MONTREAL -- Cycling on many of Montreal’s busiest streets is dangerous enough—think Sherbrooke or Papineau—and during rush hour, when bus lanes are reserved, there’s no space for cyclists at all.

But now, with cyclists growing in number and other kinds of traffic lower than usual, the city has decided to open about half of its reserved bus lanes for cyclists and buses to share.

Some are warning, however, this could end up being a deadly decision.

“It's going to be dangerous,” said Tom Mouhteros, who is retired from the STM, speaking about bus’ big blind spots.

“One accident is going to be one accident too many... and then what's going to happen?” he said.

“A reserved bus lane is a reserved bus lane. It's shouldn't be a lane for pedestrians or cyclists.”

The reserved lanes are meant to give transit users a chance to sail through rush-hour traffic during peak times.

One city councillor, Marvin Rotrand, is also concerned that allowing bikes in those lanes will defeat their purpose.

“If you want to convince people to become a transit rider, you have to give them a safe, comfortable and fast ride,” said Rotrand.

“When you slow it down for bicycles, you aren't giving them a fast ride anymore. It only takes one or two cyclists to inconvenience a whole busload of people.”

Until now, it’s been essentially illegal to ride your bike on arteries like Sherbrooke during rush hour. This is because bikes need to ride in the right lane, and that lane was reserved. 

Some cyclists were getting tickets for riding in the wrong spot, but the most concerning thing for them is their safety, say cycling advocates. 

"We know there's going to continue to be a thousand cyclists a day in summer on Sherbrooke Street,” said cycling advocate Daniel Lambert.

“And there's going to be 50 collisions a year, we know that—that's average. So the only question for the city is 'when are you going to make it safe?'"

Lambert says that while he supports the city’s new move, he wants it to find a way to create more space and widen lanes.

The city hasn’t decided yet which reserved bus lanes will be open to cyclists but has said it will be about half of them overall.