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Corps of Engineers calls for replacing ‘functionally obsolete’ Sagamore and Bourne bridges

The Sagamore Bridge (left) and the Bourne Bridge. David Kamerman/Globe Staff

The federal government is calling for a complete replacement of the two bridges that cross the Cape Cod Canal, a long-awaited decision that will reshape a crossing that has frustrated generations of travelers between the Cape and mainland.

The US Army Corps of Engineers has released a draft recommendation for a $1 billion replacement of the Bourne and Sagamore crossings, which were built 84 years ago and intended to last a half-century.

The agency, which controls the bridges, had deliberated for years over what to do about the structures, which are in poor condition and increasingly need major maintenance work that itself creates major traffic headaches. The Army Corps considered a range of proposals, from different bridge configurations, to tunnels, to causeways — even the idea of filling in the canal and directing marine traffic around the Cape.


In the end, officials decided the most practical solution is two new bridges next to the existing spans, likely on the inland side of each. The bridges would have four travel lanes, two added lanes for merging traffic, and, unlike the current crossings, a median separating the on-Cape and off-Cape-bound traffic. The current structures would remain in service until the new bridges open to traffic.

“This is the best-case scenario,” said Wendy Northcross, chief executive of the Cape Cod Chamber of Commerce. She said the bridge work, combined with a massive project by the state to improve roads and intersections leading on and off the Cape, could make a huge difference.

Northcross said that even though the bridge replacement may bring significant traffic disruption at times, the alternative that would have required closing the existing bridges and rehabilitating them in succession would have made it nearly impossible for people to come and go.

“That would have been tragic,” she said. “That would have been an economic hit to the solar plexus.”


The Army Corps said the bridges have gotten to the point where it is more economical to replace them than fix them. And the need for improvement is great; the Corps released a set of pictures from the bridge that included unnerving conditions of pitted concrete and rusted metal.

“As the bridges and their components continue to age, the cost of operation and maintenance and periodic rehabilitation slowly escalates,” the Corps said in its report, describing the existing structures as “functionally obsolete.”

The Army Corps has not laid out a timeline for the replacement. The next steps include holding five public meetings through October on the Cape and in Plymouth and Boston, and accepting public comments until Nov. 1. It hopes to finalize its recommendation early next year.

However, the agency will probably want to move quickly to head off costly repairs scheduled in coming years. The Sagamore Bridge is scheduled for a $185 million rehabilitation as early as 2025, while the Bourne Bridge would undergo a similar, $210 million project as soon as 2029.

Though the Army Corps has not commissioned detailed designs, preliminary details for the federally funded project suggest the new structures could be twice as wide as the existing spans, which have 46-foot roadways.

The new bridges’ travel lanes would be 12 feet wide; the existing travel lanes are 10.

Other additions intended to improve travel flow include the merging lanes, shoulders on both sides, and the median. The bridges would also have improved bike and pedestrian access.


For people who live on the Cape, where traffic congestion is much more than a frustrating obstacle on the way to vacation, relief can’t come soon enough.

Angela Dalpe, who has lived in Sandwich for a decade, said she wishes the Corps could keep the two existing bridges along with the new ones.

Dalpe, a nurse who works in corrections in Bristol County, said her commute can take as little as 45 minutes —“That’s using my best back roads” — but it can easily take twice as long. Bridge traffic, especially in summer, can make her commute so unpredictable that she sometimes has to decline shifts.

“It turns me into an unreliable employee,” she said. “When it’s Labor Day weekend, and I have to go over the bridge, and I don’t know how long it’s going to take me to get there, I just have to say I can’t come in.”

The bridge replacement plan had been widely anticipated. Massachusetts transportation officials are already making plans to rework the state roads that lead to and from the bridges. That work alone could cost $350 million over several years, according to preliminary estimates.

Officials believe the projects together will ultimately lead to easier drives through the notoriously congested area. They say they will do everything they can to minimize the disruptions while the work is happening.

“Our starting point on any big project is making sure that we are having the least impact on the traveling public as possible,” said Jonathan L. Gulliver, highway administrator for the state Transportation Department.


The Army Corps’ plan got early applause from the congressional delegation representing the Cape. In a statement, Senators Edward J. Markey and Elizabeth Warren, and Representative William R. Keating praised the agency’s recommendation.

“Two new bridges built up to modern standards will improve traffic flow, allow better access to the Cape and Islands in the coming years, and provide vital evacuation routes,” Keating said. “As a year-round resident of Cape Cod who depends on the Bourne Bridge, I strongly feel that this is the best outcome for our Cape and Islands community and the greater Southeastern region as a whole.”

The bridge replacement is another huge infrastructure project for Massachusetts. In Boston, where memories of the Big Dig remain fresh, the state is working toward a $1.1 billion reconstruction of the Massachusetts Turnpike’s Allston interchange — a project that will open a huge area for new development, but will also involve eight years of construction and traffic disruption.

The Cape bridge construction will have many complexities as well. The projects would probably require the Army Corps to acquire land adjacent to the bridges, including some that currently is home to a Market Basket plaza near the Sagamore Bridge and a Dunkin’ Donuts near the Bourne crossing. In total, the report estimates that the projects would require 15 acres, and cost more than $15 million.

Even with the project, people on the Cape are realistic: Bridge traffic will never really go away during the high season. But it might not get worse, either.


“If everyone still decides to come into the Cape on the same day, we should have some back-ups,” Northcross said. “But for most of the year, this should handle quite nicely. We’re unclogging the clog, if you will.”

Andy Rosen can be reached at