Switzerland is testing a bittersweet solution to clear snowbound and icy roads that replaces salt with a more environmentally friendly liquid laced with sugar.

Many European countries -- include Switzerland -- are grappling with salt shortages in the unusually harsh winter and Swiss officials said they wanted to try out the more costly British-supplied "safecote" solution.

"Apparently it's convincing," said Francoise Tschanz, a spokeswoman at the Swiss federal roads administration.

"We know that salt has some advantages, but also drawbacks, especially environmental ones," she told AFP on Friday.

The two-winter trial on a stretch of motorway in central Switzerland is due to carry on for several more months.

Saline products are corrosive, particularly for plant life, and regular intensive use on Alpine roads can contaminate the underground water table.

Tschanz said the principal drawback of the sugar derivative was its cost, while salt appeared more suitable for motorways and was available from two salt mines in Switzerland.