneling like the old Mont Cenis tunnel.
- International traffic increasingly interferes with the development of a regular-paced commuter and regional train link in Piedmont and the Rhone-Alpes region. To this day, the freight traffic potential along the existing line has not yet been fully tapped. However, the development of a regional trains will considerably reduce freight volumes along the busiest routes.
The existing line will become less and less suitable for increasingly longer trains, large container trains and a high capacity rolling motorway system.
Just like at the end of the 20th century when most of the road traffic on the old mountain passes was shifted to the new alpine tunnels, in the years to come, a large portion of freight traffic crossing the Alps will be handled by the rail network and its “base tunnel”system both in Switzerland and Austria.