Proposed locations for the new Bourne and Sagamore bridges were unveiled last night by engineering consultants for the Massachusetts Department of Transportation.
The department intends to pursue a plan to build the bridges on what the engineers called the “inboard” side of each bridge, meaning farther from the bays.
The Bourne Bridge would move slightly east, and the Sagamore Bridge slightly west.
“Our analysis indicates that the inboard option is the most favorable out of the three options studied because it has the least impacts to residential and commercial properties and is the least impactful to the traveling public during construction,” said Dave Anderson of engineering company HNTB during a public meeting.
He said the finding was consistent with the locations used by the U.S. Army Corps of Engineers in a conceptual analysis the Corps performed previously.
Anderson showed the audience maps of potential locations. He said the Market Basket supermarket, which is located on the inboard side of the Sagamore Bridge, would not be affected, but other businesses at the Sagamore would.
“Market Basket itself is quite a distance from the existing roadway and would likely be outside of any of the options discussed,” he said. “The strip mall located closer to the existing Route 6 is the one that would be impacted.”
Anderson also responded to questions about whether adding an entrance-and-exit lane would bring more vehicles to the Cape.
He said drivers in the entrance lane would have to merge into a travel lane unless they were exiting. The bridges would not be designed for more vehicles, he said.
The Department of Transportation revealed the preferred bridge type: twin arches, spaced in close parallel, at each location. Particulars of the aesthetic design have not been determined.
Also last night, a representative of the Federal Highway Administration said the agency has agreed to become the lead federal agency on the bridge project, rather than the U.S. Army Corps of Engineers.
Scott Acone, deputy district engineer for the Army Corps, said the Corps, which owns the bridges, determined it would be better to work with an agency that does bridge design and construction all the time. Those functions are “not one of our core missions,” he said.
A second public meeting is scheduled for Thursday at 6 p.m.
