Commuters between Montreal and Nuns' Island will soon have a new route, as a temporary causeway bridge is set to open for Montreal-bound traffic Monday.

It's the first step of a long-awaited process - a temporary seven-lane bridge connecting Nuns’ Island and Montreal.

“One of the last reports we received from an engineering company was telling us that the most problematic bridge part of this corridor was the Nun's Island Bridge,” said Denis Lebel, the federal minister of infrastructure.

Traffic on the 50 year-old span will be rerouted to the new Nun’s Island causeway bridge.

“This new modern bridge has a bikeway which conforms to existing standards and also we're able to, with this new bridge, have a dedicated busway which will eliminate putting the cones down every evening,” said Glen Carlin, acting CEO of the Jacques Cartier-Champlain Bridge Corporation. “Also, it will allow us to eliminate the traffic light, which also influences the rush-hour traffic on the Champlain Bridge,”

The new bridge is over a narrower section of the St. Lawrence River, making for a shorter span that was easier to build.

According to the bridge authority, building a temporary bridge to and from Nun's Island cost about the same as fixing the existing one, with less impact on traffic.

With a price tag of about $100 million, the government said completion of the project is under budget and ahead of schedule. It is expected to be finished by mid-December.

If the weather cooperates, work will begin Friday night on the Montreal-bound lanes, which will open on Monday.

Southbound traffic will be connected the new bridge the weekend of Oct. 18.

“We're also going to take advantage during this closure to get as much work done on the Champlain Bridge as well, so we are coordinating ourselves and we're working with our partners Mobilité Montreal to make sure that the other bridges aren't being affected,” said Carlin.

The bypass bridge is not permanent, and will only be used until the Champlain Bridge's replacement is completed.

Weekend Closure

The Champlain Bridge is closed to Montreal-bound traffic from 10 p.m. Friday until 5 a.m. Monday, Oct. 5, 2014.

Two out of the three lanes that normally go toward the South Shore are open to traffic, and the lanes will be skinnier than normal.

During this time the Victoria Bridge will have both lanes open toward Montreal.