Route 197 motorists in Dresden and Richmond will have a new bridge to take over the Kennebec River on Dec. 5, ending years of hairy driving experiences on a smaller bridge that dates to 1931.

A  ribbon-cutting is set for 10 a.m. Friday at the $14.5 million bridge that a Woolwich contractor has built ahead of schedule and on budget. The bridge’s opening falls one week shy of the three-year mark from when U.S. Sen. Susan Collins, R-Maine, announced federal aid for the project.

Collins plans to be at Friday’s ceremony, along with Maine Gov. Paul LePage and Greg Nadeau, acting administrator for the Federal Highway Administration, according to Maine Department of Transportation (MDOT) officials.

MDOT spokesman Ted Talbot encouraged the public to attend.

John and Edna Kennedy of Woolwich plan to be there.

The couple volunteered on an archaeological dig at the site of Fort Richmond just before work started on the new bridge. The Maine Historic Preservation Commission worked with MDOT and the contractor, Reed & Reed of Woolwich, to arrange the search for artifacts before a bridge ramp was built over the fort’s footprint, said archaeologist Bill Burgess, who co-supervised digs at the site in 2012 and 2013.

“We were in total recovery mode because once the bridge was there, there would be no going back,” Burgess said. Reed & Reed gave the commission more time to complete the dig by starting work in Dresden, he said. “They really helped us out.”

The dig turned up musket ammunition and many clay pipes, John Kennedy said.

“It was a lot of fun. It’s a really historical site.”

If the weather is poor, the event will move inside to the nearby Pownalborough Hall. Later Friday, the bridge will open to traffic and the one it’s replacing will close, Talbot said.

The 83-year-old bridge was partly rebuilt after a 1936 flood, Talbot said. Over the decades, the bridge deteriorated, and also would get scraped by the larger trucks that had come on the market. “The new bridge will be a welcome change,” said Meg Lane, MDOT’s manager of creative services.

The bridge is designed for 100 years of use; it has a 75-foot clearance over the navigation channel, enough to allow the largest Coast Guard vessels to pass. “The Coast Guard has been a wonderful partner throughout the project,” Lane said.

Collins made the old bridge’s replacement a funding priority after she crossed the bridge, an experience she recently described as harrowing.

Plans call for the old bridge’s dismantling, tentatively by next summer, according to MDOT officials.

MDOT Commissioner David Bernhardt said in advance of the new bridge’s opening: “It’s what the bridge and so many (bridges) do that is most important and that’s connecting communities. The residents of Richmond and Dresden have shown what community means.

“The bridge stands in tribute to generations past, present and future.”