L'Épine Tunnel
The Épine Tunnel is a motorway tunnel in the Savoie department of France, on the A43 autoroute between Lyon and Chambéry. It crosses the Chaîne de l'Épine mountains and is about 3.2 kilometers long.
Two separate tunnels carry traffic: westbound (about 3.18 km) and eastbound (about 3.16 km). Construction began in 1972. The westbound tunnel opened in 1974, and the eastbound tunnel opened in 1991. The project was finished in the early 1990s to allow two-way traffic.
The tunnel is operated by AREA and is tolled. Speed limit is 110 km/h, with two lanes in each direction. The western entrance is near Lac d'Aiguebelette; the eastern entrance is near La Motte-Servolex. Lyon lies about 125 km to the east, and Chambéry about 15 km to the west.
In 2009, AREA carried out drainage improvements in the western tube after heavy rain caused rising water. There was a concrete dam with a cavity near the eastern tunnel, once visible to view from above via a skylight, but visitors are no longer allowed due to exhaust emissions. The tunnel is equipped with speed cameras for safety.
This page was last edited on 3 February 2026, at 05:18 (CET).