Main roads and Tunnels in Italy
The road signs are white with black text, except for strada statali and strada provinciali, which are blue with white text.
* Strade Statali: often dual carriageway, not tolled, usually lead to cities or town centres; they are numbered and named with the prefix SS
* Strada Provinciali: regional roads which are (sometimes) numbered with the prefix SP
* Strada Bianca: can be, literally, white roads that are unpaved/not tarred and connect rural areas; they are of varying quality
As much as 75 percent of Italy is mountainous; some autostradas have long tunnels and bridges.
Tunnels link Italy with France and Switzerland: Tunnel du Frejus and the Mont Blanc Tunnel link Italy and France in the Alps and the Tunnel Gran San Bernardino crosses the border to Switzerland.