A timeline for construction of a new Route 460 was outlined earlier this month at a Commonwealth Transportation Board meeting where various mostly toll-related concerns over the project’s development and operation also were aired.

According to a presentation at the March 16 workshop meeting by Dusty Holcombe, the deputy director of the state agency implementing the $1.5 to $2 billion project, construction on the 55-mile, four-lane, limited-access highway is expected to begin next year.

Holcombe said the intended completion date is 2018, when tolling, forecast at between $5.50 and $11 for cars and three times that for tractor-trailers, would start.

A nonprofit corporation, which will issue tax-exempt bonds to partially fund the road, will be formed in June, and the successful design-build bid selected in October.

The three bidders are Cintra Infraestructuras S.A.U., 460 Partners Inc. and MultiModal Solutions LLC, all seeking to profit from the project primarily through toll collections over an anticipated 40-year period.

The private partner will contribute an estimated $400-$600 million — the commonwealth providing the remainder — and also provide equity to drive down borrowing costs, Holcombe said.

He said the bid representing the least cost to the commonwealth would be selected.

“We think the toll revenues in the early years are going to be limited,” he said. “We don’t think the traffic is going to be there first, but we think it’s going to grow over time.”

He said revenues in the first year of operation are predicted to be $14 million, increasing to $28 million by 2030.

“We think on day one it’s going to be 8,000 vehicles a day,” Holcombe said, compared to 11,500 now using the existing 460, which will remain in place as a free alternative to the toll road.

It is estimated the new 460 will shave 15 to 20 minutes from the Suffolk-Petersburg journey.

Concerns raised by board members at the meeting included what happens if toll revenues fail to meet debt-service costs, the Virginia Department of Transportation’s role in setting tolls, and how members of the nonprofit board will be selected.

Holcombe’s overriding response to these and other concerns was that Virginia has successfully implemented the project structure before in Northern Virginia, and that it represents the best possible value.

“We’re going to be creating a financial structure that looks for the cheapest type of debt … that doesn’t affect the commonwealth’s debt rating,” he said.

Gov. Bob McDonnell made the on-again, off-again 460 project the centerpiece of his 2009 campaign.

In its favor, proponents cite southeastern Virginia’s hurricane susceptibility, large concentration of defense facilities, proximity to Washington, D.C., and “inadequate” transport infrastructure as reasons the new road should be built.