Heavy snowfall brought commercial traffic to a halt for four hours on Friday on one of Switzerland's only operating Alpine routes, the San Bernardino Pass.

Authorities in canton Graubünden closed the pass to trucks after the first substantial snowfall of the winter, which caused long traffic lines.

Officials said the San Bernardino pass could not cope with the increased levels of traffic on the pass following the closure of the Gotthard tunnel, a key alternate route, last month.

Collisions resulting from the heavy traffic have forced the closure of the San Bernardino route several times since a devastating fire gutted the southern end of the Gotthard tunnel - Switzerland's main north-south axis.

Gotthard fire

The 17-kilometre tunnel was closed on October 24 after a collision between two trucks sparked an inferno, killing 11 people and causing major structural damage to the roof.

An alternate route, the Mont Blanc tunnel between France and Italy, has been closed since 1999, after a fire killed 39 people.

Heavy goods traffic is barred from using the Simplon Pass linking Switzerland with Italy as well as the Great St Bernhard tunnel in canton Valais, leaving truckers with few alternatives.

swissinfo with agencies

In compliance with the JTI standards

More: SWI swissinfo.ch certified by the Journalism Trust Initiative