Crews work on Montreal's aging Champlain Bridge. (CBC)

If a $3 toll was tacked on to crossing the Champlain Bridge, one out of three drivers would find another route during their morning commute, new projections by Transport Quebec suggest.

The figures, obtained by Radio-Canada, also show that if that toll was hiked to $5.60, two-thirds of drivers would find another route onto and off of the island in the morning.

The new Champlain Bridge is slated to be completed by 2018, and federal Infrastructure Minister Denis Lebel has been firm on tolls since the project was announced.

However, Montreal Mayor Denis Coderre, and a group of NDP MPs, have publicly decried the federal plan to institute user fees.

Seven NDP MPs are gathering signatures of those opposed to tolls on the Champlain and plan to present the petition to the House of Commons in the coming weeks.

While significant attention has been paid to the issue of the tolls itself, there’s been little public discussion about the impact on Montreal’s other crossing points.

The new estimates from Transport Quebec anticipate that the majority of drivers turned off by a toll on the Champlain would likely turn to the Jacques Cartier Bridge as an alternate route.

That could add anywhere from 2,400 to 4,200 more vehicles filtering through in the morning on that bridge, depending on the fee of the toll.

Other commuter routes would also see an influx during peak times, Transport Quebec projects. The Victoria Bridge could see between 1,500 and 3,000 more commuters between 5 a.m. and 9 a.m. The La-Fontaine Tunnel and the Mercier Bridge could see between 1,000 and 3,000 more drivers in the morning. 

The figures suggest a toll on the new Champlain Bridge would translate into an impact on public transit as well, but it’s still unclear just how many drivers would abandon their cars and turn to other means of transportation.

Transport Quebec also suggests that some commuters may choose to adjust their work schedules to avoid peak hours or give up on the commute into the city entirely.