Severe snowfalls have closed the Gotthard and San Bernardino north and southbound tunnels to heavy goods vehicles.
Trucks from Italy were being stopped at the Chiasso-Brogeda border point and those travelling south were redirected to waiting bays on the A2 motorway, the Federal Roads Authority said on Friday.
Up to 20cm of snow fell in central and northern Ticino on Thursday night. Forecasters said a depression over the southern Alps could bring up to 60cm of fresh snow on Friday.
The Gotthard road tunnel is on the main north-south artery through Switzerland and is the most busy route for the 1.2 million trucks that cross the Swiss Alps annually.
swissinfo.ch and agencies