On one point Georgia transportation officials pretty much agree: They want toll roads in metro Atlanta. Pay-as-you-go looks like a logical bridge between inadequate funds and growing traffic congestion. Beyond that consensus is a pile of unanswered questions: What kind of toll roads? Who should collect the tolls? How should we plan them?

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(ENLARGE)

The questions have stalled progress on a number of proposals from private contractors who have invested millions of dollars in them the last few years.

As the whole concept is being re-evaluated, a committee of the state Transportation Board met this week to give the companies a chance to stay in the game.

Here's what's happening:

Why tolls?

The federal gas tax once paid for big transportation projects like the interstate system. But it can't keep up anymore. It's charged as cents per gallon instead of cents per dollar and so doesn't rise with the price of gas. Congress hasn't increased it to keep up with inflation.

States such as Georgia can barely pay for road maintenance, much less the new lanes and mass transit they need to keep up with booming growth. Metro Atlanta expects another 2 million people by 2030, according to the Atlanta Regional Commission.

Georgia's bumpy road

State laws passed in 2003 and 2005 invited private companies to submit proposals to build roads and recoup their investments with tolls.

Though the final decision is the state's, the laws give the companies a lot of power to choose where and how to add toll lanes, creating concern the private companies would cherry-pick the most lucrative projects. But that was the law. Proposals rolled in.

The first was to widen Ga. 316 and charge tolls on existing, free lanes. It died in the flames of public outrage.

So DOT adopted a policy against adding tolls on free general purpose lanes, which excludes HOV lanes.

The next proposal met initial success. Preliminary work began in 2005 on a project on I-75 and I-575, to be funded mostly by the state. It dragged amid debate about whether trucks should be forced to use its truck toll lanes. A study last year revealed project cost had ballooned from $1.8 billion to $4 billion.

The next five proposals, received in 2004 and 2006, languished as state officials grew dismayed at the patchwork of projects to add toll lanes to some stretches of some roads without clear connections.

Last year the Transportation Board placed a moratorium on new proposals, trying to wrest back some planning control. DOT floated its own project to the companies, but hasn't yet officially asked for proposals.

Thursday, a committee of the Transportation Board listened to six teams of road builders defend their toll projects.

Time and inflation had changed the outlook.

The cost estimate for a stalled project on Ga. 400 has risen nearly $40 million just since November, from $1.608 billion to $1.649 billion. The project, in different form, was originally proposed in December 2004.

"The more you wait, people are thinking whether they should move out of Atlanta," said Carlos Ugarte after the meeting. Ugarte is director of business development for North America for Cintra, a Spanish company that proposed toll lanes along I-285's western wall.

What now?

Commissioner Gena Abraham is re-evaluating the toll program. DOT's financial adviser in April advised scratching the current proposals.

The decision is ultimately the DOT board's, and board members have said clearly they want a more integrated approach. To get the toll ball rolling, the state is working on converting Atlanta's HOV lanes to toll lanes. They would be free to large car pools.

The questions

DOT board members raised these questions Thursday and at other meetings:

• Should DOT allow existing free lanes to be tolled?

• Are truck-only toll lanes worthwhile if you can't force all trucks to use them?

• Should the state operate toll roads, or let private companies run them for decades in return for building them?

• How does a piecemeal collection of toll projects become a seamless network of roads?

THE PROJECTS

I-75/I-575 in Cobb and Cherokee counties

Proposed November 2004.

Originally, two truck lanes each way on I-75, mandatory for trucks. Cars could pay to use new HOV toll lanes, paying tolls that rise with traffic congestion. Now truck lanes may be out. Under contract for preliminary work.

Ga. 400 in Fulton and Forsyth

counties

Proposed December 2004.

The latest of several revisions is HOV toll lanes along Ga. 400, the toll price rising with congestion. It could be scaled back to outside I-285 only.

I-285/I-20 in Fulton and Cobb

One proposal includes Clayton and DeKalb counties.

Four proposals, received October 2006.

All four are meant to expand these roads. Variations have included truck-only toll lanes and trucks and cars together in congestion-priced lanes. One curveball: a suggestion for a reversible lane on I-20 east of I-285.

One team, Horizon Mobility Group, proposed taking this project further.

I-20 in DeKalb

Floated July 2007.

DOT told private companies it was interested in congestion-priced lanes from the Perimeter east to Turner Hill Road, then expanded the idea. DOT never offered it for proposals.

Ga. 316

Proposed January 2004.

To rebuild the road and toll existing lanes.

Suspended 2005 after public outcry.