Mayor Denis Coderre's administration is planning a "major transformation" of some of the city's key thoroughfares behind closed doors, the Opposition at City Hall says.

Luc Ferrandez, the interim head of Projet Montréal, said bus lanes — which would also be made accessible to bikes — could be added to several streets, including: Papineau, St-Denis, Sherbrooke, St-Laurent, St-Urbain, Lachapelle, Rosemont and Henri-Bourassa.

Portions of some of them — Papineau and de Lorimier — could also be turned into one-way streets. The bike path on St-Urbain could also be removed, making room for a bus lane that could also be used by cyclists.

Ferrandez said he learned of the proposals in a draft prepared by the STM last month.

Nothing final, Coderre says

Montreal Mayor Denis Coderre says the city is studying the proposals. (Jacques Boissinot/Canadian Press) Mayor Denis Coderre didn't deny the existence of the plans, but said nothing had been finalized and several options were under consideration.

Coderre said he wants to make the changes in an "inclusive and integrated manner," rather than making things more difficult like in the Plateau — a clear dig at Ferrandez, who is the borough mayor for the Plateau-Mont-Royal borough.

Ferrandez said Projet isn't necessarily against the proposals, but he said they shouldn't be explored in secret.

The boroughs, public health officials, Vélo Québec and other organizations should be consulted, he said.

Is a lane for both bikes and buses safe?

Renato Carlone, president of the bus drivers' union, said his members are against the proposal.

"I speak for 3,700 bus drivers who are completely against sharing bus lines with bike lanes," Carlone told CBC News.

He said the plan would put cyclists at risk and slow down buses. He added that, ideally, bike lanes would be separated from the bus lanes by a median.

Magali Bebronne, a member of Vélo Québec, said combined lanes for bikes and buses can be effective on some streets but "more dangerous for everyone" on others.

"Whether it's a good idea or bad idea is all about the details," she said, including the width of the lane and the speed of traffic on the street.

On Viau Street, for instance, the city tested out a bus-bike-taxi lane. The lane is larger than usual and divided into two — a one-metre-wide bike lane on the right-hand side and a standard lane for buses and taxis on the left.

Bebronne said that "only a portion of cyclists" would likely be comfortable in a situation where they share the road with buses.

One-way thoroughfares could create problems, Projet says

A project of this magnitude raises several issues that require study, Ferrandez said, such as the impact on residential streets and the safety of having bikes and buses in the same lane.

Projet Montréal interim leader Luc Ferrandez says the city should launch consultations. (CBC) He said that making busy streets one way would allow cars to go too quickly, effectively creating highways running through the city.

He decided to sound the alarm about the plans because a meeting he requested about the plans with the STM was canceled at the last minute for "political reasons."

Coderre denied the accusation, calling it a "fabrication."

Isabelle Tremblay, a spokesperson for the STM, confirmed the transportation agency and the City of Montreal were looking at making changes to some streets, but said it was too early to comment on any specifics.