Great St Bernard Tunnel

There is a toll to use the tunnel, payable in full even for drivers who already display on their vehicles a Swiss motorway vignette. The tunnel comprises a section of the E27 route linking Belfort with Aosta.

For most of its 5,798-metre (6,341 yd) length the tunnel runs in a straight line, but incorporating a gentle slope. The northern end is 1,918 m (6,293 ft) above sea level while the southern end is only 1,875 m (6,152 ft) above sea level. At both ends, the approach road to the tunnel is covered by a gallery / avalanche shelter in order to minimize the risk of access to the tunnel being temporarily blocked during bad weather. Any frontier formalities are handled at the tunnel's north end, although the actual national frontier is 2,938 m (3,213 yd) from the Swiss tunnel entrance and 2,860 m (3,130 yd) from the Italian entrance.

The name of the tunnel comes directly from that of the Grand St Bernard Pass, and thereby indirectly from the saint who in AD 1049 founded the hospice high above the tunnel, that also bears his name. Tourists on the Swiss side additionally find themselves reminded by road side billboards of the saint's association with St Bernard dogs.

Before the tunnel was constructed, the frontier was passable here only using the Great St Bernard Pass. The pass remains an option in summer, but is normally closed by snow between October and May, and sometimes for longer. The tunnel is intended to be usable for 365 days every year.

The tunnel was opened to traffic on 19 March 1964, having been under construction since 1958. It became the longest road tunnel in the world, replacing the Vielha tunnel which was opened in 1948.

The approach roads have been progressively improved, and most recently the avalanche covers extended on the southern side. The Mont Blanc tunnel tragedy of 1999 prompted a major review of road tunnel safety in several countries including Switzerland, and significant safety upgrades are planned for the Grand St Bernard Tunnel. A speed limit of 80 km/h (50 mph) is already in force inside the tunnel.

The tunnel and most of the connecting road between Aosta and Martigny are only single carriageway roads, and for most relevant city destinations in Switzerland and Italy the toll free St Gotthard Tunnel and Simplon Pass offer more direct or at least faster routes. This and the toll ensure that the Grand San Bernard Tunnel rarely suffers from the levels of holiday season congestion that plague the more popular Alpine crossing routes.

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