Turin–Lyon high-speed railway

Since 1872, the Turin–Modane railway connects Turin with Lyon via the 13.7 km (8.5 mi)-long high-altitude (mean tunnel altitude 1,123 m or 3,684 ft) Fréjus Rail Tunnel.[20] This initially single-track line was doubled and electrified in the early 20th century, and the Italian side of the line was renovated between 1962 and 1984, and again between 2001 and 2011.[21] This historical line has a low maximum allowed height, and its sharp curves force low speeds. Its very poor profile, with a maximum gradient of 30‰, requires doubling or tripling the locomotives of freight trains.

The characteristics of the line vary widely along its length. The Osservatorio (see References) divides the international and Italian sides into four sections:

• Modane - Bussoleno (Frejus tunnel and high valley section)
• Bussoleno - Avigliana (low valley section)
• Avigliana - Turin (metropolitan section)
• Turin node (urban section)

The first section comprises the Fréjus tunnel. Its low tunnel ceilings, high elevation, sharp curves, and steep gradients, make this section the limiting factor on the overall capacity of the line. A 2007 study used the CAPRES model[22] to calculate a maximum capacity of 226 trains/day, 350 days/year, under the safety regulations applicable at the time.[23] The study foresaw a maximum traffic of 180 freight trains per day, which had to be lowered to about 150 freight trains per day due to logistical inefficiency (the traffic flows between the two countries are asymmetric). A similar analysis for the full year led to a total of about 260 peak days per year.[24] These conditions defined a maximum transport capacity per year of about 20 million tonnes when accounting for inefficiencies, and an absolute limit of about 32 million in "perfect" conditions.[25] Additional traffic limitations stem from the impact of excessive train transit on the population living near the line. Some 60,000 people live within 250 m (820 ft) of the historical line, and would object to the noise from late-night transits.[26] In 2007 the conventional line was used for only one-third of this calculated total capacity.[27] This low use level was in part because restrictions such as an unusually low maximum allowable train height and the very steep gradients (26-30‰) and sharp curves in its high valley sections discourage its use.

A 2018 analysis, by contrast, found the line close to saturation, largely because updated safety regulations on train crossings in single-tube tunnels have very significantly reduced its maximum capacity.[28]

Traffic prevision by LTF (red) and BBT (green), compared to real traffic (blue) and a 2007 estimate of the capacity of existing line (pink); the 2007 capacity estimate pre-dates stricter safety regulations on train crossings in tunnels which have significantly reduced this capacity

The following table summarizes the future freight traffic predicted on both the Frejus and Mont-Blanc corridors from an analysis of current data and macroeconomic predictions (in million tons per year):[29]

Promoters of the new line predict that it will about double rail traffic on the Modane corridor compared to the reference scenario (see table above). Traffic predictions of even the early traffic of major rail infrastructures are however intrinsically uncertain, with well-known examples of both overestimates (e.g. the Channel tunnel[30]) and underestimates (e.g. the TGV Est[31]). Anyway, some experts disagree with the necessity for a new line connecting France and Italy on the Modane corridor, quoting wide margins for increase in traffic on the old line. Rather than as a natural consequence of faster transit times and a lower price for freight shipping (due to reduced energy use thanks to a much flatter profile, but without necessarily taking into account the full construction cost of the new line), they propose to increase rail traffic by coupling additional renovation of the existing rail infrastructure with sufficiently high financial incentives for rail transport and/or sufficiently heavy tolls and taxes on road transport. The political realism of such taxes is however questionable, as France demonstrated in 2013 when its government withdrew a small trucking ecotax after extensive riots initiated by the trucking industry (see Bonnets Rouges). The controversy became less relevant in 2018, when a study found that the existing line actually is close to saturation, largely because recent safety regulations on train crossings in single-tube tunnels have significantly reduced its maximum capacity.[32] The construction of a brand-new line will also make the older infrastructure fully available for regional and suburban services, which is an important consideration near the congested Turin node. It will also allow higher safety standards.[33]

The French section of the new line is planned with eventually separate paths for passengers and freight between Lyon and the Maurienne valley.

