For the first time in a decade, STM ridership was down in 2015, by almost one per cent.

It may not seem like much, but that's equivalent to about four million fewer rides. Philippe Schnobb, the head of the STM, admits the numbers are cause for concern.

He blames the decline on Canada-wide trends: a tough economy, falling gas prices, a bitterly cold winter and more alternative transportation, such as Bixi and Communauto.

But the opposition says the arguments don’t hold up.

“All those arguments are also true for Toronto – the economy, the weather, gas – but [their ridership numbers] went up five per cent so the gap between Montreal and Toronto is now 1.5 per cent. In one year, it’s a crisis,” said Luc Ferrandez, Projet Montreal’s interim leader.

And with more than 400 Montreal roads under construction last year, Projet Montreal says public transit should be growing.

“It’s an ideal time to get people in buses on the metro. People want to get around and they're not getting around. The fact that over the last 20 years, we've only seen two drops… this is very dramatic,” said city councillor Craig Sauvé.

While metros were on time almost 98 per cent of the time, 82 per cent of buses were on schedule, partly due to construction.

“That has an impact on our ability to deliver services if our buses are stuck in traffic with the rest of the traffic,” Schnobb said.

The STM says it will continue to coordinate with the city to navigate what promises to be a tough summer of construction ahead in hopes that 2015 turns out to be a fluke and not the beginning of a trend.