Malfunction on new branch of Montreal rail network caused by signalling system

By Canadian Press on December 5, 2025.

MONTREAL — A problem with the signalling system caused a service interruption this morning on Montreal’s light-rail network.

The malfunction occurred on the new branch of the rail system that opened last month, connecting downtown Montreal with its northern exurb of Deux-Montagnes, Que.

A spokesperson for the REM — Réseau express métropolitain — says the signalling system allows the automated trains to recognize the tracks ahead and the presence of other trains or objects.

Service was suspended at several stations for a few hours until the problem was resolved around 9:30 a.m.

The spokesperson did not say whether the issue was linked to the frigid weather in Montreal, with temperatures feeling like -23 C with the wind chill this morning.

The first leg of the light-rail network, which connected Montreal’s South Shore to the city’s central station, was plagued by frequent service interruptions after it opened in 2023.

This report by The Canadian Press was first published Dec. 5, 2025.

The Canadian Press