BATH — Reconstruction of the viaduct that carries Route 1 traffic over the heart of the city will cost $14 million, could take about four months, and will be complete early in 2016, according to the Maine Department of Transportation.

DOT is looking to advertise for a contractor in the summer of 2015, with the viaduct to be closed for work from January to April 2016, according to project manager Joel Kittredge. He noted that any work done outside of that time will require the contractor to do it with minimal impact to traffic.

“They would do anything and all they possibly could, without disrupting traffic, in that period of time,” Kittredge said last week, although the viaduct will be closed, with traffic detoured through downtown streets, while the work is being done.

The project cost includes $11.6 million for construction and $2.4 million for engineering work, plus other expenses, Kittredge said.

The two-lane viaduct runs a quarter of a mile, from High Street to the Sagadahoc Bridge, past Bath Iron Works.

It was last closed in 2007, with traffic re-routed to Leeman Highway and Commercial Street, to allow a new surface to be applied.

But the bridge, built in 1958, has a superstructure that has reached the end of its useful life and is in need of more comprehensive work, Kittredge said. It will be replaced, while most of its piers – which support the load – will probably remain in place and be rehabilitated or repaired, he explained.

Replacing the entire viaduct would be cost-prohibitive, and we think that we can salvage mostly what’s there for the piers. We may have to replace one or two.”

The reconstructed viaduct will not add any travel lanes, Kittredge said, and should have a life of at least 50 years.

Alex Lear can be reached at 781-3661 ext. 113 or alear@theforecaster.net. Follow him on Twitter: @learics.