MONTREAL -- Officials behind the REM electric light rail project say they expect the project to be completed on time, but stakeholders say they still have some "serious concerns."

Reporters were taken on a tour through part of the South Shore section of the rail system Thursday morning, where a complex in Brossard will become a garage and control centre. There's enough parking for some 3,000 commuters.

There are 2.5 kilometres of track already down in the area, part of a 3.5-kilometre stretch that will be used for testing the system next year.

"It's an important sector for the REM, to test the cars before going," said REM spokesperson Jean-Vincent Lacroix.

Meanwhile, near the Universite de Montreal, workers are building a new tunnel for the rail system. That work will close an existing commuter rail tunnel for four years beginning in January, bothering many in the area.

The Town of Mount Royal said in a statement to CTV News that "it has serious concerns about the impacts of the work on traffic and the quality of life of townies. No legal action is in preparation at this time."

They are still in talks, however.

"I'm focusing on construction and so is my client, and we're working together to develop that," said construction supervisor Xavier de Nettancourt. "We are developing as fast and quick and as efficient as we can to find a solution that will be safe and efficient for everybody." 

The first section to open will thread through major highways en route to the new Champlain Bridge. 

"It's going to be above (Highway) 10, under the Highway 30, and straight through the new Samuel-de-Champlain Bridge," said Lacroix. 

It will also be one of the few rail systems in North America to use a double sliding door system: one set on the train, one at the station. Testing for those is already underway. 

The reason for the doors? Montreal's weather.

"We are in Nordic conditions," said Lacroix. "We want people, when they're waiting for the REM, that it's not too cold (for them), that there's not some rain."

The project is still on schedule, officials said. The first trains are expected to make their trial runs in a year.