Transport Quebec announced Wednesday that the St. Jacques overpass will be no more sooner than anyone thought.

The work is part of the overall plan to build a new St. Jacques Bridge that will link up with the new Turcot Interchange.

And though west end dwellers knew this day would come, it was unclear when and how long the closure would last until Wednesday; the work will begin March 21 and will last 2.5 years, necessitating the closure of St. Jacques St. between Girouard Ave. and Decarie Blvd. until the fall of 2017.

The process was supposed to last a year and a half, but in the planning and analysis stages, Transport Quebec decided that a gigantic sewage water collector built in 1930 that runs directly underneath the overpass should be diverted, so it no longer runs under the new Turcot.

Workers will have to dig a mammoth hole in the ground to work on an 850-metre diversion towards a new collector along Pullman Blvd., which will create other traffic detours.

Once that process is done, which is supposed to be at the end of this year, crews will start taking down the St. Jacques overpass in sections to build a new bridge.

Peter McQueen, councillor for the section of NDG that will be hit hardest by this detour, said he was not happy to hear this closure will now last a year longer than originally forecast, and will start just weeks before the new MUHC superhospital is set to open.

He also said he'll also vote against a plan to turn part of de Maisonneuve Blvd. into a two-way street between Addington St.and Decarie Blvd., given it's already a very difficult area for cyclists and pedestrians to cross.

The time allotted to pedestrians to get across the road is currently six seconds, he said.

“That’s unacceptable. This is an intersection 150 metres from one of the busiest metro stations in Montreal,” he said.

Transport Quebec spokesperson Sarah Bensadoun said her department knows the closure and traffic headaches won't be easy, but they have a deadline they have to meet.

“This work cannot be postponed. We have to do it because the Turcot Interchange project has to be completed by 2020, so there’s a limited amount of time [for us] to start this construction site,” she said.

Transports Quebec will work closely with the city and the STM to find ways to ease the headaches for motorists and pedestrians, as well as those unhappy with the added noise pollution

An information meeting for the public will be held next Wednesday evening at the St. Raymond Centre at 7 p.m.