You won't have to wait any much longer, Montreal. The REM's Brossard to Montreal line will soon be operation (and it's sooner than you think!)
In an announcement made on Monday, REM authorities revealed that the first section of the light-rail system is expected to by mid-August. Funnily enough, this announcement came only a few hours after CDPQ Infra revealed that test runs between Brossard and Montreal will begin this Wednesday. These tests will be done without any passengers, and at planned operation hours, to simulate the REM line's expected schedule.
Source: REM press kit
By the end of 2024, residents should have access to an additional 3 of the 5 planned REM lines: Deux-Montagnes, Central and West Island. As for the Airport line, this last one should be made available by 2027.
For ticket fares and additional information, visit REM's website.