Major work on the Mercier Bridge is in its last phase, eight years after it began.

The span should be fully open to traffic by Aug. 21

With 30 million drivers using the bridge every year, its condition had deteriorated and the aging deck needed to be replaced.

“It wasn't nice to look at, the guardrails were a bit rusty, you could see the steel deteriorate from the salt over the years,” said Sterling Deer of the Mohawk Bridge Consortium.

The final phase of the eight-year project started in June.

“Once they install each slab there's going to be some wires to tension the slabs, the joint installation, the pavement, so it's a lot of work,” explained Catherine Tremblay of Jacques Cartier & Champlain Bridges Corporation.

Over 50 workers are on the project during the day and 20 at night.

“Right now we're working seven days a week. We're working two shifts, 10 hours per shift,” said Mark Standup, safety officer of the Mohawk Bridge Consortium.

As a result - 70 per cent of the 78 new slabs have been installed so far, some weighing as much as 40 tonnes.

“The work has been going even with the bad weather, the extreme heat, the rain storms and wind we've been having. The work has been moving along nicely,” said Standup.

The bridge corporation estimates the repair work will extend the life of the bridge by 75 years.

Until the scheduled completion date on Aug. 21, drivers are asked to avoid the bridge, which is down to one lane in both directions.

Trucks are banned from using the bridge in the Montreal direction.

“There's the detour by Champlain or taking Highway 30,” said Tremblay.

Once the deck project is completed, the work isn't quite over on the Mercier Bridge: Forty piers will need to be reinforced. That will take another 10 years – but it won't affect traffic.