Here's why the left lanes are always closed in the Ville-Marie and Viger tunnels

The left lane heading east in the Ville-Marie Tunnel has been closed for years, as work within the tunnel requires access. (MTQ)

Anyone who drives through the Ville-Marie or Viger tunnel on Route 136 heading east or west will know that they will not be able to access the left lane in either direction.

The left lanes have been and will be closed for a while, but drivers will rarely see a work crew doing anything in either lane.

The reason for the closure is that a long-term, multi-billion-dollar renovation project involving multiple phases is underway.

Currently, workers need to access a structure in the middle of the two tunnels.

"In the daytime there's construction on the St. Laurent overpass," said Quebec Transport Ministry (MTQ) spokesperson Louis-Andre Bertrand. "Since you can't make a lane closure in the tunnel, that's why we close it at the beginning of the tunnel."

Workers need to use the lane to safely access the central pillar on the St. Laurent Boulevard overpass, and each span of highway has three lanes with solid lines between the lanes, meaning it's illegal to change lanes.

Work on the St. Laurent overpass requires workers to have access to the pillar in the Ville-Marie and Viger tunnels, and thus requires long-term closures of the left lanes in both directions. (MTQ)

It is one of several tunnel projects that are part of the $2-billion 2020-2030 renovation plan in the tunnels.

The Quebec government is paying for the project.

It aims to preserve existing infrastructure, such as the St. Laurent overpass, replace operating equipment, reduce the tunnels' environmental footprint and strengthen user safety, according to the MTQ plan.

Bertrand said that once the St. Laurent overpass work is completed, workers will move on the St. Urbain overpass, meaning the lanes through the tunnel will remain closed.

Workers have already begun renovating the De La Montagne St. exit and replacing 37 exhaust fans in the tunnels.

Exit 4 in the Ville-Marie Tunnel before it was put into service in 2022. (MTQ)

In addition to repairing the structural elements, workers are upgrading electrical, lighting, ventilation and drainage systems on the decades-old tunnels.

The Ville-Marie Tunnel opened in 1974 and the Viger Tunnel opened in 1986.

Once the work on the St. Laurent overpass is finished, we're going to switch to the St. Urbain overpass.

Bertrand said that although drivers may not see workers, it does not mean work is not ongoing.

"The thing about the tunnel is that there is a lot of work that we do every night," said Bertrand. "A lot of work, all the mechanical, all the electrical all the ventilation, that you don't see but it's a massive undertaking."