Arlberg Tunnels are two tunnels--one a railway tunnel and the other for automobile traffic--in western Austria between the provinces of Vorarlberg and Tyrol. The tunnels run through Arlberg Mountain at the northeastern end of the Rhaetian Alps. The railway tunnel is about 6 miles (10 kilometers) long and is an important link in the Paris-to-Vienna line. It opened in 1884 and was electrified in 1923. The road tunnel is nearly 9 miles (14 kilometers) long and opened in 1978.