Montreal's new light-rail transit system had a bumpy debut on its first full day of operation as a problem with the track forced a shutdown at the height of the morning rush hour.

The Réseau express métropolitain, or REM, officially launched Monday for paying passengers after more than 120,000 people tried out the system for free over the weekend.

A spokesperson for the REM said a switch problem on the tracks caused service to shut down at around 8 a.m. before it resumed at around 9:15 a.m.

"There was a technical problem on a switch. It's part of the tracks of the REM, it was a situation that needed a field team to repair it," Jean-Vincent Lacroix said.

He said there was a partial closure of the 16.6-kilometre route starting at 8 a.m., and at 8:30 service was interrupted completely for 45 minutes to allow for repairs.

Lacroix said the first priority was to get passengers already on board to the next station. Authorities then set up a shuttle service using city buses to transport people to downtown Montreal from the South Shore suburbs. But there were hiccups as commuters were left waiting in long lines to take crammed buses across the Champlain Bridge.

"It's not a great first look," said Luc Therrien, a Brossard resident who boarded a bus at the Panama station south of Montreal. He was hopeful the afternoon ride would go more smoothly.

"Better this happens in July than in September when everyone is back at work and school," he said.

When REM service is interrupted for more than 20 minutes during peak hours or for 30 minutes off-peak, shuttle buses are offered to Central Station.

#Montreal light-rail transit system shuts down on first official day of service. #REM

But at Central Station in Montreal, one commuter trying to get to Nuns' Island for work complained that no one seemed to know where the shuttle buses were stationed. Patrice Edrocard had been waiting for well over an hour as a security guards tried to find that information for him and other stranded passengers.

"Outages can happen. It's communication that's the real problem," Edrocard said.

Lacroix was unable to specify what caused the switch malfunction, but he preached patience and said operators are hoping to keep service interruptions to a minimum and make adjustments quickly.

“These are situations that can happen," Lacroix said, adding officials want to be ready for the resumption of the school year, when the number of users will rise.

The first five stations of the 26-station, 67-kilometre electric rail network opened eight years after the project was conceived by the province's public pension fund manager, Caisse de dépôt et placement du Québec.

The planning and construction of the network are under the control of a subsidiary of the Caisse, which expects to profit from the new network.

Trains will run 20 hours a day, seven days a week with service every three minutes and 45 seconds during peak hours, transporting commuters from Brossard to downtown Montreal in as little as 18 minutes. The majority of the REM will open late next year, with an airport link to come in 2027.

This report by The Canadian Press was first published July 31, 2023.

— With files from Frédéric Lacroix-Couture.

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