The state Department of Transportation has once again asked for a $375 million federally subsidized loan to help build a massive toll project alongside I-75 and I-575 in Cobb and Cherokee counties.

The project would build optional toll lanes alongside those highways in order to give drivers who can afford it a reliable alternative to the congested main lanes.

The federal loan, called “TIFIA,” would allow the project to borrow on favorable terms that could shave $100 million off the cost over the life of the project, said David Doss, the outgoing chairman of the DOT board committee that oversees toll projects.

The overall project cost has been estimated at $1.4 billion when financing is taken into account.

DOT officials said Wednesday that they were considering a way to restructure the project's financing that would bring the overall cost down to about $1.1 billion.

That would still be a huge price tag compared with other transportation projects. To help pay for it, the state has invited private road-building companies to invest in the project up front and be repaid by tolls. Three private consortiums have been identified as qualified to apply for the project.

The project would still require public funds.

The state had already acknowledged it would need to contribute up to $350 million in tax dollars toward the project. If the federal loan doesn't come through, the board is ready to raise that public contribution up to $450 million, Doss said.

Georgia DOT is one of about three dozen applicants for the highly competitive federal loan program, said the DOT’s director of public-private programs, Sandra Burgess. Last year the DOT applied for the program and made the federal government's short list, but it did not win.

Georgia DOT officials said the federal government had not yet disclosed its deadline for awarding the loans this year.