The transfer of transalpine freight from road to rail is a prime objective of Swiss transport policy. The Swiss electorate has repeatedly voted for this objective so as to conserve the Alpine region.

The "new transalpine rail routes" (NEAT) project covering the Lötschberg and Gotthard routes is the centrepiece of the European railfreight corridor between Rotterdam and Genoa and, as such, forms the foundation of Switzerland's policy of transferring traffic from road to rail.

Once the Gotthard and Ceneri base tunnels are operational (late 2016 and late 2020 respectively), the level-track rail route between Basel and Ticino will become a reality. Thanks to the gentler gradients, freight traffic will become more efficient and environmentally friendly: goods will reach their destinations more rapidly and fewer locomotives will be needed to haul the trains.

However, these improvements will not be sufficient to attain the long-term objective of transferring traffic from road to rail. In order to encourage further growth, SBB will on behalf of the federal government upgrade the Gotthard route to a 4-metre corridor by 2020. While the Lötschberg-Simplon route already benefits from this profile, at present only semitrailers and containers with a 3.84-metre headroom can be carried on the Gotthard route. Although the Gotthard and Ceneri base tunnels have a 4-metre headroom, the approach routes from the North and the South do not.

Creating a 4-metre corridor along the Gotthard route is, therefore, an appropriate measure for transferring additional freight traffic from road to rail as of 2020 and thus for supporting the electorate's demands. The Federal Council expects that the two new Lötschberg and Gotthard transalpine rail routes will result in a threefold increase in rail traffic. In other words: instead of the 80,000 transalpine truck trips a year, from 2030 trains will reduce the number of trips by around 240,000.

The 4-metre Gotthard corridor will enhance rail traffic's competitiveness and make a further important contribution to conserving the Alpine region.

The purpose of the 4-metre corridor is to allow the carriage of semitrailers, swap bodies and containers with a 4-metre headroom. Vehicles of this size are used by the transport industry throughout Europe. The term "semitrailers" refers to trailers with their own running gear. Together with the prime mover, they form a semitrailer combination or truck-trailer unit.

At present, truck-trailer units make up 60 percent of transalpine freight journeys and thus represent the most significant category of vehicle. Transport experts and market insiders assume that truck-trailer units will be employed even more widely in future.

This means that the 4-metre corridor will help to satisfy one of the European transport industry's vital needs. In future, freight forwarders will drive their truck-trailer units to terminals in the Netherlands, Germany or Italy, where they will load their semitrailers onto the trains. Thanks to the 4-metre corridor, it will also be possible for all standard crossloading or transhipment containers currently in use throughout Europe to be carried on this route. The result will be smooth, environmentally friendly transalpine freight transport.

The 4-metre corridor on the Gotthard route also produces benefits for passenger services. Over the next few years, SBB aims to continuously expand its offering on this popular route. When the Gotthard and Ceneri base tunnels go into operation in late 2016 and late 2020 respectively, journey times between German-speaking Switzerland on the one side and Ticino and Italy on the other will be considerably shortened. For example, it will take less than two hours to travel from Zurich to Lugano. From the end of 2020, travel time between German-speaking Switzerland and Ticino will have decreased by up to an hour.

Currently, some 9,000 passengers travel through the Gotthard every day. By 2025, the planned improvement will lead to a doubling in passenger numbers on the Gotthard route. SBB is reckoning on 15,000 passengers every day as early as 2020. In order to be able to carry these additional passengers, SBB will purchase further new trains by 2020. Thanks to the 4-metre corridor, it will also be possible to run double-deck trains, allowing passengers to complete their journeys south or north speedily and in comfort at peak times such as weekends or holiday periods.

Creating a 4-metre corridor along the entire Gotthard route will require 20 tunnels between Basel and the southern side of the Alps to be enlarged. In addition, there are 80 projects for alterations to platforms, traction current systems, signalling installations and overpasses. The aim is for semitrailers with a 4-metre headroom to be carried through the Gotthard by rail by 2020.

For upgrading twelve tunnels and undertaking the 80 individual alteration measures, the Swiss parliament approved of a loan of CHF 710 million in 2013. The single biggest project is the construction of a new Bözberg tunnel in Canton Aargau, which will cost CHF 350 million. Other projects include work on the Villnachern, Morschach, Svitto, Paradiso/San Martino, Maroggia and Molino tunnels.

In order for the 4-metre corridor to achieve its full potential, sections of line in Italy are also to be upgraded to a 4-metre headroom. The routes concerned are Chiasso-Milan and Ranzo-Gallarate/Novara (the Luino line). Only by upgrading these feeder lines for the new transalpine rail routes will it be possible to move freight shipments to the loading terminals in Italy. Parliament has approved a loan of 280 million francs for upgrading the feeder lines in Italy, with 50 million francs of this to be used for the section south of the Simplon.

The upgrades to some smaller tunnels will be financed by the service-level agreement between the federal government and SBB. These projects include the Rindelfluh tunnel, the Axen lakeside track and the Crocetto/Giustizia, Dragonato, Massagno, Coldrerio and Balerna tunnels.