A state board Monday approved plans to allow a private company to set and collect tolls on the new Ga. 400 express lanes.

The State Road and Tollway Authority approved plans to seek private investment in the lanes in exchange for 50 years of toll revenue. Last summer the agency and the Georgia Department of Transportation announced a similar plan for private tolling on the top half of the Perimeter.

Georgia officials say private investment will reduce the state’s cost for two of the biggest road construction projects in state history. GDOT plans to build two lanes in each direction on the northern half of I-285 from I-20 east of Atlanta to I-20 on the west side. The total cost is estimated to be about $6.1 billion.

GDOT plans to build two lanes along Ga. 400 from the North Springs MARTA station to McGinnis Ferry Road, plus a single lane in each direction north to McFarland Parkway. The existing lanes will remain toll-free.

Last summer the State Transportation Board rejected the lone responsive bid to build the lanes because it far exceeded GDOT’s $1.7 billion budget for the project.

The resolution the SRTA approved Monday authorizes the new financing plan, allowing the authority to confer on a private firm the right to set and charge tolls on the Ga. 400 lanes. The State Transportation Board is expected to approve the new plan later this month.

GDOT says private financing will limit the state’s cost and give taxpayers more for their money. Motorists could pay higher tolls because a private firm would need to charge enough to make a profit. State officials say the tolls will be regulated by an agreement with the company selected.

It’s unclear when construction will begin on the Ga. 400 lanes or when they will open. Under the latest schedule, GDOT plans to select a company to build and operate the lanes by August 2023.