The passenger line will link the LGV Sud-Est (through a connection South of Gare de Lyon Saint-Exupéry) and the central Lyon stations to both Italy and Chambéry. It will connect near Chambéry to the Annecy via Aix les Bains and the Bourg Saint-Maurice via Albertville lines. The time gain from Paris or Lyon to Aix-les-Bains or Chambéry will be almost 45 minutes, and almost an hour to Annecy. The line may also be used to offload the saturated Lyon-Grenoble line from its TGV traffic, making much needed train paths available there for additional local trains.

The freight line will start from a connection to the future Lyon rail freight bypass, follow the A43 Motorway, and will pass South of Chambéry through a tunnel under the Chartreuse Mountains. That tunnel will eventually have two 23 km-long tubes, but it will initially be single-track. The line will then reach Saint-Jean-de-Maurienne through a second 20 to 23 km tunnel under the Belledonne mountains. The separate freight line will divert the freight traffic away from Aix-les-Bains and Chambéry, and from the shores of the Lac du Bourget where a freight accident on the existing line could catastrophically pollute this large natural freshwater reservoir.

The path of the Italian section was adopted in August 2011 by the Italian government, after extensive 2006-2011 consultations headed by Government Commissary Mario Virano within the "Italian Technical Observatory". In the Susa valley the new path sidesteps through additional tunneling the strong opposition to a previous planned path on the left bank of the Dora Riparia, which would have needed a viaduct in Venaus and a tunnel in Bussoleno.

The international section of the Lyon-Turin line spans about 70 km between Saint-Jean-de-Maurienne in Savoie and Bussoleno in Piemonte, and is the only part of the line on which work has started. The 57.5 km Mont d'Ambin base tunnel is being dug at the base of the Mont d'Ambin and is the major engineering work of the overall future Turin-Lyon line. An underground service and rescue train station is planned around the half-way point of the tunnel, East of Modane.

In Chimilin, a French town of 1,100 which will be split by the railway, the town council has opposed the plans since 1992 and the mayor, Marie Chabert, sees the economic uncertainty as damaging for the region.[10]

In Villarodin-Bourget, a small French village, residents represented by the 'Association pour la Sauvegarde du Site du Moulin' have opposed the digging of a 4 kilometre survey tunnel since 2002 and are in close communication with the No TAV movement. The mayor, Gilles Margueron, said "after we started looking at the project in details, we soon arrived at a position of complete opposition."[10]

No TAV protests in 2005

Some people in the Susa Valley in Italy have been resisting the railway project since the 1990s. The No TAV movement began in 1990, with actions to inform local people affected by the plans, supported by the mayors of the valley and the Comunita Montana (mountainous community). From 2000 onwards, there were demonstrations, squatted centres, a trade union solidarity project and a social forum. The resistance was spoken about in terms of the partisan resistance to the Nazis in World War II.[50]

The movement advocates the tactics of non-violent direct action, but some protests have turned violent.[51] Catholics pray at the Chiomonte construction site, while other networks organise communal dinners, discussions and flash mobs. In Venaus, a land squat called the 'Presidio' is situated next to where the survey tunnel was originally planned to be dug.[10]

The No TAV movement generally questions the worthiness, cost, and safety of the project, drawing arguments from studies, experts, and governmental documents from Italy, France, and Switzerland. It deems the new line useless and too expensive, and decries its realization as driven by construction lobbies. Its main stated objections are:

• Better to update existing infrastructure.[51]
• Low level of saturation on the Frejus rail tunnel and stable or decreasing traffic also on Fréjus Road Tunnel.[10] A more recent study, though, found the existing rail line close to saturation because toughened safety standards on train crossings in single-tube tunnels have sharply reduced its capacity.[28]
• Economical feasibility in doubt due to high costs.[50]
• Danger of environmental disasters.[10]
• Health concerns, due to the hypothesized presence of uranium and asbestos in and around the mountains where the tunnel is bored,[52] though the extensive reconnaissance tunneling has found none to date.[53] Supporters of the tunnel argue that the risk of contamination is overstated or non-existent.[54]

Members of the protest movement have summarized their ideas against the construction of the new line in a document containing 150 reasons against it[55] and in a wide number of specific documents and meetings.[56]

Critics of the No TAV movement, by contrast, characterize it as a typical NIMBY (Not In My Back Yard) movement and point out the pollution reduction and CO2 emission elimination benefits of the tunnel. In response, No TAV activists talk about LULU (Locally unwanted land use).[50]