Toronto's beleaguered public transit system could get even messier than usual next month, according to TTC employees, when the city officially ditches its long-running monthly Metropass program.

As usual, it all comes back to PRESTO and its notoriously faulty machines.

The cashless fare payment system that will soon replace TTC Metropasses (and eventually tickets, tokens, day passes, debit, credit cards, cash, etc.) isn't exactly reliable just yet, as anyone who takes the subway regularly well knows.

With an influx of new Presto users hitting the system on January 1, TTC workers are growing concerned about how how many riders will be delayed (or simply let into the subway for free) on account of malfunctioning machines.

"Unfortunately, Presto is not ready," reads a December 4 letter from the union representing TTC workers to Ontario Premier Doug Ford, as quoted in the Toronto Star.

"It is critical that Metrolinx, the TTC, and the Ontario government take immediate and urgent action to fix the Presto fare card system's failures to ensure a smooth transition of Metropass users to the Presto fare card system."

Anonymous members of the Amalgamated Transit Union Local 113 who drive buses say in the letter that as many as 20 per cent of all fares aren't being paid on account of broken PRESTO machines. 

They also state that it can take up to an hour for the card readers just to turn on once a driver starts his or her vehicle and that it can take sometimes take weeks for PRESTO to send a technician along to fix these faulty devices.

Metrolinx, which is responsible for PRESTO, told the star that its fare payment system is ready for the switch — though that does seem curious, given that the TTC is currently removing all debit and credit card readers from streetcars over their tendency to break PRESTO machines.

Whatever the case, we'd better hope that the union is wrong. 

Roughly 40 per cent of all trips made on the TTC are currently paid for with a Metropass and some 200,000 customers are expected to switch over to PRESTO on January 1.

Hopefully those fickle green readers can handle what's coming... but if history is any indication, don't get your hopes up.