PORTLAND – Construction will begin in November on the Maine Turnpike Authority’s new headquarters building after the Department of Transportation signed off on the project late last week.

The project had been delayed after questions on whether it made sense under Gov. John Baldacci’s plan to explore uniting the authority and the Maine Department of Transportation.

But the DOT gave the go-ahead on Thursday – a day before the $11.4 million low bid for the project was due to expire – saying the building was still needed even if the two agencies merged or their administrative staffs were streamlined.

The bid by Wright-Ryan Construction Inc. of Portland is more than $2 million below the projected cost of the building, which will be located next to the turnpike interchange near the Portland International Jetport. The new facility is expected to open in January 2009, said turnpike authority spokesman Dan Paradee.

“We’re back on track,” he said.

The Maine Turnpike Authority is an independent state agency that operates the Maine Turnpike, which runs from Kittery to Augusta. It gets no state or federal funds, instead deriving its revenues from tolls and other sources such as rent from its service plazas.

Still, the state has some oversight over the authority and must give its approval to all turnpike construction projects, said Deputy Commissioner of Transportation Greg Nadeau, who has the final say on such projects and sits on the turnpike authority’s board of directors.

Nadeau joined the board when it voted last year to approve the new administration building and award the bid earlier this fall.

But when the contract arrived in Nadeau’s office in early October, it was given extra scrutiny because it’s a unique project for the turnpike authority and because of the governor’s recently stated desire to look at the possibility of merging the DOT and the turnpike authority to realize administrative efficiencies.

After reviewing plans for the new facility, Nadeau said, the administration determined that “even under a new business model … the building of that facility would continue to be needed.”

Turnpike officials said the new headquarters will improve public access, create efficiencies and save money on rent.

It will enable the authority to consolidate operations under one roof for its administrative staff, the E-ZPass customer service center and the Maine State Police troop that patrols the turnpike.

Those operations are currently in three separate buildings on Riverside Street in Portland and in a fourth building off the turnpike.