The Société de transport de Montréal (STM) announced on Thursday that the aging MR-73 train fleet will be taken off the Metro’s Blue line and will continue to run on the Green line. The decision follows the launch of a new control system on the Blue line that cannot accommodate the older MR-73 cars.
The MR-73 series, the oldest rolling stock still in regular service on the Montreal Metro, has long been a fixture on the Green line. With the Blue line undergoing a modernization that includes an upgraded signaling and control infrastructure, the STM determined that the legacy trains are incompatible with the new technology. As a result, the Blue line will no longer use MR-73 units, and the STM will reassign those trains to the Green line where they can still operate safely.
STM officials explained that the incompatibility stems from technical differences between the control system installed on the Blue line and the equipment on the MR-73 fleet. The newer system requires communication protocols and safety features that the older trains do not possess, making it impossible for the MR-73s to run on that route without extensive retrofitting.
The move means that passengers on the Green line will continue to see the familiar MR-73 cars in service, while the Blue line will rely on newer rolling stock that matches its upgraded control environment. The STM has not indicated any immediate changes to service frequency or capacity on either line as a result of the reassignment.
The decision reflects the broader challenges of integrating legacy equipment with modern transit technologies. By keeping the MR-73 fleet on the Green line, the STM aims to maintain operational continuity while the Blue line transitions to fully modernized operations.
No further details were provided regarding the timeline for removing the MR-73s from the Blue line or any plans for future upgrades to the older fleet.