In February 2018, REM project owner CDPQ Infra awarded the rolling stock and systems and operation and maintenance (RSSOM) contract for the 67km automated network to Groupe des Partenaires pour la Mobilité des Montréalais (PMM) a consortium of Alstom Transport Canada and SNC-Lavalin O&M.

Alstom will supply 106 1.5kV dc overhead Metropolis trains for the project.

A public consultation was selected at the end of 2018 to identify the preferred styling for the train fleet. The Saint-Laurent model was ultimately chosen with 42% of the vote, ahead of the Expo (29.5%) and Mont-Royal (28.5%) designs.

The external livery and headlight design was inspired by the cables of the Samuel De Champlain Bridge, which the trains will use from 2021.

Each two-car train will be 2.94m wide and 76.2m long, accommodating up to 780 passengers, 128 of them seated.

The first section of the 26-station REM is due to open in mid-2021. Services will initially operate at minimum intervals of 2min 30 and the system will be designed to allow 1min 30 headways. Trains will operate in four-car formations at peak times, with two-car trains at other times.