BANGOR, Maine — Uncertainty surrounding the route of a proposed 220-mile highway across Maine sparked vehement questioning, opposition and doubt during a Tuesday morning meeting at the historic Penobscot County Courthouse.

Cianbro Corp. CEO Peter Vigue, the leading proponent of the east-west highway, spent much of the meeting with Penobscot County commissioners trying to dispel what he called rumors and misconceptions about the proposed private $2.1 billion project. Many of the more than 100 residents of Penobscot and Piscataquis counties in attendance weren’t satisfied after nearly two hours spent posing questions and concerns to Vigue.

Vigue argued that such a roadway, which has been discussed on and off since 1937, would help Maine’s struggling economy grow and thrive. Residents voiced concerns that their towns and properties might lie in the path of the proposed highway, putting rural, agrarian ways of life at risk.

Vigue — whose company is at the helm of Bangor’s new arena construction and in 2007 converted a defunct Brewer mill into a modular manufacturing facility — argued that the highway could help the state recover from its third consecutive year ranking as Forbes Magazine’s worst state for business in the nation.

He argued that the state’s fiscal standing isn’t showing much improvement and asked attendees to “ask [themselves] where we will be 10 years from now or 20 years from now.”

He argued that the millions saved by companies on transportation costs would attract investment and trade from national and international markets, especially Canada. Lodging and food and drink businesses would pop up along the route and thousands of construction jobs would result from the project, he said.

Cianbro, a Pittsfield-based construction company, has yet to release information about the corridor’s proposed route because its plans are fluid and changing on a regular basis, company representatives have said. The company is not obligated to release information because it is a private entity. Vigue said Cianbro hopes to release a proposed route near the end of this year.

“When we are ready and that is defined, we will be very open about it,” Vigue said. He did say the road likely would stretch from Calais to Coburn Gore, crossing the Penobscot River somewhere in Old Town before continuing on somewhere south of Dover-Foxcroft.

He said officials were carefully considering property lines, terrain, soils, wetlands, conservation lands, vernal pools and other factors when drawing the line.

Some attendees shouted out in disagreement or scoffed when Vigue provided uncertain answers or said he didn’t have or wasn’t prepared to release information related to the private project or its partners.

The lack of detail has left residents to speculate about whether the highway might cut a path through their communities.

Jim Thomas, a Garland dairy farmer with 465 milking cows, said he needs 800 acres of field to produce enough feed for his cows. He said a highway through Garland might take 30 acres of his fields.

“We’re not going to take your property,” Vigue responded. “I assure you of that — I promise you that.”

During the meeting, Terry Crouch of Garland submitted and read a petition signed by 172 Garland residents and 55 people from other central and western Maine communities calling on the Legislature, governor, Cianbro and others to “stop all present and future plans,” to build an east-west highway.

Crouch said residents were worried the highway would split and harm the town, which didn’t want to be “bullied or terrorized” by Cianbro.

“We are not going to destroy the town of Garland,” Vigue countered.

Penobscot County Commissioner Peter Baldacci said during the meeting that uncertainty among property owners about the path of the highway could lead to “condemnation blight,” a legal term referring to a reduction in property value that results from potential eminent domain claims. While Cianbro has repeatedly said that eminent domain will not be used, its decision to map out a route behind closed doors is causing uncertainty among residents who are left to speculate about the future of their land, Baldacci said.

During his presentation and in answering questions that followed, Vigue vowed that there would be no public-private partnership between Cianbro and the state, that eminent domain would not be used to acquire land, and that neither tar sands nor oil pipelines would run along the corridor in the foreseeable future.

Vigue clarified that he couldn’t predict future utility or pipeline needs over the long term, “100 or 150 years from now.”

Tuesday’s meeting came less than two months after a commissioners meeting during which more than a dozen Penobscot and Piscataquis county residents blasted the highway proposal. Commissioners asked Vigue to come and provide Cianbro’s perspective on the idea.

No one other than Vigue attending the Tuesday morning meeting spoke in favor of the highway proposal. The highway has supporters including Gov. Paul LePage, municipalities, the paper industry and other businesses interested in trade with the Midwest and Canadian provinces, Vigue said.

“It isn’t a one-sided affair,” Vigue said, adding that the state faces “catastrophic challenges” and it needs to attract investment.