As metro Atlanta prepares for an $8 billion transportation referendum next year, two local counties are considering another source of revenue for major road projects: tolls.

Gwinnett County is studying whether it makes sense for a private company to spend more than $257 million to extend Ronald Reagan Parkway to I-85 and recoup its investment by charging commuters who would use the new stretch of highway. Paulding County wants a $2 billion, 113-mile new outer perimeter bypassing Atlanta to the west that would be paid for by tolls.

Both projects face significant hurdles, including high costs, but toll roads are getting a fresh look as money for transportation projects gets tighter.

Toll roads are “an option that we all need to look at in the future,” said Gwinnett Transportation Director Brian Allen. “We didn’t have it [Ronald Reagan Parkway] funded any other way. ... We know state funding is going to be low. We know federal funding is going to be cut over the next few years. That’s why we undertook it to begin with.”

Finding money for transportation projects has become a top priority in metro Atlanta. In coming months, local officials will try to devise a list of road and transit projects that would entice voters in a 10-county area — including Gwinnett, but not Paulding — to approve a 1 percent sales tax next year for an $8 billion project list.

But even that isn’t enough to ease gridlock, so some government officials are considering private funding.

The Georgia Department of Transportation has been struggling to get public-private toll road projects off the ground since a state law established such a program in 2003. The agency is currently looking for a private investor to expand I-75 and I-575 in Cobb and Cherokee counties. That oft-delayed project was supposed to go out for bid in June but was just delayed again. The DOT is waiting to see if Georgia wins a federally subsidized loan for the project.

With that backdrop, some local governments have decided to try on their own.

Gwinnett County expects a report this fall on the feasibility of private investment in the Ronald Reagan Parkway project, which was submitted on the county’s wish list for the referendum. Though the project survived the first round of cuts, its future is still uncertain. Interest in the project has been around for several years — before the referendum became an option.

The four-lane divided highway runs from Scenic Highway in Snellville to Pleasant Hill Road near Lilburn, stopping three miles shy of I-85. Gwinnett estimates it would cost $257.5 million to connect Ronald Reagan to I-85.

Skanska USA Civil Southeast is studying whether it makes sense for the company to build the highway and convert the new section into a toll road. It’s also studying possible routes, toll prices and whether any public money is needed. The county is paying $1.4 million of the $2.6 million cost of the study, with Skanska paying the rest.

Gwinnett’s lawyers have said the approach the county is taking in this toll road project is legal, Allen said. The state DOT is working with the county on the project, state Transportation Planning Director Todd Long.

Betsey Gibbs of Loganville, who commutes to Midtown and takes Ronald Reagan Parkway home each afternoon, said she’d pay a reasonable toll — say 50 cents — to shave some time off her commute.

“I would like to see it extended [to I-85],” Gibbs said. “Any time I can avoid traffic lights, I’m going to go for that option.”

Proponents say extending Ronald Reagan Parkway also could alleviate traffic congestion on nearby roads and make it easier to reach commercial areas such as Lawrenceville Highway.

But depending on the route selected, critics say a Ronald Reagan Parkway extension would cut through wetlands or affect residential neighborhoods.

Larissa Thomas, who serves on a citizen advisory board for the project, lives in a house “practically a stone’s throw away from the likely road.” She doesn’t see why her neighborhood should suffer.

“If people in Snellville wanted to get to I-85 quicker, they should have bought a house in my neighborhood,” she said.

The hurdles for the west-side outer loop may be even greater. Multiple counties would have to approve it, rights-of-way issues would have to be resolved and area residents would have to be convinced.

Paulding County Commission Chairman David Austin and Blake Swafford, the executive director of the Paulding Industrial Authority credited with devising the idea, are in the early stages of planning and are still pitching the plan to their county neighbors. The proposed 113-mile toll road, dubbed the Western Commercial Connector, is intended to alleviate congestion by allowing traffic to bypass interstates through Atlanta, largely I-75. The road might be open to traffic by 2019, Austin said.

The proposed four-lane connector would connect to I-75 around Cartersville in Bartow County in the north and at High Falls in Lamar County in the south. The cost to build, Austin believes: $2 billion, paid fully with tolls, based on evaluations done by engineers from his county.

The roadway wouldn’t require legislation to build it, but would require support from local governments -- in Paulding, Bartow, Carroll, Coweta, Spalding and Lamar counties, and the cities of Cartersville and Villa Rica -- along the path of the road to create a joint transportation authority to administer the project. That authority would seek private contractors to build, operate and maintain the road.

But not everyone is on board: Lamar County’s commission chairman doesn’t think the project will benefit his county, where the roadway would serve mainly as a cut-through to I-75.

“Seventy-five percent of our people leave Paulding every day to go to Fulton, Cobb and Douglas counties, and all the roads are jammed at this point in time,” Austin said. “If we could take just 15 minutes off those people’s commute either way, I think we would go a long way in improving their quality of life.”

Jason Anavitarte has lived in Paulding since 2007. His daily commute to work in Dunwoody takes him along I-75.

Before Paulding moves ahead with the connector plan, Anavitarte, 32, would like some movement on other outstanding projects, including improvements along Ga. 92 to get commuters from northeast Paulding to I-75.

“We’re jumping ahead to create a new west corridor, but we’re not working on what has been planned,” he said.

The idea behind the connector already exists as an alternative to I-75 between Macon and the Georgia-Tennessee border, but not as a toll road.

Long acknowledged the need for “some kind of bypass around Atlanta on the western side.” But he said the DOT is not involved in this proposal, “partly because we think the [cost] estimates they’ve looked at so far are off by multiple factors.”

Nonetheless, Long said the state is happy to see viable projects, whether they come from the state DOT or from counties.

“If there’s a better way to catch the mouse, we’re OK with that,” he said.

Staff writer Ariel Hart contributed to this article.