It links Chamonix, Haute-Savoie, France with Courmayeur, Aosta Valley, Italy, via the French Route Nationale 205 and the Italian Traforo T1 (forming the European route E25), in particular the motorways serving Geneva (A40 of France) and Turin (A5 of Italy).

It reduces the route from France to Turin by 50 kilometres (30 miles) and to Milan by 100 km (60 mi).

Following a fire in 1999 in which 39 people died, which showed how lack of coordination could hamper the safety of the tunnel, all the operations are managed by a single entity: MBT-EEIG, controlled by both ATMB and SITMB together, through a 50–50 shares distribution.

The idea of building a tunnel underneath Mont Blanc to avoid the need for long journeys dates back to the nineteenth century during the heyday of the railway.

However, the idea did not receive widespread attention until 1907, when Francesco Farinet, a Member of Parliament of the Aosta Valley, advocated constructing of the tunnel.

[5] This was preceded by the signing of a national charter for the tunnel construction, ratified by the parliaments of France (1957) and Italy (1954).

In 1997, a fire detection system was installed along with centralized safety equipment management, and new variable message signs.

On the morning of 24 March 1999, the engine of a Belgian transport truck carrying volatile freight caught fire in the tunnel.

Mont Blanc Tunnel Tolls on the Italian side from 1 January 2022 (22% VAT included)[14] Mont Blanc Tunnel Tolls on the French side from 1 January 2022 (20% VAT included)[14]