Transportation leaders voted Wednesday night to move forward with a plan to add toll roads on Interstate 77 in order to relieve rush-hour congestion.

The Mecklenburg-Union Metropolitan Planning Organization wants a private company to build toll lanes on the interstate to help fund new construction. The toll lanes would be for cars with one or two people. The price of the toll would fluctuate throughout the day, depending on traffic conditions.

MUMPO leaders admit it's a controversial plan.

"You are all dealing with the private sector and asking them to design, to finance, to build, to operate and to maintain a public roadway asset under a 50-year contract," said Bill Coxe, the head of MUMPO's technical committee. "A lot of things will change in 50 years."

Overall, it's a $60 million project. One-third of that money would come from tolls and bonds.

The plan calls for turning existing HOV lanes from Interstate 85 to Interstate 485 into new toll lanes. Those toll lanes would then be extended to Catawba Avenue.

The state is also studying the cost and the impact of adding even more toll lanes that would stretch from Cornelius to Mooresville.

"It's actually far more complicated than anything I've ever seen," Coxe said.

Coxe said he expects some backlash to the proposal because the toll lanes will not be publicly operated.

"They are the private sector. They can't be in business without making a profit. So you have to understand how to structure (the contract)," he said.

Raleigh could start soliciting offers from private companies in early July. Construction on the toll lanes is not expected to start until 2015.