The same Cobb officials who pushed for a controversial transit line in Cobb County are proposing a retreat from that project in favor of funding reversible toll lanes along the I-75/575 corridor.

But the change, which would require state legislation to reopen the list, could be a long shot.

Still, the toll lane project is important enough to pursue all options, Lee said.

Last month, the state Department of Transportation, prompted by Gov. Nathan Deal, canceled bidding for the toll lane project. Deal is working with the state DOT to find another funding source. Lee and Mathews, along with some members of the county's delegation, would like that to come from $689 million currently in the regional transportation list for a transit line of rapid bus service from north Cobb to the Arts Center MARTA station.

“We would never have focused on the transit piece if we had known that the I-75/575 project was in jeopardy. ... There was a substantial and material change made by the state of Georgia [after the transportation referendum] process that [altered] the way the list would have been put together,” Lee said. "We would much rather have the managed lanes over [the transit] project."

The proposal from Lee and Mathews is notable, as both men were part of a roundtable of regional officials who approved the transportation list, and were both advocates for transit in the county. But some of their strongest allies in the fight for more transit -- the county's community improvement districts and the Chamber of Commerce -- were left out of discussing the proposed project shift.

Malaika Rivers, executive director of the Cumberland Improvement District, found out late Tuesday morning as an email was sent from the county, and had no comment about the proposal.

Some were appalled at the attempt to diminish the mass transit in the list. ““This will prevent the referendum from passing,” said Ashley Robbins, president of Atlanta-based public transportation advocacy group Citizens for Progressive Transit. It could turn voters who are excited about mass transit expansion against the tax, without adding votes from other quarters, she argued. “As a taxpayer, why would anyone pay to tax themselves for a toll?”

But the bigger question is whether the project list can be reopened, said Tad Leithead, chairman of the Atlanta Regional Commission and chairman of the Cumberland CID. "Both the governor and the speaker have said they wouldn't allow the list to be reopened," he said. "The bill has set up very strict guidelines regarding this. ARC stands by the original list."

Tippins said he would not support the referendum without the change.

Cobb officials have not lined up a sponsor for the proposed legislation, and not all members of the delegation have signed on to the proposal.

Staff writer Ariel Hart contributed to this article.