Melocheville tunnel

Located next to the Beauharnois generating station, the Melocheville Tunnel is an extension of the regional route from Montreal’s south-west shore.

This tunnel is located directly under the Beauharnois Canal and allows for the ongoing passage of both road and maritime traffic. It links Beauharnois Downtown sector to Beauharnois West sector.


Construction of the tunnel began in 1956 and finished in 1957.

For over 20 years, it was known as the “Beauharnois Tunnel”, and in 1991 it was officially renamed the “Melocheville Tunnel.”

The Corporation has been responsible for the tunnel’s operations, maintenance and administration since October 1, 1998. The structure was previously under the administration of the St. Lawrence Seaway Management Corporation.


  • The tunnel is made up of 18 caissons and a traffic lane in each direction, a sidewalk on the north side, and three ventilation shafts (one air exhaust and two air intakes.)
  • The two traffic directions are separated by a central support structure that forms the first ventilation shaft (the air exhaust).
  • The caissons lie directly on the bedrock.


In 1968, the tunnel was restored and resurfaced. Since then, maintenance work on the tunnel, such as pavement repairs, cleaning and painting of the walls, and restoration of the approaches, has been ongoing to preserve the structure’s integrity and to ensure users can use the tunnel safely and efficiently.