Anyone who travels over the Sagamore or Bourne bridges knows something needs to change. The 83-year-old spans — with their four narrow 10 foot lanes — provide a white knuckle driving experience for residents and tourists alike.

And while a new plan by the U.S. Army Corps of Engineers for replacing both bridges is about to be unveiled — which some believe will cost more than $1 billion — some local officials are concerned their voices aren’t being heard in the process.

The replacement project will have a significant impact on the towns where the bridges are located, where the state will spend hundreds of millions more on new intersections and approaches needed to accommodate traffic from two new larger bridges.

The Massachusetts Department of Transportation, which recommended the bridge replacements, recently released its plan for dealing with the increased traffic and the congestion it could bring. It calls for changes in intersections, rotaries and highway offramps.

“It looks like a pretty decent plan as far as tapering traffic down to two lanes after that, but a six lane bridge is pretty big," said John Morrill, who runs the Bourne Scenic Park campground and has seen the state’s proposal.

But Bourne Selectman Peter Meier said that while it may be easier to get over the bridges after the renovation, he's not at all sure that congestion will be eased on either side.

“If you make these bridges five to six lanes, you're still going back to a one or two lane highway,” Meier said. “You're not fixing the problem. You're probably making it worse.”

Meier said more information about the project is needed and is frustrated that the concerns of townspeople near the bridges haven't been heard.

“They're getting input from people down Cape and up in Plymouth, but this is in our backyard," he said. "We need to have input into what goes on because we're the ones who deal with the gridlock and live with it.”

A spokesperson for the DOT said the process has always been inclusive, and pointed to a working group that includes members from Lower and Upper Cape towns, including Bourne. The spokesperson also said there were four public meetings in Bourne, both to "present work completed to-date and (to) solicit feedback."

Meier said there are many improvements that have not been considered by the DOT, citing as an example the "southside connector" that was proposed years ago to help ease Bourne Bridge traffic on the Upper Cape.

“If that were to be constructed, you would go from the Bourne bridge to Exit 2 on Route 6, cutting through the base, but you're talking a million dollars a mile,” he said.

That base, Camp Edwards, is on leased federal land. Meier admitted that would make the connector not only more expensive, but more complicated. But, he said, it should have been part of the discussion.

Retired federal environmental engineer Steve Buckley of Chatham said the new bridges could end up carrying 50% more traffic. He's frustrated that the full impact of that potential traffic on the towns outside the immediate canal area hasn't been included in the government's study.

He said, for example, increased traffic from the new bridges — particularly during peak hours and at peak times like summer — could have ramifications all the way down to Provincetown.

The DOT's public comment period on the Canal bridges project is ending on June 20, but that may be premature in light of the questions locals have and the fact that the Army Corps has yet to release its final bridge plans to the public.

Joel Gould, the gatekeeper at the Bourne Scenic Park campground, summed up how many locals feel.

“We've read, just like everybody has, about some new bridges may be coming in, but we're not really sure where, how, or how much, or anything else yet,” said Gould.

And by the time they do find out, it may be too late for anyone to change the course of one of the biggest construction projects in Massachusetts' future.