The government has supported plans to build a second road tunnel through the Gotthard to compensate for the temporary closure of the first one for renovation. It is also seeking measures to prevent a boost in capacity.
Following consultation with political parties, organisations and cantonal authorities, the cabinet decided on Friday to uphold a proposal presented in June last year.
The plan foresees the construction of a separate, parallel tube, but traffic in both tunnels would remain restricted to a single lane, even during the particularly busy holiday season in Europe.
In the bill to parliament, the cabinet also proposes changes to the law limiting the number of lorries allowed into the tunnels at one time for safety reasons. The introduction of a toll system for vehicles transiting the main north-south thoroughfare was ruled out.
“The legal amendments ensure that a constitutional article aimed at protecting the alpine environment will be respected,” the Federal Road Authorities said.
Transport Minister Doris Leuthard insisted that the legal hurdles are high enough to stifle attempts at increasing the traffic capacity.
"Our project is not aimed at upgrading the tunnel. It is purely a renovation project," she told journalists.
Gotthard road and rail tunnels
It is the third-longest road tunnel worldwide and the main north-south traffic thoroughfare in the Swiss Alps.
Opened in 1980, the single-bore tunnel with just one lane in each direction measures 16.94 km.
At least 6.1 million vehicles, including 600,000 lorries, use the passage every year.
The first Gotthard rail tunnel was built in the late 19th century and became operational in 1882.
Construction of a second train tunnel, known as the Gotthard Base Tunnel, is under way, with the tunnel expected to open in 2016.end of infobox
In 1994 voters approved a proposal to cap alpine transit traffic. Subsequent attempts to ease regulations were rejected by both parliament and voters.
The statement reiterates that the proposed option guarantees road access to and from the southern Ticino region and central Switzerland.
Renovation work is expected to begin in 2020 at the earliest and be completed within a decade.
Once operational, the two-tube tunnel traffic system is also expected to increase safety, reducing the threat of collisions.
A serious accident followed by a fire in the tunnel killed 11 people in 2001.
The influential Association of Road Hauliers and the Automobile Club have welcomed the government decision. They said any other option would have been unrealistic.
However, the environmental Alpine Initiative group has accused the cabinet of sabotaging efforts to put road traffic onto rail.
“We hope parliament will reject the government bill,” said Fabio Pedrina, president of the pressure group, in a statement.
He called on the cabinet to reconsider alternative options to repair the existing Gotthard tunnel, which opened more than 30 years ago, without constructing an additional one.
The Alpine Initiative, which is fighting against an increase in road traffic, also says the government option would cost taxpayers up to CHF4.4 billion ($4.7 billion) – 60 per cent more than the plans to upgrade the road-to-rail shuttle through the Gotthard during the renovation work.
The pressure group and green and centre-left parties have announced they will oppose the cabinet proposal and challenge any parliamentary decision backing the government by forcing a nationwide vote.