Construction on the REM begins in earnest on Friday and it means the beginning of months without weekend train service on the Deux Montagnes and Mascouche train lines.

As of April 27, the final train leaving Deux Montagnes for Montreal on Fridays will be at 6:33 p.m., and the last train leaving Montreal will be at 7:30 p.m.

The last train from Mascouche will be at 5:17 p.m. Friday, with the last train leaving Montreal at 19:12 p.m. There will not be any weekend service on either of those lines until further notice.

To compensate monthly and annual TRAIN pass commuters who rely on weekend train service, the RTM will hand out OPUS cards that are pre-loaded with weekend passes. These passes will allow the user free STM, STL, and RTM service from 4 p.m. on Fridays until Sunday night, and will be valid until Sept. 30, 2018.

The passes will be handed out at all Deux Montagnes train stations starting at 7 p.m. Friday April 27, and on Saturday and Sunday. People can also ask the RTM to mail them a card.

To compensate for the lack of weekend train service express buses will be running on weekends between the Montmorency metro station and the Deux Montagnes and Grand Moulin train stations, while another bus will run between the Cote Vertu metro station and the Roxboro-Pierrefonds and Sunnybrooke stations.

The RTM says 4,600 people use the Deux Montagnes train line on weekends.

Mascouche schedule

Deux Montagnes schedule

Fewer trains and schedule changes in June

The REM will eventually take over the entirety of the Deux Montagnes train line, and until it is complete there will be fewer trains running along the tracks.

Starting in June crews will be working on one set of the twinned tracks in Town of Mount Royal, and as a result three trains on the Deux Montagnes schedule will be cancelled: two in the morning, and one train in the evening.

In addition the schedules for the Mascouche and the Deux Montagnes train lines will be rearranged.

Transit agencies are going to provide more details about the schedule changes in May.

As reported earlier this year the REM is also putting Deux Montagnes and Mascouche commuters on notice: the tunnel under Mount Royal will close in 2020 and be closed for two years.

Train commuters from Deux Montagnes and Mascouche will have to get off at the Du Ruisseau station and take a shuttle bus to Central Station in downtown Montreal, or to a nearby stop on the Orange metro line.

Construction in multiple locations

Crews will begin work in multiple locations throughout the summer of 2018 to lay the groundwork for REM lines and stations.

In the West Island crews will begin tearing up the old tracks along the Doney spur, which runs between Hymus Blvd. and Highway 40 and will be the basis for much of the West Island line on the REM.

On the South Shore crews will be doing work along the median of Highway 10 between the eventual locations of the Panama and Du Quartier stations, which will force the closure of one lane in each direction of the highway. At the same time reserved bus lanes will be built along Highway 10.

Students at the University of Montreal will also have to adjust to construction as crews begin working on the Edouard Montpetit station, which will connect the REM to the Blue line of the metro. One of the three entrances to the metro station will be closed as crews excavate at least 70 metres below the surface.

Meanwhile the city of Montreal's plan to turn McGill College Ave. into a public square will have to wait: the REM will begin construction on the east side of the street in the autumn as creates the downtown station, and it will frequently ban vehicle and pedestrian traffic from the worksite.