Some Atlanta drivers — who are shouldering the highest car ownership costs in the nation — have seized upon an electrifying solution.

The number of plug-in cars on the road in Georgia is increasing by about 500 a month, and last month, Atlanta was the top-selling market in the country for the all-electric Nissan LEAF, surpassing even San Francisco and Los Angeles.

Paired with gains in the number of metro Atlantans choosing to telework, the rise in electric car purchases paints a picture of weary drivers looking for unconventional ways to save time and money.

While the number of electric cars is amping up, so is the debate on their value as relief from congestion and from reliance on fossil fuels. And perhaps of equal importance, its effect on gas tax revenue, the number one source of money to pay for the nations’s aging road and highway infrastructure.

Electric and hybrid vehicles still make up a tiny portion of vehicles on the road, about 2.2 million of the nation’s approximately 253 million registered vehicles.

Nationwide, about 150,000 plug-in vehicles were in service at the end of August, according to the Electric Drive Transportation Association. About 3,000 of them were on the road in Georgia, and that number is growing by at least 500 per month, according to the Don Francis, executive director of Clean Cities Atlanta.

Accenture consulting company forecasts 1.5 million electric-only vehicles in the United States by 2015. By 2020, more than 10 million electric vehicles could be on the road.

The Clean Air Campaign has not strongly endorsed electric cars choosing instead to focus on promoting carpooling. That’s because electric cars won’t help congestion if people continue to drive alone.

“We hope they choose to carpool when they’re riding in their EVs (electric vehicles),” said Brian Carr, a spokesman for The Clean Air Campaign.

Whether an electric car is better for the environment than a hybrid or even a fuel-efficient car depends on which state you live in and how much that state relies on fossil fuels such as coal and natural gas to generate electricity.

The rising popularity of electric cars undoubtedly spells trouble for state and federal gas tax collections, a problem that lawmakers are still unsure how to tackle.

Also cutting into gas tax collections is the rising popularity of teleworking — the fastest-growing commute option in the metro Atlanta area, according to a 2010 study commissioned by the Georgia Department of Transportation. More than 600,000 people telework occasionally in the region.

State gas tax revenue isn’t keeping up with the growing population and its demands on transportation infrastructure. Instead the income has stagnated at $987 million in fiscal year 2013, slightly less than a peak high of over $1 billion that was reached in FY 2008. The national Highway Trust Fund, comprised of gas taxes, is also dwindling as more fuel-efficient and hybrid cars are introduced. Gas taxes are the primary funding source for fixing the nation’s vast network of aging highways and bridges, which is projected to cost hundreds of billions of dollars.

Federal lawmakers have kicked around several possible solutions, including a 10-cent per gallon federal fuel tax increase, a mileage-based user fee and borrowing from the general fund. But so far, Congress has deadlocked.

Regional leaders were relying on the TSPLOST, 10-year penny sales tax, to fund a laundry list of transportation projects in metro Atlanta. But since voters in the region overwhelmingly rejected the plan in a referendum last year, the focus now is on prioritizing spending on the most congested roadways, while taking advantage of cost-saving innovations in design and financing options (such as partnering with the private sector), said Toby Carr, director of planning for the Georgia Department of Transportation.

Last month, Bankrate.com ranked Georgia as the state with the highest average annual cost for car ownership in the country at $4,233 versus the national average of $3,201.

The cost of operating an electric car is almost three times lower per mile than gas-powered vehicles. But the total cost of ownership should be carefully weighed, because electric cars have a higher sale price and a battery replacement can cost more than fuel-powered engine repairs.

Incentives for electric cars can add up to big savings, though. Georgia offers a $5,000 tax credit for buyers or leasors. And buyers are also eligible for a $7,500 federal tax credit. In addition, electric car owners can use HOT lanes on I-85 without paying a toll if they register for a Peach Pass.

The cost to buy an electric car depends on the make and model. It can range anywhere from $29,760 for the Nissan LEAF at the low end to $87,400 for the Tesla Model S at the high end. But many are choosing to lease instead of buy, since the battery technology is so rapidly evolving. A typical plug-in vehicle can travel about 100 miles per charge, a distance which according to the Federal Highway Administration is sufficient for more than 90% of all household vehicle trips in the United States.

A year ago, the Atlanta market only represented about 3 percent of LEAF sales. Last month, it accounted for up to a fifth of the 2,400 sales nationwide, according to Erik Gottfried, director of electric vehicle sales and marketing for Nissan.

However, Atlanta isn’t the top market for all electric cars. The top three markets for the all-electric Ford Fusion are Los Angeles, San Francisco and Seattle, according to Ford spokesman Erich Merkle. Local sales data on other popular electric cars such as the Toyota Prius plug-in and Chevrolet Volt was not available.

East Cobb mom Rani Quirk bought the LEAF a few weeks ago and expects to save about $100-a week in fuel costs commuting to her Duluth job. Several neighbors already had electric cars, and now her next-door neighbor is interested in one.

“It’s been kind of a snowball effect,” Quirk said.