The union representing transit workers in Canada's most populous city is calling for the province to step in and fix what it describes as a faulty system intended to replace existing monthly transit passes.
December marks the last month that Toronto's commuters will be able to use Metropasses on the TTC, as the network of buses, streetcars and subways switches over to the Presto card system.
But the Amalgamated Transit Union Local 113 has sent a letter to Ontario Premier Doug Ford asking that the government take immediate action to ensure the transition is smooth.
The union says the TTC won't be able to handle the influx of Presto users as the card readers regularly fail and take too long to repair.
But Anne Marie Aikins, spokeswoman for Metrolinx, which oversees Presto, says the reliability rate for card readers on buses and streetcars is averaging 98 to 99 per cent each week.
"We always strive for 100 per cent but every system will have its issues time and again," she told NEWSTALK1010.
"We are carrying much better now [than before] - whether it's our readers or fare machines. We have many more options for customers, so we really want people to begin now to prepare for the transition of the Metropass onto the Presto card."
Aikins said every system as large as this one experiences hiccups to start.
"We went through it with GO Transit and all of the 905 agencies. We went through it with Ottawa. There's always problems initially and the TTC is the largest transit system in the country. It's a lot of machines to put out, it's a lot of work to do but we're getting there."
She added that the agency is ``confident'' Presto can handle the transition away from Metropasses.
"We appreciate that people are concerned - whether you're a customer or staff person at TTC - that this change is a big change. We're completely changing the fare system, so we appreciate that people are anxious about major change like that, but we believe we're ready."
- With files from Jackie Rosen/NEWSTALK1010