“At the end of the day, we’ll be getting more project, more value for less public dollars,” Georgia Department of Transportation Chief Engineer Meg Pirkle told the State Transportation Board on Wednesday.

Giving a private company control of tolling also carries risks for all involved. Commuters could face higher tolls than the state would charge because a private firm must charge enough to turn a profit. And some companies that invested in U.S. toll roads in recent years have filed for bankruptcy because tolls didn’t produce as much revenue as projected.

“GDOT has articulated the positives, but not the risks,” said board member Kevin Abel, whose district includes part of the project. “I’d like to see a clear statement of risks.”

The plan comes as GDOT continues to build a 120-mile network of toll lanes in metro Atlanta.

GDOT says such “managed lanes” are the best way to address metro Atlanta’s world-class traffic mess because “free” lanes fill up almost as soon as they open. The agency says traffic in the toll lanes can be managed through adjustable tolls — the worse the traffic, the higher the toll — that discourage enough people from using the lanes to keep traffic moving.

That benefits motorists willing to pay by the mile to use the lanes. But GDOT says the toll lanes also benefit other motorists by freeing up space in the free lanes.

GDOT has already completed about 67 miles of toll lanes on I-85 northeast of Atlanta, I-75 south of the city, and I-75 and I-575 to the northwest. Next up are toll lanes along a 16-mile stretch of Ga. 400 in Fulton and Forsyth counties, set to begin construction next year.

But the biggest undertaking is yet to come: toll lanes along a 40-mile stretch of the Perimeter.

Initially, GDOT broke that initiative into three projects: the top end, I-285 east and I-285 west. But it’s such a mammoth undertaking — building all the Perimeter lanes is expected to cost $6.1 billion to $6.9 billion — that GDOT split the projects into smaller pieces in 2019 to encourage more companies to bid on the work.

Now the state is shaking up the projects again, opening them up to substantial private investment in exchange for 50 years of toll revenue.

The state would still control tolls on the existing express lanes. But many details must be negotiated with the company.

State officials say the biggest benefits of private investment will be an expansion of Perimeter toll lanes and additional entry points.

With private funding, GDOT would be able to build two new toll lanes in each direction along the top half of the Perimeter from I-20 west of Atlanta to I-20 on the east side. The agency currently plans to build two new lanes in each direction roughly from I-75 to I-85, and one new lane on the east and west side of the Perimeter.

In addition, private funding could pay for more entry points. Among the possible connections are Stone Mountain Highway in DeKalb County and I-20 east and west of Atlanta. GDOT does not currently plan to make the toll lanes accessible at those intersections.

In an interview, GDOT Commissioner Russell McMurry said the effect will be to give taxpayers more for their money and to shift some of the financial risk of the lanes to the private sector.

“You move the long-term obligation from one side of the ledger to the other, from public to private,” he said.

Adding lanes to the project may mean extra construction time. The east side lanes are currently expected to open in 2028, with the eastern portion of the top end lanes set to follow in 2029. The west side lanes and the western portion of the top end would open in 2032.

McMurry said it’s not clear how much of a delay would be required by adding lanes to the project.

“We believe that the value provided is worth that time,” he said.

The possible downsides include higher tolls for commuters under private operation. Chris Tomlinson, executive director of the State Road and Tollway Authority, which sets toll rates on existing express lanes, said market factors should control toll rates on the Perimeter. If the company charges too much, he said, motorists won’t use them. And he said the state will oversee the private firm to protect the public.

“It is critical that we provide public protections,” Tomlinson said. “At the end of the day, our job is to look out for the state of Georgia.”

Abel, the State Transportation Board member, wondered whether a private company would have an incentive to encourage bus rapid transit in the lanes, as envisioned by MARTA and a group of mayors along the top end of the Perimeter.

Tomlinson said the firm selected may have innovative ideas about operating rapid buses in the new lanes. And he said transit vehicles likely would still ride for free in the Perimeter toll lanes, just as they do in the existing lanes.

A decade ago, Georgia considered a similar private tolling plan for the Northwest Corridor express lanes on I-75 and I-575. But it scrapped the plan, in part because of concerns about a contract provision designed to protect the company from losing revenue. In some circumstances, the company could have requested compensation if nearby transportation improvements eased traffic congestion along the corridor and reduced income from tolls.

It’s unclear whether the I-285 contract will include a similar provision. But McMurry said such a provision wouldn’t make much difference on I-285 because there are no parallel highways that could be improved to relieve traffic on the Perimeter.

The state must solicit public input on the private tolling plan before making a final decision on how to proceed. GDOT expects to release information about public hearings by the end of the year.

What it means for commuters

The Georgia Department of Transportation will seek private investment in toll lanes on the top half of I-285 in metro Atlanta. The selected company would recoup its investment by setting toll rates and collecting the revenue for 50 years. Here’s what it could mean for commuters:

More lanes: GDOT says private investment means more new toll lanes than the state alone can pay for. The agency says that means more traffic relief, even for motorists who don’t use the toll lanes.

More entry points: The agency says private investment may pay for more entry points to the toll lanes than GDOT currently envisions, allowing more people to easily access the lanes.

Safer lanes: GDOT’s current plans call only for a painted “buffer” separating the new toll lanes from the free lanes on the east and west side of the Perimeter. The agency says private investment would allow installation of concrete barriers to separate the toll lanes from general traffic, creating safer travel.

Higher tolls: The benefits come with a potential catch: Unlike the public agency that sets tolls on existing express lanes, a private company must charge enough to make a profit. That could mean higher tolls than a public agency would charge.