Metro Vancouver mayors are questioning the province's plans to build a new 10-lane toll bridge to replace the aging Massey Tunnel.

The province unveiled its plans on Wednesday. The project will result in B.C.'s largest toll bridge, crossing the south arm of the Fraser River, linking Delta to Richmond. 

"This bridge is going to be a triumph of imagination and engineering," said Transportation Minister Todd Stone.

But the mayors of Vancouver and Richmond have expressed concern over the project, saying it could do more to hinder than to help the region's transportation issues. 

"You're going to come over that river faster, and then you're just going to end up in that same traffic jam approaching the Oak Street Bridge that you're always in," said Richmond Mayor Malcolm Brodie. 

"The province does not seem to want to deal with that problem."

Massey Tunnel

Richmond Mayor Malcolm Brodie says a 10-lane bridge where the Massey Tunnel is now will lead to more congestion in heavy traffic areas like the Oak Street Bridge. (CBC)

Brodie also said he was concerned about the potential impacts the new bridge could have on traffic in his city. 

"We don't want a lot of cars coming off that highway through Richmond to take some kind of a shortcut," he said. 

Vancouver Mayor Gregor Robertson said he agreed that building bigger bridges fails to address long-term solutions for congestion. 

"It's a challenge to absorb the kind of car traffic that comes in on these freeways, and that's why the region has been more focused on getting transit built," said Robertson. 

Construction for the new $3.5-billion bridge is expected to begin in 2017 and take about five years to complete, meaning it will open in 2022 — if it's on time.

With files from Dan Burritt